南极昭和站平流层臭氧变化与NAT凝结温度的关系

根据南极昭和站的臭氧和气象探空资料,分析了昭和站上空平流层内几个等压面（20,30,50,70,100和150 hPa）上臭氧变化与硝酸·三水合物（分子式HNO3·3H2O,记为NAT）凝结温度的关系,给出了臭氧变化的一个基本特征。     

激光雷达探测南极平流层云

１９９３年中国南极中山站（６９°２２＇Ｓ，７６°２２＇Ｅ）的一台波长为０．６９４μｍ的激光雷达对平流层进行了５３次探测，从激光大气回波信号计算出平流层气溶胶后向散射比的垂直分布和１２～３０ｋｍ高度范围内的积分后向散射系数。探测结果表明因受菲律宾Ｐｉｎａｔｕｂｏ火山爆发的影响，１９９３年南极地区平流层气溶胶粒子含量比１９９０年明显增加，证实了南极冬季平流层云的存在。平流层气溶胶为两层结构，１２ｋｍ附近高度上始终存在着一层厚度为数公里的气溶胶层，２５ｋｍ附近高度的一层变化较大。     

探空气球漂移特征及对三角形法计算散度的影响

利用2006—2013年南京站、安庆站和杭州站探空资料,讨论华东地区探空气球的漂移特征。设计不考虑气球漂移、考虑全部气球漂移和考虑部分气球漂移3个试验,比较3种情况下三角形法计算的散度差异。结果表明:气球漂移主要受大气环流及其变化影响,纬向上7月和8月气球随高度增加,先向东漂移、后向西漂移,其他月份以向东漂移为主,冬季漂移距离大;经向上受季风影响明显。考虑全部和部分气球漂移与不考虑气球漂移的散度对比表明,平均绝对偏差各月在对流层顶附近均有极大值;相对偏差季节分布明显,前者在6—9月较大,极大值略大于7%,后者冬季大,1月在200 hPa达到25%,在50 hPa超过50%。因此,利用三角形法计算散度所在层次较高或所使用资料中传统探空和特种探空并存时,均需考虑气球漂移影响。     

2008年秋季从化山谷风观测研究

利用2008年10月15日—11月16日在广州从化获得的基线小球测风资料,分析研究了秋季从化山谷风的特征。研究表明:从化山谷风主要出现在系统风速小于1.5 m/s,谷风出现时间为10:00—18:00,山风强度比谷风强度大;山谷风厚度大致为300 m,回流出现高度在300～700 m;山谷风转换期间,静小风频率较高;系统风与山谷风方向相反时,山谷风高度内多为静小风。冷锋过境时不会出现山谷风。     

Further evidences of deep convective vertical transport of water vapor through the tropopause

A few years ago, we identified a deep convective transport mechanism, of water vapor through the tropopause, namely, storm top gravity wave breaking, such that tropospheric water substance can be injected into the lower stratosphere via this pathway. The main evidence presented previously was taken from the lower resolution AVHRR images of the storm anvil top cirrus plumes obtained by polar orbiting satellites. Recent observations have provided further supporting evidence for this important cross-tropopause transport mechanism. There are now many higher resolution satellite images, mainly from MODIS instrument, that show more definitely the existence of these plumes, many of which would probably be unseen by lower resolution images.Furthermore, a thunderstorm movie taken in Denver (USA) area during STEPS2000 field campaign and another thunderstorm movie taken by a building top webcam in Zurich also demonstrate that the jumping cirrus phenomenon, first identified by T. Fujita in 1980s, may be quite common in active thunderstorm cells, quite contrary to previous belief that it is rare. We have used a cloud model to demonstrate that the jumping cirrus is exactly the gravity wave breaking phenomenon that transports water vapor through the tropopause.These additional evidences provide increasing support that deep convection contributes substantially to the troposphere-to-stratosphere transport of water substance. This corroborates well with recent studies of the stratospheric HDO/H₂O ratio which is much highly than it would be if the transport is via slow ascent. The only explanation that can be used to interpret this observation at present is that water substance is transported through the tropopause via rapid vertical motion, i.e., deep convection.     

