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1.
利用2010年春季民勤加强观测实验的地面辐射资料,分析了民勤沙漠干旱区总紫外辐射的变化特征,并对该地区的紫外辐射进行了估算和模拟。结果表明,紫外辐射和太阳总辐射表现出一致的变化特征,层云对两者的反射能力比卷云强。2010年6月紫外辐射的瞬时最大值为55.92 W·m-2,平均日总量为1.07 MJ·m-2,紫外辐射与太阳辐射比例的平均值为4.7%,其变化范围在3%~9%之间。根据晴空指数(Kt)与最大紫外辐射(UV0)及太阳总辐射(G)建立了民勤地区紫外辐射(UV)的估算方程:UV=2.94+1.22×(Kt×UV0)和UV=0.047G,均能较好地估计该地区的地表紫外辐射。由于受输入参数精度的限制,辐射传输模式SBDART低估了晴空条件下的紫外辐射,低估的总平均值为1.12 W·m-2(约5.6%),变化范围在-2.8~0.2 W·m-2之间。 相似文献
2.
本文利用东疆红柳河黑戈壁下垫面陆气相互作用观测站2017年太阳紫外辐射、总辐射和气象站天气现象观测数据，对东疆黑戈壁不同时间尺度和不同天气背景下的太阳紫外辐射A波段(UVA)和B波段（UVB）的变化特征进行了分析。结果表明：1）紫外辐射UVA和UVB日变化呈正态分布，UVA、UVB最大瞬时辐照度为67.97W·m-2、2.15W·m-2，日均最大曝辐量为2.09MJ·m-2和0.05MJ·m-2，年曝辐量为400.31 MJ·m-2和8.63 MJ·m-2；季节变化呈现夏季高，冬季低、春季高于秋季的特点；年变化呈现倒“U”型，年变化幅度呈夏季大，冬季小的趋势。2）紫外辐射占总辐射的比例呈夏高冬低的特点。不同天气下，其比例变化幅度也不相同，晴天大于雨天。3）太阳紫外辐射的月和年平均量以及紫外辐射年均值占总辐射年均值的比例，东疆黑戈壁地区都明显高于其他地区。 相似文献
3.
利用2009年11月-2010年10月青藏高原玛多自动气象站辐射平衡观测资料,分析了高原两种不同下垫面辐射平衡各分量的季节平均日变化和年变化特征.结果表明,各季节的平均总辐射日变化和年变化在两种下垫面的趋势基本一致,夏季总辐射为非零值的时间在早上要比冬季早2h左右,而在傍晚出现零值的时间要比冬季晚2h左右.夏季总辐射最强、冬季最弱,年变化最小值为0.544 MJ·m-2,出现在1月;最大值为1.001MJ ·m-2,出现在7月.在11:00-16:00(北京时)之间反射辐射冬季最强、夏季最弱.这种现象与总辐射日变化趋势恰好相反,反射辐射的年变化最小值出现在2月,平均最小值为0.157MJ· m-2;最大值出现在11月,平均最大值为0.326 MJ· m-2.1号点和2号点反射辐射差值冬季最大,达到0.06 MJ·m-2;春季最小,为0.03 MJ·m-2.净辐射年变化最小值为-0.025 MJ·m-2,出现在12月;最大值为0.477 MJ·m-2,出现在7月.地表反射率2个观测点的变化趋势大致相同,各季节地表反射率最大值、最小值和平均值都是2号点大于1号点,平均偏大8％. 相似文献
4.
5.
根据1996～1998年由NILUV紫外辐射仪在西藏拉萨地区观测的紫外辐射资料,分析了青藏高原拉萨地区生物有效辐射的分布特征.结果表明,1997年日正午最大生物有效紫外辐射剂量率(UV dose rate)达到500mW m-2,最小值为9.7 mW m-2;晴天时生物有效辐射剂量率的日变化呈规则曲线,且早晚小,中午大;一年中紫外辐射变化的总趋势是由太阳天顶角决定的,紫外辐射的日变化和年变化是其最主要、最基本的变化;西藏拉萨地区的月平均红斑辐射剂量明显高于全球其他同纬度地区. 相似文献
6.
