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NASA NTRSDate not supplied

CALIPSO’s New ODCOD Product Compared to Langley’s HSRL and HSRL-2

CALIPSO’s Version 4.51 Level 2 data release introduces an all-new group of science data sets containing estimates of total column two-way transmittances and effective optical depths derived from CALIOP ocean surface backscatter measurements and MERRA-2 reanalysis wind speed data. This new data product is known as the Ocean Derived Column Optical Depth product (ODCOD). These estimates use CALIOP’s ocean surface lidar return to estimate the total column optical depth overhead. This new retrieval will be provided for the entire mission, day and night, at 532nm, and are reported at single shot, 1km, and 5km resolutions for all profiles in which a valid lidar ocean surface return is detected. This poster will present a collection of HSRL and HSRL-2 CALIPSO under flights and compare the HSRL measured aerosol optical depth with the estimated total column optical depth of ODCOD. The ODCOD algorithm uses CALIOP’s ocean surface lidar return to estimate the effective total column optical depth overhead; i.e., the single scattering optical depth reduced by the contributions of multiple scattering to the ocean surface signal. Because the retrieval generates a single estimate for the entire column based solely on the surface backscatter, there is currently no way to correct for multiple scattering effects from different kinds of features within the column. This new retrieval will be provided for the entire mission, day and night, at 532nm, and is reported at single shot, 1km, and 5km resolutions for all profiles in which a valid lidar ocean surface return is detected. This poster presents a collection of HSRL and HSRL-2 CALIPSO under-flight case studies that compare the HSRL measured aerosol optical depth with the estimated total column optical depth derived by ODCOD.

R. Ryan↗

NASA NTRS2024

High Spectral Resolution Lidar – Generation 2 (HSRL-2) Retrievals of Ocean Surface Wind Speed: Methodology and Evaluation

Ocean surface wind speed (i.e., wind speed 10 m above sea level) is a critical parameter used by atmospheric models to estimate the state of the marine atmospheric boundary layer (MABL). Accurate surface wind speed measurements in diverse locations are required to improve characterization of MABL dynamics and assess how models simulate large-scale phenomena related to climate change and global weather patterns. To provide these measurements, this study introduces and evaluates a new surface wind speed data product from the NASA Langley Research Center nadir-viewing High Spectral Resolution Lidar – generation 2 (HSRL-2) using data collected as part of the NASA Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) mission. The HSRL-2 can directly measure vertically resolved aerosol backscatter and extinction profiles without additional constraints or assumptions, enabling the instrument to accurately derive atmospheric attenuation and directly determine surface reflectance (i.e., surface backscatter). Also, the high horizontal spatial resolution of the HSRL-2 retrievals (0.5 s or ∼ 75 m along track) allows the instrument to probe the fine-scale spatial variability in surface wind speeds over time along the flight track and over breaks in broken cloud fields. A rigorous evaluation of these retrievals is performed by comparing coincident HSRL-2 and National Center for Atmospheric Research (NCAR) Airborne Vertical Atmosphere Profiling System (AVAPS) dropsonde data, owing to the joint deployment of these two instruments on the ACTIVATE King Air aircraft. These comparisons show correlations of 0.89, slopes of 1.04 and 1.17, and y intercepts of −0.13 and −1.05 m s−1 for linear and bisector regressions, respectively, and the overall accuracy is calculated to be 0.15 ± 1.80 m s−1. It is also shown that the dropsonde surface wind speed data most closely follow the HSRL-2 distribution of wave slope variance using the distribution proposed by Hu et al. (2008) rather than the ones proposed by Cox and Munk (1954) and Wu (1990) for surface wind speeds below 7 m s−1, with this category comprising most of the ACTIVATE data set. The retrievals are then evaluated separately for surface wind speeds below 7 m s−1 and between 7 and 13.3 m s−1 and show that the HSRL-2 retrieves surface wind speeds with a bias of ∼ 0.5 m s−1 and an error of ∼ 1.5 m s−1, a finding not apparent in the cumulative comparisons. Also, it is shown that the HSRL-2 retrievals are more accurate in the summer (−0.18 ± 1.52 m s−1) than in the winter (0.63 ± 2.07 m s−1), but the HSRL-2 is still able to make numerous (N=236) accurate retrievals in the winter. Overall, this study highlights the abilities and assesses the performance of the HSRL-2 surface wind speed retrievals, and it is hoped that further evaluation of these retrievals will be performed using other airborne and satellite data sets.

