1. Multiscale forcing and the change of East Asia monsoon Yimin LIU, Guoxiong Wu, Anmin Duan, Xiaoyun Liang and Rijun Wan LASG, Institute of Atmospheric Physics (IAP) Chinese Academy of Sciences (CAS), Beijing Buwen Dong Department of the Meteorology, University of Reading Reading UK ， July 28-30, 2008

2. Surface T trend Rainfall Trend Xu and Chang et al., 2006 1969-2000 trend for JJA

3. LIST 1. Thermal Adaptation 2. Land Distribution and Continental Scale “LOSECOD” Heating 3. Tibetan Plateau Local Scale Forcing 4. Climate changes over the TP and its impacts 5. Summary

4. Thermal Adaptation- heating heating

5. Thermal Adaptation-cooling cooling

6. Winter: Source-ocean; sink-land Summer: Source-land; sink-ocean

7. Atmospheric adaptation to summertime continental scale forcing results in ascent over eastern-continent/western-ocean but descent over eastern-ocean/western-continent; However, the atmospheric response is asymmetric: eastern signals are always stronger than the western signals. + + ---

8. LIST 1. Thermal Adaptation 2. Land Distribution and Continental Scale “LOSECOD” Heating 3. Tibetan Plateau Local Scale Forcing 4. Climate changes over the TP and its impacts 5. Summary

9. 1000 hPa velocity potential (shaded ) in unit of 10 6 m 2 /s and divergent wind component (arrow) in unit of m/s (1980-1997) January July

10. Eurasian-C N.Pacific-O N.Amer-C N.Atlan-O 图 1.5 LOSE COD LOSE CODLO SECO D

11. σ σ a) b) LOSECOD LOSECOD Kd -1 Eurasian Continent / 欧亚大陆 N. America / 北美大陆

12. AAEA PNAA b c d AAEA PNAA a LOSECOD Total vertical column heating Main heating V and H* at 100hPa V and H* at 1000hPa

13. PSAm ASAf IAU b c d a PSAm ASAf IAU LOSECOD Total vertical column heating Main heating V and H* at 100hPa V and H* at 1000hPa

14. Desert/dry climate is formed over the western continents, whereas monsoon/wet climate is formed over the eastern continents!

15. LIST 1. Thermal Adaptation 2. Land Distribution and Continental Scale “LOSECOD” Heating 3. Tibetan Plateau Local Scale Forcing 4. Climate changes over the TP and its impacts 5. Summary

16. Thermal Adaptation- heating heating

17. 气压 (hPa) Tibetan July Rockies July Andes January  v

18. + + - - + + - - + - - -

19. a) Without mountain b) With mountain b) –a) July Monsoon Experiment, Pre (shaded) and v850

20. a) 60E mountain b) 90E mountain July Monsoon Experiment, Pre (shaded) and v850

21. LIST 1. Thermal Adaptation 2. Land Distribution and Continental Scale “LOSECOD” Heating 3. Tibetan Plateau Local Scale Forcing 4. Climate changes over the TP and its impacts 5. Summary

22. Data: Station observations: 1. 64/71 surface stations in Central and Eastern Tibetan Plateau (CE- TP) during 1961-2003 ; 2.9/12 radiosonde stations in CE-TP during 1971-2000/1980-2003. Reanalysis: 1.ERA40 Reanalysis data during 1961-2001; 2.NCEP/R1 Reanalysis data during 1961-2003. Total ozone amount: NASA Goddard Space Flight Center (GSFC) (http://code916.gsfc.nasa.gov./Data_seveices/indes.html) during 1980-2003 with a horizontal resolution of 5° latitude and 10° longitude.http://code916.gsfc.nasa.gov./Data_seveices/indes.html

23. Chen et al., (2003); Du (2001;2004); Liu et al., (2000;2001;2006); Niu et al., (2004); Zhu et al., (2001); … Previous Study review: The Tibetan Plateau is one of the most significant warming area in the world Glacier retreat in Meli Jokul (98.1E, 28.06N)

24. Strong surface warming and diminished DTR Linear variation rate （ LVA ） of the annual mean surface air temperature (a) and its diurnal range (DTR) (b) during 1961-2003 in units of ℃ /decade. Triangles, open circles, and solid circles denote stations above 4000, 3000, and 2000 m, respectively.

