DOI: 10.1002/jgrd.50789
论文题名: A study on the use of radar and lidar for characterizing ultragiant aerosol
作者: Madonna F. ; Amodeo A. ; D'Amico G. ; Pappalardo G.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 17 起始页码: 10056
结束页码: 10071
语种: 英语
英文关键词: depolarization
; lidar
; radar
; ultragiant aerosol
Scopus关键词: Aerosols
; Aspect ratio
; Backscattering
; Depolarization
; Doppler radar
; Radar
; Radar measurement
; Volcanoes
; Air mass back trajectories
; Backscatter coefficients
; Environmental analysis
; Linear depolarization ratios
; National Research Council
; Number concentration
; Radar reflectivities
; Scattering simulations
; Optical radar
; aerosol
; air mass
; concentration (composition)
; lidar
; matrix
; polarization
; radar
; vertical profile
; volcano
; wavelength
; Eyjafjallajokull
; Iceland
; Italy
英文摘要: From 19 April to 19 May 2010, volcanic aerosol layers originating from the Eyjafjallajökull volcano were observed at the Institute of Methodologies for Environmental Analysis of the National Research Council of Italy Atmospheric Observatory, named CIAO (40.60°N, 15.72°E, 760 m above sea level), in Southern Italy with a multiwavelength Raman lidar. During this period, ultragiant aerosols were also observed at CIAO using a colocated 8.45 mm wavelength Doppler radar. The Ka-band radar signatures observed in four separate days (19 April and 7, 10, and 13 May) are consistent with the observation of nonspherical ultragiant aerosols characterized by values of linear depolarization ratio (LDR) higher than -4 dB. Air mass back trajectory analysis suggests a volcanic origin of the ultragiant aerosols observed by the radar. The observed values of the radar reflectivity (Ze ) are consistent with a particle effective radius (r) larger than 50-75 μm. Scattering simulations based on the T-matrix approach show that the high LDR values can be explained if the observed particles have an absolute aspect ratio larger than 3.0 and consist of an internal aerosol core and external ice shell, with a variable radius ratio ranging between 0.2 and 0.7 depending on the shape and aspect ratio. Comparisons between daytime vertical profiles of aerosol backscatter coefficient (β) as measured by lidar and radar LDR reveal a decrease of β where ultragiant particles are observed. Scattering simulations based on Mie theory show how the lidar capability in typing ultragiant aerosols could be limited by low number concentrations or by the presence of an external ice shell covering the aerosol particles. Preferential vertical alignment of the particles is discussed as another possible reason for the decrease of β. Key Points Synergy between radars and Raman lidars for the study of giant particlesUltragiant volcanic aerosols observed with a radar and likely covered by iceDecrease of lidar backscattering where ultragiant particles are observed ©2013. American Geophysical Union. All Rights Reserved. 资助项目: 262254
; RICA-025991
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63334
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Istituto di Metodologie per l'Analisi Ambientale, Consiglio Nazionale Delle Ricerche, Contrada S. Loja, Tito Scalo, Potenza I-85050, Italy
Recommended Citation:
Madonna F.,Amodeo A.,D'Amico G.,et al. A study on the use of radar and lidar for characterizing ultragiant aerosol[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(17)