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NASA/GSFC Scanning Raman Lidar measurements of water vapor and clouds during IHOP. David N. Whiteman/NASA-GSFC, Belay Demoz/UMBC Paolo Di Girolamo/Univ. of Basilicata, Igor Veselovskii, Joe Comer, Ruei-Fong Lin/UMBC, Gerry McIntire/Raytheon.
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NASA/GSFC Scanning Raman Lidar measurements of water vapor and clouds during IHOP David N. Whiteman/NASA-GSFC, Belay Demoz/UMBC Paolo Di Girolamo/Univ. of Basilicata, Igor Veselovskii, Joe Comer, Ruei-Fong Lin/UMBC, Gerry McIntire/Raytheon Acknowledgement: Interdisciplinary Research, Jim Dodge, NASA/HQ
Outline • Scanning Raman Lidar (SRL) • Extensive system modifications prior to IHOP • Error characterization • May 22 dryline event • Measurement example • June 3-4 bore • June 19-20 • Bore case • Cirrus cloud modeling study
Scanning Raman Lidar • Telescopes: 0.76 and 0.25 m • Nd:YAG (9W @ 355 nm) • Windows • 12 channel AD/PC • IHOP Accomplishments • >200 hours • Factor of 10 increase in water vapor signal • High quality daytime measurements • Aerosol depolarization • Cirrus cloud studies • RR Temperature (DiGirolamo et. al.) • Demonstration of eye-safe concept • Liquid water • Cloud droplet retrieval studies
Day Night Water Vapor Mixing Ratio Precision(Dryline May 22, 2002 - see Demoz et. al.) • Full Resolution (1 minute, 30 meters) • Less than 10% to beyond 2 km. • As Distributed (2 min, 60-210 meters) • day <10% in BL • night <2% in BL, <10% to 6km Measurement improvements permit convective processes to be studied throughout the diurnal cycle
Raman Airborne Spectroscopic Lidar (RASL) • Recent ground-based measurements validate the RASL system modeling - Appl Opt., 40, No. 3, 375-390 (2001) • water vapor, aerosol backscatter/extinction/depolarization, cloud liquid water • 10 km flight altitude • 10 second nighttime, 2 minute daytime profiles • <10% random error throughout profile, <5% in BL
Night Day Night The June 4 bore ExampleJune 3-4 (See Koch et. al.) The full dataset
IHOP Analysis Update • Preliminary release of all priority water vapor data • Final release awaiting IHOP specific calibration • Data distributed to 6 km • Higher altitude data awaiting correction for temperature dependence of water vapor spectrum • Aerosol datasets require extra attention • Correction for finite filter width and temperature dependence of rotational Raman scattering • Depolarization calibration
Anvil/Cirrus outflow UT humidification Falling ice? Wave propagation? Storm Motion Density/Bore wave June 19-20, 2002Thunderstorm outflow case
Day Night Evidence of wave action in several locations June 19-20 Bore (See also Flamant et. al.)
Upper Troposphere Humidification and Cirrus Cloud Evolution Theta Sequence of RH with respect to ice up to 12 km Cirrus evolution modeling case. Particle size and ice water content coming…
Comparison of Measurements and Modeling Model inputs: theta, RHi, P, Size Distribution for each grid box and W (uniform vertical wind for the entire air column). Size and IWC estimates from lidar coming…
Conclusions and the Future • Working hypothesis of waves on June 20 • Mechanical lift up to 6 km • Waves in cirrus clouds induced by shear • GLOW and SRL Scorer calculations • Continue cirrus cloud modeling comparison • Extend the time domain of the model • Couple 2-D cloud and mesoscale models • Seeding and source of wave energy for lower cirrus cloud layer • Simulate wave motion and study effects on microphysics • IHOP Data processing • Final release of water vapor data • IHOP specific water vapor calibration • Aerosol and liquid water analysis • SRL • Automated and eye-safe • Repackage in c-tainer