Figure 2
From: Satellite-based indicator of zooplankton distribution for global monitoring
Cluster analysis. (a) Geographic distribution of clusters. (b–g) Cumulative distribution functions for each selected variables and cluster. (b,c) Chlorophyll-a concentration (CHL, low and high ranges, respectively). (d,e) Horizontal gradient of chlorophyll-a (gradCHL, low and high ranges, respectively). (f) The biomass index using night sampling and positive biomass only data (in relative values, nobservations = 6,660). (g) Sampling month (decimal month) as illustrative variable (legend in grey). The threshold values used for the model parameterisation are, for CHL, the 3rd and 97th percentiles of the extreme clusters (red and green clusters) and, for gradCHL, the 3rd percentile of the lowest cluster (red cluster). Note that 29 points in extreme latitudes were excluded from panel (a). See text and Fig. 3 for details.
