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1.
利用中央气象台奥运火炬传递珠峰气象保障队获取的第一手资料,对2007年4月12日-5月8日珠穆朗玛峰(简称珠峰)大本营地面自动站和79次探空实测资料进行分析,揭示了珠峰地区气象要素变化的观测事实。结果表明:受珠峰北坡绒布冰川沉降风影响,珠峰大本营盛行南风;风速和气温日变化呈单峰分布,风速极小值和日最低气温出现在08:00(北京时,下同),而极大值出现在15:00前后;相对湿度峰值出现在07:00和23:00,正午前后相对湿度最小。6200 m高度以下几乎昼夜恒吹下山风,偏南风在22:00至次日00:00最强;7200-9000 m高度风向主要以偏西风为主,风速随高度也明显增加。5200-8000 m各高度上,日最低气温始终出现在08:00,最高气温出现在16:00,8200 m以上气温呈现出多波动起伏。在6700-9700 m高度能维持相对湿度的高值中心,大值区主要位于6500-8800 m高度。高空西风锋区位于12000-15000 m,对流层顶高度大约在18200 m左右。 相似文献
2.
塔克拉玛干沙漠北缘近地层气象要素变化特征 总被引：2，自引：0，他引：2
利用塔克拉玛干沙漠北缘哈德自动气象站2011年1~12月近地面层气象要素梯度观测资料,分析了该地区近地层风速、气温和相对湿度的日变化规律及四季廓线特征,并计算了哈德观测点大气稳定度和中性条件下的地表粗糙度。结果表明,哈德地区近地层0.5~10 m高度范围内气温、相对湿度和风速都呈现出明显的日变化特征。其中,风速为白天高、夜晚低,中午15:00各层风速均达到最大,凌晨04:00降至最低,其日变化幅度为1.1~1.7 m/s;14:00~15:00各层气温均为最大值,最低气温出现在05:00~06:00,昼夜温差大,最大温差为0.5 m处的16.5℃,下午17:00至次日09:00有逆温存在;相对湿度日变化在25%~55%之间,其变化规律与风速、气温的相反,凌晨06:00最大,下午15:00最低。哈德地区四季近地层风、温、湿廓线变化规律明显,14:00四季风速都呈指数形式增长,其中0.5~2 m间低层风速变化明显大于2~10 m间高层的变化;春、夏季气温主要以指数形式增长,冬季以线性增长为主,四季都有逆温存在;冬季的相对湿度明显大于其它季节。另外,哈德地区全年以东北风为主,2 m与10 m高度的主导风向一致,风频稍有差别。中性层结大气条件下的空气动力学粗糙度范围为1.42×10-11~1.7×10-3m,平均值为4.2×10-5m。 相似文献
3.
利用2006年5～6月和2007年5～6月中国科学院HEST大气科学实验在珠峰绒布寺河谷野外观测期间获得的观测资料,分析了珠峰地区河谷近地层风向、风速、温度、湿度和CO2的日变化特征,讨论了珠峰北坡冰川风和山谷风的特点以及高原地表辐射、地表反照率和近地层湍流通量的变化特征.结果表明:在复杂地形和特殊下垫面影响下,珠峰绒布河谷地区近地面层各个气象要素和湍流通量日变化特征显著,并且明显存在冰川风和山谷风复合的局地环流,冰川风对该地区地气间物质能量交换起着重要作用. 相似文献
4.
大理苍山—洱海局地环流的数值模拟 总被引：4，自引：2，他引：2
利用耦合了湖泊模型的WRF_CLM模式模拟了秋季大理苍山—洱海地区的局地环流特征。结果表明:模式对近地面温度、风向、风速的模拟与观测基本一致,模拟结果能较好地再现该地区山谷风和湖陆风相互作用的局地环流特征。在秋季,大理苍山的谷风起止时间为08:00~17:00(北京时,下同),湖风起止时间为09:00~19:00。局地环流受高山地形及洱海湖面影响明显,山谷风形成早于湖陆风1 h,夜间山风、陆风强盛于白天谷风、湖风。白天苍山谷风与洱海湖风的叠加作用会驱动谷风到达2600 m的高度,而傍晚最先形成的苍山山风则会减弱洱海的湖风环流。夜间盆地南部在两侧山风、陆风的共同作用下,形成稳定而持续的气旋式环流。日出以后,对流边界层迅速发展,边界层高度逐渐增高。陆地17:00温度达到最高,边界层高度也达到峰值2000 m,之后逐渐降低。日落后形成稳定边界层,边界层高度在夜间基本保持在100 m。相对于陆地,湖面白天边界层高度低300 m,夜间边界层高度高100 m。 相似文献
5.
