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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.


Grid configuration and bathymetry of the coupled three-dimensional pan-arctic biology/sea ice/ocean model; bathymetry contours of 400, 800, 2200, and 3600 m are plotted. The areas enclosed by thick black lines are defined here as the Pacific sector of the Arctic Ocean (PSA). The PSA is defined such that it includes most of the regions affected by the cyclone with sea level pressure (SLP) under 1000 hPa on 7 August 2012. A black cross is plotted at the location with the lowest SLP on that date, representing the center of the August cyclone. The Chukchi, East Siberian, and Laptev seas and Canada and Eurasian basins are marked by CS, ESS, LS, CB, and EB, respectively. Also marked are four locations for detailed analysis (section).
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fig01: Grid configuration and bathymetry of the coupled three-dimensional pan-arctic biology/sea ice/ocean model; bathymetry contours of 400, 800, 2200, and 3600 m are plotted. The areas enclosed by thick black lines are defined here as the Pacific sector of the Arctic Ocean (PSA). The PSA is defined such that it includes most of the regions affected by the cyclone with sea level pressure (SLP) under 1000 hPa on 7 August 2012. A black cross is plotted at the location with the lowest SLP on that date, representing the center of the August cyclone. The Chukchi, East Siberian, and Laptev seas and Canada and Eurasian basins are marked by CS, ESS, LS, CB, and EB, respectively. Also marked are four locations for detailed analysis (section).

Mentions: [3] The strong 2012 summer cyclone provides an opportunity to examine the impact of cyclones on the ecosystem. Captured by NASA satellite images, the summer cyclone swept over much of the Pacific sector of the Arctic (PSA; Figure 1) in early August 2012 (http://earthobservatory.nasa.gov/IOTD/view.php?id=78808). Dubbed “The Great Arctic Cyclone of August 2012” by Simmonds and Rudeva [2012], the storm was unprecedented in extent, intensity, and depth. It formed on 2 August in Siberia, made its way into the PSA, and intensified substantially during 6–8 August before subsiding, as shown in the NCEP/NCAR reanalysis [Kalnay et al., 1996] of surface wind speed and sea level pressure (SLP; Figure 2). The minimum central pressure of the cyclone was well below 1000 hPa and surface winds exceeded 14 m s−1 in some locations (Figure 2) [Simmonds and Rudeva, 2012], which is within the 99th percentile for August winds in the PSA [Zhang et al., 2013]. In addition, the wind circulation in the low-pressure system was strongly cyclonic [Parkinson and Comiso, 2013].


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)

Grid configuration and bathymetry of the coupled three-dimensional pan-arctic biology/sea ice/ocean model; bathymetry contours of 400, 800, 2200, and 3600 m are plotted. The areas enclosed by thick black lines are defined here as the Pacific sector of the Arctic Ocean (PSA). The PSA is defined such that it includes most of the regions affected by the cyclone with sea level pressure (SLP) under 1000 hPa on 7 August 2012. A black cross is plotted at the location with the lowest SLP on that date, representing the center of the August cyclone. The Chukchi, East Siberian, and Laptev seas and Canada and Eurasian basins are marked by CS, ESS, LS, CB, and EB, respectively. Also marked are four locations for detailed analysis (section).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig01: Grid configuration and bathymetry of the coupled three-dimensional pan-arctic biology/sea ice/ocean model; bathymetry contours of 400, 800, 2200, and 3600 m are plotted. The areas enclosed by thick black lines are defined here as the Pacific sector of the Arctic Ocean (PSA). The PSA is defined such that it includes most of the regions affected by the cyclone with sea level pressure (SLP) under 1000 hPa on 7 August 2012. A black cross is plotted at the location with the lowest SLP on that date, representing the center of the August cyclone. The Chukchi, East Siberian, and Laptev seas and Canada and Eurasian basins are marked by CS, ESS, LS, CB, and EB, respectively. Also marked are four locations for detailed analysis (section).
Mentions: [3] The strong 2012 summer cyclone provides an opportunity to examine the impact of cyclones on the ecosystem. Captured by NASA satellite images, the summer cyclone swept over much of the Pacific sector of the Arctic (PSA; Figure 1) in early August 2012 (http://earthobservatory.nasa.gov/IOTD/view.php?id=78808). Dubbed “The Great Arctic Cyclone of August 2012” by Simmonds and Rudeva [2012], the storm was unprecedented in extent, intensity, and depth. It formed on 2 August in Siberia, made its way into the PSA, and intensified substantially during 6–8 August before subsiding, as shown in the NCEP/NCAR reanalysis [Kalnay et al., 1996] of surface wind speed and sea level pressure (SLP; Figure 2). The minimum central pressure of the cyclone was well below 1000 hPa and surface winds exceeded 14 m s−1 in some locations (Figure 2) [Simmonds and Rudeva, 2012], which is within the 99th percentile for August winds in the PSA [Zhang et al., 2013]. In addition, the wind circulation in the low-pressure system was strongly cyclonic [Parkinson and Comiso, 2013].

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.