cloud type impact on surface radiation...2012/07/31 · • percentage of max radiation...
TRANSCRIPT
•Forecastsystemsareimpactedbyinaccurateradiationforecasts•Cloudamountandtypeinfluencesradiationforecasts•Inclusionofcloudtypemayimproveforecastsforavarietyofend-users
Motivation
Cloud Type Impact on Surface RadiationCurtis L. WaLker1,2 amanda anderson3 miChaeL Chapman3 sheLdon drobot3
1signifiCant opportunities in atmospheriC researCh and sCienCe (soars), university Corporation for atmospheriC researCh (uCar)2university of nebraska - LinCoLn 3researCh appLiCations Laboratory, nationaL Center for atmospheriC researCh (nCar) [email protected]
track Weather forecast system
Research
Case Study
this work was performed under the auspices of the soars program, which is managed by uCar and is funded by nsf, noaa, the Cooperative institute for research in environmental science, the university of Colorado at boulder, and by the Center for multiscale modeling of atmospheric processes.i would like to thank my communication mentor Jeff Custer, paul kucera, rebecca batchelor, david Currier and Cindy halley gotway.
tactical forecasting
Liquid Water path analysis
Naval Research Lab Cloud Classifier•Acombinationofvisibleandinfraredsatellitechannelstoproducecloudtype•Pixel-by-pixelbrightnessthresholds •Dayandnightoperation
Methods
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29 May 2012 Mean Radiation Time Series
Time (UTC)
Mea
n Ra
diat
ion
(W m
−2)
NightClearHighMidLowCumuliform
Left: mean radiation time series for 29 may 2012 with modal cloud color-coded.
right: Cumuliform cloud types impact midday radiation, reduction period of 45 minutes and a recovery period of 25 minutes. such information is useful to develop tactical forecasting products.
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2 June 2012 Mean Radiation Time Series
Time (UTC)
Mea
n R
adia
tion
(W m
−2)
NightClear
•Percentageofmaxradiationtransmission:Low20%,Mid-level32%,High40%,Cumuliform34%.
•OK-Mesonetdistributionssimilartocasestudies
Low Mid High Cumuliform Clear
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Overall Cases Solar Radiation − Cloud Type Distribution
Cloud Type
Mea
n So
lar R
adia
tion
(W m
−2)
n=33 n=8 n=55 n=41 n=339
Low Mid High Cumuliform Clear
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OK−Mesonet Cloud Type Grouped By Height
Cloud Type
Surfa
ce S
olar
Rad
iatio
n (W
m−2
)
n=4558 n=4580 n=33082 n=8714 n=205953
Cases v ok-Mesonet
Left: mean radiation time series for 2 June 2012.despite this being a clear day, something is affecting the radiation.
right: Liquid water radiometer data shows despite the clear conditions there is some trace signal possibly responsible for radiation variability.
Conclusions and Future•Cloudsandotheratmosphericparticlesimpede60-80%oftotalradiation.•32.9%variabilityinsolarradiationoncloudycasedaysduetoclouds•7.2%solarradiationvariabilityduetocloudswhenclearcasedaysconsidered•Anothersignificantinfluenceonradiation:Watervapor?Aerosols?•NextstepsaretocomputeregressionstatisticsforOK•Conductsimilarassessmentforotherregions/seasons
1915 utC 20 June 2012 nrL Cloud Class
Racetrack Temperature and Pavement Info
Better Cloud Type and Radiation Data
Numerical Weather Prediction Model
Racetrack Temperature and Pavement Info
Numerical Weather Prediction Model
Better Cloud Type and Radiation Data
Racetrack Pavement Temperature ForecastRacetrack Pavement Temperature Forecast
Decision Support for Race Teams
VictoryLaneLane
Track Weather Forecast SystemForecast System
analysis techniquesModalCloudCategorySelection
•9pixelbox,8x8kmCaseStudyAnalysis
•9casesSalisbury,NCMay-June2012
•Radiation-CloudTypeDistribution•TheoreticalMaxRadiationandWaterVaporAssessments
BulkStatisticalAssessment•June2012OK-MESONET•Radiation-CloudTypeDistribution modal Cloud Category selection