Seasonal and long-term sea level variability in the marginal seas of the Arctic Ocean

Vladimir K. Pavlov
2001 Polar Research  
One of the parameters useful for monitoring large-scale climate variability in the Arctic Ocean is sea level. It integrates virtually all static and dynamic processes in the hydrosphere and atmosphere of the Arctic. Previously unavailable mean monthly sea level data at 44 coastal and island stations in the Kara, Laptev, East Siberian and Chukchi seas covering years from 1950 to 1990 were used to analyse seasonal and inter-annual variability. Sea level has a significant annual cycle with an
more » ... ge seasonal amplitude (from peak to peak) in the coastal zone of the Arctic seas on the order of 20 -30 cm. The analysis of inter-annual and inter-decadal changes has shown that at nearly all stations in the Kara, Laptev, East Siberian and Chukchi seas from the beginning of the 1950s through the end of 1980s there is a positive trend in sea level variability. The main contribution to the sea level rise was in the 1980s; on average for the coastal zone of Siberian shelf the sea level in the 1980s was 5 -6 cm higher than in the previous decades. A reasonable agreement between observed decadal mean sea level values and the results of diagnostic model simulations suggests that this rise in the Arctic seas is connected with the reorganization of large-scale circulation of the Arctic Ocean, rather than the regional lowering of the coasts, as has been suggested previously. Influenced by the integration of a number of physical processes in the environment, sea level can serve as a representative parameter for monitoring climate changes in the Arctic (Pavlov & Stanovoy 1997). The major factors shaping sea level variability are changes in water density, the reorganization of the thermohaline circulation and the modification of atmospheric dynamics. Seasonal and inter-annual sea level variability was analysed using a virtually continuous 40-year (1950-1990) time series of mean monthly data at 44 island and coastal stations in the Kara, Laptev, East Siberian and Chukchi seas (Table 1) . These stations are irregularly distributed over the coastal zone of the Russian Arctic seas. The largest number of stations was located in the Kara Sea; the fewest were in the Chukchi Sea. Only those Chukchi Sea stations located in the Russian coastal zone were subject to analysis. Tide gauges at most coastal and island stations were not connected with the geodetic network, and therefore only relative sea level values were measured at these stations. In the analysis of seasonal and inter-annual variability, we have first removed the mean sea level value for each station, calculated over the entire period of observations. Previous analyses of seasonal and inter-annual sea level variation have been conducted for different Siberian shelf stations by Dvorkin et al. (1978 ), Pavlov (1998 . However, Dvorkin et al. (1978) used observations up to the mid-1970s, so their results did not take into account modern sea level trends. Pavlov (1998) and have conducted a similar analysis for only selected stations in the Laptev and East Siberian seas.
doi:10.1111/j.1751-8369.2001.tb00051.x fatcat:vwt4s7o3czcvpfm2skgr6ufpve