cupido gps pw & surface obs. array · 4/11/2005 · april 11, 2005 cupido meeting kursinski 3...
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April 11, 2005 CuPIDO Meeting Kursinski 1
CuPIDOCuPIDO GPS PW & Surface GPS PW & Surface ObsObs. Array. ArrayRob Kursinski
Model output courtesy of M.Model output courtesy of M. LeutholdLeuthold and W. and W. KolczynskiKolczynskiIndications of Convection from C. Indications of Convection from C. Minjarez Minjarez ThesisThesis
Understand relation between PW and Understand relation between PW and precipitationprecipitation
Assess and improve knowledge and Assess and improve knowledge and model representations of moisture and model representations of moisture and precipitationprecipitation
GPS GPS GPS
Puerto Penasco
Place GPS instrumentation near Place GPS instrumentation near Catalina mountains toCatalina mountains to
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How Does the Atmosphere Affect the GPS Signals?
Figures courtesy of Kirk Holub NOAA FSL
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GPS Atmospheric Observable: RefractivityGPS Atmospheric Observable: Refractivity
Atmospheric refractivity, N = (n-1) x 106:
221)(TPb
TPbzN w+=
P and Pw are total pressure and partial pressure of water vapor in mbar,T is temperature in K, b1 is 77.6 N-units K mbar-1 and b2 is 3.73x105 N-units K2 mbar-1.
where:
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Transformations in GPS-Met
Figure courtesy of Kirk Holub NOAA FSL
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Impact of Ground GPS on Analyses & ForecastsImpact of Ground GPS on Analyses & ForecastsRapid time variations in moisture captured by GPSRapid time variations in moisture captured by GPS⇒⇒ Significantly improve the RUC moisture analyses & forecasts Significantly improve the RUC moisture analyses & forecasts
during periods of rapid moisture evolutionduring periods of rapid moisture evolution⇒⇒ Provides detection of Provides detection of radiosondesradiosondes getting “wet”getting “wet”
Analysis 3 hr Forecast
Courtesy of Seth Gutman, NOAA FSL
RUC w/o GPSRUC w/ GPSGPSSonde
RUC w/o GPSRUC w/ GPSGPSSonde
Tucson
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Impact of Ground GPS on Impact of Ground GPS on Analyses & ForecastsAnalyses & Forecasts
Rapid time variations in Rapid time variations in moisture captured by GPSmoisture captured by GPS
⇒⇒ Significantly improve the Significantly improve the RUC moisture analyses & RUC moisture analyses & forecasts during periods of forecasts during periods of rapid moisture evolutionrapid moisture evolution
Courtesy of Seth Gutman, NOAA FSL
RUC w/o GPSRUC w/ GPSGPSSonde
Frontal passage
radiosonde
GPS
Passage of a frontyesterday in the central US
Figures courtesy of Kirk Holub NOAA FSL
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Impact on Wx Fcst AccuracyMulti-year study with the 60km RUC indicates that GPS makes a consistently positive impact on short-term weather forecast accuracy:
- primarily at the lower levels where most of the moisture resides (i.e. PW more correlated w/ low-level than upper-level moisture;
- magnitude of impact increases with the number of stations;
- RH forecast improvement is greatest in the cool months when the moisture distribution is more synoptic;
- precipitation forecast accuracy is generally better for heavy precip then light precip events.
