scholarly journals Biogeographical trends in phytoplankton community size structure using adaptive sentinel 3-OLCI chlorophyll a and spectral empirical orthogonal functions in the estuarine-shelf waters of the northern Gulf of Mexico

2021 ◽  
Vol 252 ◽  
pp. 112154
Author(s):  
Bingqing Liu ◽  
Eurico J. D'Sa ◽  
Kanchan Maiti ◽  
Victor H. Rivera-Monroy ◽  
Zuo Xue
2020 ◽  
Vol 211 ◽  
pp. 103400 ◽  
Author(s):  
Monika Soja-Woźniak ◽  
Leonardo Laiolo ◽  
Mark E. Baird ◽  
Richard Matear ◽  
Lesley Clementson ◽  
...  

2010 ◽  
Vol 33 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Carolyn Barnes ◽  
Xabier Irigoien ◽  
José A. A. De Oliveira ◽  
David Maxwell ◽  
Simon Jennings

2009 ◽  
Vol 24 (2) ◽  
pp. 436-455 ◽  
Author(s):  
Elinor Keith ◽  
Lian Xie

Abstract Seasonal hurricane forecasts are continuing to develop skill, although they are still subject to large uncertainties. This study uses a new methodology of cross-correlating variables against empirical orthogonal functions (EOFs) of the hurricane track density function (HTDF) to select predictors. These predictors are used in a regression model for forecasting seasonal named storm, hurricane, and major hurricane activity in the entire Atlantic, the Caribbean Sea, and the Gulf of Mexico. In addition, a scheme for predicting landfalling tropical systems along the U.S. Gulf of Mexico, southeastern, and northeastern coastlines is developed, but predicting landfalling storms adds an extra layer of uncertainty to an already complex problem, and on the whole these predictions do not perform as well. The model performs well in the basin-wide predictions over the entire Atlantic and Caribbean, with the predictions showing an improvement over climatology and random chance at a 95% confidence level. Over the Gulf of Mexico, only named storms showed that level of predictability. Predicting landfalls proves more difficult, and only the prediction of named storms along the U.S. southeastern and Gulf coasts shows an improvement over random chance at the 95% confidence level. Tropical cyclone activity along the U.S. northeastern coast is found to be unpredictable in this model; with the rarity of events, the model is unstable.


2005 ◽  
Vol 41 (2) ◽  
pp. 305-310 ◽  
Author(s):  
Jason H. See ◽  
Lisa Campbell ◽  
Tammi L. Richardson ◽  
James L. Pinckney ◽  
Rongjun Shen ◽  
...  

2009 ◽  
Vol 36 (7) ◽  
pp. n/a-n/a ◽  
Author(s):  
Michelle M. Gierach ◽  
Bulusu Subrahmanyam ◽  
Annette Samuelsen ◽  
Kyozo Ueyoshi

2020 ◽  
Vol 12 (20) ◽  
pp. 3313
Author(s):  
Andy Stock ◽  
Ajit Subramaniam ◽  
Gert L. Van Dijken ◽  
Lisa M. Wedding ◽  
Kevin R. Arrigo ◽  
...  

Marine remote sensing provides comprehensive characterizations of the ocean surface across space and time. However, cloud cover is a significant challenge in marine satellite monitoring. Researchers have proposed various algorithms to fill data gaps “below the clouds”, but a comparison of algorithm performance across several geographic regions has not yet been conducted. We compared ten basic algorithms, including data-interpolating empirical orthogonal functions (DINEOF), geostatistical interpolation, and supervised learning methods, in two gap-filling tasks: the reconstruction of chlorophyll a in pixels covered by clouds, and the correction of regional mean chlorophyll a concentrations. For this purpose, we combined tens of cloud-free images with hundreds of cloud masks in four study areas, creating thousands of situations in which to test the algorithms. The best algorithm depended on the study area and task, and differences between the best algorithms were small. Ordinary Kriging, spatiotemporal Kriging, and DINEOF worked well across study areas and tasks. Random forests reconstructed individual pixels most accurately. We also found that high levels of cloud cover led to considerable errors in estimated regional mean chlorophyll a concentration. These errors could, however, be reduced by about 50% to 80% (depending on the study area) with prior cloud-filling.


1995 ◽  
Vol 52 (12) ◽  
pp. 2553-2573 ◽  
Author(s):  
Eric Mellina ◽  
Joseph B. Rasmussen ◽  
Edward L. Mills

We determined the effects of zebra mussel (Dreissena polymorpha) on water column phosphorus (P) and chlorophyll a levels and algal community size structure as well as rates of P excretion in laboratory experiments. Zebra mussel at a threshold density of 0.25/L were able to decouple the nutrient–chlorophyll relationship, to induce erratic patterns in P and chlorophyll a trends, and to decrease mean algal cell sizes. Using shell length we explained 75 and 71% of the variability in P excretion rates in trials held at 17 and 22 °C. Using mass balance modeling, we examined the effects of zebra mussel growth and mortality on mean annual steady-state P levels as functions of hydraulic flushing and P loadings for the western basin of Lake Erie, for Lake St. Clair, and for Oneida Lake. Zebra mussel affected water column P levels only when the annual P accumulated into mussel biomass represented >20% of the lake's annual P loading. The mussel populations in all three lakes did not substantially affect water column P levels but decoupling of the nutrient–chlorophyll relationship was observed in lakes Erie and St. Clair. No evidence was found for increased decoupling of this relationship with increasing zebra mussel density in European lakes.


2013 ◽  
Vol 93 (8) ◽  
pp. 2155-2166 ◽  
Author(s):  
Alle A.Y. Lie ◽  
Lik Chi Wong ◽  
C. Kim Wong

Phytoplankton primary production and copepod production, and the size composition of the phytoplankton community in Tolo Harbour, a semi-enclosed bay in north-eastern Hong Kong, were studied from February 2008 to March 2009. Chlorophyll-a (Chl a) concentrations decreased from an average of 9.07 µg l−1 in the inner part of the bay to 3.07 µg l−1 at the mouth of the bay. In terms of contribution to total Chl a biomass, the >20 µm size fraction dominated the phytoplankton community. The zooplankton community in Tolo Harbour was dominated by small copepods, with cephalothorax length ranging from ~0.3 to 0.4 mm, and the density of copepods decreased from ~15,000 ind.m−3 in the inner part of the bay to ~9,700 ind.m−3 at the mouth of the bay. Depth-integrated net primary production in Tolo Harbour was high, ranging from 0.34 to 10.40 g C m−2 day−1, with an overall mean of 2.64 g C m−2 day−1. In contrast, copepod production was low, ranging from 0.19 to 16.64 mg C m−3 day−1, with an overall mean of 2.73 mg C m−3 day−1. The low transfer efficiency of 1.4% between phytoplankton primary production and copepod secondary production suggests that the large phytoplankton was inefficiently grazed by the small copepods in Tolo Harbour.


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