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1.
青藏高原及其附近地区大气周期振荡在OLR资料上的反映 总被引：19，自引：0，他引：19
本文根据最近8年卫星所接收到的地球向外长波辐射(OLR)资料,分析青藏高原及其附近地区的周期振荡特征。结果表明:除了季节变化之外,准8d振荡和30—50d低频振荡是两个很显著的周期活动,前者和高原低涡活动有关,而后者则与夏季进入高原的两条水汽通道相联系。统计说明,高原地区主要受南来系统的影响,特别在夏半年。 本文的结果表明,对于常规资料稀少的高原地区,OLR是一种很有用的资料,与其它资料结合,将有助于揭露天气事实和研究天气过程的演变。 相似文献
2.
《广东气象》2020,(3)
应用功率谱、Morlet小波变换和Butterworth带通滤波处理等方法,对1954—2018年台山站的年降水序列和逐日降水序列数据进行多尺度振荡特征分析。研究表明:台山站年降水量存在11～13、准4、准25年的周期振荡,前汛期降水量存在准13、2～5年的周期振荡,后汛期降水量存在7～8、准20、3～4、准11年的周期振荡。台山站逐日降水振荡基本表现为天气尺度振荡、准单周振荡、准双周振荡、季节内振荡和季节变化振荡等5种尺度,季节内及以下尺度振荡强度相当,季节变化振荡强度较弱。5种时间尺度的标准差,天气尺度最大,季节变化尺度最小,除季节变化振荡外均呈现出周期性循环特征。在汛期雨量偏少年,逐日降水较易呈现出准单周振荡和天气尺度振荡,而汛期雨量偏多年较易呈现出准双周振荡。 相似文献
3.
南半球中高纬大气环流年代际变率的研究 总被引：3，自引：0，他引：3
利用近百年全球海平面气压图和再分析海平面气压等资料,建立了自1871年以来1,4,7和10月份的南极涛动指数（AOI）序列。近百年来1月AOI有明显增强的趋势,7月AOI则有明显减弱的趋势。最近40多年来,1,4和10月AOI都有较强的上升趋势。4个月份的AOI都有20～30a左右的准周期波动,表现出显著的年代际尺度的变化。用1,4,7和10月的平均可以近似反映年平均南极涛动指数的变化。在年代际尺度上,年平均指数在1894～1901年、1910～1935年左右是强的负指数时期。1880～1893年、1936～1945年左右是较强的正指数时期,1980年代以来,强的正指数已经持续了近20a,且1990年代以来还有加强的趋势。模拟结果的功率谱显示气候系统内部产生的低频变化主要体现在年际尺度变率上,年代际尺度变率的谱值则远远低于观测结果,但不排除在个别情况下,通过Hasselmann机制产生AOI年代际变率的可能性。 相似文献
4.
本文利用1979年卫星观测的OLR资料和功率谱、滤波等方法,着重分析了青藏高原地区的中期振荡特征,并将所得结果与1979年青藏高原科学实验结果进行对比。分析结果表明,高原的地形对于OLR场长期平均的空间分布有很大影响;在夏季,OLR的时间变化则与降水过程有密切联系。准8天振荡是高原地区的主要中期过程,它主要反映了高原低涡的活动,这种振荡很可能是高原天气尺度系统与大尺度环流之间的联系者。 相似文献
5.
《广东气象》2016,(4)
利用新会国家站1957—2014年逐日降水数据,通过功率谱分析、Morlet小波变换对新会单站年降水、年内逐日降水进行周期分析,使用Butterworth带通滤波对年内各尺度降水振荡进行滤波分析,并对汛期少雨年景与汛期降水正常年景的降水周期对比分析。分析表明:新会单站降水在多个尺度上表现有明显周期振荡特征,其中年降水在整个分析时段内并不存在稳定周期,以阶段性周期递增演变为主;年内逐日降水周期基本表现为5 d及以下天气尺度振荡、准单周振荡、准双周振荡、季节内振荡和季节振荡等5种尺度。在少雨汛期,逐日降水振荡趋向短周期、高频率,而正常降水汛期则在低频振荡表现更明显。 相似文献
6.
