Volcanic cloud retrieval by ground-based microwave weather radar

• Published in: IEEE Transactions on Geoscience and Remote Sensing
• Main Authors: MARZANO, FRANK SILVIO, S. BARBIERI, G. VULPIANI, W. I. ROSE
• Other Authors: Marzano, FRANK SILVIO, S., Barbieri, G., Vulpiani, W. I., Rose
• Format: Article in Journal/Newspaper
• Language: English
• Published: IEEE / Institute of Electrical and Electronics Engineers Incorporated:445 Hoes Lane:Piscataway, NJ 08854:[phone], [phone], EMAIL: [e-mail], INTERNET: http://www.ieee.org, Fax: [phone] 2006
• Subjects: Iceland
• Online Access: http://hdl.handle.net/11573/43373; https://doi.org/10.1109/TGRS.2006.879116; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=000241933600002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=0c7ff228ccbaaa74236f48834a34396a; http://www.scopus.com/inward/record.url?eid=2-s2.0-33750820113&partnerID=65&md5=27f61a6d93511aecdbc22ec87e0be5d3

The potential of ground-based microwave weather radar systems for volcanic ash cloud detection and quantitative retrieval is evaluated. The relationship between radar reflectivity factor, ash concentration, and fall rate is statistically derived for various eruption regimes and ash sizes by applying a radarreflectivitymicrophysical model. To quantitatively evaluate the ash detectability by weather radars, a sensitivity analysis is carried out by simulating synthetic ash clouds and varying ash concentration and size as a function of the range. Radar specifications are taken from typical radar systems at S-, C-, and X-band. A prototype algorithm for volcanic ash radar retrieval (VARR) is discussed. Starting from measured single-polarization reflectivity, the statistical inversion technique to retrieve ash concentration and fall rate is based on two cascade steps, namely: 1) classification of eruption regime and volcanic ash category and 2) estimation of ash concentration and fall rate. Expected accuracy of the VARR algorithm estimates is evaluated using a synthetic data set. An application of the VARR technique is finally shown, taking into consideration the eruption of the Grímsvötn volcano in Iceland on November 2004. Volume scan data from a Doppler C-band radar, which is located at 260 km from the volcano vent, are processed by means of the VARR algorithm. Examples of the achievable VARR products are presented and discussed.