1. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 1 Monitoring Atmospheric Humidity from Commercial Aircraft by MOZAIC-IAGOS: In-sights from the Past and Present into the Future Herman G. J. Smit (h.smit@fz-juelich.de)h.smit@fz-juelich.de Forschungszentrum Juelich (ICG-2) Past and Present: MOZAIC Humidity Sampling Quality Assurance & Synergy of Data Future: IAGOS

2. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 2 Doubling CO2-concentration: 2-5 o C Temperature increase 1/3-part: direct via CO2 2/3-part: via positive feedback of water vapor+clouds Upper troposphere most sensitive region in climate change Why Monitoring Humidity in Upper Troposphere ??

3. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 3 Routine Aircraft Measurements in the Global Observing System: The Link Between Surface and Space

4. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 4 MOZAIC: Humidity Sampling

5. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 5 MOZAIC: Humidity Sensor in Rosemount Air Inlet System TAT, RH D SAT RH S Rosemount Housing Total Temperature Model 102 BX In inlet speed reduction (Mach  0.8 to 0) with adiabatic conversion: ► Heating (SAT to TAT) : in UT  30 o C ► Compression (P S to P D ): in UT  Factor 1.6 RH at detector (RH D ) << RH sampled air (RH S ) ► At cruise altitude RH S  13 x RH D

6. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 6 MOZAIC-Humidity Device: Pre-&Post Flight Calibration  Regular calibration (every 500 flight hours)  In environmental simulation chamber  Against Lyman(  )-fluorescence hygrometer  Under realistic flight conditions of humidity, temperature and pressure  Evaluation of two year record of pre- and post-flight calibrations  Results agree well with in-flight intercomparisons [Helten et al. Geophys.Res.1998, 1999] In: Helten et al., J.Geophys.Res., 1998

7. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 7 MOZAIC Relative Humidity in Upper Troposphere (UT) over Atlantic MOZAIC provided the first climatology of humidity in the UT Large variability in time and space More than 30% of UTH-data are Ice Super Saturated (ISS) But less than 0.5-1% of data are Saturated to Liquid %  Control of Humidity in UT??  Long Term Changes ??

8. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 8 Critical aspects on inlet system Ice Super Saturation over North Atlantic:  More than 35% of UTH ice super saturated  But less than 1% of observations are saturated to liquid Separation solid / gas phase Particle enhancement Evaporation droplets & crystals Wall memory effects Well defined P & T (cq. SH & RH)-conditions MOZAIC

9. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 9 Performance MOZAIC Humidity Device in Clouds Evaporation of Ice Crystals ??????? Clouds are clearly detected as „RHI-burst“ to 200% by the Lyman (  )-Total H 2 O In clouds the MOZAIC-Humidity Device not exceeding 100% RHI

10. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 10 Small scale phenomenon (  X < 200 km,  Z < 1-2 km) Difficult to see by satellites Importance: contrail & cirrus formation; radiative balance; OH formation 30% of the UT shows ice super saturation (ISS) Global models do not reproduce ISS ISS relates with sub-visible cirrus Horizontal extent of ISS regions MOZAIC: Ice Super Saturation (ISS) in the UT

11. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 11 -100 100-500 AIRS - MOZAIC RH (liq.%) 50 RH (liq.%) MOZAIC 0 AIRS 2040 60 80 100120 MOZAIC- UTH: Comparison with AIRS-Satellite over 2003 (Work by Co PI: Andrew Gettelman, NCAR, Boulder, USA) Development of proper „matching“ citeria of coincidence in space and time: A priori estimation of contribution of natural variability Direct comparison at (x,y,z,t) Indirect by optimizing statistics of coincidence by using backward trajectories

12. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 12 Involvment Temperature Measurements Using TAT-Housings: Comparison Temperature Aircraft versus MOZAIC T emp. Spec. Hum. Rel. Hum. In addition, important aspect at low temperatures: Which H2O-saturation pressure E s (T)-table has been applied ???

13. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 13 Development of Automatic In-flight Calibration (IFC) Based on the technology and experience obtained during 8 years of MOZAIC-operation. Long-term zero drift of MOZAIC-device, particularly at low temperatures, is the critical and accuracy determining parameter On-line determination of long term zero drift during dry stratospheric episodes (5ppmv water vapor) as a function of temperature. On-Line correction of zero drift of RH-measurements

14. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 14 MOZAIC In-Flight Calibration (IFC): Validation Comparison with MOZAIC In-flight comparison during SPURT with Ly(  )-Hygrometer (FISH) RH(IFC) – RH (MOZAIC) [%RH] IFC

15. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 15 US-NWS has installed on 25 UPS aircraft since 2005, now in evaluation phase but with plans to extend to large number Poor documentation on evaluation of performance FZJ has evaluated in the laboratory in 2005 DWD has installed on three A320 of Lufthansa since 2007 In the loop: plans to install on a MOZAIC/IAGOS A340 of Lufthansa ? Can new airborne WVSS-II measure humidity in UT and LS?: State of the Art Diode laser (2f-detection) Compact (  2.5 kg) Designed for automatic on-line sampling of humidity from aircraft for weather forecasting AMDAR Goal NWS: Reduce radiosounding network and replace by AMDAR

16. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 16 MOZAICWVSS-IIOpen Path TDLSAW-FrostpointFLASH Weight2 kg3 kg102 kg Internal Box Size 14x12x7 cm23x13x8 cm~25x25x15 cm~15x15x10 cm~20x8x8 cm Price (kEuro)~20 ~50 (estimated)~20 (estimated) Principle Capacitive (Humicap) Spectroscopic (Tunable Diode Laser) Spectroscopic (Tunable Diode Laser) Frostpoint (Surface acoustic wave chip) Lyman( α ) Fluorescence Inlet system - Wall effects Rosemount - No wall effects Wall plate in AC skin - Not known External mounting of optical cell Rosemount - Not known Rosemount (??) -Not known Calibration frequency every 6 monthsNot proven Altitude Range0-12 km0-6 km0-12 km 6-12 km Accuracy 5-10% of Rel. Hum. 5-10% of Mix. Ratio Not known 5-10% of Mix. Ratio Detection Limit5% Rel. Hum.70 ppmv1 ppmvNot known0.5 ppmv Time response 5s (0km), 60s (12km) 2s1s 4 s Long term stability Proven (12 yrs MOZAIC) Not provenNot Known Not known Maintenance Proven, every ½ year Not ProvenNot Known Not known Documentation of performance Peer reviewed literature Only internal reports ??? Under investigation (IAGOS) Only internal reports Compact Sensors for Measuring Humidity on In-Service Aircraft

17. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 17 Reports: Aircraft Identification Date Time (UTC) Position Altitude (Pressure) Temperature Windspeed Wind Direction Planned: Water Vapor Mass Mixing Ratio AMDAR = Aircraft Meteorological DAta Relay Aboard Commercial Aircraft For Weather Forecasting

18. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 18 Can new airborne WVSS-II measure humidity in UT and LS???: Performance tests at Environmental Simulation Facility at Jülich, Germany WVSS at Frostpoint Temperatures: Above ~290 K: No reliable signal 225 K – 290 K: Good performance: Accuracy ±(5-10)% 215 K – 225 K: Rapid declining sensitivity, Limited accuracy: <±(10-15)% Below ~ 215 K: Below detection limit (80 ppmv) Poor performance in UT/LS Diode laser (2f-detection) Compact (  2.5 kg) Designed for automatic on-line sampling of humidity from aircraft for weather forecasting AMDAR

19. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 19 Pre-and Post flight calibration every 500 flight hours) [Helten et al. 1998] In-flight comparisons (In-service & Research) [Helten et al., 1999] Evaluation in SPARC-water vapor assessment 2000 report Development in-flight calibration (IFC) method [Smit et al., 2008] Evaluation of detection of ice superation saturation [in-preparation] Assessment of performance of 12 years of MOZAIC-flight operation [in preparation] 12 year Climatology of MOZAIC-H2O/T data available in MOZAIC-data base at Toulouse Participating in COST-action WaVaCS (Watewr Vapor in the Climate System) Participating in new, second SPARC water vapor assessment New instruments are under investigations. MOZAIC/IAGOS: Summary QA-H2O/T Performance

20. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 20

21. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 21 Extra Material

22. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 22 Tompkins, Gierens, Rädel, Quart.J.Roy.Met.Soc, 2007 ECMWF Model Now With Ice Super-Saturation

23. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 23 MOZAIC: Comparison Temperature Aircraft versus MOZAIC ] Both measured with Rosemount TAT Assumption full adiabatic conversion: Measurement of TAT (σ=±0.25K) Determination M from TAP (σ=±0.25hPa) & SAP (σ=±0.35hPa) Determination SAT (σ=±0.50K) Practice: TAT-recovery only 99.5-99.7% Correction tables based on wind duct measurements (made in 1960/1970‘s) Dependece on angle of attack Dependence on location at aircraft skin Remaining sources of uncertainties TAT = Total Air Temperature SAT = Static Air Temperature TAP = Total Air Pressure SAT = Static Air Pressure =0.2

24. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 24 Rosemount-TAT inlet systems: No indication of evaporation of ice crystals Evaporation of liquid droplets Large temperature sensitivity of H2O-saturation: Review of water vapor saturation tables at low temperatures Temperature measurement needs more attention: - Adiabatic recovery factor - Location at aircraft - Comparison with other in-situ temperature sensing technics Scale analysis of spatial and temporal distribution of ISS Climate impact of ISS Outstanding Issues UTH-ISS Observations

25. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 25 MOZAIC Humidity Device: Performance and Quality Assurance  Evaluation of two year record of pre- and post-flight calibrations  Results agree well with in-flight inter comparisons [Helten et al., J.Geophys.Res.1999] Calibration procedure: 1.Pre-flight calibration: a 1 (T i ) & b 1 (T i ) - Installation in A340 -  500 h of flight operation - Exchange of MHD 2.Post-flight calibration: a 2 (T i ) & b 2 (T i ) - Cleaning RH- & T-sensor 3.Pre-flight calibration - Etc. etc. RH CAL (T i ) =a (T i )+b (T i ) x RH UNCAL (T i ) Uncertainty of RH is derived from: Difference between pre-and post flight calibration of RH Uncertainty Temperature In: Helten et al., J.Geophys.Res., 1998

26. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 26 MOZAIC-Humidity: In-Flight Comparison with Frost Point Hygrometer (Ovarlaz) on Falcon (DLR/Nov.1997) [Helten et al., J.Geophys.Res.1999]

27. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 27 MOZAIC-UTH: Comparison with POEM III Satellite  POEM III= Polar Ozone and Aerosol Measurement III satellite operational since April 1998  Good agreement POEM with MOZAIC (Slope=0.98)  Large variations due to  Atmospheric variability &  Limited resolution of POEM (  X=250 km) Source: Nedoluha et al., POAM III measurements of water vapor in the upper troposphere and lower most stratosphere, J. Geophys. Res., 2002 Coincidence criterion: 2.5º x 2.5º x 1 km x 6 h Total: 200 Coincidences April 1998-Feb.2000 Slope = 0.98 (r=0.70) Offset= 3.6 ppmv 0 200 100300400 200 100 300 400 POEM-UTH (ppmv) MOZAIC-UTH (ppmv)

28. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 28 MOZAIC-UTH: Comparison with MLS/UARS Satellite  MLS observe no ice super saturation (retrieval and/or limited horizontal resolution)  MLS lower than MOZAIC (Slope=0.64)  Large variations due to  Atmospheric variability &  Limited resolution of POEM (  Z=4-5 km) Source: Read et al., UARS Microwave Limb Sounder upper tropospheric humidity measurement: Method and validation, J. Geophys. Res., 2001 Coincidence criterion: 1º x 1º x 1 km x 3 h Total: 384 Coincidences Aug.1994-Dec.1997

29. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 29 MOZAIC: Distribution Relative Humidity in UT over Atlantic Z = 9-12 km, PV  2.0pvu, 10 o W-70 o W, Aug 1994 - June 2000  38% ISS  15% ISS  22% ISS

30. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 30 Performance MOZAIC Humidity Device & ISS: Artifacts due to Evaporation of Ice Crystals ???????

31. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 31 MOZAIC-IFC: In-Flight Correction of Zero Drift of RH-measurements

32. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 32 Every 6 months cleaning sensor at airport: rins with destilled water (1 min) rins with alcohol ( 1min) heat out (1 min @ ~90 o C) Every 2 year overal check at service company: exchange humidity device and send to service company overall check of device (new sensors, calibration etc.). Outlook: automatic cleaning procedure at airport collaborations with companies for instrumental and QA support (e.g.Vaisala) Operational Aspects of MOZAIC-Humidity Device From Board Commercial Aircraft

33. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 33 4/2008IAGOS Design Study completed, - Prototypes available, - Partner airlines committed 2008First aircraft equipped and commissioned: O 3, CO, H 2 O, Cloud Droplet Probe, NO y 2009Certification for CO 2 and aerosol 2016 20 aircraft equipped and commissioned 2028 20 years of data available ~ 150 000 flights http://www.fz-juelich.de/icg/icg-ii/iagos Coordinator: Dr. Andreas Volz-Thomas E-mail: A.Volz-Thomas@fz-juelich.de IAGOS-ERI: Time Table

34. H2O from MOZAIC-IAGOS // Herman Smit/FZJ ISSI-H2O Bern 11-14 Feb.2008 34 Candidates for Automatic Monitoring Humidity by Commercial Aircraft WVSS-II