Sanja Dmitrovic↗

NASA NTRSDate not supplied

HSRL-2 Observations of Aerosol Variability and Mixing During Boundary Layer Evolution in Houston

The NASA Langley airborne multi-wavelength High Spectral Resolution Lidar (HSRL-2) provides vertical distribution of aerosol optical properties as ?curtains? of aerosol extinction, backscatter and depolarization along the flight track, plus intensive properties that are used to infer aerosol type and external mixing of types. Deployed aboard the NASA Langley King Air on the DISCOVER-AQ field mission in Houston in September 2013, HSRL-2 flew a pattern that included 18 ground sites, repeated four times a day, coordinated with a suite of airborne in situ measurements. The horizontally and vertically resolved curtains of HSRL-2 measurements give an unparalleled view of the spatial and temporal variability of aerosol, which provide broad context for interpreting other measurements and models. In Houston, HSRL-2 generally observed significant variability with distinct layering: boundary layer, residual layer, and frequent upper layers of smoke transported from the Mississippi Valley. The period from Sep. 11-14 is notable for a large aerosol build-up and persistent layers in the free troposphere. We investigate the aerosol properties and evolution using the vertically resolved HSRL-2 measurements, typing and mixture analysis techniques, and boundary layer detection. Between morning and afternoon overpasses, as the boundary layer grows, many distinctions between the layers are lost as the aerosols become mixed. As the boundary layer collapses overnight, the aerosols are cut off and are observed in a distinct residual layer the following day. HSRL-2 measurements of the upper smoke layers suggest slightly different properties each day as new smoke enters the region, while the morning boundary layer indicates more similarity in local emissions day-to-day. HSRL-2 intensive variables (indicators of aerosol type) reflect complex yet predictable mixing. We will present the analysis of aerosol mixtures, and explore the WRF-Chem chemical transport model along the HSRL-2 flight path.

Sharon P Burton↗

NASA NTRSDate not supplied

HSRL-2 Observations over the Houston, TX Region during TRACER-AQ

During field missions in 2021 and 2023, the airborne NASA Langley Research Center High Spectral Resolution Lidar 2 (HSRL 2) measured the temporal and spatial evolution of ozone and aerosol distributions impacting urban air quality over the four most populated cities in the United States. HSRL-2 measurements in 2021 were acquired over the Houston metropolitan region, including Galveston Bay and the Houston Ship Channel, as part of the NASA Tracking Aerosol Convection Experiment – Air Quality (TRACER-AQ) mission conducted in collaboration with the Department of Energy. HSRL-2 measurements were acquired over Los Angeles, Chicago, and New York City in 2023 as part of the NASA Synergistic TEMPO Air Quality Science (STAQS) mission conducted in collaboration with the NOAA Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA) mission. HSRL 2 provided nadir vertical profiles of ozone, aerosol backscatter, extinction, and depolarization as the aircraft flew lawnmower type patterns at 9 km for several hours over these urban areas. HSRL-2 measured profiles of aerosol extinction and aerosol optical depth (AOD) via the HSRL technique at 355 and 532 nm and profiles of aerosol backscatter and depolarization at 355, 532, and 1064 nm. Mixed Layer Heights (MLH) were derived by locating sharp vertical gradients in the profiles of aerosol backscatter. The flights were comprised of up to three repeating lawnmower patterns over each city showing the evolution of the ozone and aerosol distributions from the morning through the afternoon. The HSRL-2 measurements reveal ozone enhancements near the surface as well as in the free troposphere above the mixed layer. Some lidar measurements over Chicago and New York City show the daytime boundary layer growing into elevated layers of biomass burning aerosol. These layers complicate efforts to use column-integrated satellite measurements to infer surface air quality. As expected, mixed layer height (MLH) typically increased significantly during the day; however, during some flights, particularly over the Houston area, MLH also showed large spatial variability associated with changes in surface cover and/or small scale circulations. Often HSRL-2 measurements of AOD also showed large spatial and temporal variability throughout the day over these cities. We discuss how the ozone and aerosol profiles are averaged over different vertical and horizontal scales near the surface for use in assessments of regional air quality models and near-surface ozone retrievals from NASA’s recently launched Tropospheric Emissions: Monitoring Pollution (TEMPO) satellite.

