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181.
STUDY ON THE VARIATION IN THE CONFIGURATION OF SUBTROPICAL ANTICYCLONE AND ITS MECHANISM DURING SEASONAL TRANSITION-PART Ⅱ:SEASONAL TRANSITION INDICES OVER THE ASIAN MONSOON REGION 下载免费PDF全文
Based on the studies in Part Ⅰ (see Mao et al.2003),this paper further examines the relationship between the Asian summer monsoon onset and variation in meridional position of the warm temperature ridge with a zonal orientation in mid-upper troposphere.During the Asian monsoon bursting consequentially over the Bay of Bengal,South China Sea,and South Asia,in addition to the reversal of winds in the lower and upper troposphere and deep convection before and after the onset,the atmospheric meridional temperature gradient (MTG) in the vicinity of the ridge-surface of subtropical high (WEB defined in Part Ⅰ) exhibits a significant reversal.Since the establishment of temperature structure with higher over north than over south of the WEB in the mid-upper troposphere (200-500 hPa) characterizes the collective essential that the Asian summer monsoon bursts over different areas,the MTG in mid-upper troposphere,based on the thermodynamics associated with the seasonal transition,should be a reasonable index to measure the Asian monsoon onset.The definition for onset date is proposed,and the time series of onset date for different sections are determined.As compared with the onset dates determined by other indices such as 850-hPa zonal wind and OLR.correlation analyses indicate that the 850-hPa zonal wind is only regional index,but the MTG index is applicable universally to the Asian monsoon regime. 相似文献
182.
In this paper,a comprehensive analysis and review of the advances in the research of human body comfort degree is made.Based on the studies of human thermal equilibrium theories contributed by previous researchers,different apparent temperature models corresponding to different environments are set up in accordance with the current situation and the characteristics of metabolism in different groups of people in China.After case studies and comparison with present dominant human body comfort degree statistical models,it is proved that the apparent temperature models have high rationality and wide adaptability.Furthermore,the comfort scaling standard according to apparent temperature is suggested,which is suitable for the middle latitude regions in China. 相似文献
183.
In this study, the relationship between fluorine in drinking water and that in urine of urban residents in China is assessed. Fluorine concentrations in tap water and those in urine show a good correlation with a linear regression coefficient of 0. 9798, indicating that the fluorine concentrations in big cities under investigation are extremely low, and the main source of fluorine is tap water. The weather effect on the intake amount of fluorine is also discussed. When air temperature is above 15℃, people would intake more fluorine through drinking water with the rise of air temperature. When temperature is below 15℃, no remarkable relationship is observed between air temperature and the intake amount of fluorine. This phenomenon indicates that the main source of fluorine in China is tap water instead of foodstuff. 相似文献
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YAN Shouxun Laboratory of Remote Sensing Information Sciences Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing China 《中国科学D辑(英文版)》2004,47(9)
To examine the application potential of hyperspectral remote sensing techniques in classifying very low-grade metamorphic belts, the composition of clay minerals and the cyrstallinity of illite from mudstones were measured using XRD and VIS-SWIR (400-2500 nm) reflectance spectroscopy. Based on the illite cyrstallinity, Kubler Index (KI), the Early Triassic LuoLou Group and the Middle Triassic lower Baifeng Formation were classified as the lower Epizone with KI△2θ° ranging from 0.22 to 0.25, the upper Baifeng Formation as upper anchizone with KI△2θ°ranging from 0.26 to 0.33, and the Hekou Formation as lower anchizone with KI△2θ° ranging from 0.38 to 0.40. According to a KI△2θ° value of 0.43, it is possible that there may exist a local diagenetic zone in the upper strata. The illite cyrstallinity Kubler index and the metamorphic grade increase from the bottom to the top of the stratigraphic sequence. The metamorphic grade boundaries nearly match the stratigraphic boundaries, indicating a burial metamorphism nature for the stratigraphic sequence. From the bottom to the top of the sequence, the spectral absorption band center of clay minerals from fresh rocks is around 2200 nm. The absorption band centers change towards shorter wavelengths: the Luolou Group being at 2220 nm, the Baifeng Formation at 2217-2213 nm, the lower member of the Hekou Formation at 2214-2206 nm, and the upper member of the Hekou Formation at 2205-2197 nm. The spectral absorption band center of illite shows the same change pattern. These results indicate that very low-grade metamorphic belts can be subdivided using spectral indices of clay minerals, which are measured by using field portable spectroradiometers. However, it may not work well with satellite and airborne sensors. 相似文献
186.
通过对阿勒泰地区1991~2000年西部区域性偏东大风天气的气候特征、环流形势及地形进行分析,归结出产生西部区域性偏东大风天气的成因及预报指标。 相似文献
187.
该文针对CAPPS在太原市运行的误差问题,在分析其主要原因的基础上,变换地形背景场,依据不同季节、不同天气形势,在模式中增加对综合误差系数和扬尘系数的调节功能,进行多种数值模拟试验。结果表明:在误差分析基础上确定的模拟试验方案,使主要污染物SO2、NOX和PM10的预报值与监测值的相关系数分别提高到0.96、0.91和0.89,最终使CAPPS成为预报准确率稳定在90%以上的业务化数值模式系统。 相似文献
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2002年我国沙尘暴天气特征分析 总被引:5,自引:1,他引:5
利用逐日8个时次地面天气报告资料,分析了2002年全国沙尘暴的时空分布特征。结果表明:2002年出现的12次沙尘暴过程以3月18~22日的强沙尘暴过程影响范围最广、强度最强;我国北方地区浑善达克沙地及其周边地区的沙尘暴日数最多。另外,2002年我国沙尘暴高频期集中、早春多于晚春。主要原因是前期北方持续气温偏高、降水偏少,3—4月上中旬影响我国的冷空气十分频繁且强度较强,4月下旬—5月上旬我国北方地区出现了几次较大范围降水,5月中下旬影响我国的冷空气势力较弱且位置偏东。 相似文献