高亚洲及其邻区2003~2017年质量平衡的气候影响分析

利用重力恢复和气候实验(GRACE)数据获得高亚洲及其邻近地区的质量变化,可分析区域气候因素如印度季风、西风带和厄尔尼诺-南方涛动(ENSO)对结果的影响。然而,最近的研究发现,西风带的贡献小于厄尔尼诺,与传统研究结论不同。因此,利用2003-01~2017-06期间GRACE RL06的Mascon数据进行复经验正交函数（CEOF）分析。研究发现,前3个主要成分对研究区质量变化的贡献率分别为53%、27%和6%,与印度季风、西风带和ENSO指数的相关系数分别是0.92±0.16、0.70±0.15和0.42±0.15,说明在长达14 a的观测时间跨度内,印度季风、西风带和ENSO对研究区质量变化的贡献分别为53%、27%和6%,西风带是研究区质量变化的第2个影响因素,这支持了传统的研究结论;ENSO通过印度季风对某些区域（如帕米尔高原、喜马拉雅山脉和印度西北部）的质量变化产生影响;在印度西北部、喜马拉雅山脉和藏东南地区,由于印度季风的减弱及其相关的ENSO作用和西风带的加强,质量变化呈现下降趋势;在兴都库什、西昆仑和东昆仑地区,由于西风带的增强,质量变化呈上升的趋势;在帕米尔和天山地区,虽然受到较强西风带的影响,但由于同时受到印度季风和ENSO减弱以及气温上升趋势的影响,质量变化呈下降的趋势。     

青藏高原500hpa高压的活动与东亚大型天气系统的演变

本文着重分析了青藏高原500hpa高压因伊朗高压脊东伸、分裂产生过程中和东移过程中,西风带波动、印度季风低压以及100hpa层流型的一系列变化,从而说明青藏高原500hpa高压产生和东移的环流背景。     

东亚季风和中国梅雨暴雨研究的评述

1998年夏季长江继54年以后再次发生全流域性洪水,江淮流域暴雨持续发生,暴雨的发生发展维持机理的研究再次引起全国气象工作者的关注和重视。本文主要介绍了中国气象学者在梅雨暴雨方面做过的一些工作,主要包括梅雨的早期研究,东亚季风的进展,持续性暴雨的研究等方面,指出东亚季风与中国梅雨期持续性暴雨之间存在必然联系,从东亚季风异常着手,一定可以在梅雨暴雨的研究上取得进展,并为暴雨的短期预报提供依据     

季风影响下的青藏高原上空甲烷、水汽及云的变化

为进一步了解季风对于水汽及其它大气成分的输送作用,利用美国Aqua卫星上AIRS反演的甲烷（CH4）和MODIS反演的水汽、云高和云量等卫星观测资料,分析了2003至2010年中国青藏高原上空CH4、水汽和云在季风期间的变化及其与季风指数的关系。研究发现：夏季（6月至9月）高原上空水汽、云量和云顶高度的变化与季风指数有很好的相关;在强对流影响下,输送到高原上空的水汽增多,引起云量增多,云顶高度增加,而向上输送的甲烷引起高原上空CH4浓度增加,并在青藏高压强大的反气旋的阻塞下CH4不断积累,在季风期的后半程维持一个高值,但最大值出现在8月底至9月初,比季风指数的峰值晚近一个月。随着季风减退和青藏高压的消失,甲烷的高值快速消失。由此可见,夏季青藏高原的强对流输送无疑是甲烷高值形成的主要动力机制之一。cH4作为一种长寿命的温室气体,有潜力作为一种示踪气体来帮助研究季风和季风期间高原上空强大的反气旋动力机制的变化。     

基于GNSS的中国大陆地区COSMIC-2 PWV精度分析

COSMIC-2可提供连续大气数据源用于改进天气预报,有助于对极端天气进行监测预警。将中国大陆地区按照气候类型划分成5个区域,依托CMONOC站点PWV序列,开展COSMIC-2 PWV在中国大陆地区的精度分析。从站间距离和高程2个角度进行COSMIC-2掩星点与GNSS站点PWV匹配方案设计,分别针对中国大陆地区、不同气候类型和部分代表站点开展COSMIC-2精度评定。研究表明,高原山地、温带大陆、温带季风、亚热带季风和热带季风气候类型的RMSE分别为1.40 mm、1.49 mm、2.68 mm、3.11 mm和3.16 mm;内陆地区精度优于沿海地区。     