Lidar↗

DOE OSTI2017

Vertically Resolved Retrievals of Aerosol Concentrations and Effective Radii from the DOE Combined HSRL and Raman lidar Measurement Study (CHARMS) Merged High-Spectral-Resolution Lidar-Raman Lidar Data Set

The Department of Energy’s (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility is a key component of DOE’s research strategy to address global climate change. The objective of the ARM Facility is to provide an experimental testbed for studying important atmospheric effects, particularly cloud and aerosol processes, and testing parameterizations of these processes for use in climate change models. ARM observational sites include a broad array of instruments to characterize cloud and aerosol properties, atmospheric state variables, and incoming and outgoing radiation. Advanced lidar systems provide valuable and unique information about the atmospheric column. We examine the potential for providing vertically resolved information about aerosol size and concentration with a combination of two such lidar systems, the Raman lidar and the High-Spectral-Resolution Lidar (HSRL). Currently ARM has a limited ability to remotely measure profiles of aerosol optical and microphysical properties on an operational basis. Although the Southern Great Plains (SGP), Eastern North Atlantic (ENA), and North Slope of Alaska (NSA, Oliktok Point location only) Raman lidars provide profiles of aerosol backscatter and extinction at 355 nm, additional information is required to better characterize the impacts of aerosols on radiation and clouds. Recent advances in lidar retrieval theory and algorithm development (Müller et al. 1999, 2014; Chemyakin et al. 2014) demonstrate that multi-wavelength lidar retrieval algorithms that use measurements of aerosol extinction at both 355 and 532 nm and backscatter at 355, 532, and 1064 nm have the potential to constrain both the aerosol optical (e.g., complex index of refraction, scattering, etc.) and microphysical properties (e.g., effective radius, concentration). This advancement greatly increases the utility of the remote-sensed aerosol observations. Based on this work, the HSRL group at the National Aeronautics and Space Administration (NASA)’s Langley Research Center (LaRC) developed automated algorithms for retrieving aerosol optical and microphysical properties, demonstrated these retrievals using data from the unique NASA/LaRC airborne multi-wavelength HSRL-2 system, and validated these retrievals using coincident airborne in situ data (Müller et al. 2014; Sawamura et al. 2017). We report here on the use of ARM instrumentation to gather a multi-wavelength ground-based lidar data set to test such retrievals. Continuous (24/7) operation of the co-located SGP Raman lidar and University of Wisconsin (UW) HSRL during the 10-week Combined HSRL and Raman lidar Measurement Study (CHARMS) (mid-July through September 2015) allowed the acquisition of a unique, multi-wavelength ground-based lidar data set. The ARM SGP Raman lidar (RLID) measured profiles of aerosol backscatter, extinction, and depolarization at 355 nm and profiles of water vapor mixing ratio and temperature. The UW HSRL simultaneously measured profiles of aerosol backscatter, extinction and depolarization at 532 nm and aerosol backscatter at 1064 nm. This RLID+HSRL combination provided a test data set to investigate these more advanced aerosol retrieval techniques with the potential to greatly improve aerosol characterization in the lower atmosphere.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRSDate not supplied

