Ice formation in Saharan dust over central Europe observed with temperature/humidity//aerosol Raman lidar -: art. no. D18S12

被引:68
作者
Ansmann, A
Mattis, I
Müller, D
Wandinger, U
Radlach, M
Althausen, D
Damoah, R
机构
[1] Leibniz Inst Tropospher Res, D-04318 Leipzig, Germany
[2] Tech Univ Munich, Abt Okol, D-85354 Freising Weihenstephan, Germany
关键词
D O I
10.1029/2004JD005000
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
[1] Three gravity-wave-induced clouds and a glaciating altocumulus layer were continuously monitored with lidar at Leipzig, Germany, on 21 November 2003. The midtropospheric clouds formed in Saharan dust at heights from 3.5 km ( - 9 degrees C) to 6.5 km ( - 27 degrees C). Distinct ice formation in the altocumulus was triggered by the gravity wave. For the first time, an aerosol/cloud study presents height profiles of temperature, water vapor mixing ratio, relative humidity, dust, and cloud optical properties ( volume extinction and backscatter coefficients, lidar ratio, depolarization ratio) within the same air column, solely derived from lidar data. The three gravity-wave-induced clouds did not show any sign of ice formation. The aged dust particles below 4.5-km height were probably partly coated and mixed with hygroscopic material and thus deactivated concerning ice nucleation. Ice crystals were generated in isolated air parcels at the cloud edges of a young, optically thin altocumulus layer between 5- and 6.5-km height. An aged altocumulus deck composed of a geometrically thin liquid water layer at cloud top and an extended ice crystal layer ( ice virga) was observed 2 hours later in the same height range. Strong ice formation occurred in the altocumulus during the downdraft induced by the gravity wave. Contact freezing was probably the main reason for the observed ice formation on dust particles. Ice depolarization ratios were relatively low with values from 10 to 15% in the altocumulus and indicate plate-like crystals.
引用
收藏
页码:1 / 12
页数:12
相关论文
共 52 条
[31]   WIND-TUNNEL INVESTIGATION OF FREEZING OF SMALL WATER DROPS FALLING AT TERMINAL VELOCITY IN AIR [J].
PITTER, RL ;
PRUPPACHER, HR .
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 1973, 99 (421) :540-550
[32]  
Pruppacher H. R., 1997, MICROPHYSICS CLOUD P
[33]   Correlations among the optical properties of cirrus-cloud particles: Microphysical interpretation [J].
Reichardt, J ;
Reichardt, S ;
Hess, M ;
McGee, TJ .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2002, 107 (D21) :AAC8-1
[34]   A LABORATORY STUDY OF ICE NUCLEATING PROPERTIES OF SOME MINERAL PARTICULATES [J].
ROBERTS, P ;
HALLETT, J .
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 1968, 94 (399) :25-+
[35]   Raman lidar measurement of water vapor and ice clouds associated with Asian dust layer over Tsukuba, Japan [J].
Sakai, T ;
Nagai, T ;
Nakazato, M ;
Matsumura, T .
GEOPHYSICAL RESEARCH LETTERS, 2004, 31 (06) :L061281-4
[36]   Ice clouds and Asian dust studied with lidar measurements of particle extinction-to-backscatter ratio, particle depolarization, and water-vapor mixing ratio over Tsukuba [J].
Sakai, T ;
Nagai, T ;
Nakazato, M ;
Mano, Y ;
Matsumura, T .
APPLIED OPTICS, 2003, 42 (36) :7103-7116
[37]   Saharan dust storms and indirect aerosol effects on clouds: CRYSTAL-FACE results [J].
Sassen, K ;
DeMott, PJ ;
Prospero, JM ;
Poellot, MR .
GEOPHYSICAL RESEARCH LETTERS, 2003, 30 (12) :35-1
[38]   Indirect climate forcing over the western US from Asian dust storms [J].
Sassen, K .
GEOPHYSICAL RESEARCH LETTERS, 2002, 29 (10)
[39]  
SASSEN K, 1991, B AM METEOROL SOC, V72, P1848, DOI 10.1175/1520-0477(1991)072<1848:TPLTFC>2.0.CO
[40]  
2