Ocean Color Image Gallery
Category: Interesting Chlorophyll Features
Three Clear Days off the eastern United States and Canada
Clear skies revealed the highly productive waters off the eastern United States and Canada to SeaWiFS over the past week.While the images appear remarkably similar at first glance, closer examination reveals significant differences in both the distribution and abundance of phytoplankton as indicated by the chlorophyll-a concentrations presented here.
Spring Returns to the Northern Hemisphere
|The greening of the northern hemisphere's land and ocean as the sun moves north of the equator can be seen in these SeaWiFS images of the global biosphere. The changes in land vegetation are represented by the SeaWiFS-derived Normalized Difference Vegetation Index and SeaWiFS-derived chlorophyll-a concentrations in the ocean show the development of the spring bloom in the North Atlantic ocean. Being able to monitor the earth's biological response to the changing environment is critical to our ability to predict how the earth's ability to support life may change in the future.< d>||
In the oceans, the regions with the lowest chlorophyll-a concentrations are shown in purple (southeast Pacific Ocean) and deep blue while the lighter blues, greens, yellows and reds represent increasing phytoplankton abundance. On the land, the densely vegetated areas are the deepest green with the deserts colored brown and the white areas representing the snow covered regions of the world. Colorbars for these images are available here
SeaWiFS data from ground stations in Virginia, Florida, Mississippi and California collected on March 6,2000 contributed to this portrait of North America . Click on any portion of the image above to view a 512 x 512 extract at approximately 1 kilometer resolution. Some parts of the image may be of lower resolution because of the position across the swath. The full image (6 MB) is available here.
On May 11, 2002 clear skies revealed the highly productive waters off the eastern United States and Canada to the SeaWiFS radiometer. The two images provided here are derived from the same raw data, but are processed in different ways.
The first image is a quasi-true-color view formed by using the red, green, and blue spectral bands from the sensor as the red, green, and blue components of the image. The second image is a pseudo-color representation of sea surface chlorophyll concentrations overlaid on the quasi-true-color image.
You will note that the chlorophyll image brings out much more of the complexity in this part of the Atlantic Ocean. In this view the waters over Georges Bank and in the Gulf of Maine exhibit the high chlorophyll concentrations that mark thriving phytoplankton populations which are the base of the food web for most of the rest of those ecosystems. To the south, chlorophyll concentrations decrease rapidly as one crosses the northern boundary of the meandering Gulf Stream. To the east of Georges Bank one of the meanders has pinched off into a large warm core ring.
One thing that the chlorophyll concentration data do not tell us is how different species of phytoplankton are distributed in an area. You can get some sense of this by looking at the quasi-true-color image and noting that the colors of the various blooms differ from each other. To the southeast of Long Island we see an aquamarine hue. Over the top of Georges Bank the color is more yellow-green. Around the edge of the Bank and in the middle of the Gulf of Maine, a reddish tinge is visible. These color differences likely reflect differences in species composition and in depth distributions of the cells whose pigments and light scattering characteristics are detected by the orbiting SeaWiFS.
Six Years in the Making - and now, One More Year
Just in time for the holidays, NASA is pleased to announce that a new contract has been signed with ORBIMAGE to acquire one additional year of SeaWiFS data starting on 24 December 2003 under the same terms and conditions as the previous agreement. NASA anticipates a resumption of global data (GAC) acquisition starting at approximately noon, 24 December 2003.
Launched on August 1, 1997, SeaWiFS began collecting global data operationally in mid-September and has continued to perform flawlessly for the past six years. The image above is the average ocean chlorophyll-a concentration as derived from SeaWiFS since launch. What is clear from this image is the tight coupling between the physical and chemical processes in the ocean and their resulting biological signature. What SeaWiFS has allowed us to do as never before, is to not only monitor the short-term spatial and temporal variability in the ocean's biology, but to have the first well calibrated, long-term data set that allows us to quantify the ocean's biological response to global change. Images and digital data sets based upon the SeaWiFS climatology for seven different geophysical parameters at a number of different temporal scales are available HERE.
One of the interesting insights that came out of the generation of this chlorophyll-a climatology is the identification of the region of the world's oceans that has the lowest chlorophyll concentration. That area, slightly west of Easter Island in the South Pacific centered at 26 degrees South and 115 degrees West had an average concentration of 0.0186 milligrams chlorophyll-a per cubic meter.
You can download aPNG-formatted or JPG-formatted full resolution version of the image above as well as a version centered at 180 degrees longitude (PNG or JPG) and an equirectangular projection of the image and the digital data in HDF-format.
Above are two different views of the waters around the Baja Peninsula on August 10, 2003. The view on the left shows the ocean in a semi-natural color. Subtle shades of green amidst the blue hint at the presence of phytoplankton blooms.
The image on the right provides a clearer picture of the distribution of these phytoplankton by showing where the surface waters contain much or little of the photosynthetic pigment, chlorophyll.
Mystery Plankton Bloom in the Bering Sea
SeaWiFS images taken on June 3, 2001 and June 4, 2001 and June 5, 2001 at 4 PM and June 5, 2001 at 5:30 PM and June 6, 2001 show the development of a large bloom of reddish-hued phytoplankton spreading across the Bering Sea. This bloom is being mixed with the lighter colored plankton assemblages (most likey made up of different species) that fill much of the region. (All dates and times are given in Alaska Daylight Time.)
This image was collected on August 1, 2003 by the Moderate Resolution Imaging Spectroradiometer (MODIS) flying aboard the Aqua satellite.
The SeaWiFS Project has begun processing MODIS data as part of a prototyping activity to demonstrate capabilities needed to support an ocean color mission scheduled for launch towards the end of this decade.
The data from which the image at left was made are available via the "Global Ocean Color Browse Utility" hyperlink below. Alternatively, you may go directly to the page displaying the Aqua-MODIS scenes collected on August 1, 2003 and click on the Gulf of Mexico.
Barents Sea Plankton Bloom
A massive plankton bloom of what are most likely coccolithophores was observed on Wednesday, August 21, 2002 by SeaWiFS spreading across the southern half of the Barents Sea. SeaWiFS has observed similar blooms in this region over the past few years although we are not sure what, if any, ground truth information may exist to help confirm these observations.
Islands in the Stream - The Galapagos
Over the course of less than two weeks, SeaWiFS captured the development of a large plume of plankton-rich water straddling the equator and extending several hundred kilometers downstream from the island of Isabela in the Galapagos Archipelago.
The large phytoplankton bloom to the west of Isabela Island is a consistent feature, constantly changing in size and shape, that sustains an ecosystem like none other. Nowhere else in the world will corals, hammerhead sharks, flightless cormorants, penguins and fur seals be found upon the same sub tidal reef! Cold water from the submarine Cromwell current deflects against the Galapagos Platform bringing trace elements such as iron into the sunlit coastal waters. This seems to trigger these huge events. To the east wind driven upwelling along the equator also encourages production.
Such high primary production also provides for local semi-intensive sea-cucumber, fin-fish and rock lobster fisheries. The future of the Galapagos marine reserve depends upon the sustainable management of these resources and improved understanding of the natural environment. In an area also renowned for the devastating impact of large El Niño events, such human impacts might tip the sensitive balance between extinction and survival. The marine scientists of the Charles Darwin Research Station continue using SeaWiFS data as a valuable tool to assess the part such productivity plays in maintaining the unique biodiversity and endemism in the marine reserve.
The Charles Darwin Foundation (CDF) for the Galapagos Islands works together with the Galapagos National Park Service towards providing the scientific advice needed for sustainable development and management of the Galapagos Marine Reserve. For more information about Galapagos and the ongoing work of the CDF please visit http://www.darwinfoundation.org/.
This sequence of images acquired on May 29th, June 8th and finally on June 10, 2003 not only document the development of the plume in the western part of the region, but also caught the decrease in chlorophyll concentrations in the east. Subsequent images taken on June 11, June 13, June 15 and June 17, 2003 show how quickly conditions around the Galapagos can change.
Mystery Plankton Bloom in the Bering SeaSeaWiFS images taken on June 7, 2001 and June 6, 2001 and June 5, 2001 show the presence of a large bloom of reddish-hued phytoplankton spreading across the Bering Sea. This bloom is being mixed with the lighter colored plankton assemblages (most likey made up of different species) that fill much of the region.
Patagonian Shelf bloom
SeaWiFS collected this remarkably clear view of the ocean east of Argentina on 27 Nov. 2001 showing the turbulent region of the confluence of the Brazil/Falkland (Malvinas) Currents. The bright turquoise waters of what is most likely a coccolithophore plankton bloom contrast dramatically with the cold, deep blue waters further offshore. The Falkland Islands (Isla Malvinas) can be seen in the southern part of the image.
Lake Michigan Blooms: July 13 - September 7, 2001
The water in Lake Michigan has gone from dark blue-green to bright turquoise again this summer as seen in this times series of true color SeaWiFS images acquired between July 13 - October 11, 2001. SeaWiFS imaged a similar event in 1999. Two possible explanations for the brightening were advanced in 1999: a large bloom of cyanobacteria such as microcystis or an inorganic precipitation of calcium carbonate triggered by warming surface waters. A variety of atmospheric aerosols and clouds over the lake also effect the perceived brightness of the water from image to image in this 2001 time series.
