Seasonal and interannual variability of coastal upwelling along northwest Africa and Portugal from 1981 to 1991

1994 ◽  
Vol 99 (C7) ◽  
pp. 14197 ◽  
Author(s):  
Leo Nykjær ◽  
Lieve Van Camp
Keyword(s):  
Interannual Variability ◽  
Coastal Upwelling ◽  
Seasonal And Interannual Variability ◽  
Northwest Africa

scholarly journals Seasonal and interannual variability of phytoplankton abundance and community composition on the Central Coast of California

2020 ◽  
Vol 637 ◽  
pp. 29-43 ◽  
Author(s):  
A Barth ◽  
RK Walter ◽  
I Robbins ◽  
A Pasulka
Keyword(s):  
Interannual Variability ◽  
Phytoplankton Community ◽  
Coastal Upwelling ◽  
Current System ◽  
Ecosystem Dynamics ◽  
Nutrient Concentrations ◽  
Ecosystem Structure ◽  
Phytoplankton Abundance ◽  
California Current System ◽  
Seasonal And Interannual Variability

Variations in the abundance and composition of phytoplankton greatly impact ecosystem structure and function. Within the California Current System (CCS), phytoplankton community structure is tightly coupled to seasonal variability in wind-driven coastal upwelling, a process that drives changes in coastal water temperatures and nutrient concentrations. Based on approximately a decade (2008-2018) of weekly phytoplankton measurements, this study provides the first characterization of the seasonal and interannual variability of phytoplankton abundance and composition in San Luis Obispo (SLO) Bay, an understudied region within the CCS. Overall, the seasonality of phytoplankton in SLO Bay mirrored that of the larger CCS; diatoms dominated the community during the spring upwelling season, whereas dinoflagellates dominated the community during the fall relaxation period. While we observed considerable interannual variability among phytoplankton taxa, of particular note was the absence of a fall dinoflagellate-dominated period from 2010 through 2013, followed by the return of the fall dinoflagellate-dominated period in 2014. This compositional shift coincided with a major phase shift of both the Pacific Decadal Oscillation (PDO) and North Pacific Gyre Oscillation (NPGO). In addition to exerting a strong influence on the seasonality of phytoplankton community succession and transition between diatom- and dinoflagellate-dominated periods, the state of both the PDO and NPGO also influenced the extent to which environmental conditions (temperature and upwelling winds) could predict community type. These results highlight the importance of long-term datasets and the consideration of large-scale climate patterns when assessing local ecosystem dynamics.

Seasonal and interannual variability in13C composition of ecosystem carbon fluxes in the U.S. Southern Great Plains

Tellus B ◽  
2011 ◽  
Vol 63 (2) ◽  
Author(s):  
Margaret S. Torn ◽  
Sebastien C. Biraud ◽  
Christopher J. Still ◽  
William J. Riley ◽  
Joe A. Berry
Keyword(s):  
Interannual Variability ◽  
Great Plains ◽  
Carbon Fluxes ◽  
Southern Great Plains ◽  
Seasonal And Interannual Variability ◽  
Ecosystem Carbon ◽  
Ecosystem Carbon Fluxes ◽  
The U.S

Seasonal and Interannual Variability of NDVI in the Republic of Adygea

2021 ◽  
Author(s):  
Sergey A. Lebedev ◽  
Andrey G. Kostianoy ◽  
Pavel N. Kravchenko ◽  
Olga P. Shevyakova
Keyword(s):  
Interannual Variability ◽  
Seasonal And Interannual Variability ◽  
The Republic

scholarly journals Environmental control on the variability of DMS and DMSP in the Mauritanian upwelling region

2012 ◽  
Vol 9 (3) ◽  
pp. 1041-1051 ◽  
Author(s):  
C. Zindler ◽  
I. Peeken ◽  
C. A. Marandino ◽  
H. W. Bange
Keyword(s):  
Surface Waters ◽  
Coastal Upwelling ◽  
Environmental Control ◽  
Hot Spot ◽  
Local Source ◽  
Surface Seawater ◽  
Near Surface ◽  
Northwest Africa ◽  
N:P Ratios ◽  
A Minor

Abstract. Dimethylsulphide (DMS) and dissolved and particulate dimethylsulfoniopropionate (DMSPd, DMSPp) were measured in near-surface waters along the Mauritanian coast, Northwest Africa, during the upwelling season in February 2008. DMS, DMSPd and DMSPp surface concentrations of up to 10 nmol L−1, 15 nmol L−1 and 990 nmol L−1, respectively, were measured. However, the DMS concentrations measured are in the low range compared to other upwelling regions. The maximum DMSPp concentration is the highest reported from upwelling regions so far, which might indicate that the Mauritanian upwelling is a hot spot for DMSP. Within the phytoplankton groups, dinoflagellates were identified as important contributors to DMS concentrations, while other algae seemed to have only a minor or no influence on DMS and DMSP concentrations. A pronounced switch from high DMSP to high DMS concentrations was observed when the nitrogen to phosphorus ratio (N:P) was below 7. The high DMS/DMSP ratios at N:P ratios <7 indicate that nitrogen limitation presumably triggered a switch from DMSP to DMS independent of the species composition. Our results underline the importance of coastal upwelling regions as a local source for surface seawater sulphur.

scholarly journals Environmental control on the variability of DMS and DMSP in the Mauritanian upwelling region

2011 ◽  
Vol 8 (4) ◽  
pp. 8591-8618
Author(s):  
C. Zindler ◽  
I. Peeken ◽  
C. A. Marandino ◽  
H. W. Bange
Keyword(s):  
Nitrogen Limitation ◽  
Coastal Upwelling ◽  
Environmental Control ◽  
Hot Spot ◽  
Northwest Africa ◽  
Induced Stress ◽  
Temporal And Spatial Variability ◽  
Temporal And Spatial ◽  
A Minor ◽  
The Tropics

Abstract. Dimethylsulfide (DMS) and dissolved and particulate dimethylsulfoniopropionate (DMSPd, DMSPp) were measured in sea surface layer along the Mauritanian coast, Northwest Africa, during the upwelling season in February 2008. DMS, DMSPd and DMSPp surface concentrations of up to 10 nmol L−1, 15 nmol L−1 and 990 nmol L−1, respectively, were measured. The maximum DMSPp concentration is the highest reported from upwelling regions so far and indicates that the Mauritanian upwelling is a hot spot of DMSP and, thus, DMS production. Dinoflagellates were responsible for the DMS production. Other phytoplankton groups seemed to have only a minor or no influence on the DMS and DMSP production. Decreasing nitrogen (i.e. increasing nitrogen limitation) most likely triggered a switch from high DMSP production to high DMS production. It seems that both nitrogen limitation and the intensive solar radiation in the tropics induced stress in DMSP producing algae and activated their antioxidant system. Our results underline the importance of coastal upwelling regions as ecosystems with a pronounced temporal and spatial variability which result in high DMSP and DMS production.

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