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1.
1971-2004年青藏高原总云量时空变化及其影响因子 总被引：7，自引：0，他引：7
利用青藏高原及其周边地区75 个地面气象台站的云量日均值资料,采用正交经验函数(EOF) 和线性倾向估计等方法,分析了高原地区1971-2004 年总云量的时空变化特征。结果表明,高原总云量分布呈自东南向西北减少的态势,且年与四季总云量变化都存在显著下降趋势。进而,研究了高原总云量变化与其他气候因子的相关性。其中,(1) 高原总云量与日照时数、日较差之间存在较好的负相关。本文从云的辐射效应出发,解释了存在这种负相关关系的原因;(2) 青藏高原总云量与相对湿度之间有很好的正相关性,受地形因素、不同云型和云水路径等因素共同影响,高原总云量与降水之间的关系却不显著。在此基础上,重点讨论了高原总云量与气溶胶和臭氧等因子之间的复杂关系。指出：青藏高原总云量减少趋势可能与高原大气气溶胶特别是吸收性气溶胶的增加以及臭氧的损耗有关。 相似文献
2.
贵州和四川盆地云量的气候研究 总被引：1，自引：1，他引：0
贵州和四川盆地是我国云量最多的地区,素有“天无三日晴”和“蜀犬吠日”之说,盆地西缘的雅安古时还有“雅州天漏”的谚语。从全球日照百分率分布推知,川黔地区也是世界上天气最阴沉的地区之一。川黔之阴一向为国内外气象界所注意,本文根据1951—1980 相似文献
3.
中天山山区大气总水汽量和云液水量的遥感研究 总被引：3，自引：2，他引：1
使用QFW-1型双通道微波辐射计,于2002年盛夏(7月10日至8月5日)在天山山区乌鲁木齐河流域上风方的小渠子进行了大气积分水汽和云中积分液水量的遥感观测。观测表明;中天山山区盛夏的晴天平均大气水汽含量与目前公认的亚洲大气中的水汽含量相近;晴天的平均大气水汽量具有明显的日变化。对降水云系的液态水含量及其变化遥感监测表明:云系降水具有先兆性;不同类型降水性云的降水临界值不同;云液水由0.5 mm开始上升到降水临界值的降水酝酿期的时间,可以作为天山山区人工增雨实施播云作业的重要参照指标。 相似文献
4.
With Empirical Orthogonal Function (EOF) and trend analysis method adopted, the spatio-temporal variation of total cloud amount is analyzed for 75 stations on the Qinghai-Tibet Plateau during the period 1971-2004. Analysis indicates that the total cloud amount decreases from the southeast to the northwest of the plateau, and that the annual and seasonal variations in total cloud amount both show an apparent declining tendency over the past decades. Correlation analysis demonstrates that the total cloud amount is negative with sunshine duration and diurnal temperature range (DTR), and is positive with precipitation and the relative humidity, respectively. The negative correlation is consistent with the radiative effect of cloud, while the positive correlation between total cloud amount and precipitation is obscured because of the influence of topographic factors. Discussion implies that the decrease of total cloud amount is possibly due to the variation of atmospheric aerosol content and ozone concentration over the plateau, although it is difficult to quantify the driving force mechanism up to now. 相似文献
5.
With Empirical Orthogonal Function （EOF） and trend analysis method adopted, the spatio-temporal variation of total cloud amount is analyzed for 75 stations on the Qinghai-Tibet Plateau during the period 1971-2004. Analysis indicates that the total cloud amount decreases from the southeast to the northwest of the plateau, and that the annual and seasonal variations in total cloud amount both show an apparent declining tendency over the past decades. Correlation analysis demonstrates that the total cloud amount is negative with sunshine duration and diurnal temperature range （DTR）, and is positive with precipitation and the relative humidity, respectively. The negative correlation is consistent with the radiative effect of cloud, while the positive correlation between total cloud amount and precipitation is obscured because of the influence of topographic factors. Discussion implies that the decrease of total cloud amount is possibly due to the variation of atmospheric aerosol content and ozone concentration over the plateau, although it is difficult to quantify the driving force mechanism up to now. 相似文献
6.
