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NDACC Water Vapor Workshop, 5 July 2006NDACC Water Vapor Workshop, 5 July 2006
Holger VömelHolger Vömel
Cooperative Institute for Research in Environmental SciencesCooperative Institute for Research in Environmental Sciences
University of ColoradoUniversity of Colorado
Water vapor observations in the upper Water vapor observations in the upper troposphere and lower stratospheretroposphere and lower stratosphere
AcknowledgementsAcknowledgements
Rigel Kivi, FMI, SodankylRigel Kivi, FMI, Sodankylä, Finlandä, Finland
Steve Ryan, John Barnes, MLO, Hilo, HISteve Ryan, John Barnes, MLO, Hilo, HI
Beatrice Morel, University La ReunionBeatrice Morel, University La Reunion
Masato Shiotani, Kyoto UniversityMasato Shiotani, Kyoto University
Fumio Hasebe, Masatomo Fujiwara, Hokkaido UniversityFumio Hasebe, Masatomo Fujiwara, Hokkaido University
Students of the Universidad Nacional, Costa RicaStudents of the Universidad Nacional, Costa Rica
David Whiteman, NASA/GFSCDavid Whiteman, NASA/GFSC
Larry Miloshevich, NCARLarry Miloshevich, NCAR
Mario Agama, Jaime Cornejo, Francisco Paredes, INAMHIMario Agama, Jaime Cornejo, Francisco Paredes, INAMHI
NASA for their supportNASA for their support
Cryogenic Frostpoint Hygrometer (CFH)Cryogenic Frostpoint Hygrometer (CFH)
• Microprocessor controlMicroprocessor control
• Vertical Range: surface to ~28 kmVertical Range: surface to ~28 km (surface to ~25 km on ascent) (surface to ~25 km on ascent)
• Uncertainty: troposphere: > 4% MRUncertainty: troposphere: > 4% MR stratosphere: ~ 9 % stratosphere: ~ 9 %
• Phase sensitive detector: Phase sensitive detector: electronic sunlight filter electronic sunlight filter
• No liquid/ice ambiguityNo liquid/ice ambiguity
• Weight: ~ 400 grWeight: ~ 400 gr
• Currently interfaced with ECC ozone Currently interfaced with ECC ozone
sonde and Vaisala RS80 sonde and Vaisala RS80
• Based on NOAA/CMDL frost pointBased on NOAA/CMDL frost point hygrometer hygrometer
• 162 soundings162 soundings
Detector
IR LED
μ Controllerμ Controller
Cryogen
Air flow
Lens
Mirror
Heater
Frost layer
Thermistor
Sounding overview 2003-2006Sounding overview 2003-2006• Bandung, Indonesia: Bandung, Indonesia: 8 8• Beltsville, MDBeltsville, MD 1 1• Biak, Indonesia: Biak, Indonesia: 9 9• Boulder, CO: Boulder, CO: 3535• Heredia, Costa Rica: Heredia, Costa Rica: 60 60 • Hilo, HI: Hilo, HI: 1313• St. Denis, La Reunion: St. Denis, La Reunion: 1111• Midland, TX: Midland, TX: 1 1• ARM/CART, Oklahoma: ARM/CART, Oklahoma: 1212• San Cristobal, Galapagos:San Cristobal, Galapagos: 9 9• SodankylSodankylä, Finland: ä, Finland: 1212• Tarawa, Kiribati: Tarawa, Kiribati: 2 2 Total (June 2006):Total (June 2006): 172172
Tropical CFH observations Tropical CFH observations
Cold tropopause season:Cold tropopause season:
Costa Rica January/February 2006Costa Rica January/February 2006
30 CFH/ECC soundings30 CFH/ECC soundings
Biak, Indonesia, January 2006Biak, Indonesia, January 2006
9 CFH/ECC soundings9 CFH/ECC soundings
Bandung, Indonesia, Dec 2004, Dec 2005Bandung, Indonesia, Dec 2004, Dec 2005
8 CFH/ECC soundings8 CFH/ECC soundings
Water vapor mixing ratioWater vapor mixing ratioTicosonde 2006, Jan 4 – Mar 4, 2006Ticosonde 2006, Jan 4 – Mar 4, 2006
