GPT2模型的精度检验与分析   总被引：3，自引：1，他引：2  

姚宜斌  曹娜  许超钤  杨军建 《测绘学报》2015,44(7):726-733

GPT模型常被用于计算气温、气压等对流层延迟气象参数,针对其不足之处,Lagler提出了改进的全球经验模型GPT2,该模型不仅提高了GPT气温和气压模型的精度,而且可提供比湿、水汽压、映射函数等对流层参数。但是目前没有相关文献对GPT2的精度进行详尽的分析,本文利用ECWMF及NOAA提供的高精度气象数据,对GPT2气温、气压和水汽压模型进行精度检验及分析。结果表明,气温的Bias均值为-0.59°C,RMS均值为3.82°C左右;气压和水汽压的Bias均值绝对值在1mb以内,气压的RMS均值为7mb左右,水汽压则不超过3mb,不同纬度精度存在差异,三者均具有明显的季节性。总体而言,GPT2模型在全球范围内具有很高的精度和稳定性。  相似文献   

NOAA Weather Radio (NWR) – A Coastal Solution to Tsunami Alert and Notification     

George?L.?CrawfordEmail author 《Natural Hazards》2005,35(1):163-171

The Washington State/Local Tsunami Work Group adopted the NOAA Weather Radio All-Hazards Warning System to warn citizens quickly and effectively of not only tsunami hazards but also other natural or man-made hazards. In concert with an array of deep ocean tsunami detectors, land-based seismic sensors, and warning messages issued by the tsunami warning centers, NWR provides a means to expeditiously get critical decision-making information to emergency managers, elected officials, and first responders. To implement the NWR strategy effectively, a partnership was developed to add a repeater to the NWR system to provide complete coverage to the coast of Washington and to shipping lanes off the coast. The Work Group also recognized the need to disseminate time critical hazard information on tsunamis to the public on beaches and in high traffic areas, so it developed a new notification system, with the first prototype installed on 2 July 2003 in Ocean Shores, Washington. A public education program also was developed to improve the impacted communities understanding of the tsunami hazard, the warning system, and actions they should take if a tsunami occurs.  相似文献   

近岸流系与长江入海悬浮泥沙输移扩散   总被引：5，自引：0，他引：5  

李四海  恽才兴 《海洋通报(英文版)》2006,8(1):22-33

通过两年较完整的序列 NOAA/AVHRR 数据和实测含沙量资料,利用考虑近岸Ⅱ类水体大气校正的泥沙定量反演算法,获得了较高精度的河口高浓度泥沙遥感反演模式;利用泥沙浓度分级图和反映流系特征的温度图象,系统分析了长江口悬浮泥沙扩散途径、范围及其与近岸流系的关系。影响长江入海悬浮泥沙扩散的近岸流系主要包括台湾暖流、黄海混合水、苏北沿岸流及浙江沿岸流等。冬季,近岸流系比较稳定,其配置状况在一定程度上影响着苏北沿岸泥沙流向长江口的扩散,并制约着入海悬浮泥沙的扩散途径;洪季,长江入海径流量是影响悬浮泥沙扩散的重要因子。同时,长江冲淡水、浙江沿岸流共同形成的冷水区与台湾暖流水之间锋面的强度,也对悬浮泥沙和冲淡水的扩散方向和范围有重要影响;春、秋两季入海悬浮泥沙的扩散型式分别向夏、冬季的分布格局过渡。此外,风应力显著影响着浑水区的扩散方向和范围。风浪掀沙引起的河口泥沙再悬浮,可使近岸泥沙扩散范围增大。  相似文献   

基于RS和GIS的中国西北不同生态类型区生态环境时空变化研究   总被引：4，自引：0，他引：4  

高丽敏  陈兴鹏  黄艳  拓学森  张艳秋 《中国沙漠》2007,27(1):65-70

采用定性与定量相结合的方法,在遥感（RS）和地理信息系统（GIS）支持下,利用1982-2000年的空间分辩率为8 km×8 km的NDVI数据（由NOAA-AVHRR提供）和地面气象资料,联合分析西北不同生态类型区生态环境的变化过程,得出中国西北地区NDVI的年平均值及其历年变化曲线、NDVI年平均值分布图和每隔10 a的差值变化图。由此可以看出,生态环境变化时空特点明显:20世纪80年代生态环境的变化波动不大,90年代以来波动变化明显,而且从1998年以后生态环境总体呈下降趋势;不同生态类型区植被指数年际变化的驱动因子不同,黄土高原区植被指数年际变化与降水量的相关性显著,而青藏高原高寒区与气温的相关性显著,其他分区与降水量和气温的相关性都不显著;生态环境变化的地域差异性明显,西北不同生态类型区中生态环境由好到差依次是陕南-陇南湿润半湿润区、黄土高原区、青藏高原高寒区、干旱区。四个分区1990年比1982年生态环境有所提高,但干旱区退化面积较大,2000年与1990年相比,生态环境都出现不同程度的退化,其中,陕南-陇南湿润半湿润区退化面积最大,其次是黄土高原区。整体生态环境状况不佳,而且近年的退化应该引起重视。  相似文献   

