Home > 2015, 34(7) > Comparing the steric height in the Nordic Seas with satellite altimeter sea surface height

Citation: SHAO Qiuli and ZHAO Jinping, . Comparing the steric height in the Nordic Seas with satellite altimeter sea surface height. ACTA OCEANOLOGICA SINICA, 2015, 34(7): 32-37. doi: 10.1007/s13131-015-0658-z

2015, 34(7): 32-37. doi: 10.1007/s13131-015-0658-z

Comparing the steric height in the Nordic Seas with satellite altimeter sea surface height

1.  Key Laboratory of Physical Oceanography, Ocean University of China, Qingdao 266100, China and Key Laboratory of Physical Oceanography, Ocean University of China, Qingdao 266100, China

Received Date: 2014-06-20
Accepted Date: 2015-01-27

In this study the steric height anomaly which is calculated from the hydrological data (EN3) is compared with the sea level anomaly derived from satellite altimetry in the Nordic Seas. The overall pattern of steric height is that it is higher in the margin area and lower in the middle area. The extreme values of steric height linear change from 1993 to 2010 occur in the Lofoten Basin and off the Norwegian coast, respectively. Such a distribution may be partly attributed to the freshening trend of the Nordic Seas. The correlation between SLA (sea level anomaly) and SHA (steric height anomaly) is not uniform over the Nordic Seas. The time series of SLA and SHA agree well in the Lofoten Basin and northern Norwegian Basin, and worse in the northern Norwegian Sea, implying that the baroclinic effect plays a dominant role in most areas in the Norwegian Sea and the barotropic effect plays a dominant role in the northern Norwegian Sea. The weaker correlations between SLA and SHA in the Greenland and Iceland Seas lead a conclusion that the barotropic contribution is significant in these areas. The area-mean SHA over the entire Nordic Seas has similar amplitudes compared with the SLA during 1996-2002, but SHA has become lower than SLA, being less than half of SLA since 2006.

Key words: steric height , EN3 hydrological dataset , altimetric sea level anomaly , Nordic Seas

利用水文数据EN3计算了北欧海的比容高度, 并将其异常与卫星高度计得到的海平面异常数据进行了比较。北欧海的平均比容高度呈现海盆中央低、沿岸高的分布状态。1993-2010年比容高度线性变化最大值分别位于罗弗敦海盆和挪威沿岸, 这一分布状态可能与北欧海的淡化趋势有关。海平面异常与比容高度异常的相关性空间分布不均。两者在罗弗敦海盆和挪威海盆北部相关性较好, 而在挪威海北部相关性较差, 这表明, 挪威海大部分海区受到斜压效应的控制, 而正压效应在挪威海北部占主导作用。海平面异常和比容高度异常在格陵兰海和冰岛海相关性较差表明这一区域正压贡献占优。北欧海区域平均的比容高度异常与海平面异常在1996-2002年振幅相近。除此之外, 比容高度异常的振幅总体低于海平面异常, 特别是在2006年以后, 前者对后者变化的解释不足50%。

[1]

Antonov J I, Levitus S, Boyer T P. 2002. Steric sea level variations during 1957-1994: Importance of salinity. J Geophys Res, 107(C12): 10-1-9-11, doi: 10.1029/2001JC000964

[2]

Cazenave A, Llovel W. 2010. Contemporary sea level rise. Annu Rev Mar Sci, 2: 145-173

[3]

George S, Sharma R, Agarwal N, et al. 2011. Dynamic height anomaly from Argo profiles and sea-level anomaly from satellite altimetry: a comparative study in the Indian Ocean. Int J Remote Sens, 32(18): 5105-5113

[4]

Gill A E. 1982. Atmosphere-Ocean Dynamics. New York: Academic Press

[5]

Gilson J, Roemmich D, Cornuelle B, et al. 1998. Relationship of TOPEX/Poseidon altimetric height to steric height and circulation in the North Pacific. J Geophys Res, 1032(C12): 27947-27965

[6]

Guinehut S, Le Traon P-Y, Larnicol G. 2006. What can we learn from Global Altimetry/Hydrography comparisons?. Geophys Res Lett, 33(10): L10604

[7]

Ingleby B, Huddleston M. 2007. Quality control of ocean temperature and salinity profiles—Historical and real-time data. J Marine Syst, 65(1-4): 158-175

[8]

Ivchenko V O, Danilov S D, Sidorenko D V, et al. 2007. Comparing the steric height in the Northern Atlantic with satellite altimetry. Ocean Sci, 3(4): 441-457

[9]

Mork K A, Skagseth Ø. 2005. Annual sea surface height variability in the Nordic seas. In: Drange H, Dokken T, Furevik T, et al., eds. The Nordic Seas: An Integrated Perspective. Washington DC: American Geophysical Union, 51-64

[10]

Orvik K A. 2004. The deepening of the Atlantic water in the Lofoten Basin of the Norwegian Sea, demonstrated by using an active reduced gravity model. Geophys Res Lett, 31(1): L01306 Østerhus S, Gammelsrød T. 1999. The abyss of the Nordic seas is warming. J Clim, 12(11): 3297-3304

[11]

Richter K, Nilsen J E Ø, Drange H. 2012. Contributions to sea level variability along the Norwegian coast for 1960-2010. J Geophys Res, 117(C5): C05038

[12]

Shao Qiuli, Zhao Jinping, 2014. On the deep water of the Nordic Seas. Adv Earth Sci (in Chinese), 29(1): 42-55

[13]

Siegismund F, Johannessen J, Drange H, et al. 2007. Steric height variability in the Nordic Seas. J Geophys Res, 112(C12): C12010, doi: 10.1029/2007JC004221

[14]

Volkov D L, Pujol M-I. 2012. Quality assessment of a satellite altimetry data product in the Nordic, Barents, and Kara seas. J Geophys Res, 117(C3): C03025, doi: 10.1029/2011JC007557

[15]

Volkov D L, Van Aken H M. 2003. Annual and interannual variability of sea level in the northern North Atlantic Ocean. J Geophys Res, 108(C6): 3204, doi: 10.1029/2002JC001459

[16]

Willis J K, Roemmich D, Cornuelle B. 2003. Combining altimetric height with broadscale profile data to estimate steric height, heat storage, subsurface temperature, and sea-surface temperature variability. J Geophys Res, 108(C9): 3292, doi: 10.1029/2002JC001755

[17]

Zhao J, Cao Y, Shi J. 2006. Core region of Arctic Oscillation and the main atmospheric events impact on the Arctic. Geophys Res Lett, 33: L22708, doi: 10.1029/2006GL027590

Metrics
  • PDF Downloads()
  • Abstract Views()
  • HTML Views()
Catalog

Figures And Tables

Comparing the steric height in the Nordic Seas with satellite altimeter sea surface height

SHAO Qiuli and ZHAO Jinping,