Doppler weather radar observations of the 2009 eruption of Redoubt Volcano, Alaska

Abstract The U.S. Geological Survey (USGS) deployed a transportable Doppler C-band radar during the precursory stage of the 2009 eruption of Redoubt Volcano, Alaska that provided valuable information during subsequent explosive events. We describe the capabilities of this new monitoring tool and present data captured during the Redoubt eruption. The MiniMax 250-C (MM-250C) radar detected seventeen of the nineteen largest explosive events between March 23 and April 4, 2009. Sixteen of these events reached the stratosphere (above 10 km) within 2–5 min of explosion onset. High column and proximal cloud reflectivity values (50 to 60 dBZ) were observed from many of these events, and were likely due to the formation of mm-sized accretionary tephra-ice pellets. Reflectivity data suggest that these pellets formed within the first few minutes of explosion onset. Rapid sedimentation of the mm-sized pellets was observed as a decrease in maximum detection cloud height. The volcanic cloud from the April 4 explosive event showed lower reflectivity values, due to finer particle sizes (related to dome collapse and related pyroclastic flows) and lack of significant pellet formation. Eruption durations determined by the radar were within a factor of two compared to seismic and pressure-sensor derived estimates, and were not well correlated. Ash dispersion observed by the radar was primarily in the upper troposphere below 10 km, but satellite observations indicate the presence of volcanogenic clouds in the stratosphere. This study suggests that radar is a valuable complement to traditional seismic and satellite monitoring of explosive eruptions.

[1]  Frank S. Marzano,et al.  Model-Based Weather Radar Remote Sensing of Explosive Volcanic Ash Eruption , 2010, IEEE Transactions on Geoscience and Remote Sensing.

[2]  Peter W. Webley,et al.  Remote observations of eruptive clouds and surface thermal activity during the 2009 eruption of Redoubt volcano , 2013 .

[3]  William I. Rose,et al.  Retrieval of sizes and total masses of particles in volcanic clouds using AVHRR bands 4 and 5 , 1994 .

[4]  David J. Schneider,et al.  OBSERVATIONS OF THE 1989-90 REDOUBT VOLCANO ERUPTION CLOUDS USING AVHRR SATELLITE IMAGERY , 2005 .

[5]  K. Bull,et al.  An overview of the 2009 eruption of Redoubt Volcano, Alaska , 2013 .

[6]  S. Freitas,et al.  Qualitative comparison of Mount Redoubt 2009 volcanic clouds using the PUFF and WRF-Chem dispersion models and satellite remote sensing data , 2013 .

[7]  J. Schaefer,et al.  Character, mass, distribution, and origin of tephra-fall deposits from the 2009 eruption of Redoubt Volcano, Alaska: highlighting the significance of particle aggregation , 2013 .

[8]  William I. Rose,et al.  Measurements of the complex dielectric constant of volcanic ash from 4 to 19 GHz , 1996 .

[9]  Frank S. Marzano,et al.  Volcanic Ash Cloud Retrieval by Ground-Based Microwave Weather Radar , 2006, IEEE Transactions on Geoscience and Remote Sensing.

[10]  J. R. Probert-Jones,et al.  The radar equation in meteorology , 1962 .

[11]  David J. Schneider,et al.  Tracking of 1992 eruption clouds from Crater Peak vent of Mount Spurr Volcano, Alaska, using AVHRR , 1995 .

[12]  Marianne Guffanti,et al.  Encounters of aircraft with volcanic ash clouds; A compilation of known incidents, 1953-2009 , 2010 .

[13]  D. Schneider,et al.  Observations of volcanic lightning during the 2009 eruption of Redoubt Volcano , 2013 .

[14]  D. Schneider,et al.  Injection, transport, and deposition of tephra during event 5 at Redoubt Volcano, 23 March, 2009 , 2013 .

[15]  Frank S. Marzano,et al.  Microphysical characterization of microwave Radar reflectivity due to volcanic ash clouds , 2006, IEEE Transactions on Geoscience and Remote Sensing.

[16]  Larry G. Mastin,et al.  A multidisciplinary effort to assign realistic source parameters to models of volcanic ash-cloud transport and dispersion during eruptions , 2009 .

[17]  William I. Rose,et al.  Weather radar observations of the Hekla 2000 eruption cloud, Iceland , 2004 .

[18]  William I. Rose,et al.  Estimating particle sizes, concentrations, and total mass of ash in volcanic clouds using weather radar , 1983 .

[19]  D. Rosenfeld,et al.  Satellite and radar analysis of the volcanic‐cumulonimbi at Mount Pinatubo, Philippines, 1991 , 2005 .

[20]  K. Dean,et al.  PUFF: A high-resolution volcanic ash tracking model , 1998 .

[21]  B. Chouet,et al.  Seismic observations of Redoubt Volcano, Alaska - 1989-2010 and a conceptual model of the Redoubt magmatic system , 2013 .

[22]  T. Lopez,et al.  Combining local and remote infrasound recordings from the 2009 Redoubt Volcano eruption , 2013 .

[23]  William I. Rose,et al.  Real-time C-band radar observations of 1992 eruption clouds from Crater Peak, Mount Spurr Volcano, Alaska , 1995 .