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DOI	10.1016/j.atmosres.2020.105210
	Contrasting changes in cloud optical properties and the influence of aerosols, meteorology and radiation feedback in the Himalaya Karakoram region
	Iftikhar M.; Alam K.; Syed W.A.; Ahmad M.; Zeb B.; Liu Y.; Gulistan N.
发表日期	2021
ISSN	0169-8095
卷号	248
英文摘要	The spatio-temporal variations in cloud optical properties and the influence of aerosols, radiation feedback and meteorological parameters were investigated at high altitudes of Diamir, Gilgit and Skardu in the Himalaya Karakoram (HK) region of northern Pakistan from 2004 to 2016. The aerosol optical depth (AOD) depicted significant variation with high values during spring months as compared to other months. The results revealed high values of cloud fraction (CF), cloud water path (CWP) and cloud optical depth (COD) in winter months, while contrasting response was observed in summer months. Due to Twomey effect, clouds become thicker and brighter with maximum COD and liberation of latent heat, which modifies temperature gradient of vertical profile. Similarly, an uneven distribution of cloud effective radius (CER) was observed throughout the study period. An increasing trend of cloud top temperature (CTT) from February to September was observed, while an opposite response was found from September to January during the study period. Likewise, minimum and maximum cloud top pressure (CTP) was found in February and November, respectively. AOD is positively correlated with CF and COD due to high humidity and the existence of hydrophilic aerosols. The results of AOD and CER correlation were in good agreement with Twomey effect. However, AOD showed contrasting relationship with CWP over Diamir and Gilgit. The negative relationships of AOD with CTP and CTT indicated the suppression of precipitation process and variability of meteorological parameters. In addition, a positive correlation was observed between COD and CTP against top of the atmosphere shortwave cloud radiative forcing (TOASWCRF), which indicates the cooling effect due to increasing COD and CTP. With TOASWCRF, a variation in CWP and CER may also lead to cooling effect due to reflection of solar radiations. While the meteorology depicted an uneven relationship with cloud optical properties at observation sites. © 2020 Elsevier B.V.
英文关键词	AOD; CER; CF; COD; HKH; Meteorology; TOA fluxes
来源期刊	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/236917
作者单位	Department of Physics, International Islamic University, Islamabad, Pakistan; Department of Physics, University of Peshawar, Peshawar, 25120, Pakistan; Department of Meteorology, COMSATS University Islamabad, Pakistan; Department of Mathematics, Shaheed Benazir Bhutto University Sheringal Dir (upper), Khyber Pakhtunkhwa, Pakistan; Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, 730000, China; Department of Physics, Shaheed Benazir Bhutto Women University, Peshawar, Khyber Pakhtunkhwa, Pakistan
推荐引用方式 GB/T 7714	Iftikhar M.,Alam K.,Syed W.A.,et al. Contrasting changes in cloud optical properties and the influence of aerosols, meteorology and radiation feedback in the Himalaya Karakoram region[J],2021,248.
APA	Iftikhar M..,Alam K..,Syed W.A..,Ahmad M..,Zeb B..,...&Gulistan N..(2021).Contrasting changes in cloud optical properties and the influence of aerosols, meteorology and radiation feedback in the Himalaya Karakoram region.Atmospheric Research,248.
MLA	Iftikhar M.,et al."Contrasting changes in cloud optical properties and the influence of aerosols, meteorology and radiation feedback in the Himalaya Karakoram region".Atmospheric Research 248(2021).