共查询到20条相似文献，搜索用时 46 毫秒
1.
遥感地表温度(Land Surface Temperature,LST)产品时序数据可用于分析基准气候站点的环境代表性,但LST空间变异性明显高于气温,容易低估站点代表性,因此提出首先建立面上气温的遥感估算模型,再用模型估算气温(和LST产品具有相同时空分辨率)评估站点代表性的方案。以藏东南林芝国家基准气候站点为例,首先提取气象站点2000-2011年8 d平均日最高气温(T-air)和MODIS地表温度产品(MOD11A2,8 d合成,1 km空间分辨率),分析LST与T-air之间的相关性以及其他因素对相关性的影响;而后利用Cubist回归树算法,建立了基于LST、日序、晴空日数的T-air估算模型(RMSE=1.4718℃,r~2=0.95);最终将模型用于林芝站周围附近区域计算T-air,并对林芝站点代表性加以评估,结果表明,新方案得到的结果更加可信,林芝站点代表范围为15 km×15 km,而基于LST计算得到的林芝站代表范围仅为3 km×3 km。 相似文献
2.
LST在农业气候热量区划中的应用方法研究 总被引：6，自引：2，他引：6
根据广西的自然地理特点和现有卫星遥感资料，对国内外10多种反演LST(1and surfacete mperature，陆面温度)的分裂窗算法及其相关的参数估算方法进行了适用性分析。在此基础上找出了适用于计算广西白天LST的算法，并应用该算法计算了晴空条件下的LST，获得了逐日各个时次的LST实况分布。通过模板分析，找到了求算多年LST气候平均图的途径。针对云剔除问题，通过对公共晴空区的统计分析，建立了不同图像间的数值补偿关系，从而有效地消除了云的影响，最终处理生成了广西多年和不同季节的平均LST空间分布图像。分析结果表明：在10km以上的宏观尺度上，广西平均LST的空间分布与平均气温的空间分布规律基本一致，而在1km尺度上，LST的空间特征更为精细、客观，更有利于反映与作物生长关系更为密切的下垫面热量资源的气候分布，是农业气候区划中更为有效的热量区划因子。 相似文献
3.
4.
起伏地形下我国太阳直接辐射的分布式模拟 总被引：2，自引：1，他引：2
运用数据集群技术,建立了我国不同时空尺度直接透射率的估算模式,对比分析了不同模式的拟合精度。基于1km×1km分辨率的数字高程模型(DEM)数据,全面考虑了地形因子对太阳直接辐射的影响,实现了实际起伏地形下我国太阳直接辐射的分布式模拟,计算了我国范围内1km×1km分辨率1—12月气候平均太阳直接辐射的空间分布。结果表明:局地地形对太阳直接辐射空间分布的影响非常强烈,尤其是在太阳高度角较低的冬季和秋季;模拟结果可靠,可进行大数据量处理,适用于遥感图像处理、地理信息系统等数据处理平台。 相似文献
5.
NO2的光解速率j(NO2)是对流层化学研究中的一个重要的参数，它是对流层臭氧（O3）和OH自由基的形成关键影响因子之一。本文利用香河站2017年11月至2018年1月的观测资料对NO2的光解速率j(NO2)、太阳辐射的变化特征，及光解速率与分波段辐射相关性进行分析，在此基础上建立了一套适合于构建香河地区j(NO2)的参数化方案。结果表明，香河地区的j(NO2)与太阳辐射的变化趋势基本一致，日变化均呈正午高、早晚低的单峰型。香河地区冬季j(NO2)的变化范围是0.00046～0.0044 s-1，平均值为0.0029 s-1。j(NO2)与晴空指数（KS）和定义的紫外辐射晴空指数（KUV）存在很好的相关性，因此，利用j(NO2)与大气质量数和晴空指数的相互依赖关系，基于KUV构建了适合于香河地区j(NO2) 的估算方程。由于总辐射是气象站的常规观测要素，晴空指数KS更容易获取，继而建立了通过KS参数化计算j(NO2)的估算方程。利用KUV和KS建立的j(NO2)估算方程的瞬时估算值与观测值的平均相对误差分别为6.5%和13.9%，均方根误差分别为0.00029和0.00051。 相似文献
6.