Science Performance Comparison Between a Spaceborne HSRL and CALIOP

NASA operates airborne and spaceborne lidar systems to answer aerosol and cloud related science questions. NASA Langley Research Center has extensive experience operating lidar systems in both regimes. These include High Spectral Resolution Lidar (HSRL) systems, which have been operating on airborne systems,and CALIOP, the spaceborne elastic backscatter lidar system on board CALIPSO. In support of NASA’s ACCP Study Plan to address the Aerosol (A) and Cloud, Convection, and Precipitation (CCP) Designated Observables called out in the 2017 Earth Science Decadal Survey, LaRC is using lidar simulation tools to evaluate the performance of spaceborne systems using both the HSRL and elastic backscatter techniques. The LaRC high-fidelity simulator tool models both HSRL and elastic backscatter lidar systems by modeling the effects of the instrument specifications and producing backscatter signals generated from molecules, aerosols, clouds, ocean surface, and ocean subsurface. It derives the solar background signals from the scene specific aerosol and cloud characteristics, surface type, and sun elevation. The tool models both random and systematic uncertainties in the retrieved geophysical parameters. In this study, we will present simulated results that compare and contrast the performance of spaceborne HSRL systems to the performance of CALIOP. As recommended by the Decadal Study, ACCP is seeking advances over performance that has been achieved by A-Train. This study will provide a description of the HSRL and elastic backscatter techniques and demonstrate how and why the performance of these HSRL systems exceeds the performance of CALIOP.

Kathleen A Powell↗

DOE OSTI2015

Final Technical Report for Interagency Agreement No. DE-SC0005453 “Characterizing Aerosol Distributions, Types, and Optical and Microphysical Properties using the NASA Airborne High Spectral Resolution Lidar (HSRL) and the Research Scanning Polarimeter (RSP)”

Measurements of the vertical profile of atmospheric aerosols and aerosol optical and microphysical characteristics are required to: 1) determine aerosol direct and indirect radiative forcing, 2) compute radiative flux and heating rate profiles, 3) assess model simulations of aerosol distributions and types, and 4) establish the ability of surface and space-based remote sensors to measure the indirect effect. Consequently the ASR program calls for a combination of remote sensing and in situ measurements to determine aerosol properties and aerosol influences on clouds and radiation. As part of our previous DOE ASP project, we deployed the NASA Langley airborne High Spectral Resolution Lidar (HSRL) on the NASA B200 King Air aircraft during major field experiments in 2006 (MILAGRO and MaxTEX), 2007 (CHAPS), 2009 (RACORO), and 2010 (CalNex and CARES). The HSRL provided measurements of aerosol extinction (532 nm), backscatter (532 and 1064 nm), and depolarization (532 and 1064 nm). These measurements were typically made in close temporal and spatial coincidence with measurements made from DOE-funded and other participating aircraft and ground sites. On the RACORO, CARES, and CalNEX missions, we also deployed the NASA Goddard Institute for Space Studies (GISS) Research Scanning Polarimeter (RSP). RSP provided intensity and degree of linear polarization over a broad spectral and angular range enabling column-average retrievals of aerosol optical and microphysical properties. Under this project, we analyzed observations and model results from RACORO, CARES, and CalNex and accomplished the following objectives. 1. Identified aerosol types, characterize the vertical distribution of the aerosol types, and partition aerosol optical depth by type, for CARES and CalNex using HSRL data as we have done for previous missions. 2. Investigated aerosol microphysical and macrophysical properties using the RSP. 3. Used the aerosol backscatter and extinction profiles measured by the HSRL to characterize the planetary boundary layer height (PBL) and the transition zone thickness, for the RACORO and CARES and CalNex campaigns as we have done for previous campaigns. 4. Investigated how optical properties measured by HSRL vary near clouds. 5. Assessed model simulations of aerosol spatial distributions and optical and microphysical properties.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS2015

HSRL-2 Observations of Aerosol Variability During an Aerosol Build-up Event in Houston and Comparisons With WRF-Chem

The NASA Langley airborne multi-wavelength High Spectral Resolution Lidar (HSRL-2) provides vertical distribution of aerosol optical properties as curtains of aerosol extinction, backscatter and depolarization along the flight track, plus intensive properties that are used to infer aerosol type and external mixing of types. Deployed aboard the NASA Langley King Air on the DISCOVER-AQ field mission in Houston in September 2013, HSRL-2 flew a pattern that included 18 ground sites, repeated four times a day, coordinated with a suite of airborne in situ measurements. The horizontally and vertically resolved curtains of HSRL-2 measurements give an unparalleled view of the spatial and temporal variability of aerosol, which provide broad context for interpreting other measurements and models. Detailed comparisons of aerosol extinction are made with the WRF-Chem chemical transport model along the HSRL-2 flight path. The period from Sept. 11-14 is notable for a large aerosol build-up and persistent smoke layers. We investigate the aerosol properties using the vertically resolved HSRL-2 measurements and aerosol typing analysis plus WRFChem model tracers and back trajectories, and modeling of humidification effects.