Cyanobacteria in the Baltic Sea
A toxic bloom in the Baltic Sea of the cyanobacterium, Nodularia spumigena,has been reported by Agence France-Presse.A more recent Reuters report indicates that the problem continues. Both reports warn of the harmful effects of the bloom, and both reports link the increasing incidence of such blooms to increased nutrient runoff into the Baltic Sea. The Reuters report further warns that fish stocks are being depleted as the dying algae consume the oxygen that the fish need for survival.
This image was collected on July 24, 2003.
Agulhas Return Current
When the southwestward flowing Agulhas Current off of southeastern Africa meets the Antarctic Circumpolar Current it gets retroflected back eastward as the Agulhas Return Current. The interactions of the various currents and the sea floor topography produce meanders in the return current such as the one visible on the right.
The colorsin this image depict the elevated chlorophyll concentrations associated with the interacting currents.
This image was collected on February 26, 2003. Click on it to download a wider view of the region (2424 x 3168 pixels, 1.67 megabytes) which also shows Tropical Cyclone Japhet swirling farther to the north.
This scene, collected on May 15th, 2003, shows a region of high chlorophyll concentration protruding jet-like from the southern end of the African continent.This feature exists in a dynamic region of colliding currents and changing sea floor topography. Major currents in the region include the Agulhas, Antarctic Circumpolar, and Benguela currents. Additional imagery and analyses can be found on the Oceanspace website in South Africa.
The same oceanographic conditions prevailed in March of 1999 when a SeaWiFS image very similar to the one above was collected.
This SeaWiFS image taken on Sunday, 25 March 2001 shows the extent of the massive bloom of poisonous algae that is threatening thousands of tons of salmon that are farmed in waters off the southern coast of Norway.
South Atlantic Bight
As scientists converge on Miami, Florida this week to discuss the current and future status of biological remote sensing at the first combined NASA Ocean Color Research Team meeting, SeaWiFS captured the biological signature of the dynamic conditions along the eastern coast of the United States on Sunday, 13 April 2003.
Gulf of Aden
Between Yemen and Somalia the waters of the Gulf of Aden swirl in topographically squared off eddies which are made visible by the chlorophyll-bearing phytoplankton that they carry.
This image was collected on November 1, 2003. Click on the above image to download a broader view of the region.
Catch the Wave: Equatorial Pacific WavesThis eleven-day SeaWiFS chlorophyll-a composite January 8-18, 2002 shows the rather remarkable development of a series of equatorial Pacific tropical instability waves. The enhanced chlorophyll concentrations associated with the waves extend from the region just west of the Galapagos Islands along the equator to the dateline - a distance of nearly 10,000 kilometers.
Coastal blooms: Pacific Northwest
Blooms of phytoplankton color the water along the coast near the Strait of Juan de Fuca in this SeaWiFS image collected on Friday, July 23, 2004. This is an area known to be afflicted by harmful algal blooms, and data such as those represented by this SeaWiFS image could be potentially useful to coastal managers seeking a broader view of water conditions in the region. The following site has information and maps of which areas in the region are currently closed toshellfish harvesting.
'Dead zone' spreads across Gulf of Mexico
Recent reports indicate that the large region of low oxygen water often referred to as the 'Dead Zone' has spread across nearly 5,800 square miles of the Gulf of Mexico again in what appears to be an annual event. Satellite observations of ocean color from both SeaWiFS and MODIS/Aqua taken on July 4, 2004 show highly turbid waters which may include large blooms of phytoplankton extending from the mouth of the Mississippi all the way to the Texas coast.
Bottom dissolved oxygen countours measured during the same period as part of NOAA's Hypoxia Watch System for the Gulf of Mexico clearly show the large region of low oxygen water in the same location as the highly turbid water in the satellite images.
Most studies indicate that nutrient over-enrichment from anthropogenic sources is one of the major stresses impacting coastal ecosystems.
Coastal blooms along the Pacific Northwest Coast
23 July 2004
Blooms of phytoplankton color the water along the coast to the north and south of the Strait of Juan de Fuca in this SeaWiFS image collected on Friday, July 23, 2004. Without corroborating data collected at sea level, one cannot say which species of phytoplankton are coloring the water in this image, nor can one say whether or not they are harmful. This is, however, an area known to be afflicted by harmful algal blooms, and data such as those represented by this SeaWiFS image could be potentially useful to coastal managers seeking a broader view of water conditions in the region. The following site has information and maps of which areas in the region are currently closed to shellfish harvesting. http://www4.doh.wa.gov/gis/mogifs/biotoxin.htm
This SeaWiFS image shows chlorophyll levels on October 6, 2004 -- toward the end of the summer monsoon season. Dust can be seen blowing across the deserts of Iran, Afghanistan, and Pakistan to the north. An alternate view of the ocean in quasi-natural color is also available.
Plumes of dust and phytoplankton are visible seaward of the central section of the Baja Peninsula in this SeaWiFS scene collected on November 2, 2004. The view is to the north and west along the southwestern edge of North America.The ocean was processed in two different ways. One shows the dust better, and the other the chlorophyll of the phytoplankton blooms.
This MODIS image shows a large eddy (about 200 kilometers in diameter) in the southwest Indian Ocean (south of Madagascar in the Agulhas Return Current region over the Southwest Indian Ridge).People that know much more about these data than I do are working to improving the chlorophyll retrievals including the removal of artifacts such as the stripes that are visible in this image. See /ocrefs.html for an introduction to some of the work that is ongoing.
This striking SeaWiFS image of the South Atlantic on Dec 12, 1997 shows interesting and dynamic structure. The Falkland Islands can be seen at the bottom of the image
The waters on the west side of New Zealand's South Island are supporting a large, high-albedo bloom (potentially coccolithophores)on Feb. 1, 1999.
Here is the same area, a new bloom on April 12, 1999.
Wind blowing across the Gulf of Tehuantepec causes upwelling of cold, nutrient-rich water which fuels phytoplankton blooms. See Article for a more complete explanation.
Very high chlorophyll concentrations observed off of Tasmania on Oct 24, 2004.
This SeaWiFS pass from July 17, 2000 shows a distinctive phytoplankton bloom in the North Atlantic possibly with the presence of coccolithophorids.
It's mid spring in the South Atlantic and the ocean is blooming. Ocean currents concentrate the phytoplankton in some areas and spread them out in others. The resulting gradients in chlorophyll concentration across the region make the flow field visible to orbiting sensors such as MODIS which collected this image on November 22, 2004.
This SeaWiFS view of the northeastern U.S.on May 25, 2000 shows several eddies along the north edge of the Gulf Stream. The one centered at 39.3 North and 68.8 West looks like a standard warm-core ring (low-chlorophyll center and clockwise rotation). The eddy farther to the northeast (40.5 North and 66 West) has a much greener center and stands out all the more for its proximity to its clearer neighbor.
SeaWiFS viewed a large, dense bloom of phytoplankton in the southern Gulf of California on April 16, 2001.
The Ross Sea is one of the most productive regions of the world's oceans, and this enhanced natural color image shows very green water just to the north of the Ross Ice Shelf, indicating high concentrations of chlorophyll-bearing phytoplankton.
This image was collected by SeaWiFS at 14:12 UTC on December 6, 2004.
SeaWiFS saw a well-defined eddy in the Drake Passage in March of 1998. The difference in surface albedo between the eddy and the surrounding waters is quite large.
Amazing springtime water colors off the coast of Argentina are visible in this SeaWiFS image collected on November 22, 2001. . In some areas the water goes from deep blue to bright aquamarine to rich green and back to deep blue within the space of a few kilometers. The city of Buenos Aires, Argentina is visible as a gray splotch on the western shore of the light brown Rio de la Plata near the top of the image. The Falkland Islands peek through the clouds near the bottom of the image.
Here is a closer view:
The Atlantic Ocean off the west coast of Portugal and Spain is developing a bright aquamarine color which is most likely caused by phytoplankton blooms. Smaller bright patches are also visible farther north in the outer Bay of Biscay (just peeking from beneath the cloud cover). This SeaWiFS image is from April 23, 2002.
This combined true-color/chlorophyll SeaWiFS image (collected on April 5, 2002) shows several eddies spinning off the western coast of Australia.
Bright blooms continue to develop in the Black Sea. To the southwest dust from Africa hangs over the Mediterranean. This image is from May, 4 2002
The waters in the Gulf of Alaska show dramatic structure in the surface constituents on May 2, 2002.
A combination of recent flooding in the central United States and agricultural runoff from farms in the regions drained by the Mississippi River and its tributaries may be causes of the large plume seen extending into the Gulf of Mexico in this SeaWiFS scene collected on December 13, 2004. One image shows the water in quasi-natural color, and the other one shows chlorophyll concentration.
Here is another SeaWiFS view of the phytoplankton blooms in the Malvinas current region. The enhanced natural color image shows actual differences in water color while the pseudocolor image shows chlorophyll concentration.