25. Tave RainTmin Tmax 64 station-averaged Linear trend During 1961 － 2003, the 64-station-averaged LVR of the annual mean Tmin (0.57 ℃ /10a) is twice larger than that of the Tmax (0.27 ℃ /decade). Strong surface warming and diminished DTR

26. Differences of Ta anomalies among observation, ERA40, and NCEP/R1 Comparison between observation and reanalysis (a) The CE-TP area; (b) Northern subtropics and Northern Hemisphere. Red, blue, and yellow curves are observed, ERA40-, and NCEP-based temperature anomalies, and the green curve denotes the observed DTR over the CE-TP; Purple and cyan curves in (b) denote the ERA40-based temperature anomalies over the Northern Subtropics and the Northern Hemisphere, respectively. Solid and dotted lines represent the linear trends and the chief abrupt change points of the curves with the same colour. CE-TP NS and NH ERA40 Observ NCEP

27. Relative change rate (RCR) in percentage of the surface air temperature (a-c), total cloud amount (d-f), and low-level cloud amount (g-i) in the period of 1961-2003. (a), (d), and (g) for 0600 LT, (b), (e), and (h) for 1200 LT, and (c), (f), and (i) represent the difference between 0600 LT and 1200 LT. 1200 LST0600-1200 LST Surface air Temp. 0600 LST Low cloud amount Total cloud amount Warming and diminished DTR related cloud change

28. NumberStation IDStation nameFirst yearLatitude, NLongitude, EElevation (m) 151886Mangai1958 38  15'90  51' 2945 252818*Geermu1955 36  25'94  54' 2808 352836Dulan1954 36  18'98  06' 3191 452866*Xining1954 36  43'101  45' 2295 555299*Naqu1954 31  29'92  04' 4507 655591*Lhasa1955 29  40'91  08' 3649 756029*Yushu1951 33  01'97  01' 3681 856046Dari1956 33  45'99  39' 3968 956137*Changdu1954 31  09'97  10' 3306 Temporal evolutions of the standardized 9 station averaged air temperature at 150 hPa (red) and 50 hPa (green) Change in upper layers Temporal evolutions of the ERA40 standardized air temperature at 150 hPa (Solid) and 50 hPa (dashed). Observation ERA40 150 50 150 50

29. Change in in upper atmosphere Time-altitude sections of the linear trends for (a) air temperature (in unit of ℃ ·decade-1), (b) geopotential height (in unit of dagpm·decade-1), and (c) wind speed (in unit of m s-1·decade-1) as averaged from the 12 radiosonde stations over the TP during the period 1980-2003. Ta GPH V

30. Temperature anomaly in upper layers for 20C3m and PICNTRL MIROC_3.2GFDL_CM2.1 150hPa 50hPa Numerical Simulation The standardized surface layer temperature and DTR anomalies over the CE-TP (85-105ºE; 27.5-37.5ºN) MIROC_3.2GFDL_CM2.1 PICNTRL 20C3M Observed change in TP can only be reproduced in 20C3m scenario by two models

31. Temporal evolution of Ta (a and b), Ts (c and d), V0 (e and f), and SH (g and h) in the CE-TP at 0000 LST/DJF (left panels) and 1200 LST/MAM (right panels). The units of Ta and Ts are ℃, V0 m·s-1, and SH W·m-2. Curves with open circles are 71-station-averaged and closed circles are 37-station-averaged. V10 Ts Ta SH Decreased sensible heat flux over TP

32. Slightly increased latent heat flux over TP Temporal evolution (upper panel, in units of W·m-2) and spatial distribution (lower panel, in units of W·m-2·decade-1) of the LVR of LH in four seasons over CE-TP during 1961-2003.

