滦河流域1965-2008年气候变化特征及对水资源的影响

利用统计分析方法,对滦河流域（承德境内段）近44 a（1965—2008年）气温、降水量和径流深度资料进行分析,研究滦河流域气候变化及其对水资源的影响。结果显示：滦河流域近44 a来气温总的趋势是上升的;而降水量的总趋势是减少的,1999—2008年是气温上升和降水减少最显著的时段;滦河流域年径流深与年降水量变化趋势相...     

兰江流域近43年气候变化及对水资源的影响

利用累积距平法对兰江流域近43年（1961-2003年）气温、降水量和径流量资料进行分析，研究兰江流域气候变化及其气候变化对水资源的影响。结果显示：兰江流域近43年来气温、降水量总的趋势是上升的；1990年代是兰江流域气温上升和降水增加最显著的时段，主要表现在冬春气温明显上升，夏季降水量明显增加：兰江流域年径流深与年降水量基本保持同步变化。兰江流域过去43年的气候变化对流域内水资源产生了较大的影响，而且由于兰江流域内水资源空间分布差异较大，致使流域内人均水资源占有量较少的金华地区易受气候变化影响而出现供水紧张。     

基于SWAT模型的洪湖流域供水资源模拟研究

利用SWAT分布式水文模型,对洪湖流域1961—2011年供水资源变化情况进行模拟。结果表明:SWAT模型对洪湖流域供水资源模拟适用性良好。近51 a流域年平均地表径流和降水量增加趋势相当,且降水量峰值对应地表径流和地下径流均较高。流域在1960s、1970s相对偏枯,1980s后降水相对丰沛,流域呈现由干转湿的变化。进入21世纪后,流域又趋于偏枯。流域季节降水量、地表径流、地下径流、蒸散发量及土壤含水量变化最大值均出现在夏季,最小值均出现在冬季,但丰、枯年季节分配不同,各要素月季节分布差异较大。洪湖年均入湖水量呈略增加趋势,春、夏季增加趋势较为明显。     

气候变化和人类活动对永定河流域径流变化影响定量研究

以永定河流域为研究对象,在对永定河流域1957-2010年降水、实际蒸发和气温实测资料进行趋势分析的基础上,建立SWAT模型,验证了还原径流的必要性,对气候变化和人类活动对永定河流域径流的影响进行了定量研究。结果表明：20世纪60、70年代为永定河流域的丰水期,80年代至今为枯水期。永定河流域80年代后的实测径流资料受气候变化和人类活动影响显著,需进行径流还原后才能保证径流资料的一致性。气候变化是80年代后期径流减少的主要原因,其贡献量约占总减少量的65.4%,人类活动的贡献量占34.6%,也是不容忽视的因素。     

新疆精河流域河川径流及对气候变化的响应

根据精河流域1957—2012年的气温、降水和径流量等资料,分析了精河流域近55 a来径流量的变化趋势和周期特征,研究了河川径流及对气候变化的响应关系,并建立基于多变量时间序列自回归CAR(Controlled Auto-regressive)径流预测模型。结果表明:(1)精河径流在年内分配不均,季节变化明显,夏季集中,枯水期长且枯季径流量小。6—9月为径流连续最大4个月,占全年径流量的74%。(2)从20世纪80年代开始,河川径流量增加,持续至90年代,在21世纪有减小的趋势,1981—2005年平均年径流总量比1957—1980年增加了3.24%。(3)精河流域年径流量序列在21 a和13 a左右的振荡周期最为明显,其次是32 a和9 a,而其中的21 a和13 a时间尺度上的振荡是全时域的。(4)建立了径流与降水和气温的CAR模型,发现拟合平均相对误差为6.54%,均方根误差为0.039。用CAR模型模拟河流年径流量误差在可接受范围内,可以利用该模型对精河流域年径流量进行预测。     

气候变化和人类活动对石羊河流域水资影响评价

石羊河流域的年平均气温(最高、最低气温)自1951年以来总体呈上升趋势,增温速率为0.22℃/10a,增幅达1.2℃。1992年是年平均气温显著变暖的年份,与显著变暖前相比,年平均气温上升了0.85℃,低于近51年1.1℃的增幅水平。在近55年中,石羊河流域的年降水总体上在增加,出山口径流量在减少,流域尾闾民勤绿洲的地下水位在快速下降。气温显著变暖后,年降水量增加了约18.2 mm,增幅达5.8%,出山口径流量减少了4.1×108m3,民勤绿洲的地下水位下降了1倍~2倍。水资源变化的成因分析表明,出山口径流量的减少源自径流补充之一的上游山区降水的减少,而红崖山水库入库径流量的持续快速减少则是民勤地下水位快速下降的主要原因之一。受气候变化的影响,石羊河流域出山口径流量峰期有所提前,而人类活动严重地影响了石羊河流域中游地表径流利用量和下游可利用量分配比例。     

