亚洲季风与ENSO循环的相互作用

ＥＮＳＯ事件对亚洲季风有很大影响,特别是对东亚夏季风环流有较大影响。许多观测事实表明,在ＥＮＳＯ事件处于发展阶段的夏季,江淮流域往往发生洪涝,黄河流域往往发生干旱,东北地区往往发生冷夏。本研究利用观测资料分析了亚洲季风对ＥＮＳＯ事件发生的影响。分析结果表明,在ＥＮＳＯ事件发生前,在热带太平洋上空对流层下层有明显的西风异常;这个西风异常将会加强东传暖Ｋｅｌｖｉｎ波和西传冷Ｒｏｓｓｂｙ波,为ＥＮＳＯ循环提供必要的赤道海洋波动条件;并且这个西风异常与东亚季风区西风异常向南传播有密切关系。通过遥相关分析表明,东亚季风西风异常的南传是通过欧亚型遥相关的波列来实现。通过分析,本研究提出一种亚洲季风与ＥＮＳＯ循环相互作用的物理图像。     

副高与阻高形成的Rossby孤立波理论Ⅱ:存在临界层

研究了存在临界层的非均匀纬向流中的Ｒｐｓｓｂｙ孤立波。在求出振幅函数满足的ＫｄＶ方程或修正ＫｄＶ方程（ＭＫｄＶ）后，选择Ｃｈｅｂｙｓｈｅｖ多项式作为展开基函数，用假谱方法，求解本征值和本征函数。对理想风场的计算表明，在临界层存在与否两种情况下，都能得到在东西风界面处的反气旋式副高型Ｒｏｓｓｂｙ孤立波，同副高有一致的演变规律：当东风带相对强于西风时，向西移动；当西风相对强于东风时，则向东移动。在西风带，则得到阻高型Ｒｏｓｓｂｙ孤立波，与阻高也有同样的演变规律。另外，我们还用连续谱方法计算了临界层附近的连续谱及离散谱，也得到与假谱方法较一致的结论。     

混合层厚度,风速和稳定度对地面SO2浓度分布影响的数值试验

利用Ｅｕｌｅｒ平流扩散方程和Ｋ模式闭合方案的数值解，讨论了混合层厚度、风速和稳定度３因子对银川市冬季地面ＳＯ＿２浓度分布的影响。结果表明，在极不稳定层结（Ａ级）下混合层厚度增加２５０ｍ时能使地面ＳＯ＿２浓度减少４０％～７５％，而在稳定层结下混合层厚度增加２００ｍ时仅减少２０％的浓度；而当混合层厚度和风速分别增加２５０ｍ和３．８ｍ·ｓ￣（－１）、层结由稳定（Ｆ）变为极端不稳定（Ａ），并且当混合层最大厚度和最大风速分别限制在６５０ｍ和４ｍ·ｓ￣（－１）时，老城西部地面浓度减少了９０％，稀释效应最显著。     

中层大气行星波在臭氧的季节和年际变化中输运作用的数值研究──Ⅰ．常定流的情况

本文构造了一个３４层球坐标原始方程波－流相互耦合谱模式，利用此模式从拉格朗日平均环流的观点研究了在常定流下行星波对臭氧的输运作用。研究结果表明，行星波对臭氧的输运有明显的季节变化，在北半球冬季，由于行星波上传到平流层而大大增强了中高纬地区向极地向下的Ｏ３输运；并且还表明，热带纬向风的ＱＢＯ不仅通过影响东、西风切变而引起热带Ｏ３分布的年际变化，而且通过影响行星波的传播引起了行星波对Ｏ３输运的年际变化，这表现为当热带纬向风处于东风位相时，中高纬地区行星波对Ｏ３的输运比西风位相时强。     

中国东部地区SO2, SO4=和HNO3(g)干沉降速度的季节变化

使用中国东部及其邻近地区各主要台站１９９２年全年００点和１２点（ＧＭＴ）地面及探空资料，由中尺度气象预报模式ＭＭ４产生中国东部地区地面以上大约４０ｍ高度（最低模式层）处二维温度、湿度和风场，使用污染物干沉降模块及该地区下垫面类型资料，计算出了该地区ＳＯ２，ＳＯ＝４和ＨＮＯ３（ｇ）全年干沉降速度的区域分布和季节变化。结果表明，由于受气象条件和下垫面类型的综合影响，３种污染物的干沉降速度有明显的变化。对ＳＯ２，全年区域平均极小值为０．０８８ｃｍ／ｓ，极大值为１．２７５ｃｍ／ｓ，平均值为０．４３０ｃｍ／ｓ；对ＳＯ＝４，分别为０．０１４ｃｍ／ｓ，０．２８７ｃｍ／ｓ和０．１１８ｃｍ／ｓ；对ＨＮＯ３（ｇ），分别为０．０６０ｃｍ／ｓ，５．２５０ｃｍ／ｓ和１．１２３ｃｍ／ｓ。ＳＯ２干沉降速度极大值分布在巴丹吉林沙漠和腾格里沙漠一带，对ＳＯ＝４和ＨＮＯ３（ｇ），除在上述沙漠地带有一极大值区域外，在靠近四川的云贵高原尚有另一极大区。对１９９２年全年来说，ＳＯ２和ＨＮＯ３（ｇ）干沉降速度极大值均出现在七月份，分别为０．５５２ｃｍ／ｓ和１．５１８ｃｍ／ｓ；而对ＳＯ＝４，干沉降速度极大值出现在九月份，其值为０．０９６ｃｍ／ｓ。这些值     

