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The great 2012 Arctic Ocean summer cyclone enhanced biological productivity on the shelves.

Zhang J, Ashjian C, Campbell R, Hill V, Spitz YH, Steele M - J Geophys Res Oceans (2014)

Bottom Line: In the central PSA, however, model simulations indicate a decrease in PP and plankton biomass.The simulated biological gain on the shelves is greater than the loss in the central PSA, and therefore, the production on average over the entire PSA is increased by the cyclone.The generally positive impact of cyclones on the marine ecosystem in the Arctic, particularly on the shelves, is likely to grow with increasing summer cyclone activity if the Arctic continues to warm and the ice cover continues to shrink.

View Article: PubMed Central - PubMed

Affiliation: Applied Physics Laboratory, University of Washington Seattle, Washington, USA.

ABSTRACT

[1] A coupled biophysical model is used to examine the impact of the great Arctic cyclone of early August 2012 on the marine planktonic ecosystem in the Pacific sector of the Arctic Ocean (PSA). Model results indicate that the cyclone influences the marine planktonic ecosystem by enhancing productivity on the shelves of the Chukchi, East Siberian, and Laptev seas during the storm. Although the cyclone's passage in the PSA lasted only a few days, the simulated biological effects on the shelves last 1 month or longer. At some locations on the shelves, primary productivity (PP) increases by up to 90% and phytoplankton biomass by up to 40% in the wake of the cyclone. The increase in zooplankton biomass is up to 18% on 31 August and remains 10% on 15 September, more than 1 month after the storm. In the central PSA, however, model simulations indicate a decrease in PP and plankton biomass. The biological gain on the shelves and loss in the central PSA are linked to two factors. (1) The cyclone enhances mixing in the upper ocean, which increases nutrient availability in the surface waters of the shelves; enhanced mixing in the central PSA does not increase productivity because nutrients there are mostly depleted through summer draw down by the time of the cyclone's passage. (2) The cyclone also induces divergence, resulting from the cyclone's low-pressure system that drives cyclonic sea ice and upper ocean circulation, which transports more plankton biomass onto the shelves from the central PSA. The simulated biological gain on the shelves is greater than the loss in the central PSA, and therefore, the production on average over the entire PSA is increased by the cyclone. Because the gain on the shelves is offset by the loss in the central PSA, the average increase over the entire PSA is moderate and lasts only about 10 days. The generally positive impact of cyclones on the marine ecosystem in the Arctic, particularly on the shelves, is likely to grow with increasing summer cyclone activity if the Arctic continues to warm and the ice cover continues to shrink.

No MeSH data available.


CNTL-simulated and SENS-simulated daily PP, phytoplankton, and zooplankton in the upper 100 m of the water column at locations 3 and 4. The difference is calculated by (CNTL – SENS)/SENS*100%. The vertical dotted and dashed lines represent 6 August 2012 and 15 September 2012, respectively.
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fig13: CNTL-simulated and SENS-simulated daily PP, phytoplankton, and zooplankton in the upper 100 m of the water column at locations 3 and 4. The difference is calculated by (CNTL – SENS)/SENS*100%. The vertical dotted and dashed lines represent 6 August 2012 and 15 September 2012, respectively.

Mentions: [24] Locations 3 and 4 are located on or near the shelves in the zone of strong winds. Strong ocean mixing (Figures 8f, 12a, and 12b) increases nitrate concentration in the surface waters (Figures 7b–7d and 12c–12d). The divergence induced by the cyclone in the central PSA transports more biomass onto the shelves (Figure 9) and locations 3 and 4; the CNTL-simulated PP and phytoplankton biomass in the surface waters as well as in the upper 100 m are much higher than the SENS simulations (Figures 12e–12h). The simulated PP and phytoplankton biomass peak prior to the cyclone's passage into the PSA, but the differences in PP and phytoplankton biomass in the upper 100 m between the CNTL and SENS runs at locations 3 and 4 are as high as 90% during the storm (Figures 13a–13d). However, the differences become smaller over time as PP and phytoplankton biomass decrease into early autumn.


