The NASA Goddard Space Flight Center (GSFC) Scanning Raman Lidar (SRL) participated in the International H2O Project (IHOP), which occurred in May and June 2002 in the midwestern part of the United States. The SRL received extensive optical modifications prior to and during the IHOP campaign that added new measurement capabilities and enabled unprecedented daytime water vapor measurements by a Raman lidar system. Improvements were also realized in nighttime upper-tropospheric water vapor measurements. The other new measurements that were added to the SRL for the IHOP deployment included rotational Raman temperature, depolarization, cloud liquid water, and cirrus cloud ice water content. In this first of two parts, the details of the operational configuration of the SRL during IHOP are provided along with a description of the analysis and calibration procedures for water vapor mixing ratio, aerosol depolarization, and cirrus cloud extinction-to-backscatter ratio. For the first time, a Raman water vapor lidar calibration is performed, taking full account of the temperature sensitivity of water vapor and nitrogen Raman scattering. Part II presents case studies that permit the daytime and nighttime error statistics to be quantified.

The NASA GSFC Scanning Raman Lidar (SRL) participated in the International H2O Project (IHOP) that occurred in May and June 2002 in the midwestern part of the United States. The SRL system configuration and methods of data analysis were described in Part I of this paper. In this second part, comparisons of SRL water vapor measurements and those of Lidar Atmospheric Sensing Experiment (LASE) airborne water vapor lidar and chilled-mirror radiosonde are performed. Two case studies are then presented: one for daytime and one for nighttime. The daytime case study is of a convectively driven boundary layer event and is used to characterize the daytime SRL water vapor random error characteristics. The nighttime case study is of a thunderstorm-generated cirrus cloud case that is studied in its meteorological context. Upper-tropospheric humidification due to precipitation from the cirrus cloud is quantified as is the cirrus cloud optical depth, extinction-to-backscatter ratio, ice water content, cirrus particle size, and both particle and volume depolarization ratios. A stability and back-trajectory analysis is performed to study the origin of wave activity in one of the cloud layers. These unprecedented cirrus cloud measurements are being used in a cirrus cloud modeling study

The NASA/GSFC Scanning Rarnan Lidar (SRL) was stationed on Andros Island in the Bahamas during August -September, 1998 as a part of the third Convection and Moisture Experiment (CAMEX-3) which focussed on hurricane development and tracking. During the period August 21 -24, hurricane Bonnie passed near Andros Island and influenced the water vapor and cirrus cioud measurements acquired by the SRL. Two drying signatures related to the hurricane were recorded by the SRL and other sensors. Cirrus cloud optical depths (at 351 nm) were also measured during this period. Optical depth values ranged from approximately 0.01 to 1.4. The influence of multiple scattering on these optical depth measurements was studied with the conclusion that the measured values of optical depth are less than the actual value by up to 20%. The UV/IR cirrus cloud optical depth ratio was estimated based on a comparison of lidar and GOES measurements. Simple radiative transfer model calculations compared with GOES satellite brightness temperatures indicate that satellite radiances are significantly affected by the presence of cirrus clouds if IR optical depths are approximately 0.02 or greater. This has implications for satellite cirrus detection requirements.https://ntrs.nasa.gov/search

A unique set of measurements of wind, water vapor mixing ratio and boundary layer height variability was observed during the first MOP dryline mission of 22 May 2002. Water vapor mixing ratio fiom the Scanning Raman Lidar (SRL), high-resolution profiles of aerosol backscatter fiom the HARLIE and wind profiles fiom the GLOW are combined with the vertical velocity derived fiom the NCAR/ISS/MAPR and the high-resolution FMCW radar to reveal the convective variability of the cumulus cloud-topped boundaxy layer. A combined analysis of the in-situ and remote sensing data fiom aircraft, radiosonde, lidars, and radars reveals moisture variability within boundary layer updraft and downdraft regions as well as characterizes the boundary layer height variability in the dry and moist sides of the dryline.The profiler site measurements will be tied to aircraft data to reveal the relative intensity and location of these updrafts to the dry line. This study provides unprecedented high temporal and spatial resolution measurements of wind, moisture and backscatter within a dryline and the associated convective boundary layer. IXXODUCTIONThe dryline occurs in the mid-west of the US and is sometimes called a "dew point ftont" or "dry fi~nt." It is a boundary between warm, moist air that originated fiom the Gulf of Mexico and hot, dry air from the Mexican Plateau and southwest desert. It is sometimes a hvored zone for initiation of severe weather (Rhea, 1966). Dryline moisture differences and sharpness (Fujita 1958 In this paper, we focus on the quantification of the small-scale variability of boundary layer parameters, key to understanding convective initiation. The variability in the convective boundary layer moisture, wind and temperature fields and their importance in the initiation of storms have been discussed in the literature (Weckwerth et al., 1996; Crook, 1986 andWeckwerth, 2000 and Convective Boundary Layer (CBL) structure with many measurements f?om aircraft, radar, profiler, and profiles of infrared moisture and temperature and other data to study thermodynamic variability in and around clear air updrafts during a dryline event. Variations of the moisture plumes as the dryline moved back and forth over the ground site are observed and the site specific profile observations are related to the larger picture using aircraft and radar based measurements.A brief description of the synoptic setting using satellite, sonde and radar data is presented in section 2. Many of the profiler instruments at Homestead are relatively new and information on their performance may not be easily accessible. Thus, in section 3, a brief discussion of the Homestead-based instruments and their measurements on 22 May 2002 are presented. 5Analysis and synthesis of the data and supporting evidence fiom aircraft observations on the day are presented in section 4. A summary and some conclusions are presented in section 5. SYNOPTIC SETTING Satellite dataSatellite and surface analysis indicated that starting about 1600 (all times UTC) there wa...

Abstract. We compare aerosol optical thickness (AOT) and precipitable water vapor (PWV) measurements derived from ground and airborne lidars and Sun photometers during the Tropospheric Aerosol Radiative Forcing Observational Experiment. Such comparisons are important to verify the consistency between various remote sensing measurements before employing them in any assessment of the impact of aerosols on the global radiation balance. Total scattering ratio and extinction profiles measured by the ground-based NASA Goddard Space Flight Center scanning Raman lidar system, which operated from Wallops Island, Virginia (37.86øN, 75.51 øW), are compared with those measured by the Lidar Atmospheric Sensing Experiment (LASE) airborne lidar system aboard the NASA ER-2 aircraft. Bias and root-mean-square differences indicate that these measurements generally agreed within about 10%. Aerosol extinction profiles and estimates of AOT are derived from both lidar measurements using a value for the aerosol extinction/ backscattering ratio Sa = 60 sr for the aerosol extinction/backscattering ratio, which was determined from the Raman lidar measurements. The lidar measurements of AOT are found to be generally within 25% of the AOT measured by the NASA Ames Airborne Tracking Sun Photometer (AATS-6). However, during certain periods the lidar and Sun photometer measurements of AOT differed significantly, possibly because of variations in the aerosol physical characteristics (e.g., size, composition) which affect Sa. Estimates of PWV, derived from water vapor mixing ratio profiles measured by LASE, are within 5-10% of PWV derived from the airborne Sun photometer. Aerosol extinction profiles measured by both lidars show that aerosols were generally concentrated in the lowest 2-3 km.