基于CMONOC的GNSS水汽短时频域特征研究

利用2016年中国大陆构造环境监测网络的GNSS数据开展水汽短时频域特征研究,按气候类型将中国大陆地区划分为5个区域,并在每个区域中随机抽取若干个站点采用快速傅里叶变换方法进行分析,提取不同季节的GNSS水汽周期特征。结果表明,各类站点的水汽频域特征存在明显的区域性变化和季节性差异;高原山地气候、热带季风气候和亚热带季风气候类型的GNSS站点的周期性变化显著;热带季风地区、亚热带季风地区及沿海地区水汽振幅较大,高原山地和温带大陆地区水汽振幅较小。     

热带东风急流的演变特征及其与亚非降水的关系

为初步了解热带东风急流与亚非降水尤其中国东部、华南地区天气系统之间的关系,利用NCEP/NCAR月平均再分析资料,结合全球综合分析降水集(CMAP)及Ni o3.4海温指数,采用突变检验、小波分析、相关分析、合成分析等方法,对TEJ的结构、演变特征及其与亚非地区降水和大气环流的关系等进行研究。分析表明:TEJ从南海上空向西延伸,经印度到达非洲北部上空,中心位于印度半岛南端、阿拉伯海上空。利用"区域平均"法,定义了热带东风急流指数(TEJI),讨论了该指数62年的年际、年代际变化特征,并分析了TEJI与亚非降水、大气环流及ENSO的关系,结果表明:TEJ呈现强度一致减弱趋势,且突变大致发生在1978年;小波分析表明标准化TEJI存在准10年振荡周期;主要降水带出现在急流入口区右侧和出口区左侧,降水主要位于南亚和东亚季风区内;亚非季风区夏季降水与TEJ响应最敏感的区域是西亚、北非(负相关)、南亚(正相关);海平面气压场和南亚高压与TEJ密切相关,对中国东部和华南地区的旱涝预报起着重要的作用。     

关于五大连池和镜泊湖联合申报世界遗产的建议

2014年6月22至23日,联合国教科文组织在卡塔尔首都多哈举行的第38届世界遗产大会上,中国大运河、中国南方喀斯特二期、中国与哈萨克斯坦、吉尔吉斯斯坦联合申报的丝绸之路获准列入世界遗产名录。联合申报是我国这次申遗的特色。其中大运河分布在我国2个直辖市和6个省;中国南方喀斯特原有重庆武隆、云南石林、贵州荔波3处,这次中国南方喀斯特二期又新增重庆金佛山、贵州施秉、广西桂林以及作为贵州荔波喀斯特遗产地拓展的广西环江。其实过去联合申报成功的还有：中国丹霞世界自然遗产（包括6省6处）,明清皇家陵寝世界文化遗产（包括5省市6处）。这给我们一个启示：联合申报世界遗产是一项通向成功的新趋势。     

蜈蚣藻中空变型Grateloupia filicina f．porracea（Mert·）Howe生殖器官的研究

本种为青岛港及黄渤海沿岸常见种，此外也产于日本及西印度等地。曾呈奎等(1962)曾描述过产于青岛港的本种形态构造。作者自1977年开始在青岛港采到大量本种标本，同时也研究了它的形态构造及其生殖器官的系统发育过程，现报导如下：     

中国猎龙的发现及其意义

中国猎龙的发现 上个世纪９０年代以来，随着大量带毛恐龙和原始鸟类化石的发现，我国辽西地区逐渐成为国际古生物学界最为引人注目的地方。得天独厚的化石宝库加上中国学者的不懈努力使得我国每年都有大量的研究成果涌现，与之相关的科研成果在国内外专业杂志上层出不穷，英国     

贵州局地大气加权平均温度模型的建立与精度分析

基于贵阳、威宁两个无线电探空站2014~2016年的气象数据,采用一元线性回归方法构建贵州整体、局地及季节大气加权平均温度Tm模型,并分析模型的精度。结果表明,贵州整体Tm模型精度高于Bevis模型、全国模型和亚热带季风气候模型;建立贵州局地、季节模型有助于进一步改善Tm的精度;相较于Bevis模型,局地Tm模型反演的PWV精度更高,与实际降水吻合更好。     

