Based on the 100-yr simulations from seasonal cycle global SST and sea ice driven by NCAR Cam3 atmospheric
general circulation model, the natural variability of East Asian summer monsoon (EASM) in the internal atmosphere is
investigated. Results suggest that the natural variability of EASM in the internal atmosphere displays 1) mainly
distinct 3-7-yr interannual period and marked interdecadal variation; 2) in the year of weak EASM, sea level pressure
(SLP) in Asian continent increases, with decreased SLP around Japan and in eastern Asian littorals; the 500 hPa height
field exhibits negative anomalies over Europe, positive anomalies about the Caspian Sea and negative anomalies
around Japan and in the Pacific area to the east, thus leading to an EU-like teleconnection wavetrain and almost v.v.
for the year of strong EASM. It is also found that the simulated EASM has a close relation to the EU-like
teleconnection wavetrain at 500 hPa on a synchronous basis.
In terms of NCEP/NCAR daily reanalysis data and some remote sensing data, effects of diabatic heating on the
short-term position variation of the west Pacific subtropical high (WPSH) during persistent heavy rain event in June
2005 in South China are analyzed based on the complete vertical vorticity equation. The results show that the position
variation of WPSH is associated with the diabatic heating. In comparison with the climatology, there is strong heating on
the north side of WPSH and relatively weak ITCZ convection on the south.. Each of westward extension of WPSH
corresponds to a significantly enhanced heating to the west of WPSH. In mid-troposphere, the vertical variation of
heating on the north (south) of WPSH during 12~24 June, 2005 is basically greater(less) than the climatology, which is
unfavorable for the northward movement of WPSH. In the mid and late of June 2005, the vertical variation of heating
over the eastern coast of the Arabian Sea and the Bay of Bengal (to the west of WPSH) is largely higher than the
climatology, which is in favor of the increase of anti-cyclonic vorticity on the west of WPSH, inducing westward
extension of WPSH. As a result, the heating on the north and south, and to the west of WPSH work together to make
WPSH extend more southward and westward in June 2005, which is in favorable for rainbelts maintaining in South
China.
Based on the sea surface temperature (SST) and sea level pressure (SLP) data, the temporal and spatial variations of sea
surface temperature anomaly (SSTA) in Kuroshio have been analyzed in this paper by means of the method of Rotated
Empirical Orthogonal Function (REOF). The results show that there is a spatial change feature as a whole in addition to
a remarkable interannual/interdecadal change of SSTA. After dividing the positive and negative SSTA years and
analyzing a lot of meteorological elements in corresponding years, it is obtained that the SLP in Kuroshio current region
and the height field at 700 hPa are negative anomaly with enhancement of winter monsoon in the negative years and vice
versa, and that there is a close relation between SSTA of this region and distribution pattern of wind anomaly at 850 hPa.
KEYWORDS: Composites, Data centers, Convection, Remote sensing, Environmental sensing, Atmospheric sensing, Information science, Information technology, Numerical simulations, Data processing
By using the NCEP/NCAR daily reanalysis data, CMAP precipitation data , daily precipitation data of 740 stations
in China and some remote sensing data, features of the short-term position variation of the west Pacific subtropical
high(WPSH) during the torrential rain in Yangtze-Huaihe river valley and its possible cause are analyzed. Results show
that the short-term position variation of WPSH is closely associated with the diabatic heating. During the torrential rain
period, the apparent heating source and apparent moisture sink are exceptionally strong over Yangtze-Huaihe river
valley( on the northwest side of WPSH )and the Bay of Bengal (to the west of WPSH). Based on the complete form of
vertical vorticity tendency equation, it is found that the heating field over Yangtze-Huaihe river valley during the
torrential rain period, which is in favor of the increase of cyclonic vorticity on the north side of WPSH, is unfavorable to
the WPSH moving northward. And the heat source over the Bay of Bengal ,which is in favor of the increase of
anti-cyclonic vorticity on the west of WPSH, may induce the westward extension of WPSH.
In terms of monthly NCEP/NCAR and 160 site temperature data from NCC (National Climate Center), the main
modes of January surface air temperature in 1979-2008 over China and possible mechanism of typical cold/warm
episodes are investigated. Results show that the first mode for January temperature is characterized by consist variation
in China, which is closely related to circulation anomalies in stratosphere. From the wave source over East Asian in
stratosphere wave fluxes propagate downward and westward, and in upper troposphere over North Atlantic there is a
remarkable convergent area of wave flux leading to the ridge enhanced with stronger heat transforming to the North and
front zone moving to more northerly. Thereby jet stream becomes strong and expands to East Atlantic with positive
(negative) NAO anomaly pattern and higher pressure occurs south to Baikal indicating stronger (weaker) than normal
cold air, which is helpful for lower (higher) temperature appearing over China
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