Burton, Sharon P.↗

NASA NTRSDate not supplied

Airborne HSRL Assessment of CALIOP Aerosol Extinction Retrievals Constrained by Column AOD

Current operational CALIOP aerosol extinction profile retrievals usually rely on accurately specifying the relationship between aerosol extinction and backscattering (i.e. lidar ratio). Uncertainties in the assigned lidar ratios are typically the largest source of systematic error (~30-50%) in the CALIOP retrievals of aerosol extinction, backscatter, and aerosol optical depth. Alternatively, column aerosol optical depth (AOD) can be used to solve the lidar equation and obtain column-equivalent lidar ratios and retrieve aerosol extinction profiles from the CALIOP attenuated backscatter profiles. These derived lidar ratios correspond to the aerosols in the altitude range from 0-7 km. We derive column-equivalent aerosol lidar ratios and aerosol extinction profiles from CALIOP attenuated backscatter profiles constrained using co-located column AODs provided by several instruments/techniques: Synergized Optical Depth of Aerosols (SODA), Ocean-Derived Column Optical Depths (ODCOD), MODIS (dark target), MODIS (Multi-Angle Implementation of Atmospheric Correction-MAIAC), and PARASOL (Generalized Retrieval of Aerosol and Surface Properties-GRASP). These various retrievals of AOD and the column-average aerosol lidar ratios and aerosol extinction profiles derived from CALIOP using these AOD constraints are evaluated using the extensive record of coincident and co-located airborne HSRL measurements of AOD, aerosol lidar ratio, and aerosol extinction profiles acquired during more than 140 HSRL underflights of CALIPSO since 2006. The HSRL technique allows for the independent measurement of extinction and backscatter without the need for external constraints or assumptions regarding the lidar ratios. Initial comparisons with these coincident HSRL aerosol extinction profiles show that the CALIOP aerosol extinction profiles retrieved using these various AOD constraints are generally in better agreement with the HSRL measurements than aerosol extinction profiles from the operational techniques. The quality of agreement depends on the accuracy and magnitude of the AOD constraint. We present these comparisons of AOD, column aerosol lidar ratio, and aerosol extinction profiles for each of the AOD constraints described above.

lidar↗

DOE OSTI2015

hsrl (01)

High-spectral-resolution lidar (HSRL) systems collect data about clouds and aerosols. These systems provide vertical profiles of optical depth, backscatter cross-section, depolarization, and backscatter phase function. All HSRL measurements are absolutely calibrated by reference to molecular scattering, which is measured at each point in the lidar profile. Like the Raman lidar, but unlike simple backscatter lidars such as the micropulse lidar, the HSRL can measure backscatter cross-sections and optical depths without prior assumptions about the scattering properties of the atmosphere. The depolarization observations also allow robust discrimination between ice and water clouds. In addition, rigorous error estimates can be computed for all measurements. A very narrow, angular field of view reduces multiple scattering contributions. The small field of view, coupled with a narrow optical bandwidth, nearly eliminates noise due to scattered sunlight. ARM operates two HSRL systems, one at the Barrow, North Slope of Alaska (NSA) site and the other in the second ARM Mobile Facility (AMF2), which is deployed at various locations on field campaigns.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2011

hsrl (00)