地表蒸散的估算在干旱半干旱区水资源研究中具有重要意义。利用NOAA/AVHRR遥感资料、NCEP再分析格点资料和气象站点资料,根据能量平衡模型和FAO-17 Penman公式,计算了研究区域内逐日蒸散发量;对于晴天,用遥感模型反演出瞬时蒸散,进而推算出日蒸散;同时用FAO-17 Penmen公式和气象资料,计算研究区域内的同一天的蒸散,利用气象资料计算得到的蒸散与遥感估算的蒸散的关系,估算非晴空日的蒸散,进而得到逐日蒸散发结果。与同类研究结果的比较表明:该方法能够估算逐日蒸散发,通过气象与遥感资料结合,提高了气象格点资料的空间分辨率,弥补了难以得到遥感逐日晴空资料的不足,同时也为流域内同类研究提供参考依据。 相似文献
7.
晴空湍流是威胁航空安全的一种极端危险性天气,因其不伴有明显的天气现象,机载雷达难以探测,故对飞行安全威胁巨大,因此对于晴空湍流的形成机制与预警预报的研究十分重要。从晴空湍流的形成机制、晴空湍流的观测手段和晴空湍流的预报方法3个方面,对近十年国内外有关研究进行归纳和综述。重点引述了惯性重力波在晴空湍流形成中的重要作用、多种新型观测手段为晴空湍流研究提供宝贵的实况资料、基于湍流指数集成算法的晴空湍流数值预报等重要进展。本文对晴空湍流未来的研究趋势进行展望。 相似文献
8.
基于MODIS资料的中国东部时间序列空气动力学粗糙度和零平面位移高度估算 总被引：1，自引：0，他引：1
空气动力学粗糙度和零平面位移高度是很多气候模型和陆面模式中的重要参数,采用气象学方法推导这两个参数对于大范围长时间序列的计算需要大量长期的野外观测,而遥感方法可以快速经济的提供大范围数据,在本研究中采用形态学模型,以MOD IS产品数据作为数据源,计算植被冠层面积指数,估算了中国东部2001—2003年归一化到植被高度的1 km空间分辨率时间序列空气动力学粗糙度和零平面位移高度,结果表明空气动力学粗糙度和零平面位移高度均存在季节变化特征,并对所采用的模型和参数估算的结果进行了讨论。 相似文献
9.
目前还没有基于国产卫星的1 km分辨率的全天候陆表温度(LST)产品,FY-3D卫星提供了中分辨率成像仪(MERSI)Ⅱ型1 km分辨率晴空LST产品与微波成像仪(MWRI)25 km全天候LST产品,因此可结合两者优势开展全天候1 km分辨率LST的融合研究。基于地理加权回归(GWR)方法,选择海拔、FY-3D归一化植被指数和归一化建筑指数等建立GWR模型对FY-3D/MWRI 25 km LST降尺度到1 km,并与MERSI 1 km LST进行融合;同时针对MWRI轨道间隙,利用前后1天融合后的云覆盖像元1 km LST进行补值,可以得到接近全天候下的1 km LST。基于以上融合算法,选择了中国区域多个典型日期FY-3D/MERSI和MWRI LST官网产品进行了融合试验,并利用公开发布的全天候1 km LST产品(TPDC LST)对FY-3D1 km LST融合结果进行了评估。研究结果表明,基于GWR法的LST降尺度方法,可以有效避免传统微波LST降尺度方法中存在的“斑块”效应和局地温度偏低等问题;LST融合结果有值率从融合前的22.4%～36.9%可提高到融合后69.3... 相似文献
10.
采用WRF v3模式, 利用AMDAR资料与NCEP再分析资料, 对2007年发生于南海周边海域的高空越洋航线上, 110个中度以上晴空颠簸事例与196个无颠簸事例进行数值模拟。选取布朗指数、水平风切变指数等6个晴空颠簸诊断指数, 通过计算各指数的有颠簸诊断准确率、无颠簸诊断准确率、TS评分、ETS评分等指标, 研究指数及其阈值的适用性。研究表明:(1)布朗指数是诊断南海周边海域越洋航线上的晴空颠簸的最佳指数, 并在取"3.2×10-5"为阈值时诊断效果最佳。(2)南海周边海域的越洋航线上的晴空颠簸对于诊断指数阈值的选取十分敏感, 在晴空颠簸的数值预报中, 在合理选择指数的基础之上, 应当认真研究设定指数的阈值。 相似文献
11.
The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics. 相似文献
12.
Fei LIU Chen XING Jinbao LI Bin WANG Jing CHAI Chaochao GAO Gang HUANG Jian LIU Deliang CHEN 《大气科学进展》2020,37(7):663-670
正The Taal Volcano in Luzon is one of the most active and dangerous volcanoes of the Philippines. A recent eruption occurred on 12 January 2020(Fig. 1a), and this volcano is still active with the occurrence of volcanic earthquakes. The eruption has become a deep concern worldwide, not only for its damage on local society, but also for potential hazardous consequences on the Earth's climate and environment. 相似文献
13.