With Empirical Orthogonal Function (EOF) and trend analysis method adopted, the spatio-temporal variation of total cloud amount is analyzed for 75 stations on the Qinghai–Tibet Plateau during the period 1971–2004. Analysis indicates that the total cloud amount decreases from the southeast to the northwest of the plateau, and that the annual and seasonal variations in total cloud amount both show an apparent declining tendency over the past decades. Correlation analysis demonstrates that the total cloud amount is negative with sunshine duration and diurnal temperature range (DTR), and is positive with precipitation and the relative humidity, respectively. The negative correlation is consistent with the radiative effect of cloud, while the positive correlation between total cloud amount and precipitation is obscured because of the influence of topographic factors. Discussion implies that the decrease of total cloud amount is possibly due to the variation of atmospheric aerosol content and ozone concentration over the plateau, although it is difficult to quantify the driving force mechanism up to now. 相似文献
7.
1960~2005年西北地区低云量的时空变化及成因分析 总被引：4，自引：0，他引：4
基于西北地区177个站点1960~2005年逐日的低云量观测资料,运用地统计学、交叉小波分析和多元回归分析,分析了近46 a来西北地区低云量的时空变化特征及影响因素。结果表明：近46 a来西北地区低云量呈较显著上升趋势,1997年之后上升显著。低云量空间呈自东南向西北递减的趋势。低云量与降水、相对湿度等呈显著的正相关,与昼夜温差、日照时数等呈显著的负相关。低云量存在2~4 a、准6 a、准11 a的周期变化,与宇宙射线在1982~1993年存在5~8 a的共振周期,与NOI指数存在2~4 a、准5 a、准11 a的共振周期,和太阳黑子的共振周期为9~11 a。 相似文献
8.
根据Aqua MODIS 2级云产品和Cloudsat的2级产品资料,结合降水数据和MODIS L1B级辐射率数据,对发生在京津冀地区夏季的三次强降水过程中冰云的宏微观物理量的特征进行分析,并探究这些物理量和降水强度的关系。结果表明：在水平分布中,强降水过程中降水强度高值区内云相为冰云,冰云云顶高度在8~17 km,冰云粒子有效半径、冰云光学厚度、冰水路径分别最高可达60 μm、 150、 5 000 g?m-2;冰云光学厚度、冰水路径、冰云云顶高度随降水强度增大而增大。在垂直分布中,冰云主要分布在3.5 km以上,发生强降水站点的冰云为深对流云,冰云粒子有效半径、冰水含量、冰云粒子数浓度分别最高可达150 μm、 3 000 mg?m-3 、 500 L-1;冰云粒子有效半径高值区存在于云层中下部,且随高度上升而减小,冰云粒子数浓度高值区存在于云层中上部,且随高度上升而增加,冰水含量高值区则存在于云层中部;冰云粒子有效半径、冰水含量、冰云粒子数浓度在9 km以上随降水强度增大而增大。 相似文献
9.
《Polar Science》2007,1(1):17-23
Variations of cloud amount and radiative fluxes are a matter of discussion related to the recent climate change in the Arctic and Antarctic. It is also of great concern related to “from dimming to brightening” recently found. Discussions based on satellite data had been conducted; however, no solid results are obtained from the surface station data for a long term in the recent.At Syowa Station, Antarctica, meteorological observation has been continued for nearly 50 years. During this term, an annual mean cloud amount showed a gradual increase at a rate of 0.014/yr. Radiation budget was observed since 1991 as one of the BSRN stations. Trends of monthly mean radiative fluxes were compared with those of cloud amount and conformable relations were seen during the period from 1991 to 2004. A cloud radiative forcing was estimated. In December, a downward trend in net longwave and net total appeared, while an upward trend in net shortwave was seen, and all corresponded to the decrease of cloud amount in this month. On the other hand in June, an upward trend in net longwave forcing was seen, corresponding to the increase of cloud amount. On an average, cloud radiative forcings at Syowa Station represented those of Antarctic costal stations near sea ice area. 相似文献