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981.
Developed is a new mechanism of photochemical reactions taking account of the dipole interaction between the molecules and the ??sharp?? inhomogeneities of electrified ice crystals in polar stratospheric clouds. This mechanism enables to explain the ozone depression formation during the winter-spring period in the polar stratosphere. 相似文献
982.
利用1971—2001年探空资料以及ERA-40和NCEP/NCAR再分析资料分别得到地面到300 hPa我国大陆上空大气柱水汽含量,对3种不同资料所得的柱水汽含量的空间分布特征以及线性趋势进行对比分析。结果表明:3种资料得到的柱水汽含量年平均和季节平均的空间分布特征一致;3种资料年平均的线性变化趋势在东北地区、内蒙古东部地区,西南地区北部、华南沿海和新疆北部地区均呈增加趋势;在华北和华东的部分地区,ERA-40和NCEP/NCAR再分析资料为降低趋势,而探空资料得到的柱水汽含量变化相对较小,但未通过信度检验;探空资料得到的柱水汽含量的相对变化显示我国东北地区、内蒙古东部地区、新疆地区的增加更显著。 相似文献
983.
M. A. Novitskii L. K. Kulizhnikova O. Yu. Kalinicheva D. Gaitandzhiev D. Barantiev E. Bachvarova K. Krysteva 《Russian Meteorology and Hydrology》2012,37(3):159-164
The characteristics of wind speed and wind direction in the boundary atmospheric layer measured at the meteorological station
in Akhtopol (Bulgaria) are presented. The measurements were carried out with the Scintec sodar and MK-15 automatic meteorological
station. The sodar measurement data on wind parameters at different heights in different months are presented as well as the
frequency of inshore and offshore wind directions, that enables to trace the intensity of the breeze circulation. The frequency
of calms and wind speeds at the heights of 50, 100, and 200 m according to gradations for different months and the probability
of wind of various speeds depending on the direction are also given. The breeze front characteristics in June–September of
2009 are computed from the speed and direction of surface wind measured with the acoustic anemometer of MK-15 complex. 相似文献
984.
985.
Feng Chen Yu-jiang Yuan Wen-shou Wei Shu-long Yu Zi-ang Fan Rui-bo Zhang Tong-wen Zhang Qin Li Hua-ming Shang 《Theoretical and Applied Climatology》2012,107(3-4):633-643
Seven different tree-ring parameters (tree-ring width, earlywood width, latewood width, maximum density, minimum density, mean earlywood density, and mean latewood density) were obtained from Qinghai spruce (Picea crassifolia) at one chronology site in the Hexi Corridor, China. The chronologies were analyzed individually and then compared with each other. Growth–climate response analyses showed that the tree-ring width and maximum latewood density (MXD) are mainly influenced by warm season temperature variability. Based on the relationships derived from the climate response analysis, the MXD chronology was used to reconstruct the May–August maximum temperature for the period 1775–2008 A.D., and it explained the 38.1% of the total temperature variance. It shows cooling in the late 1700s to early 1800s and warming in the twentieth century. Spatial climate correlation analyses with gridded land surface data revealed that our warm season temperature reconstruction contains a strong large-scale temperature signal for north China. Comparison with regional and Northern Hemisphere reconstructions revealed similar low-frequency change to longer-term variability. Several cold years coincide with major volcanic eruptions. 相似文献
986.
玛曲地区夏季强降水的环流分型及水汽轨迹分析 总被引:2,自引:0,他引:2
利用青藏高原(下称高原)东北边坡玛曲地区1967—2008年12个常规气象观测站的降水资料和NCEP/NCAR再分析资料,在环流分型的基础上,应用后向轨迹模型分析了不同等级降水的不同环流型的水汽输送轨迹。结果表明:(1)暴雨发生的环流型以高原低槽型为主,大雨的发生以切变型为主。(2)暴雨的不同环流型的水汽输送轨迹差异较大,同一型暴雨不同等压面水汽轨迹较一致;大雨的不同环流型之间水汽轨迹无明显差异,同一型大雨不同等压面的水汽轨迹差异很大。(3)通过追踪不同时间长度的水汽输送的后向轨迹发现,可以用向前追踪360h的水汽输送轨迹代表玛曲地区的水汽输送,水汽轨迹以偏南气流为主。由此可见,虽然不同等级、不同环流型强降水之间的水汽轨迹存在差异,但是玛曲地区强降水的水汽主要来自印度洋-孟加拉湾和南海-孟加拉湾的偏南气流。 相似文献
987.
