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Recent SST, Sea ice, and Snow Recent SST, Sea ice, and Snow Cover Monitoring and DiagnosisCover 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. 2013
Monthly SSTA
Feb. 2013
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: 1517-1536
ColdAWarmC
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 3.4 0.1ºC
Niño 3 0.0ºC
Niño 1+2 -0.9ºC
(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
NE NC JH YR SC
PDO 0.13 -0.2 -0.05 0.09 0.007
Precipitation data: GPCC V6 & CRU TS 3.10.01
NE9 NC9 JH9 YR9 SC9
PDO9 0.13 -0.68 0.02 0.36 0.08 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000-1.5
-1
-0.5
0
0.5
1
1.5(a)
年份
1910 1920 1930 1940 1950 1960 1970 1980 1990 2000-1.5
-1
-0.5
0
0.5
1
1.5(b)
年份
Red line: PDO9
Green and black lines: NC9
Composite Difference between positive and negative PDO phases
SSTA 850UV
500H
Negative PDONegative PDOEnhanced EASMEnhanced EASM
Eastward and northward WPSH
Eastward and northward WPSH
More summer rainfall in North
China
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
Conclusions1. 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 2013. 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!