局地相似性在近地面层大气中的一个应用

利用Ｕ．Ｈｏｇｓｔｒｏｍ教授提供的瑞典Ｕｐｐｓａｌａ大学气象系于１９８６年夏季在Ｕｐｐｓａｌａ市郊农田中观察到的近地面层大气资料，对近地面层大气的局地相似性进行了论证，并给出了一套相似性函数的经验常数。结果表明，局地相似性比Ｍｏｎｉｎ－Ｏｂｕｋｈｏｖ相似性更适合于描述复杂下垫面近地面层大气。     

北半球冬季副热带西风急流及有关环流委内振荡若干特征分析

利用１９８１￣１９８５年４个冬季的ＥＣＭＷＦ逐日网格点资料（其中包括一个ＥＮＳＯ年）,采用了最大熵谱计算、方差百分比计算和Ｂｕｔｔｅｒ Ｗｅｒｔｈ带通滤波等方法,分析了北半球冬季绕全球副热带西风急流和有关环流３０￣６０ｄ低频振荡的分布特征及其年际差异。结果表明：三支副热带西风急流核心具有很强的季内稳定性;３０￣６０ｄ振荡的显著区正常年主要分布在急流出口区南、北侧,ＥＮＳＯ年主要出现在急流入口区和出     

59—701微机数据处理系统在高空气象探测中的偏差

59 70 1微机数据系统 (以下简称系统 )已于2 0 0 0年 1月 1日开始正式在全国各高空气象台站投入业务使用。该系统的使用不仅让值班人员从繁多的数据处理中解脱了出来 ,使其劳动强度大为降低 ,而且降低了错情发生率。但该系统在宜昌高空探测站的使用过程中 ,笔者经对有关记录进行比较后发现 ,有许多数据处理与《高空气象探测规范》(以下简称《规范》)不符 ,并对其做了归纳整理。1　指示码Ｉｄ的编报错误在实际探空观测中 ,误将探空任一终止层当作规定层求取风速时就会导致指示码Ｉｄ的编报错误。这种情况出现在测风记录最后一量得风层时间高…     

TOGA-COARE IOP时期大尺度流场的分析

根据ＴＯＧＡ－ＣＯＡＲＥＩＯＰ时期（１９９２年１１月—１９９３年２月）包含加密观测的四维同化的高空格点资料,分析了这一时期热带太平洋风场的大尺度特征,发现５００ｈＰａ以下,在中东太平洋频繁出现大范围稳定的强西风,高层出现明显的东风;低层强西风高频出现区或爆发区逐月向东传播,在观测结束时,西风到达了中东太平洋地区;相应的正常冬季东亚－西太平洋局地哈得莱环流被破坏,热带太平洋的沃克（Ｗａｌｋｅｒ）环流明显地向东太平洋地区移动。所有这些环流的异常特征表明,ＴＯＧＡ－ＣＯＡＲＥＩＯＰ时期正处于一次ＥｌＮｉｎｏ事件的发展时期。     

世界银行和WMO合作预报和预防自然灾害

世界银行和ＷＭＯ签订了一份谅解备忘录（ＭＯＶ），同意在共同感兴趣的领域中，特别是在预防和减轻自然灾害、气候变化和ＥｌＮｉｎｏ等自然现象研究方面加强合作。这份备忘录由世界银行主管环境和社会可持续发展的副行长ＩａｎＪｏｎｈｓｏｎ和ＷＭＯ秘书长Ｇ．Ｏ．Ｐ．Ｏｂａｓｉ教授于８月份签订，旨在改进两单位间的战略合作。Ｏｂａｓｉ说：“这份备忘录的签订，将对世界银行和ＷＭＯ之间相关计划的协调作出进一步的贡献，从而帮助各国提高将先进的科学技术应用于各国可持续发展计划的能力。ＷＭＯ专家和各国水文气象局全球通信网将在…     

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.     

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     

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.     

Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings

正ERRATUM to: Atmospheric and Oceanic Science Letters, 4(2011), 124-130 On page 126 of the printed edition (Issue 2, Volume 4), Fig. 2 was a wrong figure because the contact author made mistake giving the wrong one. The corrected edition has been updated on our website. The editorial office is sincerely sorry for any     

Index to Vol.31

正AN Junling;see LI Ying et al.;(5),1221—1232AN Junling;see QU Yu et al.;(4),787-800AN Junling;see WANG Feng et al.;(6),1331-1342Ania POLOMSKA-HARLICK;see Jieshun ZHU et al.;(4),743-754Baek-Min KIM;see Seong-Joong KIM et al.;(4),863-878BAI Tao;see LI Gang et al.;(1),66-84BAO Qing;see YANG Jing et al.;(5),1147—1156BEI Naifang;