The great 2012 Arctic Ocean summer cyclone enhanced biological productivity on the shelves.

Zhang J, Ashjian C, Campbell R, Hill V, Spitz YH, Steele M - J Geophys Res Oceans (2014)

CNTL-simulated and SENS-simulated daily PP, phytoplankton, and zooplankton in the upper 100 m of the water column at locations 3 and 4. The difference is calculated by (CNTL – SENS)/SENS*100%. The vertical dotted and dashed lines represent 6 August 2012 and 15 September 2012, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4508965&req=5

fig13: CNTL-simulated and SENS-simulated daily PP, phytoplankton, and zooplankton in the upper 100 m of the water column at locations 3 and 4. The difference is calculated by (CNTL – SENS)/SENS*100%. The vertical dotted and dashed lines represent 6 August 2012 and 15 September 2012, respectively.
Mentions: [24] Locations 3 and 4 are located on or near the shelves in the zone of strong winds. Strong ocean mixing (Figures 8f, 12a, and 12b) increases nitrate concentration in the surface waters (Figures 7b–7d and 12c–12d). The divergence induced by the cyclone in the central PSA transports more biomass onto the shelves (Figure 9) and locations 3 and 4; the CNTL-simulated PP and phytoplankton biomass in the surface waters as well as in the upper 100 m are much higher than the SENS simulations (Figures 12e–12h). The simulated PP and phytoplankton biomass peak prior to the cyclone's passage into the PSA, but the differences in PP and phytoplankton biomass in the upper 100 m between the CNTL and SENS runs at locations 3 and 4 are as high as 90% during the storm (Figures 13a–13d). However, the differences become smaller over time as PP and phytoplankton biomass decrease into early autumn.

Bottom Line: In the central PSA, however, model simulations indicate a decrease in PP and plankton biomass.The simulated biological gain on the shelves is greater than the loss in the central PSA, and therefore, the production on average over the entire PSA is increased by the cyclone.The generally positive impact of cyclones on the marine ecosystem in the Arctic, particularly on the shelves, is likely to grow with increasing summer cyclone activity if the Arctic continues to warm and the ice cover continues to shrink.

View Article: PubMed Central - PubMed

Affiliation: Applied Physics Laboratory, University of Washington Seattle, Washington, USA.

ABSTRACT

[1] A coupled biophysical model is used to examine the impact of the great Arctic cyclone of early August 2012 on the marine planktonic ecosystem in the Pacific sector of the Arctic Ocean (PSA). Model results indicate that the cyclone influences the marine planktonic ecosystem by enhancing productivity on the shelves of the Chukchi, East Siberian, and Laptev seas during the storm. Although the cyclone's passage in the PSA lasted only a few days, the simulated biological effects on the shelves last 1 month or longer. At some locations on the shelves, primary productivity (PP) increases by up to 90% and phytoplankton biomass by up to 40% in the wake of the cyclone. The increase in zooplankton biomass is up to 18% on 31 August and remains 10% on 15 September, more than 1 month after the storm. In the central PSA, however, model simulations indicate a decrease in PP and plankton biomass. The biological gain on the shelves and loss in the central PSA are linked to two factors. (1) The cyclone enhances mixing in the upper ocean, which increases nutrient availability in the surface waters of the shelves; enhanced mixing in the central PSA does not increase productivity because nutrients there are mostly depleted through summer draw down by the time of the cyclone's passage. (2) The cyclone also induces divergence, resulting from the cyclone's low-pressure system that drives cyclonic sea ice and upper ocean circulation, which transports more plankton biomass onto the shelves from the central PSA. The simulated biological gain on the shelves is greater than the loss in the central PSA, and therefore, the production on average over the entire PSA is increased by the cyclone. Because the gain on the shelves is offset by the loss in the central PSA, the average increase over the entire PSA is moderate and lasts only about 10 days. The generally positive impact of cyclones on the marine ecosystem in the Arctic, particularly on the shelves, is likely to grow with increasing summer cyclone activity if the Arctic continues to warm and the ice cover continues to shrink.

No MeSH data available.