کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6388662 1627935 2014 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synoptic-scale upwelling indices and predictions of phyto- and zooplankton populations
ترجمه فارسی عنوان
شاخص های آپوالین در مقیاس سینوپتیک و پیش بینی های جمعیت های فیتو و زئوپلانکتون
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
چکیده انگلیسی
Seasonal upwelling is responsible for the biologically rich and productive ecosystems of coastal eastern boundary currents. In most studies of physical - biological interactions in these systems, upwelling statistics are computed on monthly, seasonal, and annual time scales, whereas upwelling naturally occurs at high frequencies (days to weeks). This simplification of the upwelling process may misrepresent relationships between upwelling and biological populations. Based on 31 years (1982-2012) of hourly-measured winds and sea surface temperature at buoys off the central-northern California coast, we characterized upwelling and relaxation events at synoptic time scales, and used event-scale statistics to relate to local lower trophic level populations. We defined three metrics to quantify synoptic-scale upwelling: (i) Intensity, a measure of cumulative wind stress forcing during each upwelling event, (ii) SSTevent, a measure of the oceanic response to wind forcing, and (iii) Nutrient Upwelling Index (NUI), a measure of the nitrate availability at the surface during upwelling events. We compared cumulative values of Intensity and NUI, and average values of SSTevent during the peak of the upwelling season (April-June in central-northern California) to proxies of phytoplankton biomass (chlorophyll-a concentrations) and krill abundance to assess the abilities of high frequency upwelling indices to predict biology. Wind forcing alone (Intensity) did not explain population variability, but SSTevent and NUI showed excellent relationships to chlorophyll concentrations (44% and 54% of variance explained, respectively) and krill abundance (68% of variance explained). All relationships appeared to be dome-shaped, supporting the hypothesis that moderate upwelling and ocean temperature are optimal for these populations. SSTevent and NUI performed better than the traditional Bakun upwelling index in predicting populations. We conclude that investigating upwelling characteristics on event scales can improve understanding of lower trophic level dynamics in eastern boundary current systems.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Progress in Oceanography - Volume 120, January 2014, Pages 177-188
نویسندگان
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