Numerical Simulation of the the the Numerical Simulation of the Bering Sea Water Propagation to Bering Sea Water Propagation to the Arctic- -North Atlantic System North Atlantic System the Arctic Victor Kuzin Kuzin, , Victor Elena Golubeva Golubeva, Gennady , Gennady Platov Platov Elena Institute of Computational Mathematics & Mathematical Geophysics Siberian Institute of Computational Mathematics & Mathematical Geophysics Siberian Division Russian Academy of Sciences Division Russian Academy of Sciences ENVIROMIS- -2008 2008 ENVIROMIS
Objectives Objectives • The priority of the climatic investigation in the Arctic was The priority of the climatic investigation in the Arctic was • concentrated on the climatic problems, because Arctic plays the concentrated on the climatic problems, because Arctic plays the key role in the Earth’ ’s climate ( s climate (J.Fletcher J.Fletcher, 1970) , 1970) key role in the Earth • The freshwater exchange between the polar and the The freshwater exchange between the polar and the subpolar subpolar • oceans is the main mechanism of the thermohaline thermohaline circulation of circulation of oceans is the main mechanism of the the World ocean and the global hydrological cycle the World ocean and the global hydrological cycle • The Arctic ocean accounts about 5 per sent of the World ocean The Arctic ocean accounts about 5 per sent of the World ocean • area and 1.5 per sent of the volume, but it transports about 10 per per area and 1.5 per sent of the volume, but it transports about 10 sent of the total freshwater in the World (Ivanov sent of the total freshwater in the World ( Ivanov, 1979) , 1979) • The Bering throw flow (freshwater flux 1680 km3/yr by The Bering throw flow (freshwater flux 1680 km3/yr by • Aagaard and and Carmack Carmack, 1989) gives about 1/3 of total fresh water , 1989) gives about 1/3 of total fresh water Aagaard inflow and play an important role not only in the regional sense inflow and play an important role not only in the regional sense for the Chukchi Sea and Arctic Ocean, but globally in the World for the Chukchi Sea and Arctic Ocean, but globally in the World Ocean water formation and global water cycle Ocean water formation and global water cycle This work was made in the range of the This work was made in the range of the RFBR grant 05- -05 05- -64990, 08 64990, 08- -05 05- -00708 and AOMIP Project. 00708 and AOMIP Project. RFBR grant 05
General features of the ICM&MG model are as General features of the ICM&MG model are as follows: follows: • Mathematical model is based on the complete Mathematical model is based on the complete “ “primitive primitive” ” • nonlinear equations of the thermo- -hydrodynamics of the hydrodynamics of the nonlinear equations of the thermo ocean; ocean; • Temperature and salinity distributions are calculated; Temperature and salinity distributions are calculated; • • The model have a possibility to include the calculation of The model have a possibility to include the calculation of • the tracers and the pollutants; the tracers and the pollutants; • The interaction with the atmosphere is realized via the The interaction with the atmosphere is realized via the • upper mixed layer with the model of the ice formation and upper mixed layer with the model of the ice formation and drift (elastic- -viscous viscous- -plastic version); plastic version); drift (elastic • The model is based on a combination of the finite element The model is based on a combination of the finite element • and splitting methods; and splitting methods; • The horizontal triangulated quasi The horizontal triangulated quasi- -regular B regular B- -grid is used; grid is used; • • The model has 33 the vertical z The model has 33 the vertical z- -coordinate levels. coordinate levels. •
Combined grid for the Arctic- -North Atlantic ocean system: North Atlantic ocean system: Combined grid for the Arctic The spherical coordinates in the North Atlantic (res. 1 deg.) The spherical coordinates in the North Atlantic (res. 1 deg.) The re- -projective grid in the Arctic basin (res. 35 projective grid in the Arctic basin (res. 35 – – 50 km) 50 km) The re