This set of SeaWIFS images from Oct 4, 2002 displays the productivity in the Arabian Sea.The top image is true color and the bottom image is chlorophyll concentration.
Winds blowing southward along the west coast of the United States -- because of friction and the effects of Earth's rotation -- cause the surface layer of the ocean to move away from the coast. As the surface water moves offshore, cold, nutrient-rich water upwells from below to replace it. This upwelling fuels the growth of marine phytoplankton which, along with larger seaweeds, in turn nourish the incredible diversity of creatures found along the northern and central California coast.
Sensors such as SeaWiFS can "see" the effects of this upwelling-related productivity because the chlorophyll-bearing phytoplankton reflect predominantly green light back into space as opposed to the water itself which reflects predominantly blue wavelengths back to space.
The ocean areas of this image (collected on 6 October 2002) are color coded to show chlorophyll concentrations. Land and cloud portions of the image are presented in quasi-natural color.
On November 26, 2002, SeaWiFS captured this relatively
clear view of southern Africa and the seas around it.
Phytoplankton distributions that are barely discernible
in the quasi-true-color image become much clearer in the
image of computed chlorophyll concentrations.
In the second image, the lower chlorophyll concentrations
associated with the Agulhas Current ar visible along the
southeastern coast of the continent. When this current meets
the Antarctic Circumpolar Current, it gets retroflexed
back towards the east and forms the meanders and eddies
visible in the lower right quadrant of the image.
Higher chlorophyll concentrations along the west coast of
Africa result from upwelling associated with the Benguela
Current which flows northward along the western edge of the
The SeaWiFS image of the waters around
southeastern Australia on Jan 6, 2003 shows
a complex eddy field highlighted by the
chlorophyll-bearing phytoplankton that
are carried along by the swirling currents.
On the land one can see the long, ruler-straight
boundaries of national parks such as the
Murray-Sunset National Park and the Wyperfeld
National Park in northwestern Victoria.
Vegetation inside the parks makes these
areas appear darker than the surrounding
Probably the most dominant oceanographic feature of
the western North Atlantic Ocean is the Gulf Stream.
The northern edge of that current is clearly visible
in the chlorophyll field measured by SeaWiFS today.
As the Gulf Stream flows eastward it forms meanders
that occasionally pinch off to form clockwise-rotating
warm-core rings to the north and counterclockwise-
rotating cold-core rings to the south. Cold-core
rings generally have higher chlorophyll concentrations
(and lower surface temperatures) than the surrounding
water, and a few of them can be descried in this
Cold core rings tend to form in the east and then gradually
migrate towards the southwest. Some have been reported to
remain recognizable for up to two years.
Between Yemen and Somalia the waters of the Gulf of Aden
swirl in topographically squared off eddies which, in
this SeaWiFS image, are made visible by the
chlorophyll-bearing phytoplankton that they carry.
This image was collected on November 1, 2003.
Late spring is coming to New Zealand.
These two SeaWiFS views collected on
December 1, 2003 show the distribution
of chlorophyll-bearing phytoplankton
in the surrounding ocean.
The first view is a quasi-natural color
view. The second view replaces the oceans
with a pseudo-color representation of chlorophyll
concentration which shows much more detail in the
A bloom in Lake Michigan is evident in this SeaWiFS image from Sept. 23, 1998. The "whiting" in the image
is probably a calcite whiting that typically occurs as a result of autogenic precipitation of calcite as a result of water warming and pH
rise caused by phytoplankton uptake of carbon dioxide.
The subtropical front is visible in this MODIS scene both in the temperature and the chlorophyll field as it stretches eastward from New Zealand along the Chatham Rise. Also visible in the data are regions of upwelling in and south of Cook Strait and around the three capes: Reinga, East (on the North Island), and Farewell (on the South Island). Two warm spots in the sea surface temperature field -- one on either side of the North Island -- show no clear correlation with the chlorophyll signal.
These data were collected on January 13, 2005 by MODIS aboard the Aqua satellite.
This image shows the first 24-hours of data from Sea-viewing Wide Field-of-view Sensor (SeaWiFS) taken on Sept. 16, 1997. The red colors show high concentrations of chlorophyll in the water, the yellows/greens indicate intermediate concentrations of chlorophyll and the blues/purples show low concentrations of chlorophyll. Where there are black swaths this indicates there is no data due to gaps between the orbits. SeaWiFS observes the Earth from a noontime sun-synchronous orbit which means that the sensor is always viewing the Earth around local noon at an altitude of 440 miles (705 kilometers). This orbit provides data at the maximum solar illumination most desirable for detecting concentrations of microscopic green plants, called phytoplankton, which live just beneath the ocean surface. These green plants absorb sunlight during photosynthesis, the most basic and essential chemical process necessary for live on Earth. The gaps between the swaths of data are filled the following day, thus providing complete global coverage every two days. Nearly complete cloud-free coverage is achieved over the course of about one week as cloud patterns shift. SeaWiFS data will allow routine assessment of global vegetation patterns, both land and ocean, needed to understand the world's ecosystems and global change. The SeaWiFS instrument will observe the world's oceans from space to measure "ocean color." SeaWiFS is an essential component of NASA's Mission to Planet Earth, an ongoing effort to study how the global environment is changing. Using the unique perspective available from space, NASA will observe, monitor and assess large-scale environmental processes, such as the oceans' productivity, focusing on climate change.
The Kerguelen Islands in the southern Indian Ocean lie in the path of the Antarctic circumpolar current. Nutrients -- either from the islands themselves or from deeper water mixed to the surface by turbulence around the Kerguelen Plateau -- support more vigorous phytoplankton growth in the wake of the islands. This shows up in the image above as higher chlorophyll concentration. Further discussion of the region is available.
You can click on the image above to get a larger version, or you can download an alternate color scheme.
In this sea surface temperature image, the Agulhas Current shows up as a tongue of warm water flowing southwest from the Indian toward the Southern Ocean. The northward flowing Benguela Current appears as a band of lower temperature along the west coast of South Africa.
A corresponding chlorophyll image shows that the nutrient-poor, subtropical water in the Agulhas Current supports relatively meager populations of phytoplankton while the coastal upwelling associated with the Benguela Current supports one of the most productive phytoplankton assemblages in the world.
The Global Biosphere (September 97 - August 2000)
Chlorophyll (Rectangular Projection)
Biosphere - Chlorophyll and SeaWiFS-derived NDVI (Mollweide Projection)
(4096 x 2048 jpg) [1.2 Mbytes]
Northern Hemisphere Fall and Winter
Northern Hemisphere Spring and Summer
The Global Biosphere (September 97 - August 98)
(1024 x 1024 jpg) approximately 200 kbytes
The Global Biosphere (September 97 - August 98)
(1024 x 1024 jpg) approximately 200 kbytes
The Global Biosphere (September 97- August 98)
Indian Ocean and Polar Projections
(1024 x 1024 jpg) approximately 200 kbytes
Blooms of phytoplankton often occur in these latitudes at this time of year when the day length is increasing and the solar zenith angle is decreasing resulting in more light for photosynthesis and for the heating of surface waters. Warmer surface water is more resistant to mixing with deeper, colder water because it is less dense than the colder water, so phytoplankton can remain closer to the well lit surface longer where they can produce the complex hydrocarbons that the rest of the food web depends upon. Eventually, if the surface waters are not replenished with the nutrients that the phytoplankton consume, such blooms wane.
The Gulf of Alaska is probably still fairly replete with nutrients mixed up by recent storms in the area. See, for example, the QuikSCAT data from two days before which shows high winds over the Gulf (click on the Gulf of Alaska when you visit the above hyperlink).
The warm heart of the Gulf Stream is readily apparent in the top sea surface temperature image. As the current flows toward the northeast it begins to meander and pinch off eddies that transport warm water northward and cold water southward. The current also divides the local ocean into a low-biomass region to the south and a higher-biomass region to the north. This is evident in the bottom chlorophyll image.
The southward flowing Brazil and northward flowing Malvinas currents meet off the coast of Argentina. These MODIS images were produced from data collected on May 2, 2005. The interacting currents support enhanced biological productivity -- particularly during the austral spring and summer, but also now during the fall.
The waters of the Barents Sea have been showing increasing chlorophyll concentrations over the past few weeks according to our standard global satellite chlorophyll algorithm. This MODIS Aqua Chlorophyll image from May 25, 2005 shows concentrations that are higher than we normally accommodate when we scale our data to produce browse images.
Eddies of different sizes are made visible by chlorophyll-bearing phytoplankton in the Mozambique Channel in this MODIS image collected on June 10, 2005.
There are more waves in the ocean than the ones you can see from a beach or a ship. The above tropical instability waves along the equator in the Pacific Ocean were "seen" by MODIS on June 20, 2005 as an undulating region of elevated chlorophyll concentration.
MODIS Aqua had a good view of an eddy in the Norwegian Sea on July 1, 2005
These MODIS (Aqua) images collected on 4 August 2005 show a couple of large Gulf Stream eddies. The eddy to the north of the warm Gulf Stream is an anticyclonic, warm core ring containing water that has lower chlorophyll concentrations and higher surface temperatures than the surrounding waters. The eddy to the south of the Gulf Stream is a cyclonic, cold core ring containing water that has higher chlorophyll concentrations and lower surface temperatures than the surrounding waters. The finger of elevated chlorophyll concentrations in the upper left quadrant of that image marks the location of the shallow, productive Georges Bank.