Water vapor mixing ratioWater vapor mixing ratioBiak, Indonesia, Jan 8-14, 2006Biak, Indonesia, Jan 8-14, 2006
Tropopause relative humidity (ice)Tropopause relative humidity (ice) Biak, Indonesia, Jan 8-16, 2006Biak, Indonesia, Jan 8-16, 2006
12 January
14 January
Wave related dehydration: Double tropopauseWave related dehydration: Double tropopause Biak, Indonesia, Jan 8-14, 2006Biak, Indonesia, Jan 8-14, 2006
Extreme dehydrationExtreme dehydrationBiak, Indonesia, Jan 8-14, 2006Biak, Indonesia, Jan 8-14, 2006
RH(ice) & lidar backscatter ratioRH(ice) & lidar backscatter ratioBandung, Indonesia, Dec 15, 2004Bandung, Indonesia, Dec 15, 2004
Instrument validationsInstrument validations
• RS92 humidityRS92 humidityAURA / MLS water vaporAURA / MLS water vapor
• JPL TDLJPL TDL
• Harvard Lyman-alphaHarvard Lyman-alpha
Ticosonde/CR-AVE 2006, 28 Nov 2005 – 2 Mar 2006Ticosonde/CR-AVE 2006, 28 Nov 2005 – 2 Mar 2006AURA MLS vs CFHAURA MLS vs CFH
CFH AdvantagesCFH Advantages
• Measurement based on simple physicsMeasurement based on simple physics• Measurement not calibrated for water Measurement not calibrated for water
vapor, but rather for temperaturevapor, but rather for temperature(assume vapor pressure equation is correct)(assume vapor pressure equation is correct)
• Extremely large dynamic rangeExtremely large dynamic range
• Long history for technologyLong history for technology
• Can be deployed easily at existing Can be deployed easily at existing sounding sitessounding sites
CFH LimitationsCFH Limitations
• Instrument may fail completely in “thick” liquid Instrument may fail completely in “thick” liquid cloudsclouds
• High costHigh cost• Availability of cryogenAvailability of cryogen• Instrument needs minor preparationInstrument needs minor preparation• Data product needs understanding of instrumentData product needs understanding of instrument
FLASH - Lyman-FLASH - Lyman-αα
• Fluorescent Lyman Alpha Stratospheric Fluorescent Lyman Alpha Stratospheric Hygrometer (FLASH) Hygrometer (FLASH)
• Vertical Range: upper troposphere to Vertical Range: upper troposphere to stratosphere stratosphere (0.5 to 500 ppmv) (0.5 to 500 ppmv)
• Calibrated against reference frost point Calibrated against reference frost point
• Uncertainty: 9% MRUncertainty: 9% MR
• Night time (descent) onlyNight time (descent) only
• Weight: ~ 1 kgWeight: ~ 1 kg
• Currently interfaced Vaisala RS80Currently interfaced Vaisala RS80
• 45 soundings45 soundings
FLASH AdvantagesFLASH Advantages
• Calibrated against frost point standardCalibrated against frost point standard
• High measurement precisionHigh measurement precision
• Very fast sensorVery fast sensor
• Largely insensitive to cloudsLargely insensitive to clouds
• Large dynamic range (low mixing ratios)Large dynamic range (low mixing ratios)
FLASH LimitationsFLASH Limitations
• Instrument measures properly on descentInstrument measures properly on descent• Can only measure during night timeCan only measure during night time• Full moon limits data rangeFull moon limits data range• High costHigh cost• Measurement range : 0.5 to 500 ppmvMeasurement range : 0.5 to 500 ppmv• Currently can’t check calibration in the fieldCurrently can’t check calibration in the field
MayComm TDLMayComm TDL
• Tunable Diode LaserTunable Diode Laser