利用架设在珠峰北坡4475m高度处的一套开路涡动协方差测量系统,对曲宗地区的大气状况进行了连续观测.分析了近地层气象要素、辐射平衡各分量和能量平衡各分量在高原雨季前(5月),雨季中(7月)和雨季后(11月)的变化特征.通过分析,发现曲宗地区气温和相对湿度日平均变化均呈单峰单谷型特征,气压则呈双峰双谷型特征,风速日变化为单峰型特征,风速一般在午后突然增大.伴随着雨季的爆发,曲宗地区气温升高,相对湿度增大,气压升高,风速减小.主导风向由东北风转换成西南风.雨季前后,辐射平衡各分量及能量平衡各分量均具有明显的变化趋势. 相似文献
6.
珠峰地区大气边界层结构及近地层能量交换分析 总被引：31，自引：20，他引：11
利用2005年中国科学院珠穆朗玛峰地区科学考察期间的无线电高空探测资料和超声风温仪观测资料,分析了珠穆朗玛峰地区边界层高度、风速、风向和比湿的日变化以及两个海拔高度不同的观测站(珠峰站和曲宗站)的近地层能量交换特征,得到珠穆朗玛峰地区5月份边界层高度日变化比较明显,因冰川风的存在影响了大气边界层,边界层高度最高为3888 m;白天珠穆朗玛峰地区低层都存在逆湿现象。因珠峰站和曲宗站海拔高度、下垫面状况不同,能量交换特征也不同:4~5月份白天珠峰站感热大于潜热,而曲宗站潜热大于感热;珠峰站土壤热通量转为正、负值的时间早于曲宗站。 相似文献
7.
利用温江观测站边界层塔和探空获取的观测资料,从地表物理量的日变化、边界层的垂直结构及逐日变化这些方面分析该站夏季边界层特征,得到以下结论:(1)地表各物理量都具有明显的日变化特征,呈现一峰一谷的演变状态,其中地表热通量、动量通量、气温以及风速的峰值皆出现在午后,谷值出现在凌晨,湿度与气温日变化是反位相的。(2)近地层低层大气气温在早晚时段,随高度的增加而上升,呈逆温状态;午间时段随高度的增加而下降。9 m以下大气在午后的比湿梯度最大。风速值随着高度的增高而增大,风切变随着高度的增高而减小。(3)探空观测的边界层垂直结构显示:夏季温江站早晚边界层大气层结稳定,而午后表现为典型的混合边界层特征。大气温/湿度差异随高度增长而降低,各个时次温/湿度的差异都主要集中边界层低层,越靠近地面大气温/湿度差异越突出。8:00的温度最低,14:00最高。14:00的大气比湿最小,2:00和20:00较大。近地层风速随高度增长较快,在离地2~300 m左右高度达到一个极值,4个时次的风速差异不大。(4)地表温度、短波辐射、感热通量对边界层的高度和降水都有一定的影响。 相似文献
8.
根据2016—2017年大理机场航空器报告的风切变事件,利用同时段的自动气象观测资料、风廓线雷达资料对大理机场风切变进行了统计和分析。结果表明:①风切变均发生在每年的11月至次年4月,1月、2月最多;主要发生于07:00—13:00,一半出现在晴天;发生在350m以下占83%。②100m以下的风切变,地面均有阵性风,最大最小风速差6m/s;发生在15～91m的6次风切变,5次报告风切变的一端风向变化超过180°,南北两端地面风出现对头风,风速差异明显。AWOS(Automated Weather Observation System)捕捉到风向风速的明显变化可为近地层风切变预警提供参考。③发生在高度较高的风切变,雷达资料在遭遇风切变高度的上下层存在≥8m/s风速差,能确定上下层风不连续的准确高度、开始时间和结束时间。④机场区域常出现地面风速大而上空风速小或地面风速小而上空风速大的情况,结合地面风和风廓线雷达资料可为今后低高度风切变的初步预警提供参考。 相似文献
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10.
《干旱气象》2020,(1)
利用塔克拉玛干沙漠大气环境综合观测试验站——塔中站2014年30 min步长实测数据,系统分析塔克拉玛干沙漠腹地地表辐射和能量平衡特征及小气候特征。结果表明:塔中地区辐射平衡和能量平衡各分量均表现为春、夏季较大,秋、冬季较小,并具有明显的日变化特征,峰值出现在12:00(地方时,下同)左右。该地区地表能量通量(净辐射通量、感热通量、潜热通量和土壤热通量)中,净辐射、感热通量和土壤热通量均在08:00开始上升,至14:00左右达到峰值,而潜热通量变化很小。感热通量为能量的主要消耗形式,春、夏、秋、冬四季分别占净辐射的百分比为44. 6%、68. 1%、55. 2%和55. 3%,其次为土壤热通量,仅有很少能量用于水的相变。云和沙尘对能量通量各分量有明显削弱作用。近地层空气温度白天随高度的增加降低,夜晚则随高度的增加升高,空气相对湿度也呈明显变化规律。近地层水平风速随高度增加明显增大,风向以东北风为主。 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