Trends in phytoplankton and primary productivity off Northwest Africa
This study is an attempt to update spatial trends previously observed in the productivity of the Canary Current Upwelling System (CCUS) from satellite SeaWiFS datasets (Demarcq, 2009) from the assembling of data from the SeaWiFS (1997-2010) and MODIS (2002-present) sensors. Data blending or simultaneous use of several sensors is a challenge in ocean color, especially in the highly productive coastal waters of the CCUS. An empirical cross-correction of both sensors shows that the estimate of linear trends is possible with an adequate level of precision, valid at least in the CCUS. Common trends between sensors show coherent spatio-temporal patterns, while it is shown that the previously contrasted trends of the 1998-2007 period tend to weaken significantly during the 1998-2014 period while being more homogeneously negative, except in the Guinean region and northern Morocco, i.e. in the extreme parts of the CCUS. These estimates also show the importance of constructing the longest as possible time series of phytoplankton biomass or primary productivity in order to minimize the effects of the decadal variability. A new challenge will be searching qualitative changes in the composition of the phytoplankton, probably more important in an ecological point of view than relatively minor quantitative changes.
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Report Section biblioteca |
| Language: | English |
| Published: |
IOC-UNESCO
2015
|
| Subjects: | Primary productivity, Chlorophyll-a, SeaWIFS, MODIS, Temporal trend, CCLME, |
| Online Access: | http://hdl.handle.net/1834/9199 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|