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Mark R Abbott - One of the best experts on this subject based on the ideXlab platform.
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Phytoplankton Pigment distribution in relation to silicic acid, iron and the physical structure across the Antarctic Polar Front, 170°W, during austral summer
Deep-sea Research Part Ii-topical Studies in Oceanography, 2020Co-Authors: C Mengelt, Mark R Abbott, John A. Barth, Ricardo M. Letelier, Christopher I. Measures, Sue VinkAbstract:In order to study the factors controlling the phytoplankton distribution across the Antarctic Polar Frontal Region (PFR), Surface Pigment samples were collected during austral summer (January/February 1998) near 170°W. Both the Polar Front (PF) and the Southern Antarctic Circumpolar Current Front (SACCF) were regions of enhanced accumulation of phytoplankton Pigments. The mesoscale survey across the PF revealed two distinct phytoplankton assemblages on either side of the front. The phytoplankton community was dominated by diatoms south of the PF and by nanoflagellates (primarily by prymnesiophytes) to the north. Surprisingly, chlorophyll a concentrations did not correlate with mixed-layer depths. However, an increase of the dominance of diatoms over prymnesiophytes was observed with decreasing mixed-layer depths. Despite this relationship, we conclude that the average light availability in the mixed layer was not an important factor influencing the shift in phytoplankton composition across the PF. Although no correlation was found between the Surface distribution of the major phytoplankton taxa and dissolved iron or silicic acid concentrations, the location of the strongest vertical gradient in silicic acid and iron concentration coincides with the maximum abundance of diatoms. We conclude that the difference in taxonomic composition is a result of increased silicic acid and iron flux to the upper mixed layer as a result of the increased vertical gradient of these key nutrients south of the front.
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seasonal and nonseasonal variability of satellite derived Surface Pigment concentration in the california current
Journal of Geophysical Research, 1990Co-Authors: Ted P Strub, Corinne James, Andrew C Thomas, Mark R AbbottAbstract:Satellite-derived Pigment concentrations from the west coast time series (WCTS) are averaged into monthly mean fields over the California Current system (CCS) for the period July 1979 to June 1986. Errors caused by the scattering algorithm used in the WCTS are reduced by an empirical correction function, although winter values (November–February) remain unreliable. For the March–October period we look at both the mean seasonal development and the nonseasonal monthly anomalies of Pigment concentration. These are compared with fields of alongshore wind stress, mixing power of the wind (u*3) and wind stress curl. Outside of the Southern California Bight there is a strong seasonal cycle with a spring-summer maximum, a northward progression of high Pigment concentrations from California to Oregon and a double maximum off Washington (spring and summer, with a lull in between). Within the Southern California Bight, seasonality is low, with a relative minimum in late summer. Off Baja California the pattern is similar to that off northern California. In regions where previous work has been done, there is general agreement with the seasonal cycles found here. Nonseasonal variability in Pigment concentration over the large-scale CCS (400 km wide) is most closely related statistically to synoptic fields of wind stress curl. Within 100 km of the coast, the strongest relations are between Pigment concentration and both u*3 and alongshore wind stress. Correlations with these wind variables account for only 25% of the monthly variance in anomalous satellite-derived Pigment concentrations. This is partly due to the noise in both wind and Pigment data sets but also demonstrates the fact that much of the anomalous Pigment variability is not a response to anomalous wind forcing on these time scales. Correlations are also low between anomalous Pigment concentrations and anomalous sea level heights, which serve as a crude proxy for the strength of the alongshore current over the shelf. The largest nonseasonal anomaly in the data occurred during the 1982–1983 El Nino, which caused a large-scale decrease in Pigment concentration, stronger and longer lasting in the south than in the north.
