热带印度洋MJO活动对孟加拉湾西南夏季风季节内振荡的影响

通过对1979—2008年热带太平洋30—60 d振荡(Madden-Julian Oscillation,MJO)指数、美国国家环境预报中心再分析资料和日本气象厅降水资料的分析,发现热带东印度洋MJO强度和传播状况影响孟加拉湾西南夏季风季节内振荡及相关低频环流、对流和降水分布。当热带东印度洋MJO在春末夏初较活跃时,孟加拉湾西南季风季节内振荡活动在4—8月比其不活跃时提前约20 d(约1/2个周期),其对于孟加拉湾西南季风季节内振荡的影响可持续整个季风期,使西南季风的季节内振荡不仅酝酿期和活跃期提前发生,季风期有所延长,季节内振荡也更强。西南季风季节内振荡具有明显的北传和东传特征,北传沿孟加拉湾通道从赤道向副热带推进,而东传则沿10°—20°N从孟加拉湾向东传至南海地区。春末夏初时热带东印度洋MJO的异常状况,正是通过对西南季风季节内振荡东传和北传的影响,进而对孟加拉湾西南季风季节内振荡在季风期的酝酿、维持和活跃产生作用,这种作用同时体现在强度和时间上。孟加拉湾西南夏季风季节内振荡强度与热带东印度洋MJO在4月21日—5月5日的活动呈现显著负相关,当热带东印度洋MJO在春末夏初较活跃时,孟加拉湾西南夏季风季节内振荡的强度较大,在5—8月经历3次季节内振荡波动,低频对流场和环流场在1—3位相(孟加拉湾西南夏季风季节内振荡为正位相)和4—6位相(负位相)时呈反位相特征,这是由MJO低频对流的东传及在孟加拉湾和南海这两个通道上的北传引起的。从印度半岛到菲律宾群岛的降水在1—3位相和4—6位相上分别为正异常和负异常,其中,在第2位相(孟加拉湾西南季风季节内振荡波峰)和第5位相(孟加拉湾西南季风季节内振荡波谷)时分别为降水最大正异常和最大负异常。反之,在热带印度洋MJO在春末夏初不活跃年时,孟加拉湾西南夏季风季节内振荡活动较弱,强度偏弱且振荡也不规律。     

孟加拉湾西南季风与南海热带季风季节内振荡特征的比较

采用美国国家环境预报中心的向外长波辐射和风场资料及日本气象厅的降水资料,用30-60d滤波后的夏季风指数在孟加拉湾和南海的区域平均值分别代表孟加拉湾西南季风和南海热带季风季节内振荡,对两支季风的季节内振荡特征进行比较分析,发现孟加拉湾西南季风的季节内振荡和南海热带季风的季节内振荡在夏季风期间(5-10月)都有约3次半的波动.夏季风期间,在阿拉伯海-西太平洋纬带上,夏季风的季节内振荡有4次从阿拉伯海的东传和3次从西太平洋的西传,其中7月后东传可直达西太平洋.孟加拉湾和南海在夏季风期间都有4次季节内振荡的经向传播,但孟加拉湾在约15°N以南为季节内振荡从热带东印度洋的北传,在约15°N以北则为副热带季风季节内振荡的南传;而在南海则是4次季节内振荡从热带的北传.在以孟加拉湾西南季风季节内振荡和南海热带季风季节内振荡分别划分的6个位相中,都存在1-3位相和4-6位相中低频对流、环流形势相反的特征,这是由热带东印度洋季节内振荡的东传和北传所致.热带印度洋季节内振荡沿西南-东北向经过约14d传到孟加拉湾,激发了孟加拉湾西南季风季节内振荡的东传,经过约6d到达南海,激发了南海热带季风季节内振荡的北传,经过约25d到达华南,形成热带印度洋季节内振荡向华南的经纬向接力传播(45d).孟加拉湾西南季风季节内振荡所影响的降水主要是在20°N以南的热带雨带随低频对流的东移而东移;而南海热带季风季节内振荡所影响的降水除了这种热带雨带随低频对流的东移外,还有在20°N以北的东亚副热带地区存在雨带随南海低频对流的北移而北移.     

2003年东亚季风季节内振荡对我国东部地区降水的影响

将2003年东亚夏季风指数IM进行30~60天带通滤波后,分析结果表明,大气季节内振荡(ISO)的经向传播主要表现为从南海南部地区向北传播,其传播过程中的高值中心分别对应我国南海地区、华南前汛期以及江淮流域梅雨的强降水过程。ISO的传播还表现出纬向与经向相互接力的特征,纬向上源于热带地区孟加拉湾向东传播的ISO和源于副热带西太平洋地区向西传播的ISO 在120 °E附近汇合后,分别补充到由南海南部向北传播的ISO中,使其可以继续加强北传,最北界可延伸到35 °N以北,对我国东部地区大尺度降水过程产生一定的影响。     