Data sources Data sources • Reanalysis NCEP/NCAR data for the Arctic region • Reanalysis NCEP/NCAR data for the Arctic region • The data of • The data of Trenberth Trenberth et al. for the North Atlantic et al. for the North Atlantic • Averaged Siberian river runoff from the measurements • Averaged Siberian river runoff from the measurements 1936- -1990 1990 1936 • Steady state inflow through the Bering strait from • Steady state inflow through the Bering strait from climatic data climatic data
a) Wind- -stress averaged for the period stress averaged for the period 1948 1948 – – 2002 2002 (left). (left). a) Wind b) ) The third EOF mode (right). The third EOF mode (right). b 2 is presented in the cones. stress in N/m 2 The value of the wind- -stress in N/m is presented in the cones. The value of the wind The color represents the module of the wind. The color represents the module of the wind. The warmer color consequences to the higher values. The warmer color consequences to the higher values. sea ice model output for cice Wind mode 0 sea ice model output for cice Wind mode 3 0.015 0.01
Ice formation in the model Ice formation in the model The upper panels: The upper panels: • • Averaged field of the Averaged field of the ice compacting ice compacting (in parts from 0 to 1 (in parts from 0 to 1 from the area of the from the area of the surface, left) surface, left) • • The monthly position The monthly position of the ice boundary for of the ice boundary for the period 1948– –1960 1960 the period 1948 (right) (right) freezing fresh water flux The low panels: The low panels: 0 0 0 .1 1 0 2 0 . 0 . 0 • • The intensity of the ice The intensity of the ice 0 0.3 0.1 0 0.2 . 0.1 1 formation ( (sm sm/ /day, left day, left) ) formation 0 0 0 .1 .5 0.01 0 • • Freshwater flux to the Freshwater flux to the upper layer of the ocean upper layer of the ocean 0 2 0 0 . 0 . . 3 5 1.5 ( right) ( right) 1 .5 0 0 . 0 0 0 1 . 1 1.5 5 1 . 0 1 0 5 . 0 1 5.5 . 1 2 .5 2.5 6 4 5 3 3.5 . 2
Velocity field at the depth 250 m (left), 500 m (right). Velocity field at the depth 250 m (left), 500 m (right). Arrows denote the the velocity 1 1 sm sm/ /s s. . Arrows denote the the velocity The color consequences to the module of the velocity. The color consequences to the module of the velocity. More warm color corresponds to the higher velocity. More warm color corresponds to the higher velocity.
Shift of the boundary between the Pacific and Atlantic waters Shift of the boundary between the Pacific and Atlantic waters at the depth 50 m in the model: at the depth 50 m in the model: (a) – 1970, (b) – 1990. The rounds indicate the zones of the contacts of the Pacific (blue arrow) and Atlantic (red arrows) waters
The velocity fields The velocity fields at the depth 100 m. at the depth 100 m. Blue arrows Blue arrows indicate the Pacific indicate the Pacific water Red arrows Red arrows water indicate the indicate the Atlantic water The Atlantic water The shift of the shift of the boundary between boundary between Pacific and the Pacific and the Atlantic waters Atlantic waters obtained in the obtained in the model for these model for these periods is in periods is in agreement with the agreement with the EWG data data EWG [Swift et al Swift et al., 2007] ., 2007] [
Pacific Ocean Pacific Ocean water spreading water spreading after 5, 10 , 15 after 5, 10 , 15 and 30 years and 30 years after beginning after beginning of the emission of the emission (1966) (1966)
Pacific water on the cross- -section section Pacific water on the cross alone the solid line after 1, 2, 5 alone the solid line after 1, 2, 5 and 10 years of emission and 10 years of emission (February- -left, August left, August – – right) right) (February
The vertical cross- The vertical cross -section of the concentration of the Pacific water section of the concentration of the Pacific water through the latitude 30 N (the West is in the right) 15, 20,25,30 years 0 years through the latitude 30 N (the West is in the right) 15, 20,25,3
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