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Seasonal and nonseasonal variability of satellite‐derived Surface Pigment concentration in the California Current
Journal of Geophysical Research, 1990Co-Authors: P. Ted Strub, Corinne James, Andrew C Thomas, Mark R AbbottAbstract:Satellite-derived Pigment concentrations from the west coast time series (WCTS) are averaged into monthly mean fields over the California Current system (CCS) for the period July 1979 to June 1986. Errors caused by the scattering algorithm used in the WCTS are reduced by an empirical correction function, although winter values (November–February) remain unreliable. For the March–October period we look at both the mean seasonal development and the nonseasonal monthly anomalies of Pigment concentration. These are compared with fields of alongshore wind stress, mixing power of the wind (u*3) and wind stress curl. Outside of the Southern California Bight there is a strong seasonal cycle with a spring-summer maximum, a northward progression of high Pigment concentrations from California to Oregon and a double maximum off Washington (spring and summer, with a lull in between). Within the Southern California Bight, seasonality is low, with a relative minimum in late summer. Off Baja California the pattern is similar to that off northern California. In regions where previous work has been done, there is general agreement with the seasonal cycles found here. Nonseasonal variability in Pigment concentration over the large-scale CCS (400 km wide) is most closely related statistically to synoptic fields of wind stress curl. Within 100 km of the coast, the strongest relations are between Pigment concentration and both u*3 and alongshore wind stress. Correlations with these wind variables account for only 25% of the monthly variance in anomalous satellite-derived Pigment concentrations. This is partly due to the noise in both wind and Pigment data sets but also demonstrates the fact that much of the anomalous Pigment variability is not a response to anomalous wind forcing on these time scales. Correlations are also low between anomalous Pigment concentrations and anomalous sea level heights, which serve as a crude proxy for the strength of the alongshore current over the shelf. The largest nonseasonal anomaly in the data occurred during the 1982–1983 El Nino, which caused a large-scale decrease in Pigment concentration, stronger and longer lasting in the south than in the north.
B. Greg Mitchell - One of the best experts on this subject based on the ideXlab platform.
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Predictive bio-optical relationships for polar oceans and marginal ice zones
Journal of Marine Systems, 1992Co-Authors: B. Greg MitchellAbstract:Mitchell, B.G., 1992. Predictive bio-optical relationships for polar oceans and marginal ice zones. J. Mar. Syst., 3: 91-105. An analysis of more than 500 stations from polar seas was undertaken to evaluate predictive models linking in situ phytoplankton Pigment concentrations to measurable optical parameters. The data set consists of profiles of spectral downwelling irradiance [Ed(A], upwelling radiance [Lu(A)], chlorophyll and phaeoPigments from 3 cruises to the Antarctic Peninsula (RACER, UVDOZ-88, UVDOZ-89), one cruise to the Barents Sea (PRO MARE) and one cruise to Fram Strait in the Greenland Sea (CEAREX). The Pigment specific diffuse attenuation coefficient [Kd*()t) m 2 mg -1 chl a +phaeo] for polar regions is significantly smaller, particularly in the blue region of the spectrum, than previous statistical models for temperate oceans predict. Consistent with the observations for Kd*(A), phytoplankton remote sensing Pigment retrieval algorithms, based on Lu(A), show significant differentiation from temperate ocean models. The presently recommended water-leaving radiance algorithm for Coastal Zone Color Scanner data processing underestimates Surface Pigment concentrations by more than a factor of two for the polar observations reported here. The observations are interpreted in the context of variations in Pigment specific particulate absorption [a*(A) m 2 mg -1 chl a +phaeo] which have been described elsewhere. Specifically, the magnitude of a~'(A) in the blue is hypothesized to be smaller for polar regions due to significant Pigment packaging effects, and a relatively small amount of detrital absorption compared to phytoplankton absorption. Implications for remote sensing of phytoplankton Pigments and Pigment-based models of light propagation in the oceans are discussed.
