Monthly
Highlights
Climate in
During March 2009, monthly mean surface air
temperatures were higher than
normal in most China, with 2
For the month,
precipitations were observed 30-200% more than normal in northern Xinjiang,
eastern Inner Mongolia, northern Northeast China, most central and southern Qinghai-Tibet
Plateau, eastern North China, eastern Huanghuai,
southern Guizhou, central South China, with over 200%
more than normal in eastern Inner Mongolia and northern Northeast China. Meanwhile,
precipitations were observed 30-80% less than normal in central and southern
Xinjiang, western and parts of central eastern Inner Mongolia, southern
Northeast China, western North China, western Huanghuai,
regions in lower reaches of the Yangtze River Valley, western Sichuan, most
Yunnan, western and southeastern Tibet, locations in central Tibet, with no
precipitation in central and southern Xinjiang, western Inner Mongolia and
parts of Tibet.
During March 2009, temperatures were 2
For
the month, precipitations were at least 50% more than normal in most
northeastern Asia, parts of Central Asia, central southern Russia and locations
in western Russia, northwestern South Asia and most Indo-China Peninsula，parts
of southern Europe, parts of western Africa, most of northern North America and
northern South America, with precipitations over 200% more than normal in northeastern
Asia and parts of northern North America. Meanwhile, precipitations were
observed over 50% less than normal in central northern and parts of eastern
Russia, northwestern and locations in southern East Asia, most West Asia and
locations in South Asia, western Europe and locations in northern Europe, parts
of northern and eastern Africa, parts of southwestern and northeastern North
America, parts of central-southern South America and most Australia, with no
precipitations in locations.
Northern
Hemisphere: During March 2009, the mean 500hPa
geopotential height field exhibited a 4-wave pattern at the mid-high latitudes.
In the 500hPa geopotential height anomaly field, positive anomalies above 4 dam
covered regions from eastern Russia to most of the North Pacific Ocean, most
southeastern North America, regions from northeastern Canada to southern
Greenland Island, parts of the northern North Atlantic Ocean, most Central
Asia, with central values above 16 dam over the central North Pacific Ocean. Meanwhile,
negative anomalies below -4 dam covered regions from southeastern Europe to
northern West Asia, locations in central-southern
Southern
Hemisphere: For the month, in the 500hPa geopotential height anomaly field,
positive anomalies above 4 dam covered parts of the South Pacific Ocean south
to 20°S and parts of the South Atlantic Ocean
south to 40°S, with
central values above 8 dam over parts of the southwestern South Pacific
Ocean nearby 60°S. Meanwhile,
negative anomalies below -4 dam covered regions from the southeastern Pacific Ocean
south to 40°S to parts of the
Tropical Features
Sea
Surface Temperatures (SSTs): During March, negative SST anomalies
dominated most of the central and eastern equatorial Pacific, and positive SST
anomalies persisted in the western equatorial Pacific. However, the negative
SST anomalies weakened obviously as compared with last month. Furthermore, in
March, indices of
NINO 1+2, NINO 3, NINO 4, NINO 3.4 and NINO Z were
Subsurface Temperatures: During March, comparing with
last month, anomalously cold subsurface water further weakened in the central equatorial
Pacific. Meanwhile, anomalously warm subsurface water in the western equatorial
Pacific extended eastward obviously.
Warm Pools: During March, both the area
and intensity of the western Pacific and
Wind Field：For the month, at lower troposphere
(850hPa), easterly anomalies prevailed over the central Pacific with central
values over
Southern Oscillation: For the month, the Southern
Oscillation Index (SOI) was 0.2, with a drop of 1.2 from last month.
Convections over the Tropics: During March, the anomalous
outgoing longwave radiation (OLR) in the equatorial
Pacific showed that the convection was enhanced over the western equatorial
Pacific, and suppressed over the central equatorial Pacific. In the lower
troposphere (850hPa) divergent wind field, a convergent center was near 150ºE, 5ºS,
and a divergent center was near 110ºW, 5ºS. At upper troposphere (200hPa), the
corresponding divergent center was near 170ºE, 15ºS, and the convergent center
was near 100ºW, 5ºS.
ENSO Monitoring and outlook
During March, atmospheric
and oceanic conditions in the tropical Pacific still maintained
Based on monitoring of recent atmospheric and oceanic conditions
in the tropical Pacific and predictions of statistical and dynamic models, the ENSO-neutral conditions are expected to
maintain during the
following 1-3 months.