988.
Hashmi Fatima H. C. Upadhyaya S. N. Tripathi O. P. Sharma Fangqun Yu 《Meteorology and Atmospheric Physics》2011,112(3-4):101-115
A significant fraction of the total number of particles present in the atmosphere is formed by nucleation in the gas phase. Nucleation and the subsequent growth process influence both number concentration of particles and their size distribution besides chemical and optical properties of atmospheric aerosols. Sulphate aerosol nucleation mechanisms promoted by ions have been evaluated here in a tropospheric interactive chemistry-aerosol module for mass and number concentration in a global atmospheric model. The indirect radiative forcing of sulphate particles is assessed in this model; indirect radiative forcing is different for ion-induced (IIN) and ion-mediated (IMN) mechanisms. The indirect radiative forcing in 10-year simulation runs has been calculated as ?1.42?W/m2 (IIN) and ?1.54?W/m2 (IMN). The 5% emission of primary sulphate particles in simulations changes the indirect radiative forcing from ?1.42 to ?1.44?W/m2 for IIN case, and from ?1.54 to ?1.55 W/m2 for the IMN case. More precisely, owing to greater nucleation rates, IMN mechanisms produces greater cooling than the IIN mechanisms in the backdrop that both mechanisms produce almost identical distribution of CDNC in their pre-industrial runs. The inclusion of primary particles in simulations with IIN and IMN mechanisms increases both CDNC and the indirect radiative forcing. 相似文献
989.
T. W. Krauss A. A. Sin’kevich N. E. Veremei Yu. A. Dovgalyuk V. S. Makitov V. D. Stepanenko 《Russian Meteorology and Hydrology》2011,36(2):102-111
Basing on airmass motion trajectory calculations over the Arabian Peninsula on April 10, 2008, it can be assumed that in the lower and middle troposphere, zones with increased air moisture exist due to air inflow from the Red Sea. As a result, mesoscale volumes of dry and moist air are neighboring, though large-scale field is comparatively homogeneous with low humidity. In the mesoscale zones, intense thunderstorm and hailstorm Cb clouds developed, whose characteristics and evolution are studied in the paper. Continuous radar observations of the clouds are carried out during 5 hours. Numerical simulation of the cloud evolution is performed with nonstationary 1.5-dimensional model. It is noted that under the mentioned atmospheric conditions, in the area under consideration, heavy rain and hail from the Cb clouds are observed. The main factors of their origination are high thermal instability of the atmosphere and moist air inflow from outside. 相似文献
990.
A. Yu. Bundel V. N. Kryzhov Young-Mi Min V. M. Khan R. M. Vilfand V. A. Tishchenko 《Russian Meteorology and Hydrology》2011,36(3):145-154
The probability multimodel forecast system based on the Asia-Pacific Economic Cooperation Climate Center (APCC) model data is verified. The winter and summer seasonal mean fields T 850 and precipitation seasonal totals are estimated. To combine the models into a multimodel ensemble, the probability forecast is calculated for each of single models first, and then these forecasts are combined using the total probability formula. It is shown that the multimodel forecast is considerably more skilful than the single-model forecasts. The forecast quality is higher in the tropics compared to the mid- and high latitudes. The multimodel ensemble temperature forecasts outperform the random and climate forecasts for Northern Eurasia in the above- and below-normal categories. Precipitation forecast is less successful. For winter, the combination of single-model ensembles provides the precipitation forecast skill exceeding that of the random forecast for both Northern Eurasia and European Russia. 相似文献