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Comparison of the seasonal and interannual variability of phytoplankton pigment concentrations in the Peru and California Current systems

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Field Value
Title Comparison of the seasonal and interannual variability of phytoplankton pigment concentrations in the Peru and California Current systems
Names Thomas, A. C. (creator)
Huang, F. (creator)
Strub, P. Ted (creator)
James, C. (creator)
Date Issued 1994-04-15 (iso8601)
Note Copyright 1994 by the American Geophysical Union
Abstract Monthly composite images from the global coastal zone color scanner
(CZCS) data set are used to provide an initial illustration and comparison of seasonal
and interannual variability of phytoplankton pigment concentration along the western
coasts of South and North America in the Peru Current system (PCS) and California
Current system (CCS). The analysis utilizes the entire time series of available data
(November 1978 to June 1986) to form a mean annual cycle and an index of interannual
variability for a series of both latitudinal and cross-shelf regions within each current
system. Within 100 km of the coast, the strongest seasonal cycles in the CCS are in
two regions, one between 34° and 45°N and the second between 24° and 29°N, each
with maximum concentrations (>3.0 mg m⁻³) in MayJune. Weaker seasonal
variability is present north of 45°N and in the Southern California Bight region (32°N).
Within the PCS, in the same 100-km-wide coastal region, highest (>45°S) and lowest
(<20°S) latitude regions have a similar seasonal cycle with maximum concentrations
(> 1.5 mg m⁻³) during the austral spring, summer, and fall, matching that evident
throughout the CCS. Between these regions, off northern and central Chile, the
seasonal maximum occurs during JulyAugust (austral winter), contrary to the
influence of upwelling favorable winds. Within the CCS, the dominant feature of
interannual variability in the 8-year time series is a strong negative concentration
anomaly in 1983, an El Nino year. The relative value of this negative anomaly is
strongest off central California and is followed by an even stronger negative anomaly in
1984 off Baja California. In the PCS, strong negative anomalies during the 1982-1983 El
Nino period are evident only off the Peruvian coast and are evident there only in the
regions 100 km or more from the coast. Although negative anomalies associated with
the El Nino were not present at higher latitudes (more than approximately 20°S) in the
PCS, the extremely sparse sampling weakens our confidence in the results of the
interannual analysis in this region. An upper estimate of the systematic winter bias
remaining in the global CZCS data after reprocessing with the multiple scattering
algorithm is given in the appendix.
Genre Article
Identifier Thomas, A. C., F. Huang, P. Ted Strub, and C. James. "Comparison of the seasonal and interannual variability of phytoplankton pigment concentrations in the Peru and California Current systems." Journal of Geophysical Research 99.C4 (1994): 7355-7370. Print.

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