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Predictive bio-optical relationships for polar oceans and marginal ice zones
Journal of Marine Systems, 1992Co-Authors: B. Greg MitchellAbstract:An analysis of more than 500 stations from polar seas was undertaken to evaluate predictive models linking in situ phytoplankton Pigment concentrations to measurable optical parameters. The data set consists of profiles of spectral downwelling irradiance [Ed(λ)], upwelling radiance [Lu(λ)], chlorophyll and phaeoPigments from 3 cruises to the Antarctic Peninsula (RACER, UVDOZ-88, UVDOZ-89), one cruise to the Barents Sea (PRO MARE) and one cruise to Fram Strait in the Greenland Sea (CEAREX). The Pigment specific diffuse attenuation coefficient [Kd*(λ) m2 mg-1 chl a + phaeo] for polar regions is significantly smaller, particularly in the blue region of the spectrum, than previous statistical models for temperate oceans predict. Consistent with the observations for Kd*(λ), phytoplankton remote sensing Pigment retrieval algorithms, based on Lu(λ), show significant differentiation from temperate ocean models. The presently recommended water-leaving radiance algorithm for Coastal Zone Color Scanner data processing underestimates Surface Pigment concentrations by more than a factor of two for the polar observations reported here. The observations are interpreted in the context of variations in Pigment specific particulate absorption [ap*(λ) m2 mg-1 chl a + phaeo] which have been described elsewhere. Specifically, the magnitude of ap*(λ) in the blue is hypothesized to be smaller for polar regions due to significant Pigment packaging effects, and a relatively small amount of detrital absorption compared to phytoplankton absorption. Implications for remote sensing of phytoplankton Pigments and Pigment-based models of light propagation in the oceans are discussed. © 1992.
Ted P Strub - One of the best experts on this subject based on the ideXlab platform.
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seasonal and nonseasonal variability of satellite derived Surface Pigment concentration in the california current
Journal of Geophysical Research, 1990Co-Authors: Ted P Strub, Corinne James, Andrew C Thomas, Mark R AbbottAbstract:Satellite-derived Pigment concentrations from the west coast time series (WCTS) are averaged into monthly mean fields over the California Current system (CCS) for the period July 1979 to June 1986. Errors caused by the scattering algorithm used in the WCTS are reduced by an empirical correction function, although winter values (November–February) remain unreliable. For the March–October period we look at both the mean seasonal development and the nonseasonal monthly anomalies of Pigment concentration. These are compared with fields of alongshore wind stress, mixing power of the wind (u*3) and wind stress curl. Outside of the Southern California Bight there is a strong seasonal cycle with a spring-summer maximum, a northward progression of high Pigment concentrations from California to Oregon and a double maximum off Washington (spring and summer, with a lull in between). Within the Southern California Bight, seasonality is low, with a relative minimum in late summer. Off Baja California the pattern is similar to that off northern California. In regions where previous work has been done, there is general agreement with the seasonal cycles found here. Nonseasonal variability in Pigment concentration over the large-scale CCS (400 km wide) is most closely related statistically to synoptic fields of wind stress curl. Within 100 km of the coast, the strongest relations are between Pigment concentration and both u*3 and alongshore wind stress. Correlations with these wind variables account for only 25% of the monthly variance in anomalous satellite-derived Pigment concentrations. This is partly due to the noise in both wind and Pigment data sets but also demonstrates the fact that much of the anomalous Pigment variability is not a response to anomalous wind forcing on these time scales. Correlations are also low between anomalous Pigment concentrations and anomalous sea level heights, which serve as a crude proxy for the strength of the alongshore current over the shelf. The largest nonseasonal anomaly in the data occurred during the 1982–1983 El Nino, which caused a large-scale decrease in Pigment concentration, stronger and longer lasting in the south than in the north.
Corinne James - One of the best experts on this subject based on the ideXlab platform.
