排序方式： 共有116条查询结果，搜索用时 156 毫秒
111.
Saharan dust absorption and refractive index from aircraft-based observations during SAMUM 2006 总被引：1，自引：0，他引：1
By ANDREAS PETZOLD KATHARINA RASP BERNADETT WEINZIERL MICHAEL ESSELBORN THOMAS HAMBURGER REAS DÖRNBRACK KONRAD KANDLER LOTHAR SCHÜTZ PETER KNIPPERTZ MARKUS FIEBIG AKI VIRKKULA 《Tellus. Series B, Chemical and physical meteorology》2009,61(1):118-130
During the Saharan Mineral Dust Experiment (SAMUM) conducted in summer 2006 in southeast Morocco, the complex refractive index of desert dust was determined from airborne measurements of particle size distributions and aerosol absorption coefficients at three different wavelengths in the blue (467 nm), green (530 nm) and red (660 nm) spectral regions. The vertical structure of the dust layers was analysed by an airborne high spectral resolution lidar (HSRL). The origin of the investigated dust layers was estimated from trajectory analyses, combined with Meteosat 2nd Generation (MSG) scenes and wind field data analyses. The real part n of the dust refractive index was found almost constant with values between 1.55 and 1.56, independent of the wavelength. The values of the imaginary part k varied between the blue and red spectral regions by a factor of three to ten depending on the dust source region. Absolute values of k ranged from 3.1 × 10−3 to 5.2 × 10−3 at 450 nm and from 0.3 × 10−3 to 2.5 × 10−3 at 700 nm. Groupings of k values could be attributed to different source regions. 相似文献
112.
冬季由印缅来的低槽对于华南天气的影响 总被引：10，自引：0，他引：10
在长江以南做天气预告的人,大致都觉到长江以南的天气不容易预告好。因为江南冬季的天气,常常是在阴沉沉的低云或浓雾笼罩之下,完全睛朗的日子比较少。一般说来,冬季江南天气变化的规律,远不如华北那麽容易握掌,除开寒潮天 相似文献
113.
能量在大气中是一个主要的因素,大气中一切的现象之所以能发生,都是因为大气有适当的能量的供给和变化。大气中能量的式样很多,不同式样的能力有不同的重要性,研究各种式样的能力的多寡和它的变化是很有意义的,因为大气环流 相似文献
114.
南京每小时雨量纪录始于民国十七年岁首,终于二十六年十二月,为期不足十年,而民国十七年一年之中,观测地点尝有迁移,实际完整之纪录仅八年,今为统计方便计,断自十九年,迄于二十三年, 虽为期甚短不规则之变化,未能尽行消除,然高低之所在,已跃然于纸上矣。以五年各小时平均总量而论,最高点在下午六时,次高点在上午八时;最低点在正午,次低点在子夜后一时,二低点雨量之差甚微,最高点与次高点则相差22粍之多,全日较差即最高点与次高点之差为44粍,各季平均之雨量日变化大致亦与年平均者相似,惟最高与最低 相似文献
115.
Vadimas Dudoitis Steigvilė Byčenkienė Kristina Plauškaitė Carlo Bozzetti Roman Fröhlich Genrik Mordas Vidmantas Ulevičius 《Acta Geophysica》2016,64(3):711-731
The aerosol chemical composition in air masses affected by large vegetation fires transported from the Kaliningrad region (Russia) and southeast regions (Belarus and Ukraine) during early spring (March 2014) was characterized at the remote background site of Preila, Lithuania. In this study, the chemical composition of the particulate matter was studied by high temporal resolution instruments, including an Aerosol Chemical Speciation Monitor (ACSM) and a seven-wavelength aethalo-meter. Air masses were transported from twenty to several hundred kilometres, arriving at the measurement station after approximately half a day of transport. The concentration-weighted trajectory analysis suggests that organic aerosol particles are mainly transported over the Baltic Sea and the continent (southeast of Belarus). Results show that a significant fraction of the vegetation burning organic aerosol is transformed into oxidised forms in less than a half-day. Biomass burning aerosol (BBOA) was quantified from the ACSM data using a positive matrix factorization (PMF) analysis, while its spatial distribution was evaluated using air mass clustering approach. 相似文献
116.
By A. BIROL KARA HARLEY E. HURLBURT CHARLIE N. BARRON ALAN J. WALLCRAFT E. JOSEPH METZGER 《地球，A辑:动力气象学与海洋学》2010,62(1):48-61
The performance of an atmospherically forced ocean general circulation model (OGCM) in simulating daily and monthly sea surface temperature (SST) is examined during the historical El Niño Southern Oscillation (ENSO) events during the time period 1993–2003. For this purpose, we use the HYbrid Coordinate Ocean Model (HYCOM) configured for the North Pacific north of 20°S at a resolution of ≈9 km. There is no assimilation of (or relaxation to) SST data and no date-specific assimilation of any data type. The ability of the model in simulating temporal variations of SST anomalies is discussed by comparing model results with two satellite-based SST products. The HYCOM simulation gives a basin-averaged monthly mean bias of 0.3 °C and rms difference of 0.6 °C over the North Pacific Ocean during 1993–2003. While the model is able to simulate SST anomalies with mean biases <0.5 °C in comparison to observations during most of the ENSO events, limitations in the accuracy of atmospheric forcing (specifically, net short-wave radiation) have some influence on the accuracy of simulations. This is specifically demonstrated during the 1998 transition period from El Niño to La Niña, when a record large SST drop of ≈7 °C occurred in the eastern equatorial Pacific Ocean. 相似文献