Whimsically featured in the recent animated movie, "Finding Nemo", the East Australian Current brings warm water from the Coral Sea southward along the east coast of Australia. The warm tongue of water in the above left image is a surface manifestation of that current. The right image shows that the current also has lower chlorophyll concentrations than the surrounding waters.
These MODIS images were collected on August 17, 2005. Click on either one to get a broader view of the region. The same images are available in different color scales from these links: SST2, SST3, CHL2, CHL3.
An updated animation of the SeaWiFS biosphere data set encompassing eight years worth of ocean color and land vegetation observations is now available. Click on the above reduced subset of that animation to learn more.
This MODIS view of the eastern North Atlantic on Sept. 13, 2005, shows a classic upwelling signature with colder nutrient-rich upwelled water near the Portuguese coast supporting higher chlorophyll concentrations near the coast.
Interactions between currents and topography around New Zealand produce many eddies in the region. On September 26, 2006 these eddies were highlighted by the varying amounts of chlorophyll bearing phytoplankton they entrained. The data from which the above image was made were collected by MODIS aboard the Aqua satellite.
The Amazon -- largest of all of Earth's rivers -- has an enormous impact on the biota of the equatorial Atlantic Ocean. Here, the elevated chlorophyll concentrations associated with the river's plume are carried northwestward by the North Brazil Current and then retroflected back to the east by the North Equatorial Counter Current.
Click on the above animation to get a larger version showing chlorophyll concentrations, or get the natural color version of the image in which the plume is just visible as a band of darker water meandering eastward.
This chlorophyll image of the southeast Indian Ocean was collected on November 6, 2006 by MODIS on the Aqua satellite. The elevated chlorophyll concentrations straddle the region of the westward flowing South Equatorial Current which gets much of its water from the Pacific Ocean via the seas of Indonesia. Numerous small eddies appear in the lee of the Cocos Islands -- the same islands that prompted Darwin to develop his theory of atoll formation.
Click on the above image for a larger view with a color scale.
November 2005 - May 2006
For the past ten years in the late summer/early fall, SeaWiFS has observed a large, eastward-propagating bloom that appears to originate just south of Madagascar and then penetrate into the oligotrophic heart of the southern Indian Ocean gyre. The bloom appears stronger about every other year. The above animation shows the progression of the bloom in early 2006. Click on the above image to see an animation (97 Mbyte) of the bloom development over the years. (Smaller [58 Mbyte] and still smaller [28 Mbyte] versions of the animation are also available as is an FTP directory containing the animation files.) Other oceans show similar blooms, but this is one of the more eye-catching ones. Does anyone have a good explanation for this? We have set up a bulletin board in our ocean color forum in case anyone would like to comment on this phenomenon.
North Pacific Bloom
A break in the clouds over the central North Pacific revealed a large patch of bright aquamarine water on June 6, 2007. Other ocean patches of a similar color have been identified as coccolithophore blooms in the past. The location and timing of this bloom is what one might expect for such phytoplankton, but surface water samples would be needed to confirm the identification. Perhaps someone in our readership knows of a cruise in the area. (Click on the above image for a larger view of the region with one-degree grid lines superimposed.)
Benguela Upwelling System
Prevailing southeasterly winds along the coast of South Africa, Namibia, and southern Angola drive Ekman upwelling of cold, nutrient-rich water thereby making the Benguela Current region one of the most productive ecosystems in the world. The above image pair, collected on 17 June 2007, shows newly upwelled cold water along the coast and the elevated phytoplankton biomass that results when nutrient-rich water flows up into the sunlight. Click on the images above for larger versions or download a true color version that includes two or three small aquamarine patches along the coast that might result from another phenomenon that results from the high productivity.
Eddies in the Mozambique Channel
A 25 July 2007 true color view of the Mozambique Channel and southwest Indian Ocean shows few features of note. When the same MODIS scene is processed to retrieve ocean chlorophyll concentrations, however, the patchiness of the region is revealed, and numerous interconnected small eddies -- many of which appear to possess characteristics attributed to spiral eddies -- appear.
Click on the above image for a larger view of the region.
Phytoplankton Bloom in the Barents Sea
A break in the clouds over the Barents Sea on August 1, 2007 revealed a large, dense phytoplankton bloom to the orbiting MODIS aboard the Terra satellite. The bright aquamarine hues suggest that this is likely a coccolithophore bloom. The visible portion of this bloom covers about 150,000 square kilometers (57,000 square miles) or roughly the area of Wisconsin.
Click on the above image for a larger view of the region.
On September 20, 1997 SeaWiFS collected its first complete day's worth of ocean color data. Ten years later it continues to collect the data that have greatly enhanced our knowledge of the ecology of Earth's oceans. Read more about how this small sensor -- for a surprisingly modest tax payer investment -- has revolutionized our understanding of Earth's biosphere.
Patchy South Atlantic Chlorophyll
Scenes such as the one above of the Patagonian Shelf region of the South Atlantic Ocean demonstrate one of the main reasons that we seek to measure chlorophyll (and other ocean color parameters) from space. The patterns shown are constantly changing -- sometimes at time scales of just a few hours. An entire fleet of ships following an exhausting sampling schedule could never hope to map this variability over such a large area. The satellite borne radiometer did it in less than ten minutes.
In addition to being valid measurements in their own right, data such as these increasingly allow researchers at sea to direct their sampling efforts to the locations that offer the greatest promise for scientific reward.
Click on the above image to get a larger version showing more of the region.
The Campbell Plateau
Currents and tides running over the Campbell Plateau stir up nutrients and fuel phytoplankton growth which is reflected in the above chlorophyll image collected on January 30, 2008 -- just before mid-summer. A click on the above image will show you similarly productive waters over the Chatham Rise and in the Tasman Sea which is reported to support "the largest noncoastal surface chlorophyll-a concentrations within the South Pacific Ocean."
Click on the above animation to see all of the pieces of this 20 February 2008 Aqua MODIS scene in one image, or here for a much larger (103 megabyte) version.
On March 23, 2008 -- just beyond the vernal equinox -- snow still covers much of northern New England and the Canadian Maritimes. In this MODIS view of oceanic chlorophyll concentrations, however, the spring bloom is already under way over Nantucket Shoals and Georges Bank making those regions stand out at the southern end of the Gulf of Maine. Still farther south, the oligotrophic Gulf Stream meanders by, carrying plenty of heat but not much chlorophyll.
Ribbons of Green in the Deep Blue Sea
If you were on a ship in this part of the world, you would normally expect to find clear blue ocean stretching from horizon to horizon. Sometimes, however, the ocean offers up the unexpected.
The above image of the ocean east of Tasmania in December, 2004 may not depict the ocean as we might expect to see it, but it does serve to highlight (in a completely unscientific fashion) subtle differences in water color that result from varying distributions of such scattering and absorbing agents in the water column as phytoplankton, colored dissolved organic matter, suspended sediment, bubbles, etc. The ocean colors shown above result from independently scaling the satellite-derived normalized water-leaving radiances (nLw) at 551, 488, and 412 nanometers and using the results as the red, green, and blue components of the image, respectively. To the extent that the methods used to compute nLw do not perfectly correct the instrument, atmosphere, and sea surface reflections seen at the Aqua-MODIS detectors, differences in the above colors may also partially reflect differences in atmospheric components or levels of sun and sky glint or differences in the path that light takes through the MODIS instrument. It is our goal as a satellite ocean color project to minimize these various sources of error so that our derived products may have maximum usefulness for the monitoring and understanding of our ever changing oceans.
Where the South Atlantic meets the Southern Ocean
The South Atlantic Ocean transitions to the recently officially recognized Southern Ocean across a number of fronts. The subantarctic and polar fronts have been found to lie fairly close to each other roughly 4 to 7 hundred kilometers north of South Georgia Island. The eddy pictured above falls within this frontal region and is made visible by the different phytoplankton communities that thrive along the fronts.
Download the 26 December 2006 MODIS image showing a larger region including partially cloud covered South Georgia Island:
The tabular iceberg visible beneath the clouds to the south of South Georgia Island has been identified as Iceberg A22A.
Remote South Pacific Phytoplankton
About 2600 kilometers northeast of McMurdo Sound, the onset of summer also brings enhanced phytoplankton growth to the South Pacific Ocean. Move your pointer over the natural color image above to see chlorophyll concentrations computed from MODIS data collected on January 3, 2009.
The small white spots clustered just beneath and to the right of the center of the above image are icebergs.
Which of These Blooms is Not Like the Others?
This is a bit of a trick question really as all of the higher chlorophyll patches shown as yellow and red features in the image above have their own unique histories and environments. For instance, the red patch showing through a break in the clouds near the top center of the above image may be influenced in part by the presence of Gough Island to the east. If you move your pointer over the image, however, you will see which bloom results from the iron fertilization experiment called LOHAFEX that took place in the South Atlantic in early 2009.