A simple method to extract tropical monsoon forests using NDVI based on MODIS data: A case study in South Asia and Peninsula Southeast Asia

Distribution of monsoon forests is important for the research of carbon and water cycles in the tropical regions. In this paper, a simple approach is proposed to map monsoon forests using the Normalized Difference Vegetation Index(NDVI) derived from the Moderate Resolution Imaging Spectroradiometer(MODIS) data. Owing to the high contrast of greenness between wet season and dry season, the monsoon forest can be easily discriminated from other forests by combining the maximum and minimum annual NDVI. The MODIS-based monsoon forest maps(MODMF) from 2000 to 2009 are derived and evaluated using the ground-truth dataset. The MODMF achieves an average producer accuracy of 80.0% and the Kappa statistic of 0.719. The variability of MODMF among different years is compared with that calculated from MODIS land cover products(MCD12Q1). The results show that the coefficient of variation of total monsoon forest area in MODMF is 7.3%, which is far lower than that in MCD12Q1 with 24.3%. Moreover, the pixels in MODMF which can be identified for 7 to 9 times between 2001 and 2009 account for 53.1%, while only 7.9% of MCD12Q1 pixels have this frequency. Additionally, the monsoon forest areas estimated in MODMF, Global Land Cover 2000(GLC2000), MCD12Q1 and University of Maryland(UMD) products are compared with the statistical dataset at national level, which reveals that MODMF has the highest R2 of 0.95 and the lowest RMSE of 14 014 km2. This algorithm is simple but reliable for mapping the monsoon forests without complex classification techniques.     

Response of the South China Sea summer monsoon onset to air-sea heat fluxes over the Indian Ocean

We objectively define the onset date of the South China Sea (SCS) summer monsoon, after having evaluated previous studies and considered various factors. Then, interannual and interdecadal characteristics of the SCS summer monsoon onset are analyzed. In addition, we calculate air-sea heat fluxes over the Indian Ocean using the advanced method of CORARE3.0, based on satellite remote sensing data. The onset variation cycle has remarkable interdecadal variability with cycles of 16 a and 28 a. Correlation analysis between air-sea heat fluxes in the Indian Ocean and the SCS summer monsoon indicates that there is a remarkable lag correlation between them. This result has important implications for prediction of the SCS summer monsoon, and provides a scientific basis for further study of the onset process of this monsoon and its prediction. Based on these results, a linear regression equation is obtained to predict the onset date of the monsoon in 2011 and 2012. The forecast is that the onset date of 2011 will be normal or 1 pentad earlier than the normal year, while the onset date in 2012 will be 1-2 pentads later.     

Characteristics of Thermal and Geopotential Height Differences Between Continent and Ocean and Its Role in the Strength of the Asian Summer Monsoon

The interdecadal factors affecting the summer monsoon winds over Somalia and the South China Sea were studied. Global geopotential heights and wind velocity fields of the 850-hPa and 200-hPa pressure levels, as well as sea surface temperature anomaly data and correlation coefficients were analyzed. The monsoons over Somalia and the South China Sea were found to be two different monsoon systems, operating on different mechanisms and being affected by different ocean-atmosphere interactions. The intensity of the Asian subtropical summer monsoon is influenced by the intensity of the summer monsoon over Somalia in the month of June and by the intensity of the summer monsoon over the South China Sea in the months of June and July. The summer monsoon wind strength over Somalia is affected by regional factors, such as the heating of the Tibetan plateau, and by global mechanisms, such as the subtropical heat exchange with Antarctica. The summer monsoon over the South China Sea is affected by different ocean-atmosphere interactions. The Somalia and subtropical summer monsoons have wind blowing down the pressure gradient from area over ocean to that over land, like typical summer monsoons. The South China Sea summer monsoon has winds that blow down the pressure gradient from area over land to that over ocean. The South China Sea summer monsoon is affected by the Kuroshio Current off the east coast of Japan.     

Does the Asian monsoon modulate tropical cyclone activity over the South China Sea?

