Inter-annual variations in the SeaWiFS global chlorophyll a concentration (1997–2007)

摘要: The SeaWiFS data set covering the period 1997–2007 is used to develop a framework for comprehensive description of inter-annual variations in chlorophyll concentration (Chla). For each grid cell, monthly Chla series decomposed into seasonal, irregular and trend-cycle terms with Census X-11 technique that an iterative band-pass filter algorithm. This approach allows annual cycle, while trend-term isolates multi-annual evolution mean level signal. patterns relatively large are selected using variance due respect total variance, compared maps monotonic trends derived by non-parametric Kendall analysis. Most these identified subtropical domain (30°S–30°N), even though there strong at mid-latitudes, particularly Northeast Atlantic South Australia. time found within pattern interest coherent. Conversely, ensemble spatially averaged trend-terms shows diversity evolutions, rather changes all or part period, abrupt shifts low-frequency oscillations, sometimes coupled modification amplitude cycle. Some correlated climate indices, those regions usually show negative correlation equivalent calculated sea surface temperature. signals should be further monitored longer can serve as test cases biogeochemical models.