The moving-window correlation analysis was applied to investigate the relationship between autumn Indian Ocean Dipole (IOD) events and the synchronous autumn precipitation in Huaxi region, based on the daily precipitation, sea surface temperature (SST) and atmospheric circulation data from 1960 to 2012. The correlation curves of IOD and the early modulation of Huaxi region’s autumn precipitation indicated a mutational site appeared in the 1970s. During 1960 to 1979, when the IOD was in positive phase in autumn, the circulations changed from a “W” shape to an ”M” shape at 500 hPa in Asia middle-high latitude region. Cold flux got into the Sichuan province with Northwest flow, the positive anomaly of the water vapor flux transported from Western Pacific to Huaxi region strengthened, caused precipitation increase in east Huaxi region. During 1980 to 1999, when the IOD in autumn was positive phase, the atmospheric circulation presented a “W” shape at 500 hPa, the positive anomaly of the water vapor flux transported from Bay of Bengal to Huaxi region strengthened, caused precipitation ascend in west Huaxi region. In summary, the Indian Ocean changed from cold phase to warm phase since the 1970s, caused the instability of the inter-annual relationship between the IOD and the autumn rainfall in Huaxi region. 相似文献
14.
Storms that occur at the Bay of Bengal (BoB) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the BoB are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the BoB storm activity, and the “bimodal period” of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the “bimodal pattern” storm activity in the BoB. The analysis on sea surface temperature (SST) shows that the SSTs of all the year around in the BoB area meet the conditions required for the generation of tropical cyclones (TCs). However, the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a “two-peak” storm activity pattern. The genesis potential index (GPI) quantifies and reflects the environmental conditions for the generation of the BoB storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms. 相似文献
15.
Observed daily precipitation data from the National Meteorological Observatory in Hainan province and daily data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis-2 dataset from 1981 to 2014 are used to analyze the relationship between Hainan extreme heavy rainfall processes in autumn (referred to as EHRPs) and 10–30 d low-frequency circulation. Based on the key low-frequency signals and the NCEP Climate Forecast System Version 2 (CFSv2) model forecasting products, a dynamical-statistical method is established for the extended-range forecast of EHRPs. The results suggest that EHRPs have a close relationship with the 10–30 d low-frequency oscillation of 850 hPa zonal wind over Hainan Island and to its north, and that they basically occur during the trough phase of the low-frequency oscillation of zonal wind. The latitudinal propagation of the low-frequency wave train in the middle-high latitudes and the meridional propagation of the low-frequency wave train along the coast of East Asia contribute to the ‘north high (cold), south low (warm)’ pattern near Hainan Island, which results in the zonal wind over Hainan Island and to its north reaching its trough, consequently leading to EHRPs. Considering the link between low-frequency circulation and EHRPs, a low-frequency wave train index (LWTI) is defined and adopted to forecast EHRPs by using NCEP CFSv2 forecasting products. EHRPs are predicted to occur during peak phases of LWTI with value larger than 1 for three or more consecutive forecast days. Hindcast experiments for EHRPs in 2015–2016 indicate that EHRPs can be predicted 8–24 d in advance, with an average period of validity of 16.7 d. 相似文献
16.
Based on the measurements obtained at 64 national meteorological stations in the Beijing–Tianjin–Hebei (BTH) region between 1970 and 2013, the potential evapotranspiration (ET0) in this region was estimated using the Penman–Monteith equation and its sensitivity to maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Vw), net radiation (Rn) and water vapor pressure (Pwv) was analyzed, respectively. The results are shown as follows. (1) The climatic elements in the BTH region underwent significant changes in the study period. Vw and Rn decreased significantly, whereas Tmin, Tmax and Pwv increased considerably. (2) In the BTH region, ET0 also exhibited a significant decreasing trend, and the sensitivity of ET0 to the climatic elements exhibited seasonal characteristics. Of all the climatic elements, ET0 was most sensitive to Pwv in the fall and winter and Rn in the spring and summer. On the annual scale, ET0 was most sensitive to Pwv, followed by Rn, Vw, Tmax and Tmin. In addition, the sensitivity coefficient of ET0 with respect to Pwv had a negative value for all the areas, indicating that increases in Pwv can prevent ET0 from increasing. (3) The sensitivity of ET0 to Tmin and Tmax was significantly lower than its sensitivity to other climatic elements. However, increases in temperature can lead to changes in Pwv and Rn. The temperature should be considered the key intrinsic climatic element that has caused the "evaporation paradox" phenomenon in the BTH region. 相似文献
17.