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seasonal and nonseasonal variability of satellite derived Surface Pigment concentration in the california current
Journal of Geophysical Research, 1990Co-Authors: Ted P Strub, Corinne James, Andrew C Thomas, Mark R AbbottAbstract:Satellite-derived Pigment concentrations from the west coast time series (WCTS) are averaged into monthly mean fields over the California Current system (CCS) for the period July 1979 to June 1986. Errors caused by the scattering algorithm used in the WCTS are reduced by an empirical correction function, although winter values (November–February) remain unreliable. For the March–October period we look at both the mean seasonal development and the nonseasonal monthly anomalies of Pigment concentration. These are compared with fields of alongshore wind stress, mixing power of the wind (u*3) and wind stress curl. Outside of the Southern California Bight there is a strong seasonal cycle with a spring-summer maximum, a northward progression of high Pigment concentrations from California to Oregon and a double maximum off Washington (spring and summer, with a lull in between). Within the Southern California Bight, seasonality is low, with a relative minimum in late summer. Off Baja California the pattern is similar to that off northern California. In regions where previous work has been done, there is general agreement with the seasonal cycles found here. Nonseasonal variability in Pigment concentration over the large-scale CCS (400 km wide) is most closely related statistically to synoptic fields of wind stress curl. Within 100 km of the coast, the strongest relations are between Pigment concentration and both u*3 and alongshore wind stress. Correlations with these wind variables account for only 25% of the monthly variance in anomalous satellite-derived Pigment concentrations. This is partly due to the noise in both wind and Pigment data sets but also demonstrates the fact that much of the anomalous Pigment variability is not a response to anomalous wind forcing on these time scales. Correlations are also low between anomalous Pigment concentrations and anomalous sea level heights, which serve as a crude proxy for the strength of the alongshore current over the shelf. The largest nonseasonal anomaly in the data occurred during the 1982–1983 El Nino, which caused a large-scale decrease in Pigment concentration, stronger and longer lasting in the south than in the north.
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Seasonal and nonseasonal variability of satellite‐derived Surface Pigment concentration in the California Current
Journal of Geophysical Research, 1990Co-Authors: P. Ted Strub, Corinne James, Andrew C Thomas, Mark R AbbottAbstract:Satellite-derived Pigment concentrations from the west coast time series (WCTS) are averaged into monthly mean fields over the California Current system (CCS) for the period July 1979 to June 1986. Errors caused by the scattering algorithm used in the WCTS are reduced by an empirical correction function, although winter values (November–February) remain unreliable. For the March–October period we look at both the mean seasonal development and the nonseasonal monthly anomalies of Pigment concentration. These are compared with fields of alongshore wind stress, mixing power of the wind (u*3) and wind stress curl. Outside of the Southern California Bight there is a strong seasonal cycle with a spring-summer maximum, a northward progression of high Pigment concentrations from California to Oregon and a double maximum off Washington (spring and summer, with a lull in between). Within the Southern California Bight, seasonality is low, with a relative minimum in late summer. Off Baja California the pattern is similar to that off northern California. In regions where previous work has been done, there is general agreement with the seasonal cycles found here. Nonseasonal variability in Pigment concentration over the large-scale CCS (400 km wide) is most closely related statistically to synoptic fields of wind stress curl. Within 100 km of the coast, the strongest relations are between Pigment concentration and both u*3 and alongshore wind stress. Correlations with these wind variables account for only 25% of the monthly variance in anomalous satellite-derived Pigment concentrations. This is partly due to the noise in both wind and Pigment data sets but also demonstrates the fact that much of the anomalous Pigment variability is not a response to anomalous wind forcing on these time scales. Correlations are also low between anomalous Pigment concentrations and anomalous sea level heights, which serve as a crude proxy for the strength of the alongshore current over the shelf. The largest nonseasonal anomaly in the data occurred during the 1982–1983 El Nino, which caused a large-scale decrease in Pigment concentration, stronger and longer lasting in the south than in the north.
Andrew C Thomas - One of the best experts on this subject based on the ideXlab platform.