中国探空气球水平漂移总体特征分析

利用2003年4月至2008年8月全国119个探空台站采集的气球漂移信息,分析了中国探空资料水平漂移距离、漂移距离标准差以及漂移方向的分布特征。研究表明:各层探空气球的漂移距离冬季明显大于夏季;一般探空气球的漂移距离随探空高度的增加而增大,但在夏季南方地区由于风向随高度的反转会出现探空气球水平漂移距离随高度减小的状况。探空气球水平漂移距离的标准差随高度增加而增大,且其大值区分布基本上与水平漂移距离的大值区分布一致。从气球漂移方向上看,冬季的情况相对简单,全国各探空台站各层的漂移方向基本以向东为主;但夏季探空气球漂移的方向比较复杂,在对流层低层,全国各台站漂移方向基本以向东为主,而在对流层高层和平流层,北方地区漂移方向基本向东,而南方地区以向西为主。     

Radical variability determined from LIMS and SAMS satellite data

Using satellite data, the variability of a large number of stratospheric trace constituents can be estimated. These constituents need not themselves be measured by the satellite; their concentrations can be derived using photochemical steady-state relationships. The global coverage provided by the satellite over a long time period means that, for example, monthly zonal mean profiles can be derived. This has been done for H, OH, HO₂, H₂O₂, Cl, ClO, HCl, HOCl, ClONO₂, NO and O. The standard deviation of these quantities is a measure of their variability. We argue that comparing theoretical variability estimates with measurements is a better test of a photochemical theory than simply the comparison of single modelled and observed profiles.     

Stratospheric and total NO2 column measurements with a modified Canterbury filter photometer

A programme of ground-based stratospheric and total NO₂ column measurements was instituted at the Laboratory of Atmospheric Physics (40.5° N, 22.9° E) in August 1985. We present here the results of the first two years of measurements with a modified Canterbury filter photometer, details of which are given in the text. The stratospheric NO₂ column, obtained at twilight during low local NO₂ levels, shows the seasonal variation with monthly mean values of about 6×10^-15 molec. cm^-2 in the summertime to about 2.2×10^-15 molec. cm^-2 in the wintertime. These measurements compare well with measurements obtained with different instruments by other groups at similar latitudes (about 40° N) but in different places. Also, the asymmetry of the evening-to-morning stratospheric NO₂ over Thessaloniki was found to be on the average equal to 1.58. Total NO₂ column over Thessaloniki has a pronounced seasonal variation with amplitude of 0.68 matm. cm which can be explained partly from measured local NO₂ sources which discharge in the mixing layer and partly from photolysis of the NO₂ reservoir species.     

Synoptic meteorological observations and weather conditions during MONTBLEX-90

In the present paper a review of meteorological observations conducted by India Meteorological Department during MONTBLEX-90, including intensive observation periods, has been made. Also, an exhaustive weather summary, discussing the special weather features that occurred during the MONTBLEX observational period, is presented. The paper has been prepared to provide a ready reference of the synoptic features to research workers who are utilizing MONTBLEX data for their studies.     

The Slippery Slopes of Climate Engineering Research

Climate engineering research attracts Slippery Slope concerns – the idea that initial research will inevitably lead to inappropriate deployment. Some have dismissed it as an unrealistic, unproductive critique. However, extant climate engineering discussions of the Slippery Slope discuss an unorganised set of different causal mechanisms with little detail. These range from technological cost reduction, to the creation of special interest lobby groups, to normalisation across society and policymakers. Dismissing the Slippery Slope may be premature if its causal nature is unclear, especially given the potentially high impacts and controversy of global climate engineering deployment. Disaggregating and clarifying the Slippery Slope can reduce unnecessary ambiguity, promote productive debate, and highlight risks that require further attention. Drawing on previous Slippery Slope literature and mechanisms of change from range of disciplines, this paper creates a typology of Slippery Slopes for application to stratospheric aerosol injection and other emerging technologies. Initial research can lead to deployment by 1) sparking price-performance improvements and sunk cost biases, 2) contributing to normalisation and legitimisation, 3) altering power structures, 4) sparking hype, and 5) incrementally progressing development. These feedback loops may currently seem unlikely, but unforeseen dynamics could still trigger rapid development and implementation of stratospheric aerosol injection. Conversely, there is no guarantee one of these Slippery Slopes will occur. The point is that they could – the future is too uncertain to fully dismiss non-linear change, particularly for high impact and accessible technologies like stratospheric aerosol injection. This can provide direction and clarity for effective technology governance and Slippery Slope discussion. Furthermore, this typology differentiates the Slippery Slope from lock-in and highlights their interaction points. Slippery Slope dynamics are processes that can (but are not guaranteed to) lead to different types of lock-in. Lock-in is when a technology is entrenched in existing sociotechnical systems. Given the risks of unchecked undesired lock-in, lock-in is a state to be encouraged instead of avoided.