To evaluate the stratospheric process in the response to the increased surface CFCs emissions, some simulations were
carried out by the NCAR interactive chemical, dynamical and radioactive two-dimensional (SOCRATES) model. The
investigation showed that when the surface CFCs emissions increased by 30%, these chemical components would be
transported into the stratosphere and would play an important roles in stratospheric chemistry and radiation. In the layers
from 40km to 48km, the relative variety of active component was ClOx by 20%, HOx by -2%, NOx by -2% and O3 by
-5%, respectively. At the same time, temperature reduced by 0.6K.
The Tibetan long-term monthly mean rainfall exhibits a SE to NW decrease, showing strong regionality. The summertime vigorous rainfall centers are roughly coincident with those of heat sources <Q1> averaged throughout the atmospheric extent, with latent heating making the greatest contribution to <Q1>. In the heat source stronger (weaker) year than normal, the western Pacific subtropical high amplifies (falls off), making westward extension (eastward withdrawal); the South-Asian high intensifies (weakening), eastward expanding (westward extending); summer monsoon becomes intense (enfeebled). In that case, the precipitation is more (less) in the Jiang-Huai valley compared to normal in relation to the rainfall lower (higher) than mean over the littoral provinces of South China, and two parallel anomalously deep wavetrains (just one wavetrain) of cyclones alternate with anti-cyclones over the Pacific.
The ERA-40 reanalysis ozone data sets provided by ECMWF are most widely used at present, in order to use the data
more effectively and reasonably, a comparison analyses are done and the features are discussed between the ERA-40
reanalysis and Halogen Occultation Experiment (HALOE) Observations on Upper Atmosphere Research Satellite
(UARS). The spatial and temporal variations of the differences between two ozone data are analyzed in detail.
Signal-to-Noise Ratios are estimated firstly by HALOE observational ozone concentration in seasonal and interannual
time-scales, respectively. The results indicate that there are significant seasonal and interannual variations in a large part
of stratosphere. The comparison analysis suggests that seasonal variation in ozone from ERA-40 is similar to HALOE
observations and interannual variation in ozone from ERA-40 is greatly weaker than that of HALOE observations in the
tropical middle stratosphere, but is enhanced at low latitudes in the lower stratosphere.
The water vapor data by HALOE from 1993 to 2002 were analyzed to study the major variance of interannual variability, Quasi-Biennial Oscillation (QBO). Three centers of water vapor QBO located in upper, middle and lower stratosphere were found. The simulation results from model SOCRATES3 indicated that the QBO forcing of tropical zonal wind
would induce three pairs of residual circulations, the transportation of which played an important role in the cause of water vapor QBO's formation. The QBO of temperature could control the chemical production of water vapor in the middle stratosphere. On the other hand, the temperature's QBO had an important effect on the water vapor condensation in the lower stratosphere.
Using the humidity profiles from Atmospheric Infrared Sounder (AIRS) data set, rainfall from TRMM GPI and
winds from QSCAT as well as SST from Aqua/AMSR_E, We analyze the structure of summer quasi biweekly mode
(QBM) over western Pacific region in 2003-2004. We find that the signal of 10-20d oscillation in western Pacific
originates from Philippine Sea, which propagates northwestward to south of China. The AIRS data reveal much larger
tropospheric moisture perturbations than those depicted in ECMWF analysis. It also reveals that the boundary-layer
moisture leads the mid-troposphere moisture during the QBM propagation. The positive SST anomaly may play an
important role to moistening the boundary-layer, which preconditions the QBM propagation. Therefore, the 10-20d SST
anomaly could positively feed back to the atmosphere through moistening the boundary layer, destabilizing the
troposphere, and contributing to the northwestward propagation of the QBM in western North Pacific. On the other hand,
the salient feature that the boundary-layer moisture anomaly leads mid-troposphere moisture does not exist in ECMWF
analysis.
Based on NCEP/NCAR daily reanalysis data and precipitation data, the circulation background of the extremely
heavy rain causing severe floods in Huaihe River valley (HHRV) in 2003 and its relationships to the apparent heating
were analyzed. The results showed that the El Nino events with middling intensity during 2002~2003 was the previous
background of this extremely heavy rain. The abnormal apparent heating source (Q1) and vapor sink (Q2) may be
one of the important causes for subtropical high maintaining southward than usual. Compared with summer in 2003, the
positive abnormal (Q1) and (Q2) were located to the HHRV during June 21~July 22. The centers of high value bands of (Q1) and (Q2) were in agreement with those of rainfall. But the negative abnormal (Q1) and (Q2) were situated in South China and most of South China Sea areas. The abnormal heating source over the Bay of Bengal
forced an abnormal anticyclonic circulation over its northwest high level leading to the South Asian High enhancing and
maintaining over the Tibetan Plateau, the south of Yangtze River valley and South China, so HHRV areas just located
the updraft areas which was in the south of the high-level jet, making for heavy rain and severe floods.
Based on NCAR/NCEP daily reanalysis, a study is performed of the circulation background for the South-China
torrential rains leading to flash floods in June 2005 with the possible causes explored. Results show that a weak El Nino
episode in 2004-2005 is the climate background of the flooding. Compared to the situation of the summer 2005, the
apparent heat source
(Q1) and the apparent vapor sink (Q2) are anomalously intense in the rainy period June 17~26 over the study region, with their high-value belts resembling the rainfall distribution and their centers roughly coincident
with the rainfall cores. The anomalous heating source from the eastern coast of the Arabian Sea to the Bay of Bengal
excites a high-level abnormal anticyclone to the northwest, making the south-Asian high intensified and westward of
normal, during which China mainland is under the effect of an anomalous cyclonic circulation that keeps the south-Asian
high from northward displacement, allowing it to stay in the south of the Tibetan plateau - South China, a situation that
South China is situated in the rising area on the south side of upper-air westerly jets, making for the occurrence and
maintenance of the intense rains, resulting in extensive flooding.
The analysis of photochemical theory and HALOE, SAGE II, ECMWF/ERA-40 data indicate that ozone variations are
inversely correlated with temperature in the upper stratosphere, while ozone variations are positively correlated with
temperature in the middle stratosphere. Ozone layer mainly locates at middle stratosphere, where solar UV radiation is
largely absorbt. The radiation is main action in middle stratosphere, so temperature variation depends on ozone variation.
In the upper stratosphere, the ozone concentrations decrease rapidly, the photochemical actions instead of radiation
actions play a principal role. The ozone-depleting reaction rates depend on temperature, so the coefficient correlation of
Ozone and temperature is reverse.
The trends of water vapor and methane in the stratosphere have been analyzed by using the HALOE data from 1992 to
2005. The variations of water vapor and methane averaged along latitude circle are analyzed in the levels 2hPa, 10hPa,
30hPa and 80hPa, which are taken as the upper, middle and lower stratosphere. Besides the seasonal and inter-annual
variations, The trends of water vapor and methane in various levels are not the same. The variations of water vapor and
methane generally are contrary. In the years when the water vapor increases, the methane decreases, and when the water
vapor decreases, the methane increases.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.