• Vertical Range: mid troposphere to Vertical Range: mid troposphere to stratosphere stratosphere
• Calibrated against reference frost point Calibrated against reference frost point
• Uncertainty: 5% MRUncertainty: 5% MR or 0.5 ppmv or 0.5 ppmv
• Payload weight: ~ 1 kgPayload weight: ~ 1 kg
MayComm TDLMayComm TDLCosta RicaCosta RicaJanuary/February 2006January/February 2006
5 TDL soundings5 TDL soundings
MayComm TDL vs CFHMayComm TDL vs CFHCosta RicaCosta RicaJanuary/February 2006January/February 2006
13 CFH soundings13 CFH soundings
MayComm TDL AdvantagesMayComm TDL Advantages
• High measurement precisionHigh measurement precision
• Very fast sensorVery fast sensor
• Insensitive to cloudsInsensitive to clouds
• Large dynamic range (low mixing ratios)Large dynamic range (low mixing ratios)
• Easy to useEasy to use
MayComm TDL LimitationsMayComm TDL Limitations
• Prototype onlyPrototype only• High costHigh cost• No lower troposphere No lower troposphere
(Can extend to surface with second path)(Can extend to surface with second path)• No stable interface/telemetry system yetNo stable interface/telemetry system yet
Claimed Claimed accuracyaccuracy CalibrationCalibration LimitationsLimitations
Dynamic Dynamic rangerange HistoryHistory CostCost
Ease of Ease of useuse
EngineeringEngineeringstatusstatus
CFHCFH0.5°C DP/FP
4-9% ++ No "wet" clouds ++ + - (o) o
research /small series
Snow WhiteSnow White 0.1°C DP/FP +Some cloudsRH > 3-6%
No stratosphereo + o ++
productionsmall series
Lyman-alpha (FLASH)Lyman-alpha (FLASH)9%
(20% below 2 ppmv)
+Night time onlyDescent only
No lower troposphere + o -- +
research /small series
TDL (MayComm)TDL (MayComm)5%
0.5 ppmv o ? + - -- (++)
Proof of concept
Polymer (Vaisala RS92)Polymer (Vaisala RS92) 1% RH -
No stratosphereLarge radiation error
Chemical contaminationVery hard to trace
sensor/calibration changes
- + ++ + (++)Large scale production
Instrument validationsInstrument validations
• RS92 humidityRS92 humidity
• AURA / MLS water vaporAURA / MLS water vaporJPL TDLJPL TDL
• Harvard Lyman-alphaHarvard Lyman-alpha
Ticosonde/CR-AVE 2006, 14 Jan 2006 – 10 Feb 2006Ticosonde/CR-AVE 2006, 14 Jan 2006 – 10 Feb 2006JPL TDL vs CFHJPL TDL vs CFH
Instrument validationsInstrument validations
• RS92 humidityRS92 humidity
• AURA / MLS water vaporAURA / MLS water vapor
• JPL TDLJPL TDLHarvard Lyman-alphaHarvard Lyman-alpha
Ticosonde/CR-AVE 2006, 14 Jan 2006 – 10 Feb 2006Ticosonde/CR-AVE 2006, 14 Jan 2006 – 10 Feb 2006Harvard Lyman-Harvard Lyman-αα vs CFH vs CFH
AcknowledgementsAcknowledgements
Rigel Kivi, FMI, SodankylRigel Kivi, FMI, Sodankylä, Finlandä, Finland
Steve Ryan, John Barnes, MLO, Hilo, HISteve Ryan, John Barnes, MLO, Hilo, HI
Beatrice Morel, University La ReunionBeatrice Morel, University La Reunion
Masato Shiotani, Kyoto UniversityMasato Shiotani, Kyoto University
Fumio Hasebe, Masatomo Fujiwara, Hokkaido UniversityFumio Hasebe, Masatomo Fujiwara, Hokkaido University
Students of the Universidad Nacional, Costa RicaStudents of the Universidad Nacional, Costa Rica
David Whiteman, NASA/GFSCDavid Whiteman, NASA/GFSC
Larry Miloshevich, NCARLarry Miloshevich, NCAR
Mario Agama, Jaime Cornejo, Francisco Paredes, INAMHIMario Agama, Jaime Cornejo, Francisco Paredes, INAMHI
NASA for their supportNASA for their support
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