Arctic dimension of global warming

Transcription

1 Climate Changes in the Arctic and Northern Eurasia and their Regional and Global Implications Arctic dimension of global warming Genrikh Alekseev, Arctic and Antarctic Research Institute, St. Petersburg, Russia St.-Petersburg 5 November 13 1

2 OUTLINE INTRODUCTION Arctic part of global climate system Energy balance of the Arctic OBSERVED CHANGES OF THE ARCTIC CLIMATE Surface air temperature (SAT) Atmospheric circulation Solar radiation Sea ice cover Arctic Ocean DYNAMIC FORCING OF THE CLIMATE CHANGE Role of the meridional and zonal transport of heat (MHT&ZHT) MHT and ZHT indexes Contribution of MHT and ZHT to the Arctic and global warming Arctic amplification CONCLUSIONS

3 ARCTIC CLIMATE SYSTEM Arctic in the Global climate system S U N OZON LAYER Moisure Warm, salty water World Ocean Heat Open Ocean deep convection E P FW + ice outflow Arctic Ocean Freezing melting CLOUDS Shelf Convection FW discharge E P Permafrost Land CO Accumulation melting ICE CAP snow; sheet; glacier Runoff Aerosol Deep water outflow

4 Energy balance of the Arctic Monthly and Annual Mean Components of the Atmospheric Energy Budget of the North Polar Cap From ERA-4 (Serreze et al., 7) Fluxes and Storage Changes, W m - RB top MHT atm F sfc Albedo plan EB Residual January July Mean annual F sfc from Nakamura,.Oort, (1988).4 Wm -. 4

5 -1 T зима Winter (DJF) Surface air temperature (SAT) г. Mean SAT from 3 stations to north of 6 N 7194 Зимняя граница льда 13 T Summer (JJA) T T г г. Зимняя граница льда Mean SAT from 41 stations in the marine Arctic 5

6 Increase of ice free area in the end of summer followed by rise of SAT in fall and early winter Тренд, /год Trends of monthly mean SAT in the marine Arctic for

7 Atmospheric circulation Number of summer low over the Arctic basin Atmospheric dipole in summer 1 (Serreze and Barrett, 8) Overland et al., 1 Cold winter extreme (Petoukhov, Semenov, 1) 7

8 Solar radiation Moisture in the Arctic atmosphere Spectral albedo (April ) Fig Trend of annual solar heat input to the ocean (Perovich et al., 7 ).98 Albedo A1 A A3 A4 A5 A6 A7 A8 A9 A1 A11 A1 A13 Wavelength, nm Wavelength nm Spectral albedo of snow The difference between the seasonal mean surface temperature (K) under cloudy and 8 cloud-free conditions (Liu et al., 8)

9 Sea ice cover in September September SIE and summer SAT T C (6-8) S 9,1 6 km R = -.93 (-.78)

10 Arctic Ocean Atlantic water mean temperature and the volume inflow in the Fram Strait Maximal T AW in the Arctic Basin Пр. Фрама ( T AW North Pole м а к с. т е м п е р а т у р а, oc Жел. Св. Анны 3 83oN 9E 5 81oN 15E 6 Сев. Полюс 4 8oN 1E

11 - 8 anomalies in the Arctic Basin from 197s Max Т AW Depth (m) of upper AW border FWC in upper layer, m (from depth of 34.8 psu) 11

12 Influence of summer ocean heat on freezing Influence of AW spreading on winter SIE

13 Influence of MHT on SAT from EBM дт c дt 1 k(x) S (1 A) 4 д дт = ψ ( x) δt + [(1 x ) k( x) ] 4 дх дч x 1, x = sinϕ, k(x) - к - т макродифузии = k + k ψ ( x) = 1.477P 1 x 1 x ( x), P = k ( x) + k 1 sin ϕ 3x 1 = δ, k= K 19.8K δ 1, k= K δ k= 77.83K 3.3K δ 1, k= 31.13K δ, k= 54.K 9.54K δ 1, k= 83.76K 57.46K 86.8K 66.48K -6.4K 4.46K -7.84K.99K 3.44K 3.98K δ, k K 8.8K δ 1, k K δ, k K 3.88K δ 1, k 1 3.9K δ, k K 9.99K δ 1, k 1 87.K T p T e T NH 13

