Quasi-true color images of the Baltic - looking for cyanobacteria blooms

Mati Kahru, mkahru@ucsd.edu

NASA's Aqua and Terra satellites provide daily coverage with Terra's descending overpass at approximately 10:30 local time and Aqua's ascending overpass at approximately 13:30 local time.   Below is a list of quasi-true color images made with MODIS-Aqua or MODIS-Terra data produced as RGB (red-green-blue) images using MODIS bands 1, 4, 3. The 250 m and 500 m data were remapped to a map with 250 m resolution. To see the image you need to click on the image thumbnail. That shows the image fit into your browser window. To see the full 250-m image you need to click on the + sign on that image. Images are large and may take a while to download. You can save the image locally (with right-click). The details of software used in creating these images is described  here; more at http://wimsoft.com.

Date	Julian Day, Sensor	Comment	PNG
2012-08-04	217, Aqua	Accumulations visible, particularly around Gotland
2012-08-02	215, Aqua	Accumulations visible around Gotland
2012-07-27	209, Aqua	Thick surface accumulations visible in S Baltic
2012-07-25	207, Aqua	Thick surface accumulations visible in S Baltic
2012-07-24	206, Aqua	Thick surface accumulations visible in S Baltic
2012-07-22	204, Aqua	Surface cyanobacteria accumulations visible in many areas.
2012-07-15	197, Aqua	Windy weather is preventing the accumulations to develop but the bloom is still visible S of Gotland and in Hano bight.
2012-07-13	195, Aqua	Windy and rainy weather has mixed the accumulations away from the surface but the bloom (increased turbidity) is still visible in open Baltic
2012-07-09	191, Aqua	It's cloudy but blooms/accumulations visible S of Gotland
2012-07-08	190, Aqua	Accumulations/blooms in Southern Baltic
2012-07-04	186, Aqua	It's cloudy but weak cyanobacteria accumulations appearing  in Northern Baltic Proper.
2012-07-03	185, Aqua	Cyanobacteria blooms visible but accumulations not dense due to weather.
2012-07-03	185, Terra	Cyanobacteria blooms visible but accumulations not appearing due to weather.
2012-07-02	184, Aqua	Cyanobacteria blooms visible, especially in Northern Baltic, accumulations not dense due to weather.
2012-07-02	184, Terra	Finally the cyanobacteria are close to pop up to the surface. The dark green colors show where the bloom is more intense. Both Northern and Southern Baltic images are clear enough to be shown.
2012-06-29	181, Terra	Cyanobacteria blooms are visible in Northern Baltic Proper and in Gulf of Finland but due to windy weather they don't form surface accumulations. Enhanced turbidity in the Gulf of Riga may be due to various phytoplankton.
2012-06-28	180, Aqua	It is cloudy but cyanobacteria blooms are visible E and N of Gotland and in the opening to the Gulf of Finland
2012-06-28	180, Terra	It is cloudy and hazy but cyanobacteria blooms are visible in Northern Baltic Proper north of Gotland and in the opening to the Gulf of Finland.
2012-06-23	175, Aqua	Due to rainy and windy weather, no significant cyanobacteria blooms but some increase evident in filaments just outside of the Gdansk Bay.
2012-06-22	174, Aqua	Cyanobacteria bloom evident in the Northern Baltic Proper (judging by increased turbidity) not not forming surface accumulations yet. See the mushroom-like eddy south of Hanko eddy in the opening to the Gulf of Finland.
2012-06-21	173, Terra	Cyanobacteria bloom starting NE of Gotland and in the mushroom eddy in the opening to the Gulf of Finland. Technical problem with NASA's LAADS website prevents making current images although data exist.
2012-06-18	170, Aqua	Likely cyanobacteria bloom starting in the Bay of Gdansk.

 

 

Fig. 2. Mean frequency of cyanobacteria accumulations (FCA) for July-August in the Baltic Sea. From Kahru, Elmgren et al., in preparation;  revised and extended from Kahru et al [2007].