Click on the image above for a larger view of the 14 February 2009 MODIS scene, or download the corresponding natural color view.
The Japanese island of Hokkaido may have still been largely snow covered, but the surrounding ocean was blooming on April 3, 2009. The cold Oyashio current flows past the island bringing a rich nutrient supply from the north which feeds phytoplankton powered by the spring sunshine. The warm Kuroshio Current collides with the Oyashio near the bottom right of the above image and both turn eastward to become the North Pacific Current.
The Chatham Rise
The Chatham Rise -- extending from New Zealand's South Island (just beyond the left edge of the above image) to the Chatham Islands (shown) -- separates two areas of deeper water to the north and south. Tides and other currents flowing over this submarine topography cause increased mixing in the water column. That and the location of the rise along the subtropical front often results in large blooms of phytoplankton in the area -- particularly during the austral spring and summer. The above image collected by Aqua-MODIS on December 23, 2009 shows such blooms coloring the waters above the rise.
Roll your pointer over the above image to see ocean depth contours given in meters which show the location of the rise extending horizontally across the middle of the image. Click on the image for a higher resolution view of a broader region.
Prydz Bay Productivity
Some, but not all, of the coastal regions around Antarctica are highly productive during the austral summer. Prydz Bay at the terminus of the Lambert Glacier in East Antarctica is one of these regions. The above MODIS image from January 3, 2010 shows the very green, phytoplankton filled water that contrasts markedly with bluer coastal waters farther west in the image. Higher levels of nutrients and the presence of sunlight-passing polynyas in areas such as Prydz Bay may partially explain why some of these icy water masses are more productive than others.
Ocean Color Patagonian Style
Environmental factors off the east coast of Patagonia make large phytoplankton blooms possible every spring and summer. The resulting variations in water color -- seen in the above image collected on January 9, 2010 -- are in large part due to spectral variations in light absorbtion by the phytoplankton, detritus, and colored dissolved organic matter in the water. Light scattering agents such as the calcite plates produced by coccolithophores also contribute to the observed color differences. (The bright aquamarine regions of the above image likely contain large numbers of coccolithophores.) Further complicating the ocean color field above, sunlight reflecting directly from the ocean's surface gives a washed out look to the lower left corner of the image.
Prince Edward Islands Plume
The topographic effect of the Prince Edward Islands in the predominantly eastward flowing currents of the southwestern Indian Ocean along with input of nutrients from the volcanic soils of the islands themselves and significant runoff of seabird and seal guano in the abundant local rainfall often results in a down-current plume of relatively high chlorophyll concentrations.
Farther north in the larger image, the higher chlorophyll associated with the Agulhas Return Current is visible. North of that a cyclonic, cold-core eddy stands out from its low chlorophyll surroundings.
Phytoplankton Blooms in the Arabian Sea
The above MODIS view of the northern Arabian Sea on 18 February 2010 -- toward the end of the winter monsoon -- shows very green water drawn into thin ribbons by a turbulent eddy field. Recent research in the area hints that "phytoplankton blooms may perhaps be undergoing a systematic species shift, with traditional winter-time diatom bloom populations being replaced by Noctiluca miliaris" which "may be an indication that the Arabian Sea ecosystem is becoming more eutrophic."
The identification of phytoplankton species from satellite data alone is generally ill-advised, so the best that can be said regarding the above blooms is that they might be Noctiluca miliaris based on the authors' statement that this species "tends to aggregate at the surface to form large, slimy green patches."
Move your pointer over the above image to see the depicted region in relation to the rest of the Arabian Sea. Click on the image to download a larger version.
The Color of Spring
With the exception of a few areas such as the New Jersey Pine Barrens which support many evergreen trees, most of the northeastern United States is still rather brown as we pass the vernal equinox. Offshore, much brownish water is also evident where runoff from recent rains and snowmelt carries suspended sediment to the ocean. Click on the above image, however, and you will see broad bands of green still farther offshore where the phytoplankton of the spring bloom are becoming visible to sensors like MODIS.
Northeast Atlantic Blooms
The waters of the northeastern Atlantic Ocean are swirling with various phytoplankton communities in this May 22, 2010 MODIS image. The brighter waters, which lie very roughly along the edge of the continental shelf, are most likely colored by coccolithophores.
Coccoliths in the Skagerrak
All of southern Norway was enveloped in turquoise water on June 4, 2010. While the bright color in some of the fjords may be caused by suspended rock flour, most of the color offshore likely results from blooms of coccolithophores.
Click on the image above to zoom out to a broader region that includes a bloom along the edge of the Celtic Sea that was significantly brighter two weeks before.
As is common this time of year, the waters of the Barents Sea are once again brightened by blooms of coccolithophores which give the ocean a turquoise hue. The variations in color in the above image likely reflect differences in phytoplankton community composition and depth distribution. Diatoms, which tend to dominate earlier in the season, may account for some of the greener patches of water.
The above Aqua-MODIS image was collected on August 31, 2010.
A broader version of the above Aqua MODIS image from October 5, 2010 can be downloaded (3.4 megabytes) by clicking on the above view.
The Chatham Islands
The waters around New Zealand's Chatham Islands host large phytoplankton blooms this time of year. The above MODIS image was collected on December 5, 2010.
Phytoplankton Soup du Jour
Take water, salts, nutrients, sunlight, and a diverse assemblage of phytoplankton and then blow across the water and spin the planet to stir it all. The result can, at times, be a rich, colorful brew as in this summer-solstice view of the waters off the Patagonian coast.
The above 21 December 2010 Aqua-MODIS image was created from seven separate spectral bands to highlight differences in the plankton communities across the region. A separate version of the image -- closer to natural color -- is also available.
We of the Ocean Biology Processing Group wish you a happy and safe holiday season.
The Bottom of the Food Web at the Bottom of the World
Every summer the waters of the Ross Sea -- pictured above on January 22, 2011 -- host large phytoplankton blooms which eventually, through the food web, feed everything from small krill to whales. Researchers are currently plying those waters in search of the source of the nutrients that, together with the 24-hour sunlight, fuel those blooms.
New Zealand: Antarctic Staging Ground
To an oceanographer, the ocean around New Zealand in the summertime must provide a fascinating field of study. The above February 10, 2011 Aqua-MODIS image cries out for closer investigation from sea level. Some ocean scientists, however, come to New Zealand with different waters in mind.
Christchurch (just northwest of the large, rounded Banks Peninsula in the above image) serves as a staging ground for Antarctica, and that is where our staff member, Aimee Neeley, was waiting for her flight to McMurdo Station where she boarded the R/V Nathaniel B. Palmer to spend several weeks studying the Southern Ocean. She is keeping a blog to share her Antarctic experiences with the community. She will discuss daily life on an oceanographic vessel and describe the scientific questions and measurements that are the basis of the cruise. We invite you to follow along.
The Kerguélen Islands are rarely this cloud free when ocean color sensors orbit overhead. This Aqua MODIS image from 24 February 2011 clearly shows the plume of increased phytoplankton biomass that is usually found in the wake of these islands.
Northwest Pacific Blooms
The Northwest Pacific Spring Bloom
The MODIS instrument detected the clear chlorophyll signal of the yearly spring bloom in the waters south of the Japanese island of Hokkaido on March 27, 2013. Increasing daylength and stratification of the water column combined with abundant macronutrients and micronutrients such as dissolved iron provide ideal conditions for phytoplankton to grow.
Ten Years of Chlorophyll Measurements in the Western North Atlantic
The MODIS instrument on NASA's Aqua satellite has been measuring ocean color since mid-2002. Roll your pointer over the above image of the east coast of North America to view an animation of 10 years (2003 - 2012) of MODIS-derived oceanic chlorophyll concentrations in the region.
What Just Happened in Micronesia?
A change in the western tropical Pacific caught our eyes when the October 2013 monthly composite chlorophyll image became available. Click the image to read more.
Southeastern Atlantic Color
Different sorts of information can be derived from the ocean color data collected by orbiting radiometers. The above pseudo-color image represents chlorophyll concentration around South Africa. If one computes the reflectance of the ocean at different wavelengths measured by the radiometer, one can form a multiband composite that reveals differences in phytoplankton community structure which are not apparent just from the chlorophyll concentration.
SST and Chlorophyll
Sea surface temperature (top panel) and chlorophyll concentration (bottom panel) are often correlated in the ocean... except when they are not. See examples of both cases in the above images of the Leeuwin Current region off of Western Australia on June 6, 2014. (Clicking on either panel will get you a larger version with a color scale.)
Barents Sea Bloom Transition
Recent work suggests that diatoms predominate during May in the Barents Sea while coccolithophores bloom in August. The above MODIS scene, collected on July 10, 2014, may show those arctic waters in transition between greener diatom-dominated and milkier coccolithophore-dominated waters.
Ocean colors in the above image represent remote-sensing reflectance in the red, green, and blue portions of the spectrum. Green and blue reflectances have been scaled the same way, but the red reflectance has been scaled brighter to accentuate differences in this relatively dark portion of the spectrum. (Note that positive identification of phytoplankton species is not possible from these data alone; sea-surface sampling would be required for that.)