西南地区东部夏季典型旱涝年的OLR特征

利用1959—2006年西南地区东部20个测站的逐日降水量资料和1979—2006年全球OLR（Outgoing Longwave Radiation）逐日格点资料, 分析了西南地区东部夏季典型旱涝年OLR的异常特征。结果表明： 按照区域降水指数可确定3个典型干旱年（2006, 1994和1997年）和3个典型洪涝年（1998, 1980和1993年）, 而1998年和2006年分别是1959年以来西南地区东部降水偏多和偏少最明显的年份。西南地区东部典型旱涝年夏季OLR分布有明显的差异, 洪涝（干旱）年, 从青藏高原东部一直到江淮地区OLR值偏低（高）, 同时孟加拉湾南部及赤道东印度洋地区OLR值也偏低（高）, 而菲律宾及其附近地区OLR值偏高（低）。从3个关键区平均的逐日变化来看, 赤道东印度洋地区对流活动典型涝年强于典型旱年, 菲律宾及其附近地区对流活动则是旱年强于涝年, 青藏高原东部至江淮流域地区（包括西南地区东部）极端涝年盛行上升运动。涝年热带地区的ITCZ以向西移动的特征为主, 而旱年热带地区的ITCZ夏季前期则以向东移动的特征为主。典型涝年孟加拉湾南部及赤道东印度洋地区的对流北传的特征较明显, 6月中旬以后大部分时间可以传到30°N以北, 典型旱年孟加拉湾南部及赤道东印度洋地区的对流主要呈现南北振荡、 偶有中断的活动特征, 很少时间能达到30°N。低纬热带地区关键区域OLR 5～9月一般都具有准40天左右的显著低频变化周期, 而准12～15天的准双周变化周期在部分时段也显著。典型涝年夏季OLR 40天左右低频对流经向和纬向传播在西南地区东部区域得到加强, 低频对流偏强, 引起降水偏多, 而典型旱年夏季则相反, OLR 40天左右低频对流经向和纬向传播在该区域得到削弱, 低频对流偏弱, 引起降水偏少。     

亚洲热带气候态夏季风涌传播特征及其对中国降水的影响

基于1979—2020年逐日的NOAA向外长波辐射资料、NCEP/NCAR再分析风场资料,以及全球CMAP再分析降水资料,探讨了气候态亚洲热带夏季风涌的传播过程及与我国夏季相应的降水联系。分析结果表明,主汛期亚洲热带气候态夏季风季节内振荡(CISO)活动是亚洲夏季风活动的主要特征,随时间北传的亚洲热带夏季风CISO称为亚洲热带夏季风涌,主要有南亚夏季风涌和南海夏季风涌。亚洲热带夏季风涌的传播可分为四个阶段。在亚洲热带夏季风涌的发展阶段,印度洋区域低频气旋与对流活跃,孟加拉湾和南海热带区域被低频东风控制,我国大部分地区无降水发生,降水中心位于两广地区。当进入亚洲热带夏季风涌活跃阶段,孟加拉湾和南海热带地区低频气旋和对流活跃,东亚低频“PJ”波列显著,我国降水中心北移到长江以南的附近区域。亚洲热带夏季风涌减弱阶段,孟加拉湾与南海低频气旋消亡,对流减弱,低频西风加强,日本南部附近为低频反气旋控制,我国长江中下游低频南风活跃,降水中心也北移到长江中下游地区,而华南地区已基本无降水,此阶段的大气低频环流场与亚洲热带夏季风涌发展阶段基本相反。进入亚洲热带夏季风涌间歇阶段时,孟加拉湾和南海热带地区低频反气旋活跃,对流不显著,日本南部附近的低频反气旋北移减弱,我国东部基本在低频南风的控制下,降水中心也逐步北移到华北-朝鲜半岛一带,此时的大气低频环流场与亚洲季风涌活跃阶段基本相反。      

亚洲夏季风季节内振荡对云南主汛期降水的影响Ⅱ:云南主汛期季节内振荡活动过程及其对MJO活动的响应

利用NCEP OLR、风场再分析资料和日本APHRO_MA_V1003R1降水资料,针对云南主汛期季节内振荡(ISO)活跃年分析了对应低频对流场、环流场和降水的异常特征,以及热带印度洋大尺度振荡MJO分别激发孟加拉湾西南季风ISO和南海热带季风ISO,从而对云南主汛期ISO和降水产生的影响.在云南主汛期ISO活跃年,低频对流场和环流场在云南ISO波动的1～3位相和4～6位相呈反位相特征,这主要由热带印度洋低频对流东传、北传和副热带西太平洋低频对流西传造成的.热带印度洋的低频对流在发展过程中,一方面沿孟加拉湾西岸向西南-东北方向传播,激发了孟加拉湾西南季风ISO活跃并继续向云南传播;另一方面沿孟加拉湾以南继续东传到南海,激发了南海热带季风ISO活跃并北传到副热带中国东部地区,再沿副热带西传至云南,越过云南后与沿孟加拉湾西岸从东北方向传来的低频对流在孟加拉湾以北地区交汇,完成了一个经纬向接力传播的周期.云南主汛期降水在1～3位相由于副热带低频对流西传和孟加拉湾低频对流东北向传播而处于正距平(第2位相降水最多);在4～6位相,由于副热带低频对流抑制区西传和孟加拉湾低频对流抑制区东北向传播而降水减少(第5位相降水最少),云南主汛期降水与当地低频对流有较好的对应关系.当热带印度洋MJO较强时,4-7月以两条路径向云南的三次传播增强和提前,使得云南主汛期ISO活动也加强,对应产生三次低频对流活跃期,这种MJO由热带印度洋向云南的传播需要30～40天的时间.因此,正是热带印度洋MJO分别对孟加拉湾西南季风ISO和南海热带季风ISO的激发,使得东亚夏季风和南亚夏季风这两个亚洲夏季风系统共同作用于云南主汛期ISO,影响当地降水.     

