Recent SST, Sea ice, and Snow Cover Monitoring and Diagnosis Beijing Climate Center, CMA YUAN Yuan, ZHOU Bing ( Thanks to Dr. Guo Y J and Dr. Ma L J )
1.Recent SST monitoring and diagnosis 2.Possible impacts of negative PDO 3.Sea ice and snow cover monitoring Outline
Jan Monthly SSTA Feb Dec. 2012
SSTA & OLR in DJF 2012/13
Anomaly percentage of rainfall in DJF 2012/13 A Atmospheric Circulation Anom. DJF Red contour: Climatological WPSH
Wang et al. 2000, J. Climate, 13: Cold A Warm C A Physical Mechanism for the Anticyclone e.g. Watanabe and Jin, 2002; Xie et al. 2009; Wu et al. 2010; Yuan et al, 2012
SSTA in March 2013 The latest weekly SST departures are: Niño 4 0.0ºC Niño ºC Niño 3 0.0ºC Niño ºC (From CPC)
1.Recent SST monitoring and diagnosis 2.Possible impacts of negative PDO 3.Sea ice and snow cover monitoring Outline
Composite difference of summer rainfall anomaly between positive and negative PDO years NENCJHYRSC PDO Precipitation data: GPCC V6 & CRU TS NE 9 NC 9 JH 9 YR 9 SC 9 PDO Red line: PDO 9 Green and black lines: NC 9
Composite Difference between positive and negative PDO phases SSTA 850UV 500H
Negative PDO Enhanced EASM Eastward and northward WPSH More summer rainfall in North China
1.Recent SST monitoring and diagnosis 2.Possible impacts of negative PDO 3.Sea ice and snow cover monitoring Outline
Sea Ice Concentration in NH--DJF Over 40% below normal in the Barents Sea and western Kara Sea The fourth least since 1978
Sea Ice Concentration in SH--DJF
Snow Cover Days in NH--DJF
Average Snow Depth in China--DJF China Northeast China Northern Xinjiang Tibet Plateau
Conclusions 1.In DJF 2012/13, SSTA over the equatorial eastern-central Pacific was slightly below normal; PDO persisted in its negative phase; SSTA over the tropical Indian Ocean was significantly above normal, which excited anomalous low-level anticyclone to the east of the Philippines 2.The significant negative PDO would lead to a strong East Asian summer monsoon and a weak WPSH in summer Therefore, more precipitation tends to occur in North China. 3.In DJF 2012/13, sea ice concentrations were over 40% below normal in Barents Sea and western Kara Sea, while mostly above normal in the sea areas around Antarctica. 4.The area of snow cover was evidently larger than normal in Northeast China, with the average snow depth the deepest since 1973.
Thank You!