cupido gps pw & surface obs. array · 4/11/2005 · april 11, 2005 cupido meeting kursinski 3...

$: CuPIDO GPS PW & Surface Obs. Array · 4/11/2005 · April 11, 2005 CuPIDO Meeting Kursinski 3 GPS Atmospheric Observable: Refractivity Atmospheric refractivity, N = (n-1) x 106:$
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


How Does the Atmosphere Affect the GPS Signals?

Figures courtesy of Kirk Holub NOAA FSL


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:


Transformations in GPS-Met

Figure courtesy of Kirk Holub NOAA FSL


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


Tucson


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


Frontal passage

radiosonde

GPS

Passage of a frontyesterday in the central US

Figures courtesy of Kirk Holub NOAA FSL


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


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


GPS & GPS & Simulation Simulation

ResultsResults

Mt. Hopkins

TucsonWRFGPS

Diurnal PW variations over 4 days

WRF simulation

2003

Time derivative of PW

Monsoon in Tucson


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)


Movie of Time Derivative of PWMovie of Time Derivative of PW

....\\namename\\wrf dpwwrf dpw__dtdt\\wrfoutwrfout_d01__d01_dpwdpw__dtdt.gif.gif


Possible GPS Sampling of Catalina ConvectionPossible GPS Sampling of Catalina Convection


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


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


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

cupido gps pw & surface obs. array · 4/11/2005 · april 11, 2005 cupido meeting kursinski 3...

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