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seasonal and nonseasonal variability of satellite derived Surface Pigment concentration in the california current
Journal of Geophysical Research, 1990Co-Authors: Ted P Strub, Corinne James, Andrew C Thomas, Mark R AbbottAbstract:Satellite-derived Pigment concentrations from the west coast time series (WCTS) are averaged into monthly mean fields over the California Current system (CCS) for the period July 1979 to June 1986. Errors caused by the scattering algorithm used in the WCTS are reduced by an empirical correction function, although winter values (November–February) remain unreliable. For the March–October period we look at both the mean seasonal development and the nonseasonal monthly anomalies of Pigment concentration. These are compared with fields of alongshore wind stress, mixing power of the wind (u*3) and wind stress curl. Outside of the Southern California Bight there is a strong seasonal cycle with a spring-summer maximum, a northward progression of high Pigment concentrations from California to Oregon and a double maximum off Washington (spring and summer, with a lull in between). Within the Southern California Bight, seasonality is low, with a relative minimum in late summer. Off Baja California the pattern is similar to that off northern California. In regions where previous work has been done, there is general agreement with the seasonal cycles found here. Nonseasonal variability in Pigment concentration over the large-scale CCS (400 km wide) is most closely related statistically to synoptic fields of wind stress curl. Within 100 km of the coast, the strongest relations are between Pigment concentration and both u*3 and alongshore wind stress. Correlations with these wind variables account for only 25% of the monthly variance in anomalous satellite-derived Pigment concentrations. This is partly due to the noise in both wind and Pigment data sets but also demonstrates the fact that much of the anomalous Pigment variability is not a response to anomalous wind forcing on these time scales. Correlations are also low between anomalous Pigment concentrations and anomalous sea level heights, which serve as a crude proxy for the strength of the alongshore current over the shelf. The largest nonseasonal anomaly in the data occurred during the 1982–1983 El Nino, which caused a large-scale decrease in Pigment concentration, stronger and longer lasting in the south than in the north.
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Seasonal and nonseasonal variability of satellite‐derived Surface Pigment concentration in the California Current
Journal of Geophysical Research, 1990Co-Authors: P. Ted Strub, Corinne James, Andrew C Thomas, Mark R AbbottAbstract:Satellite-derived Pigment concentrations from the west coast time series (WCTS) are averaged into monthly mean fields over the California Current system (CCS) for the period July 1979 to June 1986. Errors caused by the scattering algorithm used in the WCTS are reduced by an empirical correction function, although winter values (November–February) remain unreliable. For the March–October period we look at both the mean seasonal development and the nonseasonal monthly anomalies of Pigment concentration. These are compared with fields of alongshore wind stress, mixing power of the wind (u*3) and wind stress curl. Outside of the Southern California Bight there is a strong seasonal cycle with a spring-summer maximum, a northward progression of high Pigment concentrations from California to Oregon and a double maximum off Washington (spring and summer, with a lull in between). Within the Southern California Bight, seasonality is low, with a relative minimum in late summer. Off Baja California the pattern is similar to that off northern California. In regions where previous work has been done, there is general agreement with the seasonal cycles found here. Nonseasonal variability in Pigment concentration over the large-scale CCS (400 km wide) is most closely related statistically to synoptic fields of wind stress curl. Within 100 km of the coast, the strongest relations are between Pigment concentration and both u*3 and alongshore wind stress. Correlations with these wind variables account for only 25% of the monthly variance in anomalous satellite-derived Pigment concentrations. This is partly due to the noise in both wind and Pigment data sets but also demonstrates the fact that much of the anomalous Pigment variability is not a response to anomalous wind forcing on these time scales. Correlations are also low between anomalous Pigment concentrations and anomalous sea level heights, which serve as a crude proxy for the strength of the alongshore current over the shelf. The largest nonseasonal anomaly in the data occurred during the 1982–1983 El Nino, which caused a large-scale decrease in Pigment concentration, stronger and longer lasting in the south than in the north.