利用1961～2000年赣州站、南昌站的年太阳总辐射与相关气象要素资料,结合Penman公式,运用6种计算净长波辐射的方法估算了两站的年太阳总辐射;建立了估算该地区年太阳总辐射的绝对误差权重法（Method of Absolute Errors,MAE）,并给出了适用于江西省的绝对误差权重系数,以此方法计算了江西省其他76站的年太阳总辐射;并分析了该地区年太阳总辐射的时空分布特征及其变化趋势,发现：（1）1961~2000年间,江西省大部分地区太阳总辐射在3800～4400 MJ·m-2·a-1;南部偏东地区较大,且存在有一大值中心;西部地区为江西省太阳总辐射最小的地区;（2）40年间,江西省年太阳总辐射呈明显下降趋势,每10年减少143.70 MJ·m-2。78站中,有63站的太阳总辐射的下降趋势通过了α=0.05的显著性检验,8站表现为上升趋势;江西省北部及南部地区太阳总辐射下降较大;中部地区下降相对较小,且在鄱阳湖东侧有一低值中心。 相似文献
7.
山东禹城紫外辐射变化特征及其估测方程的建立 总被引：1，自引：0，他引：1
本文对2005～2011年山东禹城地区观测得到的紫外辐射的时间变化特征及紫外辐射与总辐射比值的变化特征进行了分析, 并结合气温、降水和露点温度资料建立了禹城地区的紫外辐射估测方程。结果表明:紫外辐射日累计值的变化范围为0.10～1.20 MJ m-2 d-1, 年平均值为0.468 MJ m-2 d-1;紫外辐射日、季节变化规律与总辐射一致, 季节变化都表现为冬季小夏季大, 最小值出现在1月, 最大值出现在6月, 日变化则呈现早晚小中午大的特征;紫外辐射与总辐射的比值范围为0.023～0.046, 其季节变化特征也是冬季小夏季大, 该比值随晴空指数的增大而减小, 而在晴空指数大于0.5时比较稳定。利用温度日较差(日最高气温与最低气温的差值)建立了紫外辐射估测方程, 决定系数R2达0.80, 平均相对误差为0.19, 估测紫外线等级与实测紫外线等级相差不大于1的数据占95%, 该方法可以较好地进行紫外辐射等级的估测。 相似文献
8.
青藏高原瓦里关地区大气臭氧柱总量及UV—B观测结果的特征分析 总被引：2，自引：0，他引：2
利用Brewer臭氧分光光谱仪对青藏高原东北部瓦里关地区的大气臭氧柱总量及太阳紫外B生物有效辐射剂量进行了连续的观测。通过对1996-1996年的资料分析表明：该地区的臭氧柱总量具有明显的年季变化特征，并存在着减少的趋势，与TOMS卫星的观测结果相一致；臭氧垂直廓线的Umkehr反演得出这一地区的臭氧数密度最大值出现在20-30km处，冬春季的高度低于夏季；太阳紫外B生物有效辐射剂量夏季最高可达0．4W／m^2。 相似文献
9.
上海地区地面太阳紫外辐射的观测和分析 总被引：21，自引：0，他引：21
通过对上海地区2001～2003年地面太阳总辐射和紫外辐射观测资料的分析表明：（1）上海地区太阳辐射和紫外辐射年总量分别为4487．1MJ／m^2和149．6MJ/m^2。（2）紫外辐射的季节变化特征十分明显，夏半年（4-9月）各月极大紫外辐射强度远大于冬半年（10月～次年3月），7月份最强，12月份最弱。（3）不同天气条件下，紫外辐射日变化显示出明显的差异，晴天强且稳定，多云天气波动较大，阴天则次之。（4）紫外辐射占总辐射的比例（η）也显示冬半年低，夏半年高的分布特征。（5）影响上海地区到达地面紫外辐射的主要因子有：太阳高度角的大小大致决定了到达地面紫外辐射的强弱，两者具有相近的年变化趋势；云、雨等天气类型是影响紫外辐射的重要因子；大气能见度对紫外辐射也有比较明显的影响。 相似文献
10.
