Advances in Radio Science www.adv-radio-sci.net 1684-9965 1684-9973 7 Kleinheubacher Berichte 2008 2009 10.5194/ars-7-273-2009 http://www.adv-radio-sci.net/7/273/2009/ http://www.adv-radio-sci.net/7/273/2009/ars-7-273-2009.html http://www.adv-radio-sci.net/7/273/2009/ars-7-273-2009.pdf 273 277 2009-05-19 Classification of ice crystals at C-band J. Steinert joerg.steinert@etit.tu-chemnitz.de M. Chandra Chair of Microwave Engineering and Photonics, Chemnitz University of Technology, Germany Clouds consist of water particles (hydrometeors) in different aggregate states. Above the melting layer these hydrometeors are formed mainly as ice crystals and other completely or partly frozen particles. <br><br> With measurements from the C-band dual polarimetric radar POLDIRAD (Oberpfaffenhofen, Germany) the backscattered signals of the ice particles in the horizontal/vertical polarisation base were analysed. The focus is lying on the co-polar reflectivities and therefore the differential reflectivity. In the next step a simulation of the backscattered signals deliver the physical ansatz for the creation of an ice crystal class. Finally the comparison of this class with a raindrop classification is shown. Auer, A H. and Veal, D L.: The dimensions of ice crystals in natural clouds, J. Atmos. Sci., 27, 919–926, 1970. Aydin, K. and Singh, J.: Identification of cloud ice crystals using a 95 GHz polarimetric radar, in: Geoscience and Remote Sensing Symposium Proceedings, 2002, IGARSS '02. 2002, IEEE Int., 5, 2814–2816, 2002. Aydin, K. and Walsh, T.: Separation of millimeter-wave radar reflectivities of aggregates and pristine ice crystals in a cloud, in: Geoscience and Remote Sensing Symposium Proceedings, 1998, IGARSS '98, 1998 IEEE Int., 1, 440–442, 1998. Dissanayake, A W., Chandra, M., and Watson, P A.: Prediction of differential reflectivity due to various types of ice particles and ice-water mixtures, in: ICAP 83, Norwich, UK, 56–59, IEE Publication No. 219, 1983. Holt, A R.: Some factors affecting the remote sensing of rain by polarization diversity radar in the 3- to 35-GHz frequency range, Radio Science, 19, 1399–1412, 1984. Katz, J I.: Subsuns and Low Reynolds Number Flow, J. Atmos. Sci., 55, 3358–3362, 1998. Ray, P S.: Broadband complex refractive indices of ice and water, Applied Optics, 11, 1836–1844, 1972. Schroth, A C., Chandra, M S., and Meischner, P F.: A C-Band Coherent Polarimetric Radar for Propagation and Cloud Physics Research, J. Atmos. Ocean. Techol., 5, 803–822, 1988. Steinert, J. and Chandra, M.: Cloud physical properties and empirical polarimetric measurements of rain signatures at C-band, URSI Germany, Adv. Radio Sci., 6, 315–318, 2008. Vivekanandan, J., Bringi, V., Hagen, M., and Meischner, P.: Polarimetric radar studies of atmospheric ice particles, Geoscience and Remote Sensing, IEEE T., 32, 1–10, 1994. Wolde, M. and Vali, G.: Polarimetric Signatures from Ice Crystals Observed at 95 GHz in Winter Clouds. Part I: Dependence on Crystal Form, J. Atmos. Sci., 58, 828–841, 2001.