Limits...
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.


Simulated difference in PP, phytoplankton, and zooplankton in the upper 100 m of the ocean between the CNTL and SENS runs over the period 5 August 2012 to 15 September 2012.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4508965&req=5

fig06: Simulated difference in PP, phytoplankton, and zooplankton in the upper 100 m of the ocean between the CNTL and SENS runs over the period 5 August 2012 to 15 September 2012.

Mentions: [16] On 5 August 2012, the storm moved into the Arctic Basin from Siberia. The CNTL simulation including the cyclone wind forcing compared with the SENS run without the cyclone indicates that the storm caused an increase in the simulated PP in the Chukchi, East Siberian, and Laptev shelves and in part of the Eurasian Basin (Figure 6a) where wind speed increased (Figure 2b). The cyclone intensified substantially during 6–8 August (Figures 2c–2e); the model simulates a strong increase in PP in much of the shelf areas, the Eurasian Basin, and even in some areas near the Canadian Archipelago (Figure 6b). The increase in PP in those areas remains strong on 9 August (Figure 6c) but starts to fade (Figure 6d) as the cyclone passes its peak and begins to weaken (Figures 2f–2h). The simulated increase in PP on the shelves and in part of the deep basins during the storm leads to an increase in phytoplankton biomass (Figures 6f–6i). A phytoplankton increase on the shelves and in part of the deep basins in turn leads to an increase in zooplankton that graze on phytoplankton (Figures 6k–6n). By 15 September, there is almost no increase in PP on the shelves (Figure 6e). There is still an increase in phytoplankton biomass on most of the shelves, but the increase is diminished by mid-September (Figure 6j). The increase in zooplankton biomass appears to be more persistent than that in phytoplankton biomass (Figure 6o).


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)

Simulated difference in PP, phytoplankton, and zooplankton in the upper 100 m of the ocean between the CNTL and SENS runs over the period 5 August 2012 to 15 September 2012.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig06: Simulated difference in PP, phytoplankton, and zooplankton in the upper 100 m of the ocean between the CNTL and SENS runs over the period 5 August 2012 to 15 September 2012.
Mentions: [16] On 5 August 2012, the storm moved into the Arctic Basin from Siberia. The CNTL simulation including the cyclone wind forcing compared with the SENS run without the cyclone indicates that the storm caused an increase in the simulated PP in the Chukchi, East Siberian, and Laptev shelves and in part of the Eurasian Basin (Figure 6a) where wind speed increased (Figure 2b). The cyclone intensified substantially during 6–8 August (Figures 2c–2e); the model simulates a strong increase in PP in much of the shelf areas, the Eurasian Basin, and even in some areas near the Canadian Archipelago (Figure 6b). The increase in PP in those areas remains strong on 9 August (Figure 6c) but starts to fade (Figure 6d) as the cyclone passes its peak and begins to weaken (Figures 2f–2h). The simulated increase in PP on the shelves and in part of the deep basins during the storm leads to an increase in phytoplankton biomass (Figures 6f–6i). A phytoplankton increase on the shelves and in part of the deep basins in turn leads to an increase in zooplankton that graze on phytoplankton (Figures 6k–6n). By 15 September, there is almost no increase in PP on the shelves (Figure 6e). There is still an increase in phytoplankton biomass on most of the shelves, but the increase is diminished by mid-September (Figure 6j). The increase in zooplankton biomass appears to be more persistent than that in phytoplankton biomass (Figure 6o).

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.