Click on the above image for a broader view, or get a full-resolution version (8 megabytes).
Baltic Sea Cyanobacteria
The Baltic Sea often supports massive blooms of diazotrophic cyanobacteria during the summer. The above MODIS image from July 25, 2014 shows that this year is no exception.
Click on the above image for a broader view, or get a full-resolution version (14 megabytes).
Massive Red Tide Approaching Florida
Recent reports indicate that a massive red tide event comprised primarily of Karenia brevis has been developing off the west coast of Florida. Indications are that this is the largest event since 2006 and has already been linked to reports of large fish kills. The most recent survey of Karenia brevis concentration indicates that the large offshore feature to the west, northwest of Tampa seen in the image above that was taken on Friday, 8 August 2014 by the MODIS instrument on the Aqua spacecraft is the bloom. The image below is a natural-color rendition of the bloom.
More recent satellite images have been generally cloud-covered in this region but we will continue to monitor the situation and post any updated images as they appear.
Chlorophyll as a Current Tracer
Phytoplankton, for the most part, move wherever ocean currents take them. Because of this they can sometimes be used to reveal current flows in the ocean through the chlorophyll they carry. If you move your pointer over the above Suomi-NPP-VIIRS image of chlorophyll concentrations off the northwestern coast of Australia, you will see how currents moved the phytoplankton around during the month of August, 2014. Click on the image to see an animation of a larger portion of the eastern Indian Ocean that reveals eddies within eddies in this turbulent region. (Black patches within the animation are clouds moving through the scene.)
Springtime East of Patagonia
Connoisseurs of ocean color must take note when spring moves on toward summer over the Patagonian Shelf. Complex circulation in the region produces flamboyant color variations that bespeak a high level of biodiversity in the resident phytoplankton populations.
The above VIIRS image was collected on December 2, 2014.
Trichodesmium in Melanesia
The MODIS image above shows blooms of the nitrogen-fixing cyanobacterium, Trichodesmium, to the northeast of the New Caledonian island of Lifou on December 19th, 2014. Click on the image above for more information about this particular bloom.
The Patchiness of Ocean Color
The ability to capture nearly instantaneous views of large areas of ocean surface makes satellite radiometers invaluable for the study of this often patchy and dynamic environment. That same patchiness can, however, challenge developers of satellite ocean color algorithms when they compare satellite and in situ measurements with each other.
The VIIRS data used to create the above image were collected on February 7, 2015.
Arabian Sea Winter Blooms
Filamentous green swirls fill the northern Arabian Sea in February 2015. Recent research in the area has found that while winter blooms used to be dominated by diatoms, they are now largely composed of dinoflagellates -- a change that may have significant effects on the food web.
Click on the above image for a larger view or get the full-resolution, 14 megabyte version.
Spring Bloom in the North Atlantic
Phytoplankton accumulations lent their green color to the central North Atlantic Ocean just north and east of the Azores in May of 2014. The above May 17, 2014 image is part of a larger perspective view with Europe and Africa along the Eastern horizon.
Eddies in the Southern Ocean
The cloud cover over the Southern Ocean occasionally parts as it did on January 1, 2015 just west of the Drake Passage where VIIRS glimpsed the above collection of ocean-color delineated eddies which have diameters ranging from a couple of kilometers to a couple of hundred kilometers. Recent studies indicate that eddy activity has been increasing in the Southern Ocean with possible implications for climate change.
Click on the above image for a larger view. A 6-megabyte version is also available.
Spring Bloom in the Bay of Biscay
The Bay of Biscay usually reaches the peak of its spring phytoplankton bloom in April, and this VIIRS image shows a bloom well underway on April 13, 2015. If trends during the past seventeen years are any indication, then we may expect the peak bloom in this region to grow still larger next year and perhaps even larger the year after that.
Northeast Atlantic Spring Bloom
As it does every year, the spring bloom has once again returned to the North Atlantic. These blooms are arguably important events in Earth's biosphere, and yet, as stated in a recent paper on this phenomenon, "there remains little consensus as to the environmental and ecological conditions required to initiate high-latitude spring blooms."
Spring phytoplankton communities paint eddies in the Gulf of Alaska on May the 4th, 2015 while aerosols hint at the motions of the overlying atmosphere. The above view was collected by the VIIRS instrument aboard the Suomi-NPP spacecraft.
Mid June in the North Atlantic
Phytoplankton communities and sea ice limn the turbulent flow field around Iceland in this Suomi-NPP/VIIRS scene collected on June 14, 2015.
Click on the image above to see a broader region at higher resolution.
Phytoplankton abundance peaks in the summer in the central Labrador Sea — depicted above in a VIIRS image collected on August 9, 2015. In addition to routine satellite and ship monitoring, a new mooring is expected to begin monitoring this dynamic region in the near future.
Cloudfree skies on August 24, 2015 reveal a frozen moment in the ever changing distribution of phytoplankton communities in the southern end of the Norwegian Sea.
To the southeast of the Rio de la Plata — flanked by the grayish human population centers of Buenos Aires and Montevideo — float much larger populations of phytoplankton borne along by the currents and eddies of this dynamic region of the southwestern Atlantic Ocean.
Click on the above Aqua MODIS image collected on September 6, 2015 to download a larger version of the image.
North Atlantic Spring Bloom
Every year during the boreal spring the phytoplankton biomass in the North Atlantic Ocean increases in bloom events. Much of this activity is hidden from ocean color sensors by cloud cover, but sometimes large areas go cloud free as happened on April 26, 2013 when the VIIRS sensor captured this scene of the bloom.
Click on the above scene for a broader view with a hemispherical context image.
The patchiness exhibited by phytoplankton communities around New Zealand in the above image provides the raison d'être for satellite remote sensing of ocean color; a whole fleet of ships, drifters, gliders, and buoys could not capture this variability before it morphed into a new pattern.
Click on the above VIIRS image collected on September 30, 2015 to download a larger version of the image.
The patchiness exhibited by phytoplankton communities around New Zealand in the above image provides the raison d'être for satellite remote sensing of ocean color; a whole fleet of ships, drifters, gliders, and buoys could not capture this variability before it morphed into a new pattern.
Click on the above VIIRS image collected on October 7, 2015 to download a larger version of the image.
The R/V Atlantis leaves Woods Hole on November 6, 2015 to participate in the North Atlantic Aerosols and Marine Ecosystems Study. Since ocean color plays a prominent role in this research, it is hoped that the usually cloudy November skies over the North Atlantic will open up occasionally to allow satellite ocean color instruments to extend the reach of the ship-borne instruments to the ocean beyond the ship's horizon.
The above VIIRS image was collected on September 23, 2015, and it shows the line along which Atlantis plans to make her primary stations. Click on the image for a larger, broader view.
The dark streaks in the image above show up in VIIRS and MODIS data as low-chlorophyll features. Since this region is right at the edge of the Southern Ocean, one could speculate that the features might have something to do with icebergs that are too small to be detected by these particular sensors.
The above image was collected by VIIRS on November 7, 2015.
Springtime in the South Atlantic
The springtime phytoplankton communities shown above were spotted between the Falkland Islands to the west and South Georgia Island to the east by the VIIRS instrument aboard the Suomi-NPP satellite on November 16, 2015. Click on the image for a broader view of the region.
Iron rich waters around the Kerguelen Islands support spring phytoplankton blooms which are often hidden from satellite view by cloud cover. November 21, 2015 was a sunny day in the region, however, as can be seen in the above VIIRS image.
Phytoplankton Gyrations in Remote Locations
Microscopic Particles in the Air and In the Water
Clouds of dust can be seen drifting in the air currents over the Arabian Sea while clouds of phytoplankton drift in the ocean currents below. Each set of microscopic particles — through selective absorption and scattering of solar photons — makes its own modifications to the reflected colors that are detected by orbiting spectrophotometers.
The above VIIRS image was collected on December 21, 2015. Click on it to get a larger version.
The Earthdata group has published an article about recent wintertime Noctiluca blooms in the Arabian Sea.
On January 13, 2016, eleven thousand kilometers due south of the U.S. city of Chicago (a.k.a. a long way from wherever you are), vast numbers of phytoplankton were consuming carbon dioxide and giving off the waste gas that we humans need to survive.
You may click on the above image to get a larger version, or you may view a smaller version with a map of North America's Great Lakes region overlaid to get a sense of the size of this particular patch of the southeastern Pacific Ocean.
Winter Blooms in the Arabian Sea
Phytoplankton communities were blooming in the Arabian Sea on February 3, 2016 as can be seen in this Aqua-MODIS scene. Outbreaks of Noctiluca scintillans in recent years are a disturbing symptom of a changing ecosystem in the northern Indian Ocean and are likely responsible for many of the water features in this image.
The Turbulent North Atlantic
The relatively laminar flow of the Gulf Stream slices across what is otherwise a fairly turbulent western North Atlantic Ocean in the above VIIRS image collected on March 9, 2016. If you click on the above image you will see (around clouds and sun glint) that the turbulence — made visible by the pigmented phytoplankton it entrains — extends across the whole North American Basin from Anegada to Bermuda to Cape Cod.