The Change in Outgoing Long-wave Radiation before the Ludian MS6.5 Earthquake Based on Tidal Force Niche Cycles     

Zhang Yan  Kang Chunli  Ma Weiyu  Yao Qi 《中国地震研究》2017,31(3):422-430

The cycle process of the tidal force niche for the Ludian M_S6.5 earthquake occurring in Ludian County, Yunnan Province, China on August 3, 2014 was calculated. The earthquake occurred near the middle point phase. It indicates that the type of seismogenic fault that the tide force acted on belongs to the thrust fault. According to the tidal niche cycle,the abnormal OLR( Outgoing Long-wave Radiation) change was analyzed based on NOAA satellite data around the whole land area of China before and after the earthquake.The result shows that the OLR changed evidently with tide force change. Temporally,the change went through the evolution process of initial OLR rise → strengthening → abnormal peaking → attenuation → returning to normal; and spatially,the abnormal area wound its way along the Zhaotong-Ludian fault and went through a scattered → conversion →scattered process. This process is similar to the change process of rock breaking under stress loading. The results indicate that the tidal force of a celestial body could trigger an earthquake when the tectonic stress reaches its critical breaking point and the OLR anomaly is proportional to the seismic tectonic stress change. It is of great use to combine OLR and tidal force in earthquake precursory observation.  相似文献   

交叉定标产生的NOAA卫星长期大气温度观测资料   总被引：1，自引：0，他引：1       下载免费PDF全文

邹成治  高梅 《应用气象学报》2008,19(5):582-587

介绍一套用于气候变化研究的NOAA卫星微波观测资料, 资料为全球5 d平均, 2.5°×2.5°经纬网格, 3个深层大气(对流中层、对流层顶以及平流层下层)的温度分布。该文简介了资料产生的方法, 包括交叉定标、角度订正、网格化以及网格误差修正等, 给出了使用这套资料分析得到的1987—2006年间不同大气层的温度变化趋势, 并提供了获取这套资料的方法。  相似文献   

中天山北坡草地生物量估产模型研究     

武鹏飞  李良序  朱进忠 《沙漠与绿洲气象(新疆气象)》2008,2(6):49-53

分别对草甸、草原和荒漠3种草地类型进行了生物量的实测工作。根据同步的MODIS与AVHRR资料,应用ENVI软件提取出这两种传感器在3种草地类型上的植被指数：NDVI和RVI。经过统计分析得到两种传感器在3种草地类型上的生物量模型,从而建立起MODIS植被指数与草地生物量的相关关系,并对MODIS和AVHRR植被指数估产模型进行了评价与分析。  相似文献   

基于NOAA/AVHRR的中亚地区荒漠化动态变化监测   总被引：1，自引：0，他引：1  

韩旭  孙一权  冯仲科  程彦培  曹忠 《测绘科学》2012,37(5):69-71

本文通过对影像特征的荒漠化解译,监测荒漠化土地面积和荒漠化程度,分析探讨1989年至2009年中亚地区荒漠化的变化趋势。结果表明本文所采用的监测方法,具有一定可靠性和实用性,能够对中亚地区进行快速地荒漠化的宏观实时监测。  相似文献   

利用NOAA/AVHRR数据获取地表特征参数的方法研究   总被引：5，自引：1，他引：4  

王黎明  周云轩  万力 《地球物理学进展》2004,19(3):672-677

地表特征参数的正确与否直接影响到区域陆面蒸散量估算精度,因此在区域非均匀陆面蒸散研究中,地表特征参数的获取方法是一个值得探讨的问题．与传统的方法相比,卫星遥感技术在求取地表特征参数时有其独特的优势．NOAA气象卫星AVHRR资料以其时间分辨率高、覆盖面广、价格低廉等优点广泛应用于非均匀陆面蒸散研究和应用中．本文建立了NOAA／AVHRR计算地表特征参数的参数化模型,选取中国东北松嫩平原西部地区2000年7月8日的AVHRR资料,试算了研究区地表温度、地表发射率、地表反照率、NDVI等主要地表特征参数,并且参照2000年研究区土地利用数据对各参数的空间分布特征及合理性进行了分析。  相似文献   

Retrieval of Atmospheric Horizontal Visibility by Statistical Regression from NOAA/AVHRR Satellite Data     

HUANG Fei WANG Hong QIAN Junping WANG Guofu 《中国海洋大学学报(英文版)》2006,5(3):207-212

Based on the atmospheric horizontal visibility data from forty-seven observational stations along the eastern coast of China near the Taiwan Strait and simultaneous NOAA/AVHRR multichannel satellite data during January 2001 to December 2002, the spectral characters associated with visibility were investigated. Successful retrieval of visibility from multichannel NOAA/AVHRR data was performed using the principal component regression （PCR） method. A sample of retrieved visibility distribution was discussed with a sea fog process. The correlation coefficient between the observed and retrieved visibility was about 0.82, which is far higher than the 99.9% confidence level by statistical test. The rate of successful retrieval is 94.98% of the 458 cases during 2001 2002. The error distribution showed that high visibilities were usually under-estimated and low visibilities were over-estimated and the relative error between the observed and retrieved visibilities was about 21.4%.  相似文献