西拉木伦河流域降水和径流特征分析

在搜集整理西拉木伦河流域近30a(1981—2010年)降水资料和同期径流数据的基础上,运用统计方法分析了该流域的降水和径流年内和年际变化特征,并对年降水量和径流二者之间的关系进行了初步探讨。结果表明,西拉木伦河流域年内降水分配不均匀,降水主要集中在夏季,近30a年际降水量呈波动减少趋势。受降水影响,西拉木伦河流域径流年际变化同样也较为强烈。以西拉木伦河流域年降水量、径流量建立数学模型为:Q=-4.624+0.029P年(R=0.706)。     

近47a来青海湖流域气候变化分析

选取青海湖流域内及临近7个气象站点,对各站1959～2005年的降水和气温数据采用泰森多边形法进行了计算,并运用Mann-Kendall方法对其变化趋势进行了分析,同时对流域近47 a的气候变化与青海湖水位变化做了相关分析。结果表明:①青海湖流域近47 a来降水存在明显的阶段性变化,20世纪60年代、80年代、90年代降水都呈上升的趋势,70年代为下降趋势;同时年、夏季降水有增加的趋势。②同时期气温存在显著的上升趋势,尤其是冬季增温显著,年变化倾向率达到0.53℃/10 a,1987～2000年与1961～1986年相比,平均气温增加了0.79℃,显著高于全国水平。③青海湖流域近47 a来春、夏、秋、冬陆面蒸发变化倾向率均为正值,夏季陆面蒸发增加趋势显著,年变化倾向率为4.17 mm/10 a。④流域降水量对湖水位的年变化、布哈河径流、沙柳河径流有着显著的影响;在9 a尺度上讲,未来5 a流域秋季降水处于上升阶段,湖水下降会有所减缓或者回升。     

近47 a来青海湖流域气候变化分析

选取青海湖流域内及临近7个气象站点,对各站1959～2005年的降水和气温数据采用泰森多边形法进行了计算,并运用Mann-Kendall方法对其变化趋势进行了分析,同时对流域近47 a的气候变化与青海湖水位变化做了相关分析.结果表明:①青海湖流域近47 a来降水存在明显的阶段性变化,20世纪60年代、80年代、90年代降水都呈上升的趋势,70年代为下降趋势;同时年、夏季降水有增加的趋势.②同时期气温存在显著的上升趋势,尤其是冬季增温显著,年变化倾向率达到0.53℃/10 a,1987～2000年与1961～1986年相比,平均气温增加了0.79 ℃,显著高于全国水平.③青海湖流域近47 a来春、夏、秋、冬陆面蒸发变化倾向率均为正值,夏季陆面蒸发增加趋势显著,年变化倾向率为4.17 mm/10 a.④流域降水量对湖水位的年变化、布哈河径流、沙柳河径流有着显著的影响;在9 a尺度上讲,未来5 a流域秋季降水处于上升阶段,湖水下降会有所减缓或者回升.     

三峡库区降水—径流关系及径流量预报模型研究

利用2000—2007年长江上游各分流域面雨量实测资料、雷达遥测面雨量资料以及各水文站的历史资料,对流域降水量、洪水传播时间、径流数据以及基流值进行了针对性处理;通过单日产流Pa+P—R(降水量加前期影响雨量—径流)分析和场次洪水总量Crr—P(a径流系数—前期影响雨量)分析,结合各分流域拟合效果及检验,研究了三峡库区降水—径流关系,证明采用雷达遥测的降水数据作为降水量输入来预报各分流域未来时段内产流量是最佳选择,由此建立了三峡库区径流量的预报模型。     

CHARACTERISTICS AND TRENDS OF CLIMATIC EXTREMES IN CHINA DURING 1959–2014

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.     

Could the Recent Taal Volcano Eruption Trigger an El Ni?o and Lead to Eurasian Warming?

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.     

VARIABILITY OF INTER-ANNUAL RELATIONSHIP BETWEEN INDIAN OCEAN DIPOLE AND HUAXI REGION’S AUTUMN PRECIPITATION

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.     

ANALYSIS OF “BIMODAL PATTERN” STORM ACTIVITY CHARACTERISTICS OF THE BAY OF BENGAL

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.     

LOW-FREQUENCY CIRCULATION AND EXTENDED-RANGE FORECAST IN CONNECTION WITH AUTUMN EXTREME HEAVY RAINFALL PROCESS IN HAINAN

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.     

AN ATTRIBUTION ANALYSIS OF CHANGES IN POTENTIAL EVAPOTRANSPIRATION IN THE BEIJING–TIANJIN–HEBEI REGION UNDER CLIMATE CHANGE

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.     

Revisiting the Concentration Observations and Source Apportionment of Atmospheric Ammonia

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     

全球贸易隐含碳变化及其影响分析

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。     

COMPARATIVE ANALYSIS OF VARIOUS DATA OF AIR–SEA TEMPERATURE DIFFERENCE AND ITS VARIATION ACROSS SOUTH CHINA SEA IN THE PAST 35 YEARS

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 Nio3.4 index in summer and autumn but negatively correlated in spring and winter.     

Retrieval of outgoing longwave radiation from COMS narrowband infrared imagery

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.