No. Sta 18 56 67 100+ 200+Level 1998-99 2000 2001 2002 2003
% improvement (normalized by total error)850 1.5 3.8 3.9 5.0 5.4700 1.1 4.1 6.3 6.5 7.0500 0.7 2.1 2.0 2.4 3.1400 0.3 0.1 -0.4 -0.5 1.0Mean (850-400) 0.9 2.5 2.9 3.3 4.1Mean (850-500) 1.1 3.3 4.1 4.6 5.2
No. Sta 18 56 67 100+ 200+Level 1998-99 2000 2001 2002 2003
% improvement (normalized by total error)850 1.5 3.8 3.9 5.0 5.4700 1.1 4.1 6.3 6.5 7.0500 0.7 2.1 2.0 2.4 3.1400 0.3 0.1 -0.4 -0.5 1.0Mean (850-400) 0.9 2.5 2.9 3.3 4.1Mean (850-500) 1.1 3.3 4.1 4.6 5.2
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GPS NAMEGPS NAMEPlace 5 additional instrumentation sets in Place 5 additional instrumentation sets in MexicoMexico–– GPS receiver, barometer, thermometer, GPS receiver, barometer, thermometer,
hygrometer,anemometer & web camhygrometer,anemometer & web cam–– Locations being finalizedLocations being finalized
MeasureMeasure column water vapor column water vapor && surface surface meteorological conditions meteorological conditions –– In convectively active area in SMOIn convectively active area in SMO–– In clear and cloudy conditionsIn clear and cloudy conditions–– 5 to 30 minute sampling 5 to 30 minute sampling –– Resolve diurnal water vapor cycleResolve diurnal water vapor cycle
Internet for near realInternet for near real--time access & time access & monitoringmonitoringFSL will provide GPS processing in near FSL will provide GPS processing in near realreal--time at 30 minute resolutiontime at 30 minute resolutionBegin by early to midBegin by early to mid--JuneJuneRun continuously through end of NAME Run continuously through end of NAME Summer 04 campaignSummer 04 campaign
6 Existing SuomiNet sites of UA/UNISON:Phoenix, Tucson, Mt. Hopkins, Douglas, Puerto Penasco, Hermosillo
RR
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GPS & GPS & Simulation Simulation
ResultsResults
Mt. Hopkins
TucsonWRFGPS
Diurnal PW variations over 4 days
WRF simulation
2003
Time derivative of PW
Monsoon in Tucson
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Indications of Convection in PW and Surface Indications of Convection in PW and Surface ObsObsCase of large PW Case of large PW discrepancy between GPS discrepancy between GPS & & sonde sonde due to local due to local convection near GPS site convection near GPS site (C. (C. Minjarez Minjarez thesis 2005)thesis 2005)
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Movie of Time Derivative of PWMovie of Time Derivative of PW
....\\namename\\wrf dpwwrf dpw__dtdt\\wrfoutwrfout_d01__d01_dpwdpw__dtdt.gif.gif
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Possible GPS Sampling of Catalina ConvectionPossible GPS Sampling of Catalina Convection
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Possible GPS Sampling of Catalina ConvectionPossible GPS Sampling of Catalina Convection
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GPS Receivers & Met. Packages on Mt. LemmonGPS Receivers & Met. Packages on Mt. Lemmon8 sites?: 2 on top, 3 on valley floor & 3 on flanks?8 sites?: 2 on top, 3 on valley floor & 3 on flanks?Useful existing or nearUseful existing or near--future sitesfuture sites–– Mt. Lemmon PBO GPS site end of 2004 (no met.)Mt. Lemmon PBO GPS site end of 2004 (no met.)–– COT2 in eastern Tucson (no met. but met. at UA)COT2 in eastern Tucson (no met. but met. at UA)–– 2 UA GPS & met packages potentially available2 UA GPS & met packages potentially available
Request additional receivers from UNAVCORequest additional receivers from UNAVCOOther issuesOther issues–– Finding accessible flank locations may be problemFinding accessible flank locations may be problem–– Power and data access?Power and data access?–– Met packages?Met packages?–– We will have to process 5 minute GPS here at UAWe will have to process 5 minute GPS here at UA
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Vertical Water Vapor InformationVertical Water Vapor InformationGPS constrains the time evolution of theGPS constrains the time evolution of the–– horizontal moisture structurehorizontal moisture structure–– layer moisture between valley floor & mountaintop layer moisture between valley floor & mountaintop
GPS provides relatively little information on GPS provides relatively little information on –– vertical water vapor structure above the mountain.vertical water vapor structure above the mountain.
We need frequent vertical information to complement We need frequent vertical information to complement GPS informationGPS informationMultiMulti--frequency microwave radiometer?frequency microwave radiometer?–– Borrow or rent from Borrow or rent from RadiometricsRadiometrics??–– NOTE: Following figures on radiometer from NOTE: Following figures on radiometer from Liljegren et al.
2001 AMS paper 8.6
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Data Assimilation Experiment?Data Assimilation Experiment?
Assess model consistency with observations and ability to Assess model consistency with observations and ability to assimilate observationsassimilate observationsEstimate system state by combining Estimate system state by combining CuPIDOCuPIDO observations and hiobservations and hi--res res model (WRF) model (WRF) –– Rapid update cycle (every 5Rapid update cycle (every 5--10 minutes)10 minutes)
Use “improved” state estimate to assess Use “improved” state estimate to assess CuPIDOCuPIDO hypotheseshypothesesOSSE to suggest instrument locations (may not have time)OSSE to suggest instrument locations (may not have time)PersonnelPersonnel–– Collaboration with Jeff Anderson & Collaboration with Jeff Anderson & HuiHui Liu at NCARLiu at NCAR–– Requires PostRequires Post--doc at UA for ~2 years, 1 to set DA system up doc at UA for ~2 years, 1 to set DA system up
and one to analyze resultsand one to analyze results»» Would have to develop forward operatorsWould have to develop forward operators