LASE Measurements of Water Vapor During IHOP Edward

LASE Measurements of Water Vapor During IHOP Edward V. Browell, 1 Syed Ismail, 1 Richard A. Ferrare, 1 Susan A Kooi, 1 and Vince G. Brackett, 1 1 NASA Langley Research Center, Hampton, Virginia 2 Space Science & Engineering Center, University of Wisconsin, Madison, WI Funding provided by Dr. Jim Dodge, NASA Headquarters IHOP Water Vapor Intercomparison Meeting, NCAR, 2 -3 October 2003

Lidar Atmospheric Sensing Experiment (LASE) • Airborne Water Vapor DIAL • Laser - 5 Hz doubled-pulsed Ti: sapphire - 100 mj at lon and loff • Wavelengths - 815 nm (lon- loff = 40 -70 pm) - Two separate line pairs • NASA ER-2, P-3, DC-8 aircraft • Simultaneous nadir, zenith operations • Real-time data analysis and display

LASE Water Vapor, Aerosol, & Cloud Profiling on NASA DC-8 9 June 2002 (Flt. 9) Morning Low Level Jet and Convective Initiation #3 • Water vapor profiles - daytime and nighttime - 0. 2 km to upper trop. - 0. 01 to 25 g/kg - accuracy: 6% or 0. 01 g/kg - resolution (variable) vertical: 330 m horizontal: 14 km (1 min) • Aerosol/cloud profiles - daytime and nighttime - 0. 03 to 25 km -resolution (variable) vertical: 30 m horizontal: 200 m

LASE Water Vapor & Relative Humidity Profiling on NASA DC-8 9 June 2002 (Flt. 9) Morning Low Level Jet and Convective Initiation #3 • Water vapor profiles - daytime and nighttime - surface to upper trop. - 0. 01 to 25 g/kg - accuracy: 6% or 0. 01 g/kg - resolution (variable) vertical: 330 m horizontal: 14 km (1 min)

LASE Water Vapor & Relative Humidity Profiling on NASA DC-8 9 June 2002 (Flt. 9) Morning Low Level Jet and Convective Initiation #3 • Water vapor profiles - daytime and nighttime - surface to upper trop. - 0. 01 to 25 g/kg - accuracy: 6% or 0. 01 g/kg - resolution (variable) vertical: 330 m horizontal: 14 km (1 min) • Relative humidity profiles - derived Scanning-HIS or radiosonde temperature distributions

LASE Measurements during IHOP • Participated in 8 IHOP science flights from May 23 -June 14, 2002

LASE Water Vapor Comparisons Nighttime Daytime

LASE/IHOP 2002 ALL COMPARISONS (delta time < 75 min, delta location < 75 km) Flight Date RS 90 BF CF 5 5/24 6 5/30 7 6/02 4 8 6/03 1 9 6/09 10 6/11 11 6/14 TOTAL 2 RD 93 Lear Falcon RS 80 HS MG 8 DC 5 2 1 8 1 3 BF - Boundary Facility sonde CF - Central Facility sonde Lear - Dropsonde Falcon - Dropsonde 2 1 3 7 15 8 2 3 4 4 1 4 3 9 2 8 11 28 5 22 39 15 1 3 7 9 SRL 2 1 1 AERI CARL DLR HS - Homestead sonde MG - MGLASS mobile sonde DC - Dodge City sonde (VIZ) AERI- at Homestead 2 17 3 9 11 3 3 Total 1 3 30 3 38 23 7 3 9 31 18 158 CARL - Raman Lidar at CF DLR - Lidar on Falcon SRL- Scanning Raman Lidar at Homestead

LASE/IHOP 2002 CLOSEST COMPARISONS (delta time < 20 min, delta location < 20 km) Flight Date RS 90 BF CF RD 93 Lear Falcon 5 5/24 6 5/30 7 6/02 8 6/03 1 9 6/09 4 10 6/11 2 11 6/14 TOTAL BF - Boundary Facility sonde CF - Central Facility sonde *Lear - Dropsonde Falcon - Dropsonde * = “ BEST” HS RS 80 MG DC AERI CARL DLR 1 7 Total 2 3 2 1 1 3 4 1 3 1 2 1 3 2 5 SRL 2 3 3 5 1 3 12 3 17 4 2 4 1 8 8 6 1 22 *HS - Homestead sonde *MG - MGLASS mobile sonde DC - Dodge City sonde (VIZ) AERI- at Homestead 8 8 7 3 9 24 18 77 CARL - Raman Lidar at CF DLR - Lidar on Falcon *SRL- Scanning Raman Lidar at Homestead

LASE-Raman Lidar (RL) Comparisons (<20 km & <20 min) Current Comparison CART CF-RL + Homestead (HS)-SRL Previous Comparison

LASE-Dropsonde Comparisons (<75 km & <75 min) +

LASE-Balloonsonde Comparisons (<75 km & <75 min) + +

LASE-AERI Comparisons (<20 km & <20 min) Previous Comparison Latest Comparison

LASE-DLR DIAL Comparisons (<20 km & <20 min)

LASE-All Instruments Comparisons (<75 km & <75 min) LASE-All Instruments Comparisons (<20 km & <20 min)

LASE-All Instrument Comparisons by Flight (<20 km & <20 min) (“Best”: L-DS; H-RL; H-BS; MG-BS)

Summary • Comparisons were possible on only 7 of 8 flights and Flight #5 (5/24) only had 3 close comparisons. • Most comparisons were within 50 min and 50 km although a few went to 75 min and 75 km. In all there were 158 comparison opportunities with less than half of them (77) within 20 min and 20 km. • Raman lidar (CARL & H-RL) comparisons were excellent (generally <5%). • Lear dropsondes were in good agreement overall (<5%), but Falcon dropsondes were consistently drier by ~8%. • Reasonable overall agreement (<10%) with balloons, but large scatter on individual comparisons. • Excellent comparisons (<5%) with AERI. • Average agreement with DLR (~10%) but few comparisons available. • Comparisons with all instruments shows no systematic difference greater than the 5% level. • Some localized large differences in mid trop due to presence of very dry layers that are difficult to measure with sondes. • LASE water vapor data appear to be within <6% absolute accuracy.