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81.
Summary A pilot tropical cyclone reanalysis project was conducted to construct a reliable, high temporal and spatial resolution tropical
cyclone dataset for selected western Pacific typhoons in summer 2004, with the application of the latest satellite observations
and a 4-dimensional variational data assimilation method. Primary data used for the reanalysis include SSM/I rain rate, GOES-retrieved
upper-level wind, QuikSCAT surface wind, Aqua AIRS/AMSU retrieved temperature and moisture profiles, and JTWC best track data.
A regular reanalysis procedure was established and up to 12 western Pacific typhoons have been reanalyzed. The reanalysis
period covers the entire life cycle of a tropical cyclone, from a few days prior to its genesis to its final decay stage.
A preliminary analysis shows that the reanalysis product significantly improves typhoon intensity, structure, and track, compared
to the NCEP operational final analysis. The validation of the TC structure against independent observations shows that the
reanalysis reproduces well the asymmetric characteristics of TC rain bands and cloud bands. A further modeling experiment
with an initial condition from the reanalysis product reveals a significant improvement in typhoon intensity forecast compared
to a parallel experiment with an initial condition from the NCEP final analysis, which provides a further indication of quality
of the tropical cyclone reanalysis. The reanalysis product and the raw observational data will soon be posted on the data
server of the IPRC Asia-Pacific Data-Research Center () for public use. 相似文献
82.
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84.
在HAc-NaAc形成的中性缓冲溶液体系中,利用碘的催化动力学原理,使N-N-四甲基-4-4-二氨基二苯甲烷与氯胺T的氧化反应,生成蓝色络合物来测定地探样中微量碘的含量。通过实验,最佳试剂加入量为8%的HAc溶液5mL,8%的Na2CO3溶液3mL,0.1%的N-N-四甲基-4-4-二氨基二苯甲烷溶液5mL所组成的溶液体系中,在加入0.1%的氯胺T1mL显色后,其测定结果准确度、精密度高,检出限低,测定化探样中微量碘时该方法可以推广应用。 相似文献
85.
“7.15”宜昌大暴雨的地形影响特征 总被引:2,自引:0,他引:2
湖北地形复杂,受地形影响产生的局地强降水造成的灾害很多。2010年7月15日宜昌地区的强降水是在满足大尺度降水条件下受地形作用加强的局地暴雨。本文利用实况高空、地面、加密自动站、雷达以及LAPS再分析资料对背景场、低层流场、雷达回波等几个方面进行了分析。得出:冷空气南下和副热带高压的加强促进低层风场的调整,在大尺度降水条件下,地形对低层风场的辐合作用触发了局地强降水的发生。此次过程中地形对降水的触发主要有两方面的作用:一方面为地形迎风坡抬升触发作用,另一方面为地形对近地层流场的影响造成的辐合触发。 相似文献
86.
本文利用广东省气象台站的风速自记资料,计算风能资源,并分析风能资源的分布特点及规律,得到的结果是沿海岛屿风能丰富,内地风能贫乏,冬半年风能条件比夏半年好。按全省风能蕴藏量可划为三大区:沿海岛屿为风能丰富区,沿岸为风能可利用区,大陆内地和海南岛五指山区为风能贫乏区。 相似文献
87.
