The Rapid X-band Polarimetric Radar, commonly abbreviated as RaXPol,
is a mobile research radar designed and operated by the
University of Oklahoma
The University of Oklahoma (OU) is a Public university, public research university in Norman, Oklahoma, United States. Founded in 1890, it had existed in Oklahoma Territory near Indian Territory for 17 years before the two territories became the ...
, led by
Howard Bluestein. RaXPol often collaborates with adjacent mobile radar projects, such as
Doppler on Wheels
Doppler on Wheels (DOW) is a fleet of quickly deployable truck-mounted weather radars managed by FARM (Flexible Array of Radars and Mesonets), an American research company affiliated with the University of Alabama Huntsville. The group, which ...
and
SMART-R.
Unlike its counterparts, RaXPol typically places emphasis on temporal resolution, and as such is capable of surveilling the entire local atmosphere in three dimensions in as little as 20 seconds, or a single level in less than 3 seconds.
RaXPol scanned the
2013 El Reno tornado
The 2013 El Reno tornado was an extremely large, powerful, and erratic tornado that occurred over rural areas of Central Oklahoma during the early evening hours of Friday, May 31, 2013. This rain-wrapped, multiple-vortex tornado was the wide ...
, capturing wind speeds exceeding 300 mph, the second highest ever recorded.
History and deployment
Ever since meteorological observations on radar were first made widespread, the need for high-temporal resolution and comprehensive volumetric imagery of all three dimensions of weather phenomena has been a very high priority, due in large part to the fact that hazardous weather often happens in the span of seconds, and often in the lowest 1 kilometer of the atmosphere.
In pursuit of better resolution in time, the
NEXRAD
NEXRAD or Nexrad (Next-Generation Radar) is a network of 159 high-resolution S-band pulse-Doppler radar, Doppler weather radars operated by the National Weather Service (NWS), an agency of the National Oceanic and Atmospheric Administration (NOAA) ...
network deploys several time-saving measures to accelerate data rates in these three dimensions, such as
M.R.L.E. and
MESO-SAILS, which can be bringing scan time down from 5–7 minutes to 2–3 minutes. In 2010, the University of Oklahoma's Advanced Radar Research Center began development of RaXPol, with a focus on rapid deployment and analysis of the atmosphere.
By early 2011, RaXPol was being deployed in field campaigns across
Tornado Alley
Tornado Alley, also known as Tornado Valley, is a loosely defined location of the central United States and, in the 21st century, Canada where tornadoes are most frequent. The term was first used in 1952 as the title of a research project to st ...
, and has taken part in numerous
NSF
NSF may stand for:
Political organizations
*National Socialist Front, a Swedish National Socialist party
*NS-Frauenschaft, the women's wing of the former German Nazi party
* National Students Federation, a leftist Pakistani students' political g ...
funded research projects and organizations, such as PECAN,
TORUS,
and IMPACTS.
Findings
RaXPol has documented numerous hazardous weather events throughout its deployment history, among them being several dozen particularly intense tornadoes. On May 24, 2011, RaXPol observed
an extremely violent EF-5 tornado near El Reno, Oklahoma at very high temporal resolution, measuring doppler velocities in excess of 250 mph.
Two years later, RaXPol observed the
widest tornado in recorded history (2.6 miles wide), also near the town of El Reno. RaXPol recorded winds up to inside the tornado, marking the fastest winds ever observed by radar in history.
Based on this data, the tornado was initially rated EF-5, but was later downgraded to an EF-3 due to the lack of supporting damage on the ground.
Data gathered from RaXPol also indicates that the formation of tornadoes may not be a top-down process as was once thought.
References
{{US wx radar
Weather radars
University of Oklahoma