While the absence of wind reduces the sun glint in this MODIS scene through the flattening of the water's surface, it may also reduce the evaporative cooling of the ocean surface layer and at the same time reduce the vertical mixing in the water column. Since MODIS can only sense the temperature of the top 0.01 millimeters or so of the water column, this effect could result in skin temperatures that are significantly warmer than those under windier air.
The heating of the sea surface is also enhanced because of a lack of cloud cover over the feature. Reduced cloud cover and drier air is another recognized aspect of the horse latitudes in both the northern and southern hemispheres.
If you click on the images at right you can view higher resolution versions of the corresponding images with the QuikSCAT wind fields overlaid. The linear SST local maximum feature roughly matches the local wind speed minimum. Note that there are differences between the morning and evening wind vectors. The winds at the time of the MODIS overpass in the early afternoon were likely somewhere in between the two. (There is another SST maximum in the larger image [around 21.5 South and 31 West] that also seems to be in an area of lower wind speed.)
