image: 

The image shows a map of 700nm backscatter from the combined float and glider sensors over the last few days. Variations of about a factor of 2 are seen over scales of 10 km or less. This is consistent with the MODIS images shown here several weeks ago. In this cloudy place, we get very few such images.

We expect backscatter to be a proxy, perhaps imperfect, for particulate carbon. Backscatter has been tracking beam attenuation at 660nm quite well. Beam-c has been shown to be a proxy for Particular Organic Carbon (POC) so perhaps backscatter is also. It has also been tracking dissolved oxygen and chlorophyll, so there is good reason to interpret these maps as a proxy for 'intensity of bloom'.

The combination of rapid time and space variations has made it difficult to construct maps. The bloom intensity has varied on a time scale of several days, as storms have varied the depth of mixing. Thus data a few days apart cannot be used in the same map. However, the number of measurements in this short time is insufficient to make a map. This problem has plagued measurements of the bloom for decades; it was one of our major goals to overcome it.

Float measurements for the the last few days have indicated a relatively steady bloom. I have taken advantage of this to composite all the float and glider measurements and construct the map. In the long run, we will be able to use more sophisticated space-time mapping techniques, perhaps with models, to construct maps even during times of variability.