Understanding Radar Refractivity: Sources of UncertaintySource: Journal of Applied Meteorology and Climatology:;2011:;volume( 050 ):;issue: 012::page 2543Author:Bodine, David
,
Michaud, Dan
,
Palmer, Robert D.
,
Heinselman, Pamela L.
,
Brotzge, Jerry
,
Gasperoni, Nick
,
Leng Cheong, Boon
,
Xue, Ming
,
Gao, Jidong
DOI: 10.1175/2011JAMC2648.1Publisher: American Meteorological Society
Abstract: his study presents a 2-yr-long comparison of Weather Surveillance Radar-1988 Doppler (WSR-88D) refractivity retrievals with Oklahoma Mesonetwork (?Mesonet?) and sounding measurements and discusses some challenges to implementing radar refractivity operationally. Temporal and spatial analyses of radar refractivity exhibit high correlation with Mesonet data; however, periods of large refractivity differences between the radar and Mesonet are observed. Several sources of refractivity differences are examined to determine the cause of large refractivity differences. One source for nonklystron radars includes magnetron frequency drift, which can introduce errors up to 10 N-units if the frequency drift is not corrected. Different reference maps made at different times can ?shift? refractivity values. A semiautomated method for producing reference maps is presented, including trade-offs for making reference maps under different conditions. Refractivity from six Mesonet stations within the clutter domain of the Oklahoma City, Oklahoma, WSR-88D (KTLX) is compared with radar refractivity retrievals. The analysis revealed that the six Mesonet stations exhibited a prominent diurnal trend in differences between radar and Mesonet refractivity measurements. The diurnal range of the refractivity differences sometimes exceeded 20 or 30 N-units in the warm season, which translated to a potential dewpoint temperature difference of several degrees Celsius. A seasonal analysis revealed that large refractivity differences primarily occurred during the warm season when refractivity is most sensitive to moisture. Ultimately, the main factor in determining the magnitude of the differences between the two refractivity platforms is the vertical gradient of refractivity because of the difference in observation height between the radar and a surface station.
|
Collections
Show full item record
contributor author | Bodine, David | |
contributor author | Michaud, Dan | |
contributor author | Palmer, Robert D. | |
contributor author | Heinselman, Pamela L. | |
contributor author | Brotzge, Jerry | |
contributor author | Gasperoni, Nick | |
contributor author | Leng Cheong, Boon | |
contributor author | Xue, Ming | |
contributor author | Gao, Jidong | |
date accessioned | 2017-06-09T16:39:18Z | |
date available | 2017-06-09T16:39:18Z | |
date copyright | 2011/12/01 | |
date issued | 2011 | |
identifier issn | 1558-8424 | |
identifier other | ams-71653.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4213569 | |
description abstract | his study presents a 2-yr-long comparison of Weather Surveillance Radar-1988 Doppler (WSR-88D) refractivity retrievals with Oklahoma Mesonetwork (?Mesonet?) and sounding measurements and discusses some challenges to implementing radar refractivity operationally. Temporal and spatial analyses of radar refractivity exhibit high correlation with Mesonet data; however, periods of large refractivity differences between the radar and Mesonet are observed. Several sources of refractivity differences are examined to determine the cause of large refractivity differences. One source for nonklystron radars includes magnetron frequency drift, which can introduce errors up to 10 N-units if the frequency drift is not corrected. Different reference maps made at different times can ?shift? refractivity values. A semiautomated method for producing reference maps is presented, including trade-offs for making reference maps under different conditions. Refractivity from six Mesonet stations within the clutter domain of the Oklahoma City, Oklahoma, WSR-88D (KTLX) is compared with radar refractivity retrievals. The analysis revealed that the six Mesonet stations exhibited a prominent diurnal trend in differences between radar and Mesonet refractivity measurements. The diurnal range of the refractivity differences sometimes exceeded 20 or 30 N-units in the warm season, which translated to a potential dewpoint temperature difference of several degrees Celsius. A seasonal analysis revealed that large refractivity differences primarily occurred during the warm season when refractivity is most sensitive to moisture. Ultimately, the main factor in determining the magnitude of the differences between the two refractivity platforms is the vertical gradient of refractivity because of the difference in observation height between the radar and a surface station. | |
publisher | American Meteorological Society | |
title | Understanding Radar Refractivity: Sources of Uncertainty | |
type | Journal Paper | |
journal volume | 50 | |
journal issue | 12 | |
journal title | Journal of Applied Meteorology and Climatology | |
identifier doi | 10.1175/2011JAMC2648.1 | |
journal fristpage | 2543 | |
journal lastpage | 2560 | |
tree | Journal of Applied Meteorology and Climatology:;2011:;volume( 050 ):;issue: 012 | |
contenttype | Fulltext |