Monthly
Highlights
During November 2006，the monthly mean surface air temperature
ranked the third highest over China since 1951. Monthly mean surface air
temperatures were generally 2℃ above
normal in most of China, with maximum
above 4℃ in northern Xinjiang，but temperatures were slightly below normal in eastern
Inner Mongolia, northern Heilongjiang and locations in Southwestern China.
For the month, the averaged precipitation in China was observed more
than normal. Precipitations were 30-200% more than normal in most of the
Huanghuai area and the Jianghuai area, south and northeast of the Jiangnan
area, most of South China, western and northeastern Inner Mongolia, northern
Heilongjiang, western Sichuan and eastern Tibet. Meanwhile, precipitations were
observed 30-80% below average in southeastern Southwest China, northern North
China, and mideastern Inner Mongolia, midsouthern Northeast China, the Shandong
Peninsula, mideastern Northwest China and southwestern Tibet, with no rainfall
in parts of above regions.
Climate in the world
During November 2006，monthly mean surface air temperatures were 2-4ºC above normal in most Europe, most of
central and eastern Asia in the mid latitudes, northern Russia, northwestern Africa,
northeastern and southwestern America, and most of Australia, with maximum 6-10℃ in northeastern Russia. Meanwhile,
temperatures were 1-2ºC below normal in central and western Russia, parts of
West Asia, eastern West Africa, northwestern North America, and locations of
South America, with 3-7℃ below
normal in part of middle and western Russia and Alaska.
For
the month, precipitations were observed 50~100% more than average in northern
and eastern Europe, eastern Russia, eastern China, most of Central Asia,
northwestern America and central South America，with 200%
above normal in locations. Meanwhile, precipitations were more than 50% below
average in southeastern Europe, most of West Africa, mid-western America and
Alaska, southern and northwestern South America and most of Australia, with no
rainfall in parts of above regions.
General Circulation Features
Northern
Hemisphere: During
November 2006, the mean 500hPa geopotential height field exhibited mainly a
4-wave pattern at the mid-high latitudes. In the 500hPa height anomaly field, positive anomalies above 4 dam covered the
southwestern Europe, regions from northern Russia to the northwestern North
Pacific, northeastern North America and its nearby ocean regions, with maximum
above 24 dam over the northwestern North Pacific. Meanwhile, negative anomalies
below -4 dam covered the middle North Pacific, northwestern North America, the
northern North Atlantic Ocean and regions near the Caspian Sea. For the month,
the Northwest Pacific subtropical high was larger and located in farther south
and extended farther west than normal. Its intensity was near normal.
Southern
Hemisphere: For the month,
the mean 500hPa geopotential height field exhibited mainly a 3-wave pattern at
the mid-high latitudes. In the 500hPa height
anomaly field, negative anomalies below -4 dam were found over regions from the
southern South Pacific to the southwestern South Atlantic Ocean and parts of
the South Indian Ocean, with central values below –8 dam over the South
Pacific. Meanwhile, positive anomalies above 4 dam were observed over
the regions from the eastern South
Atlantic Ocean eastward to the southwestern South Pacific and the southeastern
South Pacific with maximums above 8 dam. Heights were near normal in the
other regions.
Tropical Features
Sea Surface Temperatures (SSTs): During November 2006, positive SST anomalies above 0.5℃ were observed in the equatorial Pacific east of 160ºE with maximums above 1.5℃ in the eastern Pacific and above
2.0℃
in the central Pacific, respectively. All of the NINO indices
increased with the exception of NINO1+2 and Nino3. NINO Z，NINO
3.4, NINO 3, NINO 4 and NINO 1+2 indices were 1.2℃，1.2℃，1.1℃，1.3℃ and 1.0℃，respectively.
Meanwhile, SSTs
were 0.5℃ above normal in the most
equatorial Indian Ocean.
Warm Pools: During November 2006, areas of the western Pacific and Indian Ocean warm pools were near
normal and their intensities were both stronger than normal.
Subsurface Temperatures: During October 2006,
the anomalously subsurface warm waters persisted in the most equatorial Pacific
Ocean, with their intensities increased obviously. Meanwhile, the anomalously
cold water in offshore of South American weakened but its area enlarged
compared with last month.
Wind Field：During November 2006, at the lower troposphere (850hPa), westerly
anomalies covered most of the equatorial Pacific east of the Date Line and
winds near normal covered the rest of the equatorial Pacific. Meanwhile, strong
easterly anomalies covered the equatorial Indian Ocean. At the upper
troposphere (200hPa), easterly anomalies above 4m/s covered most of the
equatorial Pacific and westerly anomalies were over the mid- western equatorial
Indian Ocean.
Southern Oscillation: For the month, Southern Oscillation Index (SOI) was 0.2,
with an increase of 1.5 from last month.
Convection over the Tropics: During November 2006, the anomalous outgoing longwave radiation (OLR) showed that
convections were suppressed over regions from the eastern equatorial Indian
Ocean to Indonesia and enhanced slightly over the equatorial Pacific around the
Date Line. In the lower troposphere (850hPa) divergent wind field, a convergent
center was observed over 175ºE, 5ºS, and a divergent center was located in
around 112.5ºW, 12.5ºS. Correspondingly, at the upper troposphere (200hPa), the divergent
center was found over 172.5ºE,
5.5ºN, and the convergent center was over 115ºW, 17.5ºS.
ENSO Monitoring and Prediction
(1) During November
2006, positive SST
anomalies above 0.5ºC maintained in the equatorial
Pacific Ocean east of 160ºE. The index of NINO Z was
1.2ºC.
(2) The anomalously subsurface warm waters persisted in the most
equatorial Pacific Ocean, with their intensities increased obviously.
(3) Southern
Oscillation Index (SOI) was 0.2.
(4) At the
lower troposphere (850hPa), westerly anomalies covered most of the equatorial
Pacific east of the Date Line and winds near normal covered the rest of the
equatorial Pacific. Meanwhile, strong easterly anomalies covered the equatorial
Indian Ocean.
(5) The
anomalous outgoing longwave radiation (OLR) showed that convections were
suppressed over Indonesia and enhanced
over the equatorial western Pacific.
(6) Most of models predicted that SSTs could
be above normal during following 3-6 months.
In
conclusion, tropical oceanic and atmospheric conditions showed obvious features
of ENSO warm phase which had been maintaining for 4 months and these features
are expected to persist in the following 2~3 months.