14 A 1 E ] D M yr T N yr R =-.88(-.73) T a M /a T, % 1 MHT index and contribution of MHT to warming D M = ( T T ), T = T, T = Arctic Northern Hemisphere Globe -9 ϕ D M yr ϕ T NH yr R = %% 1 ϕ ' = γc p[( T ) dm - available eddy potential energy (Van Mieghem, 1977) M atm ϕ D M NH yr T gl yr C R = MHT in NH contribution to trend of average SAT for = β DT DM, TM = β DT ( αmt + D' ) ; α M M = β DTαM ; αm α T = αm + α R ; C M = α Arctic ϕλ Northern Hemisphere λ ϕ T ϕ ϕ %% 1 Globe T yr w sp sm fl год зима весна лето осень yr w sp sm fl год зима весна лето осень yr w sp sm fl 14 год зима весна лето осень

15 ZHT index and average SAT π 1 D Z = cosϕ ( Tϕλ Tϕ ) π (sinϕ sinϕ ) Winter N. D Z,[ C] T, C (-.8) ϕ ϕ dλdϕ Northern Hemisphere. D Z,[ C] T, C (-.49) mean square deviation of SAT at latitude ϕ from its mean value Tϕ averaged over the latitude band [ϕ1 - ϕ] Summer N NH D Z, [ C] T, C D Z, [ C] T, C (.45) (.45) ZHT in NH contribution to trend of average SAT in winter (W) and cold half of year (C) for N NH N W NCEP C Hadcrut3 NIERSC ECHAM 8 6 % NCEP Hadcrut3 ECHAM % NAO AO D Z /

16 Global forcing: rise of CO / increase of solar radiation Increase of temperature and evaporation in low latitudes Amplification of heat and moisture transport to the Arctic Warming in the Arctic Ice melting, albedo decrease, ocean heating Rise of vapor content and cloudiness Scheme of dynamic amplification and feedbacks in the Arctic warming 16

17 CONCLUSIONS Main reason of the arctic amplification is increase of heat and moisture transport from low latitudes that is followed by many arctic feedbacks. Suggested indexes confirm that most part of the Arctic and noticeable part of the global warming related to amplification of the energy transport in the global climate system Recent observations show to slowing down of the Arctic warming that follows low latitudes The results take out under support from the Ministry of Education and Science of Russia (project ), by Roshydromet and the Russian Fund for Basic Research (project а). Author thanks N. Ivanov, S. Kusmina and N.Kharlanenkofa for preparation of data sets from reanalysis and ECHAM calculations. 17

18 Publications: Alekseev GV, Podgorny IA, Svyaschennikov PN (199) Advective-radiative climate variations. DAN USSR 315 4:84-87 Alekseev GV, Podgorny IA, Svyaschennikov PN (1991) Influence of variations of heating from ocean on the global climate. DAN USSR 3 1:7-73 Alekseev G.V., Podgorny I.A. Simulation of advective global climate fluctuations. In: C.J. Boer, Research activities in atmospheric and oceanic modeling. GAS/JSC Working Group in Numerical Experimentation. 199, Report 14, WMO/TD 33, pp Alekseev G.V., Podgorny I.A. Modelling the effect of ocean s heating on global climate fluctuations. In: C.J. Boer, Research activities in atmospheric and oceanic modeling. GAS/JSC Working Group in Numerical Experimentation. 199, Report 17, WMO/TD 467, pp

19 Корреляция индекса меридиональной циркуляции и D M c температурой воздуха зимой (ДЯФ) в Северном полушарии за NCEP ECHAM D M 31 T NH R = D M T NH R =

20 Корреляция индексов зональной циркуляции и ПТВ зимой DZ NCEP NAO DZ ECHAM -.8 AO