During
this spring, mean surface air temperatures were 1¡æ above average in much of
China. Positive anomalies above 2¡æ were observed in central Northwest China
and western Tibet Plateau. In this season, rainfall totals were 30% ~100% more
than normal in most of Southwest China, southern Northwest China, western and
northern Xinjiang, northern and eastern Northeast China and parts of North
China. Meanwhile, precipitation totals were 30~90% less than normal in the
regions from the western Tibet Plateau to eastern Xinjiang, western Inner
Mongolia, most of the bend of the Yellow River, middle and southern Northeast
China.
During
this spring, mean surface air temperatures were obviously below average at
mid-high latitudes of the Northern Hemisphere, such as much of northern Russia
and middle and eastern Canada, with negative anomalies below -4¡æ
in parts of above regions. At most of the middle latitudes of the Northern
Hemisphere, temperatures were generally 1~2¡æ¡¡above
normal. In northern South America, temperatures were 1¡æ above normal.
Temperatures were generally 1~2¡æ above normal in Australia except the
southwestern part. Temperatures were 1¡æ above normal in parts of West and
South Africa.
In
the spring, rainfall totals were 30% ~100% more than normal in middle and
eastern Europe, parts of Middle Asia, southeastern Russia, most of Southwest
China, southern and eastern North America, most of South America and central
Australia, with totals of 200% more than normal in parts of above regions.
Precipitation
totals were 30~90% less than normal in most of West Asia, West Africa and
eastern Australia, with no rainfall in parts of above regions during this
season.
Northern Hemisphere: During
the spring, the mean 500hPa geopotential height field exhibited that the trough
over Northern America was stronger than normal. Correspondingly, below -4
dam negative anomalies covered middle and northern Canada. Meanwhile, positive
departures above 4 dam controlled most of the North Pole and the nearby regions,
regions from the Northeast Pacific to the western North Atlantic Ocean with
center values above 8 dam. In this season, the Northwest Pacific subtropical
high was stronger than normal.
Southern
Hemisphere: In
the mean 500hPa geopotential height field during this spring£¬zonal
circulation dominated mid-high latitudes. In the height anomaly field, 4 dam
below-normal heights were observed over the southeastern Pacific, and the ocean
south to Africa, while 4 dam above-normal heights were observed over the South
Pole and the nearby regions.