FLASH-B FLuorescent Advanced Stratospheric Hygrometer (for balloon and aircraft) Instrument design.Observations and comparison.Central Aerological ObservatoryKhaykin S., Yushkov V., Korshunov L., Lukyanov A.ISSIAtmospheric Water Vapour 10-15 Febr.2008 Bern

Aircraft FLASH-B uses closed optical cell

Day&night time mesurementsBalloon FLASH=B uses open optical cell

Night time measurements

Short balloon & long duration balloonISSIAtmospheric Water Vapour 10-15 Febr.2008 Bern

FLASH-B instrument ISSIAtmospheric Water Vapour 10-15 Febr.2008 Bern

Source of VUV radiationh =121,6 nm (Lyman-)2 (2S) (2+) (2 ) PMT2 + h (2+) + (2S) Fluorescense (2+) (2) + h

Quenching (2+) + N2, 2 products Ifl fluorescense intensity J - photodissotiation rate= 0,05 - quantum efficiency for excited OH production=1,26106 s-1 Einstein coefficient,kqair. = 2,310-11 sm3 s-1 quenching coefficient of the excited OH in air300 < < 330 nm [H2O]I fl = Scal-------- [ air]

FLASH-B optical layout

Electronic block-layout of FLASH-BVUV lamp Lyman-alpha 1 KHz 121,6 nmH2OOH* 310 nm Interference filter Photomultiplier P, T, UReceiverModemPCOSCLampdriverPMTpower microcontrollerVAISALARS-80radiosondeSynchrofilterSynchrodetectorData frameISSIAtmospheric Water Vapour 10-15 Febr.2008 Bern

CompressorFLASH-BVacuum pumpdehumidifier H2O bubbler flow controllerhomogenizer Reference dew point mirror hygrometerMBW 373Lair out Calibration facility layoutflow controllerVacuum chamberPressure:3 ..1100 hPaTemperature:-80 .. +20 0CWVMR:1 .. 1000 ppmv

FLASH-B characteristicsISSIAtmospheric Water Vapour 10-15 Febr.2008 Bern

Range of water vapour measurementsResponse timeIntegration timeMeasurement precisionTotal uncertaintyTemperature rangeHeight rangeRequired powerWeight w/out batteriesInterface cardRadiosonde0.5...500 ppmv0.2 sec4 sec5.5% 3 ppmv-950C +400C7 35 km9-30V, 10W max0.5 kgBuilt-in (T-MAX type)Vaisala RS80-15 A(L)

Ny-AlesundSodankylLindenbergMeasurement sites since winter 2004

Intercomparison of FLASH-B and NOAA/CMDL hygrometers in the stratosphere Descent data only

Mean difference in the 11,8 25,6 km range is: 2.6 3.1 % (1 )

Large disagreement in the 8,8 11,8 km range is caused by the feedback gain change in the NOAA hygrometer

Comparison of in-situ balloon-borne and remote microwave water vapour measurementsB. Deuber et al., 2005, JGRComparison of MIAWARA (solid grey), NOAA(dashed black)/CU-CFH (dashed-dotted black) and FLASH-B (solid black) (balloon descent) profiles for different days. The black dots are measurements by NOAA/CU-CFH which were not considered due to remaining wet contamination from theascent or instrumental failure. The balloon profiles were reduced to the microwave retrieval grid usingthe Curtis - Godson equation. The CU-CFH sonde was flown on Feb-15 and Feb-25, on the other flights the older NOAA version was used.

Simultaneous humidity measurements in the troposphere during LAUTLOS 11 February 2004

Simultaneous humidity measurements in the troposphere during LAUTLOS 23 February 2004

Water vapour profiles inside, otside and at the edge of polar vortex during LAUTLOS campaign (Sodankyla, Jan-Feb 2004).

Water vapour soundings at the Arctic stations in 2006/2007

Water vapour soundings in the tropics in 2006 (SCOUT-AMMA)

SCOUT-AMMA balloon campaign.Local convection on 23 August1510520Hydration of LS by ice geysersC-band radar cloud tops height at 16:51 UT on 23 August, two hours before the sounding from Niamey

NASA TC4 campaign, Costa-Rica, 100 N, August 2007 (sonde programme): simulataneous measurements of water vapour and ozone by FLASH-B and CFH hygro-sondes.

NASA TC4 campaign, Costa-Rica, 100 N, August 2007 (sonde programme): simulataneous measurements of water vapour and ozone by FLASH-B and CFH hygro-sondes.Comparison between FLASH-B and CFH H2O descent profilesMean relative difference in the 10% range

Comparison between FLASH-B and ECMWFArcticISSIAtmospheric Water Vapour 10-15 Febr.2008 Bern

Comparison between FLASH-B and ECMWFTropicsISSIAtmospheric Water Vapour 10-15 Febr.2008 Bern

tropopause (17 km):cold point and cold trapSCOUT-O3 Darwin, Australia, 120 S, November 2005H2O and O3 measurements with FISH on board M55-GeophysicaCourtesy of C. Schiller

SCOUT-O3 Darwin, Australia, 120 S, November 2005H2O and O3 measurements with FLASH and FOZAN on board M55-Geophysica16 NovemberWell mixed dry air between LRT and CPTCPTLRTNo signs of hydration in LS above HectorWarmer T and higher O3 in LS above Hector

SCOUT-O3 Darwin, Australia, 120 S, November 2005H2O and O3 measurements with FLASH and FOZAN on board M55-GeophysicaH2O, temperature and O3 profiles above DarwinNo signs of hydration in LS above HectorEnhanced ozone inside HectorDry and mixed TTL with H2O amounts controlled by saturation at CPT

Ice geyser hydration across the tropopause may be the dominant factor controlling water vapour at global scale in the stratosphere.Concluding remarks WVMR observations above Darwin do not show strong signatures of LS hydration above HectorH2O, O3 and particles measurements above Africa during monsoon season strongly indicate that convective overshooting above continental region hydrates lower stratosphere Ice geyser hydration across the tropopause may be the dominant factor controlling water vapour at global scale in the stratosphere.

FLASH-B on board long duration super pressure balloon CNES SPB mission in Esrange, Kiruna, Sweden (March 2007)1st day of flight contamination from the payload5th day of flight dry payload, no contamination

FLASH-B on board long duration super pressure balloon CNES SPB mission in Esrange, Kiruna, Sweden (March 2007)12 m2 CNES SP balloon launched from Esrange on 05.03.20078 days flight around the pole inside vortexFLASH-B in the bottom of flight train15 minutes measurements every 2 hours during night timeLanding and recovery in Sweden

THANK YOU

Simultaneous humidity measurements in the troposphere during Scout-AMMA

Water vapour soundings at the Arctic stations in 2004/2005

FLASH-B water vapour observations in the presence of PSCsFLASH-B water vapourTemperature and PSCs thresholdsNy-Alesund (78,9 N, 11,9 E) 6 January 2005

lidarwater vapourFLASH-B water vapour observations in the presence of PSCsNy-Alesund (78,9 N, 11,9 E) 26 January 2005

********Since 2004 FLASH-B was regularly flown from the 3 European stations, Ny-A, Sod and Lindenberg. We have obtained a valuable dataset with a number of interesting case examples of WV verticval distribution under different stratospheric conditions. In Jan-Feb 2004 FLASH-B participated in the intercomarison balloon campaign LAUTLOS-WAVVAP hosted by FMI in the ARC at Sodankyla. Different hygrosondes have been flown on one payload to compare their performance both in troposphere and stratosphere. ****