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.
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 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
The spatial and temporal distributions of snow depth on Tibetan Plateau are revealed by comparing the data retrieved
from satellite remote sensing i.e. SSMR and SSM/I with station observations. All of the results show that snow depth on
the Tibetan plateau plays an important role in East Asia summer precipitation anomalies and in consequence, some
possible mechanisms are proposed.
Since the summer rainfall over Yangtze River and Huaihe River often leads to the occurrence of floods, with inconsistent distribution among those years, it is important to investigate the characteristics and the causes of rainfall anomalies. Therefore, REOF analysis is performed on 1951-1998 monthly mean precipitation from both CMA (China Meteorological Administration)-provided 160 weather stations and NCEP/NCAR re-analyses. Results show that: 1) summer rainfall over the mid-lower reaches of Yangtze River (MLRYR) can be divided into two rain belts in the south and north of the study region, called as the southern and northern branch of rain belt, respectively. In detail, the southern belt is located in south of the MLRYR, i.e. regions of Jiangxi, Hunan and Zhejiang, and the other is located in regions of Chongqing, southeast Shaanxi, Hubei, south Henan and Anhui, with east-west zonal distributions for the both; 2) both the rain belts are marked by conspicuous intra-annual and inter-decadal oscillations, with remarkable 14-/8-yr periods on the inter-decadal scale for the southern/northern belt. Besides, two belts are different in the amount of precipitation during the same stage, which is closely related to the large-scale circulation, especially the strength of summer monsoon and subtropical high, both impacting greatly on amount and distribution of the precipitation in two belts.
Shipboard hand-held sun photometers measurements which were collected over the East China Sea from December 15,
2006 to February 11, 2007, were used to discuss temporal and spacial distributions of aerosol optical thickness(AOT),
and the type and source of aerosol particles over the East China Sea. The results of this study suggest that AOT was
normally large in the coastal areas and became small gradually with the distance away from the coastal areas. The value
of AOT also was larger in the coastal areas with industry than those without industry. AOT was closely related to the
development of human activity and wind transportation. The analysis of many cases showed that the minimum AOT
value over sea appeared at noon during a day and its reason could be found in weather data. The calculated Ångstrom
wavelength exponent showed that the radius of aerosol particles was small in the coastal areas and large in the central
area of the East China Sea. It can provide the basic data for marine regional climate and remote sensing.
This paper analyzes the position and function of the meteorological work in the whole national economy construction,
studies the concept, classification and characteristics of the meteorological service, focuses on the basic thoughts of the
benefit valuation of profession meteorological service, determines the basic methods of studying the high
meteorology-sensitive industry, analyzes the basic methods of determining the profession annual value ratio of
production occupied by the high meteorology-sensitive industry. Based on the above works, the Chinese high
meteorology-hypersensitive industry is put forward, the benefit of meteorological service of the typical operation of the
high meteorology-sensitive industry is analyzed, the profession annual value ratio of production occupied by the high
meteorology-sensitive industry is obtained, and the benefit of the national profession meteorological service is initially
assessed through the expert valuation method (Dephi method). At the present level of meteorological service and
economic development, the annual mean efficiency of meteorological service is no less than 279 billion 3 million
yuan.( The cost is not included.)
China is in the fragile climate area and is one of the most serious countries that suffered serious natural disaster in the world. This text had analyzing the climate conditions of China for the three-year difficult period of 1959-1961 scientifically, and told us about the number of the disaster (20, 29, 26 times) that occurred in the main natural areas by analyzing meteorological factors in 1951-1961, and the result is serious. The disasters of these years are mainly drought and typhoon, other natural disasters such as flood, hail are mainly in some areas in China. On the basis of analyze the three years' meteorological materials from the whole country (670 observation stations at national level and national basis, 4/24 times a day) year by year, and do the comparative analysis according to a common way (considered the average value of climate conditions in 1961-1990 as the standard value), analyze the impact of the natural disasters on national economy objectively with specific and accurate materials at that time, and give us suggestions on how to organize the deference of climate emergency system, etc. According to analysis, during 1959 - 1961, China's climate characteristic was lack of precipitation, especially in 1960, the space and time for the precipitation was not fair. As a whole, the weather and climate conditions are very disadvantageous to China's agricultural production during those years, especially 1960. According to loss caused by the disasters, the year 1960 was much more serious than 1959 and 1961.
Knowledge of the size and chemical composition of aerosols is important to assess their role in several processes occurring in the atmosphere. The aerosol optical thickness is a byproduct of the atmospheric correction, but it is possible to research atmospheric aerosol by those byproducts. In this paper, we first calculated the aerosol optical thickness over other wavelengths using SeaWiFS-derived aerosol optical thickness at 865nm and atmospheric-correction parameters <i>ε</i>(<i>λ</i>,865). Then we classified the aerosol over the ocean into three classes: nuclei mode (r < 0.04μm), accumulation mode (0.04μm < r < 1.0μm) and coarse mode (r > 1.0μm), which are all described by the log-normal distribution. The derived relationship of aerosol optical thickness and number distribution at different wavelengths and Monte-Carlo method are used to obtained the total number of those three classes over the ocean and we analysis their distribution. The reasonable results show that the aerosol optical thickness by SeaWiFS is nice for atmospheric aerosol research.
Due to the significant climatic effects of snow cover, it is very important to improve numerical simulation of snow cover in climate models. With the field data from Col de Porte, Freance and BOREAS, the evolution of seasonal snow cover is simulated with Compreshensive Land Surface Model. The objective of this study is to validate the model and investigate the snow cover proceses in both the alpine regions and the boreal forest. The sensitivity of the simulated results to some model parameters and the different phsyics responsible for the snow cover variation in vegetated and non-vegetated cases are investigated. The modeling results are in good agreements with the observational, and the model represents the snow-pack development and both the timing and the rate of seasonal snowmelt accurately in both cases, indicating that the model has the capacibilty to capture the main features of seasonal snow cover under water holding capacity have significant effects on the simulation of snow cover. The physical processes related to the snow cover variaiotn are different whether vegetation exits or not. Vegetation plays an important role in the dynamics of seasonal snow cover by controlling the radiative fluxes at the snow surface and thus the surface energy balance.
Based on long-time observational datasets, the inter-decadal variations of East Asian summer monsoon (EASM) and summer precipitations over North China together with the relationship between them are investigated by using composite analysis and wavelet transform. Results show that both EASM and summer precipitations over North China have undergone considerable inter-decadal variations over the last 100 years. The Inter-decadal variation of EASM is
characterized by four major strong-weak phases, including two strong EASM periods, that is, the period of 1900~1910 and that from the late 1930s to end of 1960s, as well as two weak EASM periods from late 1910s to the end of 1930s and after 1970s. Corresponding to the inter-decadal variation of EASM, three evident abrupt changes have taken place in 1905, 1948 and 1971 respectively. It has been found that the atmospheric anomalous patterns for strong EASM years are completely distinct from that in weak EASM periods. The inter-decadal variability has been found in the summer precipitations over North China as well. Summer precipitations in North China have gone through four major dry-damp periods, and richer (less) rain periods are in good agreements with strong (weak) EASM periods on inter-decadal scale. Further investigations suggest that summer precipitation anomalies over North China are closely related to the variations of EASM on inter-decadal scale. During stronger (weaker) EASM periods, summer SLP and 500hPa geopotential height both exhibit negative (positive) anomalies over East Asia, implying Indian Low deepens and West Pacific Subtropical High (WSPH) is north (south) than normal. As a result, the North China summer precipitation is richer (less). It is noted that the relationship between precipitation and EASM is changeable with time and also shows inter-decadal features.