利用NCAR/NCEP-1再分析资料、NOAA的OLR资料以及GPCP降水资料等,通过功率谱分析、超前滞后回归等方法,对夏季南海周边105 °E、125 °E以及150 °E三支越赤道气流进行了多尺度特征分析,重点探讨三支越赤道气流季节内振荡与热带大气环流异常及南海周边降水的联系。结果表明,在季节内时间尺度上,105 °E与125 °E越赤道气流均具有10~20 d以及30~60 d低频振荡显著周期,而150 °E越赤道气流则以10~20 d周期为主。在年际尺度上,105 °E、125 °E、150 °E越赤道气流分别具有2~4年、2~3年、2~6年振荡周期。无论是季内还是年际变化,皆以105 °E与125 °E这两支越赤道气流之间关系较密切。南亚-南海-西太平洋地区对流层低层10~20 d振荡的气旋(对流加强)和反气旋(对流减弱)的环流活动变化,决定着105 °E及125 °E越赤道气流的10~20 d振荡的演变。这两支越赤道气流之30~60 d振荡所伴随的异常变化与热带夏季季节内振荡(BSISO)的演变过程非常相似,而150 °E越赤道气流之30~60 d振荡所伴随的异常低频环流则与南半球热带辐合带关系密切。105 °E及125 °E越赤道气流的季节内振荡及年际异常均与南海周边降水异常密切相关。 相似文献
7.
中国东南部地区4-6月强降水的低频变化特征 总被引：3，自引：2，他引：1
利用全国2 400多台站逐日降水资料,分析了中国东南部地区4—6月10~30 d低频强降水的时空变化特征。结果表明:4—6月10~30 d低频强降水的方差大值区在中国的长江及其以南地区,中心位于江南的中东部,东南部地区4—6月10~30 d低频强降水距平的第一模态反映该区域呈一致变化。功率谱分析表明第一模态时间变化的周期以10~30 d低频分量为主。根据区域强降水及其10~30 d低频强降水、区域强降水正交经验函数(EOF)分析的第一模态时间系数(PC1)及PC1的10~30 d低频分量的年际方差,结合它们两两之间逐年的相关系数,确定了区域强降水10~30 d强振荡典型年份。对典型年降水异常分布的方差分析,表明强振荡年区域总降水量异常主要是由10~30 d强降水的低频变化引起的。 相似文献
8.
本文利用1980～1984年逐日OLR资料,分析其功率谱的年际变化、低频OLR的传播特征和年际变化规律。揭示了30—60天振荡与ENSO的可能联系。 相似文献
9.
长江中下游旱涝急转年多尺度低频振荡特征及其对旱涝急转的影响 总被引：1，自引：0，他引：1
利用国家气候中心提供的753站逐日降水及TRMM 3b42卫星降水资料,NOAA向外长波辐射(OLR)资料及NCEP/NCAR再分析数据集,对长江中下游地区春夏出现的旱涝急转现象进行详细分析,探讨了长江中下游旱涝急转年多尺度低频振荡特征及其对旱涝急转的影响。(1) 2011年作为长江中下游夏季旱涝急转的典型年,转折前后大气环流场存在显著差异,副高短期活动、孟加拉湾低槽及中高纬度槽脊对旱涝急转具有重要影响。(2) 2011年长江中下游夏季降水具有多时间尺度周期特征,10～20 d 及30～60 d 低频分量是夏季降水的重要组成部分,不同低频分量具有不同的作用关键区域,相应的低频系统也有差别。前者在南海-西太平洋地区最活跃,具体表现为低频反气旋的发生发展;后者则主要活跃在阿拉伯海-孟加拉湾地区,低频对流加强是该地区最主要的特征。(3) 副高的短期活动是造成2011年长江中下游旱涝急转的关键,它的西伸和加强在低频场上表现为南海-西太平洋附近10～20 d 低频反气旋的发展加强,后者与孟加拉湾地区30～60 d低频对流的影响相互叠加,在旱涝急转期作用达到最强;孟加拉湾地区30～60 d低频对流旺盛发展,OLR极值转变要早于南海-西太平洋地区副高极值的变化约5 d的时间,可能是影响副高西伸的一个重要因素。 相似文献
10.
该文利用1979～1991年卫星观测的OLR逐候资料，分析青藏高原OLR场的季节变化特征。结果表明:青藏高原OLR场具有显著的季节变化特点，在冬、夏两季高原OLR场表现为“缓变”态，在春、秋两过渡季节表现为“急变”态。同时发现，在春季高原西南部出现持续强的OLR候际正变化区，表明高原加热场在春季的持续加强。各年高原OLR场的季节变化有很大差异，在高原夏季来得早且季节过渡快的年份，相应印度地区的季风雨偏多；在高原夏季来得晚或正常时，印度地区的季风雨偏少或正常。 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