Yuepeng PAN Mengna GU Yuexin HE Dianming WU Chunyan LIU Linlin SONG Shili TIAN Xuemei Lü Yang SUN Tao SONG Wendell W. WALTERS Xuejun LIU Nicholas A. MARTIN Qianqian ZHANG Yunting FANG Valerio FERRACCI Yuesi WANG 《大气科学进展》2020,37(9):933-938
正While China’s Air Pollution Prevention and Control Action Plan on particulate matter since 2013 has reduced sulfate significantly, aerosol ammonium nitrate remains high in East China. As the high nitrate abundances are strongly linked with ammonia, reducing ammonia emissions is becoming increasingly important to improve the air quality of China. Although satellite data provide evidence of substantial increases in atmospheric ammonia concentrations over major agricultural regions, long-term surface observation of ammonia concentrations are sparse. In addition, there is still no consensus on 相似文献
18.
基于最新的GTAP8 (Global Trade Analysis Project）数据库,使用投入产出法,分析了2004年到2007年全球贸易变化下南北集团贸易隐含碳变化及对全球碳排放的影响。结果显示,随着发展中国家进出口规模扩张,全球贸易隐含碳流向的重心逐渐向发展中国家转移。2004年到2007年,发达国家高端设备制造业和服务业出口以及发展中国家资源、能源密集型行业及中低端制造业出口的趋势加强,该过程的生产转移导致全球碳排放增长4.15亿t,占研究时段全球贸易隐含碳增量的63%。未来发展中国家的出口隐含碳比重还将进一步提高。贸易变化带来的南北集团隐含碳流动变化对全球应对气候变化行动的影响日益突出,发达国家对此负有重要责任。 相似文献
19.
Using the International Comprehensive Ocean-Atmosphere Data Set(ICOADS) and ERA-Interim data, spatial distributions of air-sea temperature difference(ASTD) in the South China Sea(SCS) for the past 35 years are compared,and variations of spatial and temporal distributions of ASTD in this region are addressed using empirical orthogonal function decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect actual distribution characteristics of ASTD in the SCS, but values of ASTD from the ERA-Interim data are smaller than those of the ICOADS data in the same region. In addition, the ASTD characteristics from the ERA-Interim data are not obvious inshore. A seesaw-type, north-south distribution of ASTD is dominant in the SCS; i.e., a positive peak in the south is associated with a negative peak in the north in November, and a negative peak in the south is accompanied by a positive peak in the north during April and May. Interannual ASTD variations in summer or autumn are decreasing. There is a seesaw-type distribution of ASTD between Beibu Bay and most of the SCS in summer, and the center of large values is in the Nansha Islands area in autumn. The ASTD in the SCS has a strong quasi-3a oscillation period in all seasons, and a quasi-11 a period in winter and spring. The ASTD is positively correlated with the Nio3.4 index in summer and autumn but negatively correlated in spring and winter. 相似文献
20.
Hourly outgoing longwave radiation(OLR) from the geostationary satellite Communication Oceanography Meteorological Satellite(COMS) has been retrieved since June 2010. The COMS OLR retrieval algorithms are based on regression analyses of radiative transfer simulations for spectral functions of COMS infrared channels. This study documents the accuracies of OLRs for future climate applications by making an intercomparison of four OLRs from one single-channel algorithm(OLR12.0using the 12.0 μm channel) and three multiple-channel algorithms(OLR10.8+12.0using the 10.8 and 12.0 μm channels; OLR6.7+10.8using the 6.7 and 10.8 μm channels; and OLR All using the 6.7, 10.8, and 12.0 μm channels). The COMS OLRs from these algorithms were validated with direct measurements of OLR from a broadband radiometer of the Clouds and Earth's Radiant Energy System(CERES) over the full COMS field of view [roughly(50°S–50°N, 70°–170°E)] during April 2011.Validation results show that the root-mean-square errors of COMS OLRs are 5–7 W m-2, which indicates good agreement with CERES OLR over the vast domain. OLR6.7+10.8and OLR All have much smaller errors(～ 6 W m-2) than OLR12.0and OLR10.8+12.0(～ 8 W m-2). Moreover, the small errors of OLR6.7+10.8and OLR All are systematic and can be readily reduced through additional mean bias correction and/or radiance calibration. These results indicate a noteworthy role of the6.7 μm water vapor absorption channel in improving the accuracy of the OLRs. The dependence of the accuracy of COMS OLRs on various surface, atmospheric, and observational conditions is also discussed. 相似文献