The Patagonian Sea is "one of the most biologically productive regions in the global ocean". Recent studies show chlorophyll concentrations have increased there over the past seventeen years.
The above VIIRS image was collected on March 12, 2016.
Springtime on the Grand Banks
The phytoplankton on the Grand Banks of Newfoundland are starting to bloom. The second NAAMES cruise will be traversing these waters in May of 2016.
Click on the above March 23, 2016 VIIRS image to get a larger version, or download a version with chlorophyll concentration contours overlaid.
Chlorophyll Concentrations over The Grand Banks
This 26 April 2016 VIIRS image shows gradients in the chlorophyll concentration across the region that will be visited by the R/V Atlantis during her second NAAMES cruise which begins on May 11, 2016.
Click on the above image to see the legend that explains the colored chlorophyll contours.
The North Sea
The above 9 May 2016 view of the North Sea shows some variation in water color that might be related to differences in the phytoplankton communities that live in that body of water. Measuring these differences is difficult enough from sea level, never mind from orbit. With future ocean color missions such as PACE, NASA hopes to make the task a bit more tractable.
Northwest Atlantic Ocean
Phytoplankton color the waters off of Atlantic Canada and New England on September 13, 2016.
Mar Argentino Phytoplankton
Diverse springtime phytoplankton communities ride the turbulent currents of the Argentine Sea. The above Aqua/MODIS image was collected on October 24, 2016. Click for a larger version.
Southern Indian Ocean
"The southern Indian Ocean is characterized by a confluence of diverse water masses, each with distinct physical characteristics, nutrient conditions, plankton communities and production rates."
Northwest Arabian Sea
The Arabian Sea phytoplankton community has begun to change in recent years as the mixotrophic dinoflagellate, Noctiluca scintilans, displaces other phytoplankton species in the region.
The Tasman Sea is painted in "ocean tones" by the phytoplankton in this Aqua-MODIS view off the southeastern corner of Australia collected on November 17th, 2016.
Southern Central Chilean Coast
The Pacific Ocean around Concepción, Chile receives dissolved inorganic carbon from the Biobío River and from coastal upwelling.
Southern Ocean Phytoplankton Blooms
Clouds and ice part over the portion of the Southern Ocean that is due south of eastern Africa and just north of Lützow-Holm Bay, Antarctica to reveal thick blooms of phytoplankton photosynthesizing in the sun.
This Aqua-MODIS image was collected on December 19, 2016. Click on the image above to retrieve a larger version.
Gulf of Alaska
Sea of Okhotsk
The Sea of Okhotsk supports high levels of primary production in the springtime. Click on the above Aqua/MODIS and Suomi-NPP/VIIRS composite to get a larger version of the April 25, 2017 image.
High phytoplankton productivity helps make today's Norwegian Sea a carbon dioxide sink. Analyses of boron isotopes in fossil foraminifera tests from that part of the world hint that the sea may have occasionally become a CO2 source during the last 135 thousand years.
The above Aqua/MODIS and Suomi-NPP/VIIRS composite image was generated from data collected on June 12, 2017. Click on it to get a larger version.
Numerous algal blooms are visible in this Aqua/MODIS image of the Caspian Sea collected on August 3, 2017. Click on the image to get a larger version.
The Benguela Upwelling Ecosystem
Phytoplankton thrive in the nutrient-replete waters of Africa's Benguela upwelling ecosystem — supporting a rich panoply of marine life from snails to whales. The upwelling that drives this productivity appears to be changing in response to climate variability.
The above Aqua/MODIS image was collected on September 2, 2017. Click on it to get a larger version.
Gulf of Oman & Arabian Sea
This Aqua/MODIS image of phytoplankton blooms off the coast of Oman was collected on October 17, 2017. Click the above image for a larger version.
Photosynthetic Pigments by Land and Sea
Autumn has once again come to eastern North America and, on land, chlorophyll begins to cede its dominance to other accessory pigments in the photosynthetic apparatus thereby revealing their yellow and orange tones. Meanwhile, in the ocean and lakes, phytoplankton pigments highlight different water masses and current systems.
The above Aqua/MODIS image was collected on October 20, 2017. Click on it to get a larger version.
Although the ultimate fate of the carbon is not yet clearly known, much of the Patagonian Sea serves as a carbon dioxide sink during the yearly spring bloom largely because of the photosynthetic activity of the phytoplankton living there.
The above Aqua/MODIS view of the region was collected on November 6, 2017. Click on the image to get a larger version.
Arabian Sea in Bloom
The northeast monsoonal winds carry haze and dust from the Asian continent across the northern Indian Ocean in winter. This makes remote sensing of ocean color there difficult. On January 14, 2018, the Aqua/MODIS radiometer was nevertheless able to detect the massive phytoplankton blooms that are once again filling much of the surface water of the Arabian Sea.
Click on the above image for a much larger version.
Western South Atlantic
On February 14, 2018, Suomi-NPP/VIIRS captured this view of phytoplankton in the western South Atlantic Ocean. Click the image for a larger view.
Gulf of Oman Blooms
A dense bloom of phytoplankton — likely the dinoflagellate mixotroph, Noctiluca scintillans — is visible in this Landsat 8/OLI image collected on December 22, 2017.
Click on the above image to get a larger version that shows the bloom's position and size relative to Oman's al Dimaniyyat Islands in the lower left corner.
Northern Arabian Sea Blooms
This Landsat 8 / OLI image of phytoplankton blooms in the northern Arabian Sea was collected on January 2, 2018.
Gulf of Oman
These bands of green in the Gulf of Oman are most likely caused by the Dinoflagellate known as Noctiluca scintillans.
Click on the above Landsat 8 image collected on January 27, 2016 to get a larger version with a locator map.
North and west of Ireland and Scotland, the clouds opened upon a blooming North Atlantic Ocean on May 30, 2018 when Aqua/MODIS flew by and captured the above image.
Bering Sea Green Belt
The waters of the Bering Sea are highly productive in the springtime when increasing sunlight and ample nutrients fuel explosive growth of phytoplankton. Over the years of the satellite-ocean-color era, researchers have noted that a green belt of productive water often forms along the edge of the continental shelf. The phytoplankton in this green belt may be benefitting from extra dissolved iron flowing in from the outer shelf sediments.
The orange line on the above VIIRS image shows the rough location of the shelf break as the 200-meter depth contour. These data were collected on June 13, 2018 (June 14 on the Russian side).
Gulf of Alaska
Suspended sediment and late summer phytoplankton blooms color the Gulf of Alaska in this composite of MODIS and VIIRS data collected on August 28, 2018. Click the above image to get a larger version.
Gulf of Alaska and Station Papa
The skies over Ocean Station Papa are cloudy more often than not, and the North Pacific there is often anything but. On September 30, 2018, however — while a storm churned to the west — Station Papa and much of the Gulf of Alaska basked in sunshine. The VIIRS instrument aboard the Suomi-NPP spacecraft took advantage of the clear skies to image phytoplankton communities swirling in the turbulent ocean.
Station Papa has recently been the site of the first stage of the EXPORTS field campaign.
Click on the above image to get a larger version.
Unusual Chlorophyll Pattern Off New Zealand
The spring bloom is underway in the South Pacific Ocean around New Zealand. Patchiness is common in phytoplankton distributions, but the small, high-chlorophyll patches to the east of the North Island struck this writer as noteworthy because they appear different from the distributions I am used to seeing. I wonder what sort of plankton makes those patches?
Move your pointer over the above Suomi-NPP/VIIRS image to just display relative chlorophyll concentration in gray scale (the brighter the pixels, the higher the chlorophyll). Click on the image to download a larger version of the enhanced-color image.
Tasman Sea Chlorophyll
The interaction of the East Australian Current with the bathymetry of the Tasman Sea results in a turbulent flow field that can be "seen" from orbit when phytoplankton are blooming in that part of the southwestern Pacific Ocean.
The above image was collected on October 17, 2018 by the VIIRS instrument that is part of the relatively new JPSS1 (NOAA-20) spacecraft. It shows relative chlorophyll concentrations in the Tasman Sea. Click on it to get a larger version.
This Aqua MODIS image of the Arabian Sea was collected on October 22, 2018. Click on it to get a larger version.
Spring Blooms around Southeastern Australia
Some fraction of the carbon fixed by phytoplankton blooming around Tasmania will eventually sink deep enough in the water column that it is unlikely to re-enter the atmosphere for a long time. Warming temperatures in the region may be reducing this carbon sequestration by increasing microbial respiration of organic carbon as it drifts downward through the water column.
Click on the above Suomi-NPP/VIIRS composite collected on November 18, 2018 to get a larger version.
This Aqua MODIS image of the Arabian Sea was collected on November 23, 2018. Click on it to get a larger version.
Western South Atlantic
From Mar del Plata, Argentina south to the Drake Passage and east past South Georgia Island, the western South Atlantic Ocean reveals its spring phytoplankton communities to the orbiting Aqua/MODIS instrument on November 23, 2018.
Click on the above image to get a larger version.