Relationships between Interannual and Intraseasonal Variations of the Asian-Western Pacific Summer Monsoon Hindcasted by BCC_CSM1.1(m) 总被引:4,自引:0,他引:4
LIU Xiangwen ;WU Tongwen ;YANG Song ;LI Qiaoping ;CHENG Yanjie ;LIANG Xiaoyun ;FANG Yongjie ;JIE Weihua ;NIE Suping 《大气科学进展》2014,31(5):1051-1064
Using hindcasts of the Beijing Climate Center Climate System Model, the relationships between interannual variability (IAV) and intraseasonal variability (ISV) of the Asian-western Pacific summer monsoon are diagnosed. Predictions show reasonable skill with respect to some basic characteristics of the ISV and IAV of the western North Pacific summer monsoon (WNPSM) and the Indian summer monsoon (ISM). However, the links between the seasonally averaged ISV (SAISV) and seasonal mean of ISM are overestimated by the model. This deficiency may be partially attributable to the overestimated frequency of long breaks and underestimated frequency of long active spells of ISV in normal ISM years, although the model is capable of capturing the impact of ISV on the seasonal mean by its shift in the probability of phases. Furthermore, the interannual relationships of seasonal mean, SAISV, and seasonally averaged long-wave variability (SALWV; i.e., the part with periods longer than the intraseasonal scale) of the WNPSM and ISM with SST and low-level circulation are examined. The observed seasonal mean, SAISV, and SALWV show similar correlation patterns with SST and atmospheric circulation, but with different details. However, the model presents these correlation distributions with unrealistically small differences among different scales, and it somewhat overestimates the teleconnection between monsoon and tropical central-eastern Pacific SST for the ISM, but underestimates it for the WNPSM, the latter of which is partially related to the too-rapid decrease in the impact of E1 Nifio-Southern Oscillation with forecast time in the model. 相似文献
88.
NASA/GEWEX (National Aeronautics and Space Administration/Global Energy and Water Cycle Experiment) Surface Radiation Budget (SRB) has released its latest radiation dataset, version 3.0. We examine the accuracy of the monthly mean global radiation in China using surface-observed radiation (SOR) data at 42 stations during the period 1984?C2004. Overall comparison shows a general overestimation of satellite retrieval radiation data with a bias of 14.6?W?m?2 and a root mean square error of 25.9?W?m?2. Differences at individual stations suggested satellite data are consistently higher than surface measurements over eastern China (110°E), but occasional underestimation occurs in Western China, especially Southwest China. Intra-annual variation analysis indicates that SRB satellite radiation can capture the annual cycle well. For trend of global radiations, there are evident discrepancies between satellite retrievals and surface measurements for both the entire period and segmental terms. For the entire period from 1984 to 2004, most stations show a positive trend based on surface measurements, while the majority of collocated pixels show a negative trend. Segmental trends demonstrated that the principal difference occurred during the first period of 1981?C1994. After 1994, the two datasets change similarly. Therefore, trend analysis in terms of detecting global dimming/brightening remains very difficult as surface measurements and satellite products do not agree yet. In addition, some proposals are made towards better understanding of the bias of satellite products and to improve further the satellite retrieval algorithm with better representation of both cloud and aerosol properties. 相似文献
89.
水下光照分布是影响水生态系统的重要因素,研究光合有效辐射衰减特征对于沉水植物恢复具有一定的指导意义.根据沉水植物生物量资料,将东太湖划分为沉水植物茂盛区、沉水植物稀疏区和无植物区3种区域.基于2019年夏季原位水下光场资料,探讨了东太湖光衰减特性和光照衰减因子的空间差异以及不同区域内的主导衰减因子,分析了东太湖的稳态阶段和富营养化水平,并阐述了真光层深度与透明度的关系,以期为东太湖沉水植物恢复和保护提供相关资料.结果表明:东太湖不同区域光衰减特性差异显著,光合有效辐射衰减系数(k d(PAR))在0.73~11.80 m^-1之间变化,真光层深度范围为0.39~6.31 m.不同区域的无机悬浮物和有机悬浮物浓度存在显著性差异,稀疏区叶绿素a浓度显著高于茂盛区,而与无植物区没有显著差异,有色可溶性有机物(CDOM)吸收系数在3种区域无显著性差异.k d(PAR)与无机、有机悬浮物的线性拟合效果较好,而与叶绿素a、CDOM拟合较差.水体吸收和散射作用是茂盛区光衰减的主要原因,无植物区域主导衰减因子仅有无机悬浮物,稀疏区由叶绿素a和无机悬浮物共同主导,是生态修复需要重点关注的区域,有机悬浮物和CDOM对东太湖光照衰减没有太大影响.东太湖目前正处于从草型稳态向藻型稳态过渡的阶段,整个湖泊属于富营养水平,真光层深度大约为透明度的2.7倍. 相似文献
90.