Effects of Melting Layer in Airborne Meteorological X-Band Radar Observations

• Published in: IEEE transactions on geoscience and remote sensing Vol. 50; no. 6; pp. 2318 - 2324
• Main Authors: Pujol, O., Mesnard, F., Sauvageot, H.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.06.2012; Institute of Electrical and Electronics Engineers
• Subjects: Airborne radar; Applied geophysics; Atmospheric and Oceanic Physics; Attenuation; Earth sciences; Earth, ocean, space; Exact sciences and technology; Internal geophysics; melting layer; Meteorological radar; microphysical heterogeneities; Physics; Rain; Snow; wet snow; X-band attenuation; Zirconium; antenna; X-band attenuation; melting layer; attenuation; sampling; adaptation; melting; isotherms; heterogeneity; frequency; precipitation; wet snow; corrections; Airborne radar; snow; microphysical heterogeneities; inhomogeneity; radar methods; airborne radar
• ISSN: 0196-2892; 1558-0644
• DOI: 10.1109/TGRS.2011.2172111

Most civil aviation aircraft are equipped with meteorological radar working at the X-band ( f ≈ 10 GHz; λ ≈ 3.2 cm) . These radars use a small antenna and, thus, a large beamwidth, around 3°-4°, for observations over long distances (up to 350 km). In the presence of microphysical inhomogeneities inside a radar sampling volume, as filling by different hydrometeor categories, radar reflectivity measurements are biased. An important bias occurs when a radar cell is cut by a nonresolved layer of melting snowflakes whose attenuation is high compared to those of rain and dry snow. This paper illustrates the effects in precipitation-attenuation correction schemes (PACS) of the inhomogeneity associated with the 0 °C isotherm. It proposes a method to take into account these effects in PACS. Adaptation of the method to other frequency bands and ground-based radar observations is easy.