对2011—2016年部分夏季时段分别在西藏那曲、拉萨、林芝和阿里观测的大气向下长波辐射（L↓）进行分析,结果显示:L↓具有明显的日变化,最大值出现在北京时间15:00前后,而最低值出现在凌晨至10:00,日平均值林芝最高（368 W·m-2）,其次是拉萨（319 W·m-2）、阿里（305 W·m-2）和那曲（299 W·m-2）。晴天L↓ ?ngstr?m（1915）的经验公式最适合林芝,而Konzelmann（1994）的公式则适合那曲、拉萨和阿里;随着人工观测总云量的增加,L↓增强趋势明显,满云（云量7~10成）情形4个站点云增强效应均从20 W·m-2上升至50 W·m-2以上,低云量对L↓的增强效应明显高于总云量。云份额数（CF）上升所对应天顶方向平均云底高度下降,但云增强效应上升。在晴天（CF为-5%~5%、平均云底高度大于4 km）时,云增强效应仅为5 W·m-2左右（林芝接近20 W·m-2）,但当CF为90%以上（云底高度小于3.5 km）时,云增强效应则上升到60 W·m-2（林芝接近50 W·m-2）。固定云底高度,CF与L↓云增强效应呈显著相关（r2为0.91~0.97）,远高于云底高度与L↓云增强效应的相关（r2为0.32~0.58）。 相似文献
11.
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
12.
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
13.
Various features of the atmospheric environment affect the number of migratory insects, besides their initial population. However, little is known about the impact of atmospheric low-frequency oscillation(10 to 90 days) on insect migration. A case study was conducted to ascertain the influence of low-frequency atmospheric oscillation on the immigration of brown planthopper, Nilaparvata lugens(Stl), in Hunan and Jiangxi provinces. The results showed the following:(1) The number of immigrating N. lugens from April to June of 2007 through 2016 mainly exhibited a periodic oscillation of 10 to 20 days.(2) The 10-20 d low-frequency number of immigrating N. lugens was significantly correlated with a low-frequency wind field and a geopotential height field at 850 h Pa.(3) During the peak phase of immigration, southwest or south winds served as a driving force and carried N. lugens populations northward, and when in the back of the trough and the front of the ridge, the downward airflow created a favorable condition for N. lugens to land in the study area. In conclusion, the northward migration of N. lugens was influenced by a low-frequency atmospheric circulation based on the analysis of dynamics. This study was the first research connecting atmospheric low-frequency oscillation to insect migration. 相似文献
14.
The atmospheric and oceanic conditions before the onset of EP El Ni?o and CP El Ni?o in nearly 30 years are compared and analyzed by using 850 hPa wind, 20℃ isotherm depth, sea surface temperature and the Wheeler and Hendon index. The results are as follows: In the western equatorial Pacific, the occurrence of the anomalously strong westerly winds of the EP El Ni?o is earlier than that of the CP El Ni?o. Its intensity is far stronger than that of the CP El Ni?o. Two months before the El Ni?o, the anomaly westerly winds of the EP El Ni?o have extended to the eastern Pacific region, while the westerly wind anomaly of the CP El Ni?o can only extend to the west of the dateline three months before the El Ni?o and later stay there. Unlike the EP El Ni?o, the CP El Ni?o is always associated with easterly wind anomaly in the eastern equatorial Pacific before its onset. The thermocline depth anomaly of the EP El Ni?o can significantly move eastward and deepen. In addition, we also find that the evolution of thermocline is ahead of the development of the sea surface temperature for the EP El Ni?o. The strong MJO activity of the EP El Ni?o in the western and central Pacific is earlier than that of the CP El Ni?o. Measured by the standard deviation of the zonal wind square, the intensity of MJO activity of the EP El Ni?o is significantly greater than that of the CP El Ni?o before the onset of El Ni?o. 相似文献
15.
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
16.
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
17.
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
18.
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
19.
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
20.
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