In the preceding studies by many authors, in particular they found that moist processes were responsible for the strong initial error growth in meso-scale. In the present study they take a more systematic look at the processes by means of the initial introduced mall errors and found that the errors first grow as small-scale differences associated with moist convection, then spread upscale as their growth begin to slow. In the context, we use vastly different initial perturbation methodologies to investigate the initial error growth in the storm scale with open boundary conditions. Comparison of
the perturbation methodologies indicates that the ensuing patterns of ensemble spread converge within only a few minutes, irrespective of the initial perturbations employed. In the vertical direction, the largest errors in different variable fields concentrated in different layers (e.g., the largest errors in the temperature field concentrated in the upper tropopause, but in the horizontal wind field, the largest errors converged in the troposphere.). The error growth in the first and middle time contact with the storm tightly, but at last, the error growth goes their ways very slow and flat. The
growth of the uncertainties is limited by the saturation effects, which in turn is controlled by the larger-scale atmospheric
environment.
Interdecadal features of summer rainfall in North China, East Asia summer monsoon (EASM) and the anomaly of
general circulation were explored by using NCEP/NCAR reanalysis data and summer rainfall collected from 20 stations
over North China. Results showed that the periods of summer rainfall in North China are not in agreement with those of
EASM, interdecadal features are obvious, the former with notable periods of 8a and18a, with an abrupt change occurred
in 1960s, the latter 18a and 28a, with abrupt change in 1970s. There is marked correlation between the summer
precipitation of North China and EASM, strong/weak summer monsoon with more/less precipitation in North
China .Weak EASM is an important factor of the rainfall decreasing, but not the only one, for general circulation
anomaly is close related to the rainfall decrease. The decline of air temperature in Tibetan tableland and North China
results in less low pressure here; lack of water vapor is another factor for the rainfall decreasing. The weakened
southwest monsoon in East Asia leads to the fact that water vapor can't arrive in the region to the north of 30°N. As
opposite to the 1950s', the EU teleconnection pattern of 1980s is of the character with Europe(+),Ural(-),and mid-Asia(+)
at 500hPa, which means the Ural ridge and Baikal trough weakening, zonal circulation is not good for exchanging cold
and warm air. As a result, the activity of cold and warm air and precipitation over North China reduced.
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.