Winter Blooms in the Black Sea
It's the middle of winter and snow covers the mountains north and south of the eastern Black Sea. Nonetheless, phytoplankton appear to be blooming in the surface waters of that deep landlocked sea. The brightest feature in the above image has the appearance of a coccolithophore bloom. That calcite-shedding protist is more commonly found blooming in this region during the summertime.
The above image was collected by Landsat 8 on February 4, 2019. Click on it to get a larger version.
Summer Phytoplankton Communities around Patagonia
It's unusual for almost all of Patagonia and the surrounding ocean to be free of cloud cover, but so it was on February 4, 2019 when the Aqua spacecraft passed three times over the region and collected the MODIS data that comprise the above image. Both the Pacific Ocean off of Chile and the Atlantic Ocean off of Argentina support thriving phytoplankton communities stirred around by the turbulent surface currents.
Click on the above image to get a larger version.
Tasman Sea Eddy Pair
This counter-rotating eddy pair (cyclonic on the left, anticyclonic on the right) was imaged by the Suomi-NPP/VIIRS instrument in the Tasman Sea between Tasmania and New Zealand on March 1st, 2019.
The Crozet Islands are remote and surrounded by some of the roughest seas on the planet. Those seas are home to a recently discovered new type of killer whale, and they support what was reported to be the world's largest king penguin colony before it suffered a mysterious, massive decline in population.
When the clouds occasionally clear, we can derive some information about the phytoplankton that support these remote inhabitants of Earth from ocean color sensors such as MODIS on the Aqua spacecraft. The above image was collected on March 6, 2019. Click on it to get a larger version.
Northeastern Pacific Ocean
This view of the northeastern Pacific Ocean in the vicinity of Vancouver Island was collected by Aqua/MODIS on March 18, 2019. Click on it to get a larger version.
Submesoscale Variability in and around the Bay of Biscay
As the North Atlantic spring bloom kicks into high gear, the multiplying phytoplankton color the water as they are moved around by its turbulent mesoscale and submesoscale currents. The above JPSS1/(NOAA 20)/VIIRS image was collected on March 28, 2019. Click on it to get a larger version.
Benguela Upwelling Ecosystem
This May 10, 2019 Aqua/MODIS image exhibits patterns driven by the same physics as the patterns found in the Benguela upwelling a year earlier. Recent measurements in part of the region indicate that the ocean here is a source of the potent greenhouse gas, nitrous oxide.
Click on the above image to get a larger version.
Western Bering Sea
Clouds cleared over the western Bering Sea at the end of May 2019 to reveal phytoplankton assemblages stirred by ocean currents. Variations in species composition, depth distribution, and even the physiological state of the phytoplankton all contribute to subtle changes in water color as measured by the orbiting radiometer.
North Atlantic Spring Bloom
This view of Iceland and the North Atlantic Ocean to its southwest shows the spring phytoplankton bloom near its peak. The above image was collected by Aqua/MODIS on June 12, 2019. Click on it to get a larger version.
Southwest Pacific Phytoplankton
One thinks of the waters of the Coral Sea in the southwestern Pacific Ocean as being relatively clear. These waters are home to the corals of New Caledonia and Australia's Great Barrier Reef, for example, and tropical corals require clear water (among other things) to remain healthy. Nevertheless, phytoplankton are present in the water column, and these VIIRS data (from the NOAA-20 and Suomi-NPP satellites) have been enhanced to show their presence as they are stirred around by the turbulent flow field in the region.
While one cannot identify which types of phytoplankton are shown in the different areas of this image, it is likely that some of the brighter features just inside and south of the Great Barrier Reef are blooms of a nitrogen-fixing cyanobacterium called Trichodesmium.
The data for this image were collected on August 19, 2019. Click on it to get a larger version.
Central California Coastal Blooms
Aqua/MODIS collected this view of algal blooms along the central California coast on September 24, 2019. Click on the above image to get a larger version.
A few hours earlier Landsat 8 captured a more highly resolved image of a portion of the blooms.
Indian Ocean Spring
Were it not for satellite ocean color sensors and periodic breaks in cloud cover over the southwestern Indian Ocean, we humans would have little idea of the complex dance of the photosynthesizing phytoplankton that is constantly playing out on that remote stage. This springtime view was collected by Suomi-NPP/VIIRS on October 11, 2019. Click on it to get a broader view of the region.
The orbiting Aqua/MODIS instrument found the above phytoplankton-brightened cyclonic eddy swirling in the Tasman Sea on the first day of November 2019. Some of the haze in the overlying atmosphere comes from fires burning in New South Wales, Australia. Click on the above image to get a larger version that includes a portion of southeastern Australia.
Spring in the Southwestern South Atlantic Ocean
The South Atlantic Ocean east of Argentina is always a riot of color in the springtime when sunlight and nutrients are plentiful and grazers in the water column have a tough time keeping up with all of the phytoplankton fecundity. Haze visible in the upper right quadrant of the above image may be smoke from brush fires in Australia.
The above image is a composite of VIIRS data collected by the Suomi-NPP and NOAA 20 satellites on November 18, 2019. Click on it to get a larger version.
Primary Producers in the South Atlantic
Two thousand kilometers east of Argentina the turbulent South Atlantic Ocean exhibits eddies and filaments colored by plant-like wanderers which are aptly named, phytoplankton. The above scene was collected on January 4, 2020 by two VIIRS instruments: one aboard the Suomi-NPP satellite and one aboard the NOAA-20 satellite. Click on it to see more of the region.
Under a Winter Dust Cover
The skies over the Arabian Sea can be dusty during the winter monsoon, but orbiting radiometers designed to measure ocean color often have enough sensitivity to measure what is going on in the water beneath all the dust. In this case, a little processing of the above Aqua/MODIS data reveals widespread phytoplankton blooms.
The mixotrophic dinoflagellate, Noctiluca scintillans, may be responsible for some or many of the patterns seen here if trends noted in previous years are continuing.
The above image was collected on January 29, 2020. Click on it to get a larger version of the enhanced image.
South Atlantic Summer Blooms
This view of phytoplankton blooms in the South Atlantic Ocean was collected by NOAA-20/VIIRS on January 21, 2020. Click on the above image to get a larger version.
Western North Atlantic
Snow still frosts the northeastern USA and eastern Canada in this February 23, 2020 Aqua/MODIS image, but the phytoplankton of the adjacent North Atlantic are gearing up for another spring bloom under sunny skies and warming temperatures. Blue centered warm core rings spin clockwise amidst the teeming green just north of the similarly blue Gulf Stream that birthed them. The brighter waters east of Cape Cod overlie the shallow, productive Georges Bank.
Click on the above image for a larger version. The following day, Landsat 8 collected a higher resolution view of the region north and south of Cape Cod.
The Chatham Rise
Stretching from New Zealand's Banks Peninsula eastward past Chatham Island, the Chatham Rise is a shallower part of the sea floor over which water masses from the north and south mix leading to high production among the phytoplankton. The above Aqua/MODIS view of the resulting biomass distribution was collected on March 1, 2020 near the end of the summer. Click on it to get a larger version.
Aqua/MODIS collected this view of accumulating phytoplankton biomass in the western Mediterranean Sea and the Bay of Biscay on March 11, 2020. Click on the above image to get a larger view.
Northern Indian Ocean
The above image comprises data collected by two VIIRS instruments (on Suomi-NPP and NOAA-20) on March 8, 2020. It features the northern Indian Ocean and the surrounding portions of Africa and Asia. Conspicuous in the Arabian Sea are dense blooms of Noctiluca scintillans that have been plaguing the region in wintertime for many years now. Click on the image to get a much larger (33 megabyte) version.
Southern Benguela Upwelling System
This view of the southern portion of the Benguela upwelling system off of South Africa's west coast was collected by Aqua/MODIS on March 27, 2020. Click on the above image to get a larger version.
Gulf of Oman
This eddy in the Gulf of Oman northeast of Muscat is made visible by slicks of the mixotrophic dinoflagellate, Noctiluca scintillans, that has plagued the Gulf in recent decades. This view of the blooms was collected on April 2, 2020 by Landsat 8. Click on the above image to get a much larger (41 megabyte) version.
This view of the springtime North Sea is another good illustration of the importance of remote sensing to understanding our planet's oceans. There is no imaginable way for surface-based observers to capture the level of phytoplankton variability seen in this image.
The above image comprises data collected by Aqua/MODIS on April 20, 2020. Click on it to get a larger version showing a broader region.
Twenty-Year-Old Sensor Views Benguela Upwelling
Although the MODIS instrument on the Terra spacecraft has proven suboptimal for use in quantitative ocean-color work, it still is capturing useful qualitative ocean color features more than twenty years after it collected its first-light image. The above view of dust storms crossing the Benguela upwelling system was collected on June 16, 2020. Click on it to get a larger version.
Just a bit less than ten hours before the summer solstice of 2020, the Aqua/MODIS instrument captured the above view of the spring bloom in full swing in the Norwegian Sea. Click on the image for a larger view.
Phytoplankton blooming in the Denmark Strait between Iceland and Greenland overlie an unseen waterfall of prodigious proportions. The above Aqua/MODIS image was collected on July 2, 2020. Click on it to get a larger version.