气候变化领域集成服务门户(CCPortal): Satellite observations of seasonality and long-term trends in cirrus cloud properties over Europe: investigation of possible aviation impacts

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DOI	10.5194/acp-22-15963-2022
	Satellite observations of seasonality and long-term trends in cirrus cloud properties over Europe: investigation of possible aviation impacts
	Li, Qiang; Gross, Silke
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	15963
结束页码	15980
卷号	22 期号:24 页码:18
英文摘要	Linear contrails and contrail cirrus induced by global aviation have long been known to contribute to climate change by warming the atmosphere. Besides increasing global cirrus cloudiness, aviation may also alter the properties of natural cirrus clouds by soot emissions which lead to more heterogeneous freezing. During the first COVID-19 lockdown in Europe, changes in the properties and occurrence of cirrus clouds were determined with the lidar measurements of CALIPSO, which are presumed to be caused by the corresponding reduction in civil aviation. In the 10 years before the COVID-19 outbreak, however, aviation grew strongly in terms of CO2 emissions and flight densities in Europe. In this study, 10-year lidar measurements with CALIPSO are analysed to determine the seasonality and long-term trends in cirrus clouds as well as their correlations with the ambient temperatures and air traffic. The results show that there is a distinct seasonal cycle in the occurrence rates (ORs) and particle linear depolarization ratio (PLDR) of cirrus clouds. In addition, cirrus clouds appear within a broader altitude range in winter than in summer and they are characterized by larger OR and PLDR values in winter than in summer. The monthly medians of PLDR as well as their deseasonalized time series in the 10-year period before COVID-19 both show positive trends, which are statistically significant according to the Mann-Kendall (MK) significance test. However, the ORs of cirrus clouds show a negative trend, which might be connected with the background meteorological conditions. Since the cirrus PLDR strongly depends on the ambient temperatures, the contributions induced by temperature are further removed from the cirrus PLDR with a simple linear regression model. The derived residuals show significant positive trends according to the MK test. To compare the cirrus PLDR and air traffic (with the CO2 emissions from aviation as a proxy), the deseasonalization of both datasets were previously conducted since the seasonal cycles in both are not consistent. The deseasonalized time series determined for the cirrus PLDR and CO2 emissions from aviation both show increasing trends and their correlation coefficient is r=0.54 at the confidence level above 99.5 %. Finally, comparisons between the cirrus PLDR and aviation in every season were made and revealed a strong correlation in other seasons than in summer.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000901256300001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273669
作者单位	Helmholtz Association; German Aerospace Centre (DLR)
推荐引用方式 GB/T 7714	Li, Qiang,Gross, Silke. Satellite observations of seasonality and long-term trends in cirrus cloud properties over Europe: investigation of possible aviation impacts[J],2022,22(24):18.
APA	Li, Qiang,&Gross, Silke.(2022).Satellite observations of seasonality and long-term trends in cirrus cloud properties over Europe: investigation of possible aviation impacts.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(24),18.
MLA	Li, Qiang,et al."Satellite observations of seasonality and long-term trends in cirrus cloud properties over Europe: investigation of possible aviation impacts".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.24(2022):18.