THE APPROACH TO REMOTE SENSING OF WATER VAPOR BASED ON GPS AND LINEAR REGRESSION T_m IN EASTERN REGION OF CHINA

The approach to remote sensing of water vapor by using global positioning systems(GPS)isdiscussed.In order to retrieve the vertical integrated water vapor(IWV)or the precipitable water(PW),the weighted“mean temperature”of the atmosphere,T_m would be estimated to the specificarea and season.T_m depends on surface temperature,tropospheric temperature profile,and thevertical distribution of water vapor.The surface temperature dependence is borne out by acomparison of T_m and the values of surface temperature T_s using radiosonde profiles of BeijingStation(No.54511)throughout 1992.The analysis of radiosonde profiles spanning a one-yearinterval(1992)from sites in eastern region of China with a latitude range of 20-50°N and alongitude range of 100-130°E yields the coefficients α and b of a linear regression equation T_m=α bT_s.     

NUMERICAL EXPERIMENT OF IMPACT OF SEA SURFACE TEMPERATURE IN SOUTH CHINA SEA AND WARM POOL/WEST PACIFIC ON EAST ASIAN SUMMER MONSOON

By using the NCAR CCM1 model, we have designed six sensitive experiments, which areincreased and decreased SST (sea surface temperature) by 1℃ each in the SCS (South China Sea)and in the West Pacific warm pool, increased and decreased SST by 1℃ in the warm pool withincreased SST by 1℃ in the SCS. All experiments are integrated from April to July. Comparingwith the control experiment, we have analyzed the anomalies of the wind field at the upper andlower layers, the anomalies of the seasonal variability of the monsoon and precipitation for eachexperiment. In the result, we have found that the SST anomaly (SSTA) in the SCS greatly affectsthe seasonal variability of the SCS monsoon and precipitation in China, especially during the coldperiod of SST in the SCS. The impact of SSTA in the warm pool on SCS monsoon is also found.but is weak as compared to the effect of SST anomaly in the SCS. Besides, its impact on rainfall inChina is uncertain.     

祁连山海北冬春气温变化对草地生产力的影响

祁连山海北地区冬春气温与高寒草甸牧草产量具有很高的反相关关系。冬春气温升高导致牧草产量有所下降,主要原因是冬春气温升高,使冬季土壤冻结层变薄,土壤水分散失严重;在牧草营养生长阶段初期,又正值我国北方天气气候“干旱”胁迫最严重的时期,自然降水量显得不足,进而限制了牧草生长发育的水分需求,最终影响到牧草年产量的提高。对冬春气温进行主成分处理后建立的气温影响牧草产量的回归关系表明,回归模型拟合率较高,试报１９９５年牧草产量误差很小,效果良好。     

夏季高温期间空调房间人体舒适度研究

根据人体舒适度指标,考虑到温度和湿度的关系,研究了长江中下游地区夏季高温期间,没有减湿条件的空调房间的最佳降温幅度,并计算出有降温降湿条件的不同场所的最佳降温降湿幅度     

陆面生态过程的一维数值模拟

建立了一个研究大气、植被、土壤相互作用的传播模式。模式是由多层大气模式、多层土壤模式和植被模式通过界面上能量、水汽传输平衡方程耦合而成。对植被和土壤的不同性质,进行了一系列的数值试验。结果表明,不同的植被覆盖以及降水等因子会对大气、植被、地表界面上能量、水汽传输以及热状态产生显著的影响。此模式还可以耦合进中尺度模式用以研究非均匀区域陆面过程和大气的相互作用。     

1997年我国天气气候特点

我国１９９７年天气气候有如下几个主要特点：冬暖、夏热、春来早,降水北少南多,登陆台风少而集中,低温危害较普遍。     

青海省最高、最低气温不对称性变化的诊断分析

利用青海省１３个站逐月最高、最低气温资料,分析了月、季、年平均最高、最低气温的变化。结果表明最高、最低气温存在明显不对称变化趋势,尤其是３、４月存在明显的反向变化趋势。同时分析了西宁城市效应对最高、最低气温的影响。     

低温对玉米种子发芽的影响

通过发芽试验研究了东北地区早、中、晚熟３个玉米品种在４℃、８℃、１３℃、１７℃、２１℃和２５℃黑暗条件下的发芽率、发芽势和发芽指数;并求出不同品种的发芽临界温度。结果表明,低温抑制了种子发芽,降低了发芽能力;３个品种发芽的临界温度为３．２￣５．２℃。发芽临界温度愈低,种子的耐低温发芽能力愈强。稀土浸种有提高玉米种子发芽率和促进发芽的作用。     

长江中下游盛夏持续性高温干旱对短期降水影响的数值试验

应用IAP 2-L AGCM模式,并考虑了下垫面异常,模拟了长江中下游盛夏不同强度的持续性地表高温干旱对短期天气的影响。结果表明,这种持续性高温干旱对长江中下游及我国东南沿海短期降水有十分明显的影响,持续高温干旱的强度不同,其影响结果不同。持续性适度高温和严重干旱造成短期降水减少,高温干旱仍继续维持达1个月的正反馈过程。在此持续过程中,土壤湿度变化起主导作用,而土壤热力状况的影响相对较小。     

用可见光与红外云图资料综合作降雨量估算的试验

利用红外和可见光云图亮温资料估算单站降水量级,结果发现红外和可见光云图结合估算降水量效果比单用红外云图效果要好,大雨的空报率明显降低。