ENSO事件对我国天气气候的影响   总被引：19，自引：4，他引：19       下载免费PDF全文

刘永强  丁一汇 《应用气象学报》1992,3(4):473-481

从东亚环流、旱涝、台风活动和东北夏季低温等方面总结了ENSO对我国天气气候影响的观测结果和可能的物理机制，并讨论了与之有关的问题。通过总结和讨论期望对ENSO的影响及预报价值有一个总的评估。  相似文献   

INFLUENCE OF SOIL MOISTURE AND VEGETATION ON CLIMATE CHANGES INDUCED BY THERMAL FORCING          下载免费PDF全文

刘永强  叶笃正  季劲钧 《Acta Meteorologica Sinica》1992,(1)

A land-process scheme has been incorporated in a vertical one-dimensional time-dependent atmospheric modeland numerical experiments have been performed with the coupled model to examine influences of soil wetness and vege-tation on climate changes associated to thermal forcing.It is showed that response of land-surface temperature to thethermal forcing becomes small with increase of soil water content and vegetation cover.Furthermore,the response ismore obvious in arid climate region than in humid one.The result also shows that there exist two patterns of corre-sponding relation between variations in air temperature and humidity on the land surface in response to hydrologic andthermal focing.  相似文献   

基于便携式雷达维修测试平台的高稳时钟源设计          下载免费PDF全文

刘永强  梁华 《气象科技》2022,50(4):506-511

便携式雷达维修测试平台是集雷达系统性能参数测试、故障诊断、维修保障等功能于一体的智能化移动式技术保障平台，该平台硬件系统采用基于嵌入式机箱设计架构的通用测试仪器。文章针对通用测试仪器板载时钟不能满足雷达系统对测试仪器时钟要求的问题，提出了一种适合于便携式雷达维修测试平台的高稳时钟源设计方案，设计方案包括高稳定度恒温晶振、FPGA、晶振电源控制模块和电源滤波电路模块，实测结果表明，高稳时钟源设计参数达到了输出频率稳定度为±0.5×10-6、相位噪声为-160 dBc/Hz的设计标准，据此设计的高稳时钟源已实际应用于便携式雷达维修测试平台中，平台运行稳定，测试结果优于原板卡自带时钟源，达到了系统设计要求。  相似文献