LASE Measurements During IHOP

Edward V. Browell, Syed Ismail, Richard A. Ferrare, Susan A Kooi, Anthony Notari, and Carolyn F. Butler

NASA Langley Research Center, Hampton, Virginia

Funding provided by Dr. Jim Dodge, NASA Headquarters

• LASE water vapor, aerosol, & cloud measurements• Water vapor comparisons• Example of LASE measurements & investigations• Status and future activities

IHOP Data Workshop, Boulder, CO, 24-26 March 2003

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 mhorizontal: 14 km (1 min)

• Aerosol/cloud profiles- daytime and nighttime- 0.03 to 25 km-resolution (variable)

vertical: 30 mhorizontal: 200 m

LASE Water Vapor, Aerosol, & Cloud Profiling on NASA DC-8

• 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 mhorizontal: 14 km (1 min)

• Aerosol/cloud profiles- daytime and nighttime- 0.03 to 25 km-resolution (variable)

vertical: 30 mhorizontal: 200 m

9 June 2002 (Flt. 9) Morning Low Level Jet and Convective Initiation #3

LASE Measurements during IHOP • Acquired data on 8 IHOP science flights

Nighttime Daytime

LASE Water Vapor Comparisons

LASE - Vaisala & H. AERI Water Vapor Comparisons

LASE-Dropsonde Water Vapor Comparisons

May 24, 2002 CI #1 DC-8 Flight 5 18:28-18:53 UT

May 24, 2002 CI #1 DC-8 Flight 5 19:53-20:18 UT

LASE CI#2 Flight on 3 June 2002

• Dry line and associated convective evolution (3 LASE passes).• Capping inversion east of dry line near Homestead (H) ground site.

H H H

ConvectionLow Clouds (Descend Under)

Dry Line

Dry Moist

In Situ Measurements

June 9, 2002 DC-8 Flight 9 Morning LLJ and CI #3

LLJ

Terra MODIS Precipitable Water Vapor

Terra MODIS 17:45 UT Near IR PWV

Terra MODIS 17:45 UT IR PWV

• June 9, 2002 DC-8 Flight 9• LASE and Terra MODIS measurements within 1 hour• Integrate LASE profiles to

derive PWV

-104 -103 -102 -101 -100 -99 -980

1

2

3

4

5IHOP June 9, 2002

Latitude 39 N

PW

V (

cm)

Longitude

MODIS Near IR 17:45 UT MODIS IR 17:45 UT LASE 16:50-17:25 UT

-104 -103 -102 -101 -100 -99 -98-30

-20

-10

0

10

20

30MODIS near IR - LASE

Dif

fere

nce

(%

)

Longitude (deg)

MODIS IR - LASE

• MODIS near IR PWV 10-20% higher than LASE

• MODIS IR PWV 0-30% lower than LASE

• Results consistent with DOE ARM SGP PWV comparisons (Ferrare et al., 2002)

Terra MODIS Precipitable Water Vapor

June 9, 2002 DC-8 Flight 9 Morning LLJ and CI #3

Forest Fire Smoke

• June 9, 2002 DC-8 Flight 9• Elevated Smoke Layer• HYSPLIT4 backtrajectories show smoke

transported from NM fires• RH computed from LASE water vapor and S-HIS temperature • Increased scattering due to hygroscopic aerosols

HYSPLIT4 (HYbrid Single-Particle Lagrangian Integrated Trajectory) Model, 1997. Web address: http://www.arl.noaa.gov/ready/hysplit4.html, NOAA Air Resources Laboratory, Silver Spring, MD.

May 30, 2002 DC-8 Flight 6 Boundary Layer Heterogeneity

Start

H C

H HC

June 14, 2002 DC-8 Flight 11 Boundary Layer Evolution

start

June 14, 2002 DC-8 Flight 11 Boundary Layer Evolution

start

LASE Data Status and Future Research Activities

LASE Data Archived:

• LASE nadir water vapor and aerosol scattering ratio measurements from DC-8 are in IHOP data archive and images are on web via Lidar Applications Group Home Page at http://asd-www.larc.nasa.gov/lidar/lidar.html (LASE water vapor profiles >400 m AGL)

Additional LASE Data Processing: • Complete extension of LASE water vapor below 400 m to surface and archive by May 2003• Zenith LASE water vapor and aerosol data processing and archiving by September 2003

Research Activities:• Collaborate with IHOP Science Team in utilizing LASE data in investigating/evaluating:

Development of the convective PBL; Impact on forecasts of CI; Relationship between moisture gradients and LLJ development; Relationships between surface and PBL processes; Impact on quantitative prediction forecasts; Compare water vapor measurements between active and passive sensors for future measurement systems.

• Produce Relative Humidity (RH) profiles using LASE water vapor and temperature profiles (Scanning HIS, NAST-I, AERI, radiosonde, high resolution model)

• Compute Precipitable Water Vapor (PWV) using LASE water vapor profiles• Retrieve cirrus cloud optical and geometrical thickness from LASE cloud profiles• Compare/evaluate other water vapor measurements• Investigate relative humidity and aerosol humidification factor• Characterize vertical distribution of forest fire smoke during IHOP flights• Assess MODIS/MISR aerosol and water vapor measurements