33. Sensitivity experiments by HadAM3 JJA Difference between less and more albedo over the TP Ts Ta SHv850

34. Sensitivity experiments by Had3 JJA Pre. In CON Run Pre. diff. between less and more TP albedo

35. Wang et al, 2008

36. Surface T trend 1969-2000 Rainfall Trend Xu and Chang et al., 2006

37. LIST 1. Thermal Adaptation 2. Land Distribution and Continental Scale “LOSECOD” Heating 3. Tibetan Plateau Local Scale Forcing 4. Climate changes over the TP and its impacts 5. Summary

38. Summary Asian Monsoon are formed due to the atmospheric thermal adaptation to Continental Scale “LOSECOD” forcing and certain kind of Local Scale Forcing

39.  1961-2003, a striking climate warming is accompanied by the decreasing trends of the surface DTR;  The change of cloud amount seems to be directly related to this change;  Simulation results of two IPCC models suggest that, the recent climate warming over TP may be closely connected with the anthropogenic GHGs emissions;  1961-2003, Ts and Ta over the TP both get warmer, with the latter stronger than the former; V10 gets weaker  Surface sensible heating is reduced;  Radiation cooling increased, not much change in latent heating  TP thermal forcing is reduced;  Weekend TP thermal forcing contributes to the dry of Northern China. Summary for climate change over the TP

40. Thank You!

41. Related Publications Wu, Guoxiong and Yimin Liu, 2003: Summertime quadruplet heating pattern in the subtropics and the associated atmospheric circulation. Geophys. Res. Lett., 30(5), 1201, doi:10.1029/2002GL016209, 5_1-4 Wu, Guoxiong, Yimin Liu, Jianyu Mao, Xin Liu And Weiping Li. 2004: Adaptation of the atmospheric circulation to thermal forcing over the tibetan plateau. Obseervation, Theory And Modeling Of The Atmospheric Variability. Selected Papers Of Nanjing Institute Of Mateorology Alumni In Commemoration Of Professor Jijia Zhang, Edited By Xun Zhu Etc.World Scientific 92-114. YIMIN LIU, GUOXIONG WU, AND RONGCAI REN, 2004: Relationship between the Subtropical Anticyclone and Diabatic Heating. J. Climate, 2004, 17: 682-698. Wu, Guoxiong, Yimin Liu, and Png Liu, 2004: Formation of the summertime subtropical anticyclone. East Asian Monsoon, Edited by C. P. Chang.World Scientific 499-544. Xiaoyun Liang, Yimin Liu, and Guoxiong Wu ★, 2005: The role of land-sea distribution in the formation of the Asian summer monsoon. Geoph. Res. Lett. 32: 10.1029/2004GL021587 Guoxiong Wu, Yimin Liu, Tongmei Wang, Rijin Wan, …,2007: The Influence of the Mechanical and Thermal Forcing of the Tibetan Plateau on the Asian Climate. J. Hydrometeorology. 8: 770-789. WU Guoxiong1, LIU Yimin1,*, YU Jingjing1,2, ZHU Xiaying1,2 and REN Rongcai ： Modulation of Land-Sea Distribution on Air-Sea Interaction and Formation of Subtropical Anticyclones ， To appear in Chinese JAS.

43. 10mm d -1 ~2.5*10 -5 Ks -1, maximum heating layer Z M ~300-400mb, Q~ 10 -4 Ks -1 for z Z M Northerlies are forced above Z M ; southerlies are forced below Z M. Thermal Adaptation - Sverdrup balance

44. Fig. 10 (a) SENSIBLE HEATING 30 o N CONTINENT 30 o N OCEAN (b) LATENT HEATING 30 o N CONTINENT 30 o N OCEAN (c) RADIATION COOLING 30 o N CONTINENT 30 o N OCEAN S C L

45. Annual mean time series at Golmud for years 1961-2003. (a) surface air temperature,(b) DTR, (c) low-level cloud amount, (d) total cloud amount, (e) horizontal direct radiation flux, (f) diffuse radiation flux, and (g) global radiation flux. Temperature and DTR are in units of oC. Cloud amount varies from 0 to 10 tenths of sky cover. Units of radiation flux are 10e6 J m-2. Ta DTR Low cloud Total cloud Horizontal direct solar radiation flux Diffuse solar radiation flux Global solar radiation flux Warming and diminished DTR related cloud change: A case study at Golmud