The effect of using local mean versus constant reference salinity to estimate Arctic Ocean freshwater content changes
https://doi.org/10.30758/0555-2648-2021-67-3-230-235
Аннотация
Changes of high-latitude freshwater content (FWC) play an important role in shaping the variability of polar oceans. FWC is defined as depth-integrated departure of salinity from a reference salinity Sref divided by this Sref . A constant Sref is often used for high-latitude FWC estimates. Here it is argued that for analyzing FWC spatiotemporal changes the use of local mean Sref is a better choice. Analysis of 2007 FWC anomalies in the 25–75 m layer demonstrated, for example, that the choice of Sref = 34.8 (which is often used in climate studies) leads to FWC spatial anomalies exaggerated, on average, by ~0.6 m, which is a substantial fraction of total spatial FWC changes. The problem is aggravated in areas where the difference between the local Sref and Sref = 34.8 is greater. Thus, it is concluded that using climatological mean salinities as Sref provides superior estimates of spatiotemporal Arctic Ocean FWC changes.
При поддержке: This study was supported by NSF Grants 1708424, 1708427, and 1724523.
Об авторе
I. V. Polyakov
International Arctic Research Center, University of Alaska Fairbanks
Соединённые Штаты Америки
Соединённые Штаты Америки
930 Koyukuk Drive, Fairbanks, AK, 99775
Список литературы
1. Dickson R. R., Yashayaev I., Meincke J., Turrell W. R., Dye S., Holfort J. Rapid freshening of the deep North Atlantic Ocean over the past four decades. Nature. 2002, 416: 832–837.
2. Visbeck M., Chassignet E., Curry R., Delworth T., Dickson B., Krahmann G. The ocean’s response to North Atlantic Oscillation variability. The North Atlantic Oscillation: Climate Significance and Environmental Impact. Hurrell, J., Y. Kushnir, G. Ottersen, and M. Visbeck (eds.). Washington, AGU, 2002, Geophysical Monograph Series, 134: 113–146.
3. Aagaard K., Carmack E. The role of sea ice and other fresh water in the Arctic circulation. J. Geophys. Res. 1989, 94: 14485–14498.
4. Proshutinsky A., Bourke R.H., McLaughlin F.A. The role of the Beaufort Gyre in Arctic climate variability: Seasonal to decadal climate scales. Geophys. Res. Lett. 2002, 31: L11311. doi: 10.1029/2004GL020039
5. Häkkinen S., Proshutinsky A. Freshwater content variability in the Arctic Ocean. J. Geophys. Res. 2004, 109: C03051. doi: 10.1029/2003JC001940
6. Swift J. H., Aagaard K., Timokhov L., Nikiforov E.G.Long-term variability of Arctic Ocean waters: Evidence from a reanalysis of the EWG data set. J. Geophys. Res. 2005, 110: C03012. doi: 10.1029/2004JC002312
7. Peterson B., McClelland J., Holmes M., Curry R., Walsh J., Aagaard K. Acceleration of the Arctic and subarctic freshwater cycle. Science. 2006, 313: 1061–1066.
8. Steele M., Ermold W. Steric sea level change in the Northern Seas. J. Climate. 2007, 20: 403–417.
9. Carmack E., McLaughlin F., Yamamoto-Kawai M., Itoh M., Shimada K., Krishfield R., Proshutinsky A. Freshwater storage in the Northern Ocean and the special role of the Beaufort Gyre. Arctic-Subarctic Ocean Fluxes: Defining the Role of the Northern Seas in Climate. Dickson R.R., Meincke J., Rhines P. (eds.). New York: Springer, 2008: 145–170.
10. Polyakov I. V., Alexeev V., Belchansky G.I., Dmitrenko I.A., Ivanov V., Kirillov S., Korablev A., Steele M., Timokhov L.A., Yashayaev I. Arctic Ocean freshwater changes over the past 100 years and their causes. J. Climate. 2008, 21 (2): 364–384.
11. McPhee M.G., Proshutinsky A., Morison J.H., Steele M., Alkire M.B. Rapid change in freshwater content in the Arctic Ocean. Geophys. Res. Lett. 2009, 36: L10602. doi: 10.1029/2009GL037525
12. Proshutinsky A., Krishfield R., Timmermans M.-L., Toole J., Carmack E., McLaughlin F., Williams W.J., Zimmermann S., Itoh M., Shimada K. Beafort Gyre freshwater reservoir: State and variability from observations. J. Geophys. Res. 2009, 114 (C00A10). doi: 10.1029/2008JC005104
13. Dickson R.R., Dye S., Karcher M., Meincke J., Rudels B., Yashayaev I. Current estimates of freshwater flux through Arctic and Subarctic seas. Progress in Oceanography. 2007, 73: 210–230. doi: 10.1016/j.pocean.2006.12.003
14. Curry R., Mauritzen C. Dilution of the northern North Atlantic Ocean in recent decades. Science. 2005, 308: 1772–1773.
15. Polyakov I.V., Timokhov L.A. Mean fields of temperature and salinity of the Arctic Ocean. Russian Meteorology and Hydrology. 1994, 7: 33–38.
Рецензия
Для цитирования:
Polyakov I.V. The effect of using local mean versus constant reference salinity to estimate Arctic Ocean freshwater content changes. Проблемы Арктики и Антарктики. 2021;67(3):230-235. https://doi.org/10.30758/0555-2648-2021-67-3-230-235
For citation:
Polyakov I.V. The effect of using local mean versus constant reference salinity to estimate Arctic Ocean freshwater content changes. Arctic and Antarctic Research. 2021;67(3):230-235. https://doi.org/10.30758/0555-2648-2021-67-3-230-235
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