Climate changes according to the Arctic North Atlantic ice- ocean - - PowerPoint PPT Presentation
ENVIROMIS-2008 TOMSK,June,28 July,5 Climate changes according to the Arctic North Atlantic ice- ocean numerical model Golubeva E.N., Platov G.A. Institute of Computational Mathematics and Mathematical Geophysics Siberian Branch of the
Institute of Computational Mathematics and Mathematical Geophysics Siberian Branch of the Russian Academy of Sciences ENVIROMIS-2008 TOMSK,June,28 –July,5
A schematic drawing of North Atlantic and Arctic Ocean circulation. Red arrows represent relatively warm water from lower latitudes entering the Arctic, while blue arrows represent the export of colder water from the Arctic.Shaded white shows the average area covered by sea ice. (Figure courtesy of G. Holloway, Institute of Ocean Sciences, Sidney, British Columbia).
3D Ocean Circulation Model of ICMMG based on z-level vertical coordinate approach (Kuzin1982, Golubeva at al.,1992, Golubeva,[2001], Golubeva and Platov,[2007])
and ‘rigid lid’ approximations
advection.
energy equation
W.D.Hibler ,1979, E.C.Hunke, J.K.Dukowicz,1997, G.A.Maykut 1971 C.M.Bitz, W.H.Lipscomb 1999,J.K.Dukowicz, J.R.Baumgardner 2000, W.H.Lipscomb, E.C.Hunke 2004
The characteristics of the lower atmosphere and radiation are prescribed, taken from the NCEP/NCAR reanalysis (Kalnay et al., [1996]) and CIAF( Large and Yager[2004]) . As initial condition for temperature and salinity, the winter season distribution was taken from PHC (Steele et al., [2000]) data set. The initial ice distribution was prescribed as ice of 2 m thickness and 0.9 compactnes in the areas of the negative lower atmosphere
run provide a more reasonable sea ice distribution, which is further used as initial sea ice state.
www.ldeo.columbia.edu/NAO by Martin Visbeck
Positive phase Negative phase
A leading pattern of weather and climate variability over the Northern Hemisphere is the North Atlantic Oscillation, which refers to a redistribution
Previous investigation - Gudkovich(1961), Nikiforov and Shpaiker(1980), Proshutinky and Johnson,1997 and others.
1960,1961,1963,1965,1966,1969, 1970-1973,1977-1980,1982-1983, 1985-1986, 1988, 1992,1994, 1996, 1998,2001 1967,1968,1981,1984,1989,1993,1995, 1997,1999,2000,2002,2003
Model results
Anticyclonic regime Cyclonic regime
(following Rudels et al/.[1994])
According to the investigations [J.H. Swift, K. Aagaard, L. Timokhov, and Ev.G. Nikiforov, 2004] , based on the enhanced version of the 1948-1993 data EWG (Gore-Chernomyrdin environmental bilateral agreement, Environmental Working Group,1997), there were some warm and cold events in the Atlantic layer of the Arctic Ocean during this period The phase propagation of the strong warm anomaly of the early 1990s is consistent with a Fram Strait origin Warm period 1989-1993 enhanced cooling of the Atlantic waters entering the Arctic Ocean via the Barents and Kara seas Cold period 1974- the end of 1980-s enhanced horizontal heat advection and reduced vertical heat loss associated with increased upper-ocean stratification. Warm period 1963 -1969 The phase propagation of the warm anomaly of is consistent with a Fram Strait origin Warm period 1955- the end of 1950-s HYPOTHESIS Period
Temperature vertical distribution at the selected points NAO INDEX
Temperature at the depth of 200m Surface salinity
Warm Cold
Temperature vertical distribution at the selected points. Cold period NAO INDEX
Temperature distribution at the depth of 200 m Ice velocity distribution
Cold period Warm period
Temperature vertical distribution at the selected points. Warm period NAO INDEX
Velocity distribution at the depth of 200м.
1960 - 1974 1990-1995
Ice thickness distribution during the model run
Summer ice thickness in 2005 and 2007 (model run)