新疆地区夏季平流层低层风场特征分析及数值模拟

利用2017年6—8月的FNL再分析资料分析了新疆地区夏季平流层低层风场的时空演变特征，开展了平流层低层风场的高分辨率数值模拟和检验。结果表明：新疆地区夏季平流层纬向风随时间的变化存在经向差异，同时准零风层开始和结束的时间也存在经向差异，准零风层开始时间南部地区早于北部地区，而准零风层结束时间则相反。整个夏季新疆地区上空的准零风层处于70～40 hPa之间，其高度随时间呈先降低而后升高的变化趋势。准零风层数值模拟结果表明，模拟的准零风层参数与探空资料分析结果相比二者存在一致的变化趋势，准零风层起始高度的平均绝对误差为467 m，该高度对应的风速均方根误差为1.75 m/s。     

Intercomparison of measurements of stratospheric hydrogen fluoride

Observations of the vertical profile of hydrogen fluoride (HF) vapor in the stratosphere and of the vertical column amounts of HF above certain altitudes were made using a variety of spectroscopic instruments in the 1982 and 1983 Balloon Intercomparison Campaigns. Both emission instruments working in the far infrared spectral region and absorption instruments using solar occultation in the 2.5m region were employed. No systematic differences were seen in results from the two spectral regions. A mean profile from 20–45 km is presented, with uncertainties ranging from 20% to 50%. Total columns measured from ground and from 12 km are consistent with the profile if the mixing ratio for HF is small in the tropophere and low stratosphere.     

HCl Quasi-Biennial Oscillation in the Stratosphere and a Comparison with Ozone QBO

1. Introduction The quasi-biennial oscillation (QBO) of the mean zonal wind in the equatorial stratosphere was discov- ered by Reed et al. (1961) and Veryard and Ebdon (1961). Later, Funk and Garnham (1962) and Ra- manathan (1963) were the first to descri…     

The cause of the spring strengthening of the Antarctic polar vortex

The stratospheric polar vortex strengthening from late winter to spring plays a crucial role in polar ozone depletion. The Arctic polar vortex reaches its peak intensity in mid-winter, whereas the Antarctic vortex usually strengthens in early spring. As a result, the strong ozone depletion is observed every year over the Antarctic, while over the Arctic short-term ozone loss occasionally occurs in late winter or early spring. However, the cause of such a difference in the life cycles of the Arctic and Antarctic polar vortices is still not completely clear. Based on the ERA-Interim reanalysis data, we show a high agreement between the seasonal variations of temperature in the subtropical lower stratosphere and zonal wind in the subpolar and polar lower stratosphere in the Southern Hemisphere. Thus, the spring strengthening of the Antarctic polar vortex can occur due to the seasonal temperature increase in the subtropical lower stratosphere in this period.     

On the nonlinear response of lower stratospheric ozone to NOx and ClOx perturbations for different CH4 sources

The impact of sulfate aerosol, ClOx and NOx perturbations for two different magnitudes of CH4 sources on lower stratospheric ozone is studied by using a heterogeneous chemical system that consists of 19 species belonging to 5 chemical families （oxygen, hydrogen, nitrogen, chlorine and carbon）. The results show that the present modeled photochemical system can present several different solutions, for instance, periodic states and multi-equilibrium states appearing in turn under certain parameter domains, through chlorine chemistry and nitrogen chemistry together with sulfate aerosol as well as the increasing magnitude of CH4 sources. The existence of catastrophic transitions could produce a dramatic reduction in the ozone concentration with the increase of external sources.     

2003年北极科考期间一次极涡个例天气学分析

2003年9月3日到14日,"雪龙"号考察船进入北冰洋楚科奇海观测期间,正值一次典型的北极极涡环流过程形成和发展。以往研究大多集中于极涡的平均水平环流特征和季节变化,该例为我们研究它的瞬时环流形势和特征提供了条件。利用NCEP全球分析资料及第二次北极科考资料对这次个例进行天气学分析,通过描述极涡个例的发展情况,平流层、对流层的环流特征以及二者之间的关系,并分析卫星遥感图像及"雪龙"号考察船的气象资料,分析结果发现:2003年中国第二次北极科考期间经历的极涡形成和发展,典型地表现出极地冬夏环流型的转换过程。首先在平流层发生,然后向对流层传播,该个例是一次在平流层西退加强,在对流层东移南下的过程。     

Nitric oxide profiles measured in situ during the Globus '85 campaign

Nitric oxide profiles obtained from three flights of chemiluminescent instruments during the Globus '85 campaign held in France in the autumn of 1985 are reported. When the profile obtained in the early morning of 20 September is compared with the flight made the previous afternoon, an average morning to midday NO ratio of 0.7 for the region between 26 and 33 km is obtained. This value is in good agreement with theoretical studies involving the photolysis of N₂O₅ and the establishment of the NO₂–NO equilibrium.     

A note on some early radiosonde temperature observations in the Antarctic lower stratosphere

The behaviour of the Southern Hemisphere stratosphere has attracted considerable interest, and been compared with the Northern Hemisphere, since the International Geophysical Year (1957–58) when the sudden (explosive or accelerated) springtime warming phenomenon in the Antarctic was first observed. Over the years studies of upper air temperature and wind observations have been made, principally through the spring months when the polar vortex breakdown occurs, utilising both ground-based (rawinsonde, rocket) and more recently, satellite-derived data. Although the radiosonde-derived temperature data are limited both by the number of reporting stations, and the practical difficulty of securing observations much above the 100 hPa level, useful records exist from 1956 or 1957. These have shown that in the 1959 southern spring, the lower stratosphere was relatively colder, and the warming rate through the season was essentially more regular, with little evidence of the marked but short-lived temperature fluctuations usually found. Similar, but not quite such wide-spread conditions occurred again in the 1961 spring. In another study, 30 hPa temperature fields over the Antarctic continent, which could be drawn for the 1967 spring, showed the complexity of the polar vortex breakdown. These features are recalled because extension of the 100 hPa springtime temperature series for the Australian Antarctic station at Casey (66.3°S, 110.5°E) shows that in 1985 and part of 1986, the temperature behaviour there was similar to, but not quite so extreme as that which occurred at Mirny (66.5°S, 93.0°E) in 1959.     

Extremely low temperatures in the stratosphore and very low total ozone amount above northern and central Europe during winter 1989

On 1 February 1989, -83.5°C was recorded in 27.8 hPa over Hohenpeißenberg, the lowest temperature in the 22-year series. This was measured together with a very low total ozone amount of 266 DU. This may be compared with nearly twice this amount on 27 February 1989. The situation was very unusual: following an extremely cold winter in the Arctic stratosphere, the stratospheric cold pole was located over southern Scandinavia on 1 February in a very southerly position. The analyzed temperatures of -92 °C in 30 hPa were also unusual. Even though the low ozone amounts over Hohenpeißenberg were probably dynamically caused, an additional very small ozone decrease due to heterogeneous reactions in altitudes from 23–28 km, where the temperatures lie below -80 °C, cannot be ruled out. Extinction measurements by the orbitting SAGE II instrument indeed show polar stratospheric clouds over Europe near 50° N during the period 31 January–2 February. Also, polar stratospheric clouds were previously observed over Kiruna at similarly low temperatures and signs of a corresponding small ozone decrease were noted there.