To investigate whether the Asian monsoon influences tropical cyclone (TC) activity over the South China Sea (SCS), TCs (including tropical storms and typhoons) over the SCS are analyzed using the Joint Typhoon Warning Center dataset from 1945 to 2009. Results show an increasing trend in the frequencies of TC-all (all TCs over the SCS) and TY-all (all typhoons over the SCS), due mainly to an increase in the number of TCs moving into the SCS after development elsewhere. Little change is seen in the number of TCs that form in the SCS. The results of wavelet analysis indicate that the frequency of typhoons (TY) shows a similar oscillation as that of TCs, i.e., a dominant periodicity of 8-16 years around the 1970s for all TC activity, except for TC-mov (TCs that moved into the SCS from the western North Pacific). To examine the relationship between typhoon activity and the summer monsoon, a correlation analysis was performed that considered typhoons, TCs, and five monsoon indexes. The analysis reveals statistically significant negative correlation between the strength of the Southwest Asian summer monsoon and typhoon activity over the SCS, which likely reflects the effect of the monsoon on TC formation in the western North Pacific (WNP) and subsequent movement into the SCS. There is a statistically significant negative correlation between TY-loc (typhoons that developed from TCs formed over the SCS) and the South China Sea summer monsoon and Southeast Asian summer monsoon.     

1998年东亚夏季风波包传播特征研究

利用NCEP/NCAR 850hPa风场资料和高度场资料,分析了1998年东亚夏季风强弱变化与波动能量传播特征,表明东亚夏季风存在着加强和减弱的阶段性特征,其季风的爆发、加强、北推东扩与波包的加强和传播有显著的联系.在季风加强期,中、低纬地区一般为波包大值区并有波包加强和向东传播.东亚夏季风爆发前,季风加强主要受中低纬度系统能量的东传影响;东亚夏季风爆发后,季风加强期波包的经向传播十分明显,但期间波包也表现出一定的北传特征,表明低纬地区的系统能量也起一定作用.在东亚夏季风减弱期东亚为波包小值区控制,显示出在季风减弱阶段波包能量的传播也有减弱的特征.     

用大气热源表征的东亚夏季风指数的研究

利用1965—2007年NCEP／NCAR再分析资料和同期的中国160站降水资料,在讨论大气热源的气候特征基础上,用整层积分的大气热源定义了一个东亚夏季风指数,并用该指数研究了东亚夏季风和中国气候的关系。研究表明：定义的大气热源季风指数能反映夏季风的异常变化,高（低）指数年对应的东亚夏季风偏强（弱）;该指数与长江中下游降水存在高度的同期负相关,对长江中下游夏季降水有较强的分辨能力。     

用大气热源表征的东亚夏季风指数的研究

利用1965—2007年NCEP／NCAR再分析资料和同期的中国160站降水资料,在讨论大气热源的气候特征基础上,用整层积分的大气热源定义了一个东亚夏季风指数,并用该指数研究了东亚夏季风和中国气候的关系。研究表明：定义的大气热源季风指数能反映夏季风的异常变化,高（低）指数年对应的东亚夏季风偏强（弱）;该指数与长江中下游降水存在高度的同期负相关,对长江中下游夏季降水有较强的分辨能力。     

Antarctica Sea-ice Oscillation and Its Possible Impact on Monsoon of South Sea

Antarctic sea-ice oscillation index with a seesaw pattern is defined using NCEP/NCAR reanalysis girds data of monthly Antarctica sea-ice concentration from 1979 to 2002. The relationships between the index of winter and the summer precipitations in China as well as the onset date of the summer East Asia monsoon are presented. The study result shows that the grids of correlation coefficients passed 5% confidence level between Antarctic sea-ice oscillation index and Antarctic sea-ice concentration are more than 1/3 of all grids of Antarctica sea-ice, that means the index can represent 1/3 sea-ice area. The winter index has a significant correlation with abnormal summer (June-August) precipitation in China. The area of positive correlation lies in the Yangtze River basin and its south, and that of negative correlation lies mainly in the north of Yangtze River basin. While the winter index is positive (negative), the onset date of South China Sea monsoon is earlier (later), with a probability of 79% (80%). Consequently, a conceptual model is given in term of discussing the possible process between the winter Antarctic sea ice and the monsoon precipitation in China.