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

OverviewOverview

• Frost pointFrost point

• Lyman-Lyman-αα

• TDLTDL

• SummarySummary

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 2005, July 8-24, 2005Ticosonde 2005, July 8-24, 2005AURA MLS vs CFHAURA MLS vs CFH

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 - Lyman-FLASH - Lyman-αα

FLASH - Lyman-FLASH - Lyman-αα

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 – CFH comparisonMayComm TDL – CFH comparison

MayComm TDL VariabilityMayComm TDL Variability

TDLTDL CFHCFH

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

Questions?Questions?

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