[1] In this note, we investigate the impacts of the winter Arctic Oscillation (AO) and Siberian High (SH) on the East Asia winter monsoon (EAWM). It is found that the winter AO and the SH are relatively independent of each other in influencing the EAWM. The winter AO influences directly surface air temperature (SAT), sea level pressure (SLP) and the East Asian Trough at 500 hPa over the region northwards of 35°N in East Asia rather than through its impact on the SH. Compared with influences of the winter AO, the SH shows more direct and significant influences on the EAWM, particularly on SLP and northerly wind along the East Asian Coast. Impacts of the SH on the SAT occur primarily in the southwards of 50°N over East Asia, the northwestern Pacific and the South China Sea, because the AO suppresses the SH's influences in high latitudes of Asian Continent and the some subarctic regions.

Recent record lows of Arctic summer sea ice extent are found to be triggered by the Arctic atmospheric Dipole Anomaly (DA) pattern. This local, second–leading mode of sea–level pressure (SLP) anomaly in the Arctic produced a strong meridional wind anomaly that drove more sea ice out of the Arctic Ocean from the western to the eastern Arctic into the northern Atlantic during the summers of 1995, 1999, 2002, 2005, and 2007. In the 2007 summer, the DA also enhanced anomalous oceanic heat flux into the Arctic Ocean via Bering Strait, which accelerated bottom and lateral melting of sea ice and amplified the ice–albedo feedback. A coupled ice–ocean model was used to confirm the historical record lows of summer sea ice extent.

The Tibetan Plateau (TP) surfaces have been experiencing an overall rapid warming and wetting while wind speed and solar radiation have been declining in the last three decades. This study investigated how climate changes influenced the hydrological cycle on the TP during 1984∼2006. To facilitate the analysis, a land surface model was used to simulate surface water budget at all CMA (China Meteorological Administration) stations on the TP. The simulated results were first validated against observed ground temperature and observation-derived heat flux on the western TP and observed discharge trends on the eastern TP. The response of evaporation and runoff to the climate changes was then analyzed. Major finding are as follows. (1) Surface water balance has been changed in recent Climatic Change (2011) 109:517-534 decades. Observed precipitation shows insignificant increasing trends in central TP and decreasing trends along the TP periphery while evaporation shows overall increasing trends, leading to decreased discharge at major TP water resource areas (semi-humid and humid zones in the eastern and southern TP). (2) At the annual scale, evaporation is water-limited in dry areas and energy-limited (radiation and air temperature) in wet areas; these constraints can be interpreted by the Budyko-curve. Evaporation in autumns and winters was strongly controlled by soil water storage in summers, weakening the dependence of evaporation on precipitation at seasonal scales. (3) There is a complementary effect between the simulated actual evaporation and potential evaporation, but this complementary relationship may deviate from Bouchet's hypothesis when vapor pressure deficit (or air temperature) is too low, which suppresses the power of vapor transfer.