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

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。      

热带印度洋MJO活动异常对四川盆地降水的影响

利用四川省132个气象观测站降水资料和NOAA的逐日向外长波辐射(OLR)资料,分析了主汛期热带东印度洋MJO活动异常年低频对流传播的显著差异,及其影响四川盆地主汛期降水的物理过程。探讨了热带东印度洋MJO活跃年低频振荡向四川盆地传播的路径和源头,以及孟加拉湾西南季风系统、东亚副热带季风系统的低频振荡分别对四川盆地主汛期低频对流活动的影响。结果表明:热带印度洋的低频对流激发了孟加拉湾西南季风ISO进入活跃期,并在西南气流的引导下继续向四川盆地传播;低频对流先从热带印度洋东传至菲律宾群岛南部的热带洋面,并向东亚副热带地区北传,激发了东亚副热带季风ISO的活跃加强,进而向四川盆地西传。热带印度洋MJO活动异常对四川盆地降水的调制,正是通过两支季风系统(孟加拉湾夏季风和东亚副热带夏季风)的共同作用,影响了四川盆地主汛期异常的对流活动以及降水的多寡。      

2004年南海夏季风活动概述

利用NCEP逐日再分析资料、向外长波辐射（OLR）和卫星降水资料,分析了2004年影响南海夏季风活动的一些特征。结果表明,2004年由于西太平洋副热带高压主体位置比正常偏北、偏西,导致南海夏季风爆发日期比正常偏晚（5月19日）、强度偏大,并主要在南海地区活动。南海季风爆发期间存在明显的季节内振荡,有两个显著振荡周期：一个峰值为20-30天,另一个峰值为40～50天。南海夏季风期间,主要的水汽通量输送集中在南海一西太平洋地区,向北到达华南的水汽输送减少,致使华南地区干旱。     

亚洲夏季风季节内振荡对云南主汛期降水的影响Ⅰ:云南主汛期季节内振荡特征及其传播过程

利用云南省124个气象观测站降水资料和NCEP OLR再分析资料,分析了云南主汛期(6-8月)季节内振荡(ISO)的活动特征及其传播的年际差异,并着重分析了云南主汛期ISO活跃年热带印度洋ISO向云南传播的两条路径和两个亚洲季风系统ISO分别对云南主汛期ISO的影响。云南主汛期平均降水量与区域平均OLR呈显著负相关,用低频(30～60天)OLR表征云南夏季风ISO,其强度具有明显的年际差异。在云南主汛期ISO活跃年,ISO主要来自于两条传播路径:一条是从副热带西太平洋或中国东南部的三次西传,强度较大,分别造成云南主汛期内3次低频对流显著活跃期;另一条是从热带印度洋沿孟加拉湾西岸的西南-东北向传播,到达云南时加剧了云南主汛期的低频对流。在云南主汛期ISO不活跃年,主汛期仅有两次弱的低频对流,主要来自于副热带两次弱的纬向低频OLR传播,第一次是从副热带西太平洋的西传,第二次是从阿拉伯海北部的东传。在云南主汛期ISO活跃年,热带印度洋低频对流一方面沿孟加拉湾西岸向西南-东北方向传播,激发了孟加拉湾西南季风ISO继续向云南传播;另一方面东传到南海以南的热带洋面并向南海北传,激发了南海夏季风ISO北传到副热带中国东部地区,再向云南西传,越过云南后与从东北方向传来的低频对流在孟加拉湾以北地区交汇,完成了一个经纬向接力传播的周期。因此,正是热带印度洋ISO通过两条路径对南海夏季风ISO和孟加拉湾西南季风ISO的激发,使得东亚夏季风和南亚夏季风这两个亚洲季风系统共同作用于云南主汛期ISO。     

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.     

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.     

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.     

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     

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.     

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。     

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正AIMS AND SCOPE Atmospheric and Oceanic Science Letters (AOSL) publishes short research letters on all disciplines of the atmosphere sciences and physical oceanography. Contributions from all over the world are welcome.SUBMISSIONAll submitted