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2025

High-Spectral Resolution Lidar (HSRL) Instrument Handbook

High-spectral-resolution lidar (HSRL) systems provide vertical profiles of optical depth, backscatter cross-section, depolarization, and backscatter phase function. All HSRL measurements are calibrated by reference to molecular scattering, which is measured at each point in the lidar profile. Like the Raman lidar (RL), but unlike simple backscatter lidars such as the micropulse lidar (MPL), this enables the HSRL to measure backscatter cross-sections and optical depths without prior assumptions about the scattering properties of the atmosphere. The depolarization observations allow robust discrimination between ice and water clouds. Rigorous error estimates can be computed for all measurements. A very narrow angular field of view reduces multiple scattering contributions. The small field of view, coupled with a narrow optical bandwidth, nearly eliminates noise due to scattered sunlight. The laser transmitter is a diode-pumped, frequency-doubled Nd:YAG laser. Narrow-band, single-frequency operation is provided by injection seeding with a single-frequency, cw-diode-pumped diode laser. The main laser cavity is maintained in resonance with the seed laser by adjusting the cavity length to minimize the time between the Q-switch trigger and the emission of the laser pulse. The emission wavelength is tuned via temperature control of the seed laser crystal and is locked to line #1109 of the iodine absorption spectra. Locking is accomplished by minimizing the transmission through a 2-cm-long iodine absorption cell. Use of a high-repetition-rate laser and expansion of the transmitted beam through a 400-mm telescope reduces the transmitted energy density to eye-safe levels. It is possible to look directly into the output beam without hazard. The receiver and transmitter use the same afocal telescope, simplifying the maintenance of stable alignment of the transmitter and receiver although the angular FOV is only 100 μrad. The small FOV and the 4-kHz repetition rate also limit the near-field signal strength, making it possible to record continuous profiles that start at an altitude of ~100 m and extend to 30 km using photon counting detectors. The small FOV also suppresses multiple scattering contributions.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRSDate not supplied

Remotely-Sensed Aerosol Optical Properties Retrieved from a High Spectral Resolution Lidar (HSRL) During the FIREX-AQ Field Campaign

The NASA Langley Research Center’s High Spectral Resolution Lidar with Differential Absorption Lidar (HSRL-DIAL) instrument was flown on the NASA DC-8 aircraft during the Fire Influence on Region to Global Environments and Air Quality (FIREX-AQ; https://www.esrl.noaa.gov/csl/projects/firex-aq/) field campaign. The airborne HSRL-DIAL system retrieves aerosol backscatter and depolarization at 3 wavelengths (355, 532, and 1064 nm), aerosol extinction at 532 nm, and ozone concentration (differential at 290 and 300 nm). Additionally, the HSRL-DIAL system incorporates both a zenith and nadir telescope allowing for retrievals from in-smoke sampling to be integrated through the plume. During the first portion of the FIREX-AQ campaign, the DC8 aircraft sampled more than ten large-scale fires with varying fuels, combustion stages, and metrological conditions, with some fires being sampled multiple times across separate days. This presentation focuses on the retrievals of aerosol backscatter (at 532 and 1064 nm), aerosol depolarization (at 532 nm and 1064 nm), aerosol optical thickness (at 532 nm), lidar ratio, and color ratio to examine the changes in these properties in the smoke plume as they are advected downwind.

Taylor Shingler↗

DOE OSTI2014

Airborne Multiwavelength High Spectral Resolution Lidar (HSRL-2) observations during TCAP 2012: vertical profiles of optical and microphysical properties of a smoke/urban haze plume over the northeastern coast of the US

Here, we present measurements acquired by the world's first airborne 3 backscatter (β) + 2 extinction (α) High Spectral Resolution Lidar (HSRL-2). HSRL-2 measures particle backscatter coefficients at 355, 532, and 1064 nm, and particle extinction coefficients at 355 and 532 nm. The instrument has been developed by the NASA Langley Research Center. The instrument was operated during Phase 1 of the Department of Energy (DOE) Two-Column Aerosol Project (TCAP) in July 2012. We observed pollution outflow from the northeastern coast of the US out over the western Atlantic Ocean. Lidar ratios were 50–60 sr at 355 nm and 60–70 sr at 532 nm. Extinction-related Ångström exponents were on average 1.2–1.7, indicating comparably small particles. Our novel automated, unsupervised data inversion algorithm retrieved particle effective radii of approximately 0.2 μm, which is in agreement with the large Angstrom exponents. We find good agreement with particle size parameters obtained from coincident in situ measurements carried out with the DOE Gulfstream-1 aircraft.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2011

HSRL Liquid cloud base height (nsaC1)

Liquid layers in clouds affect their microphysical processes, as well as the surface energy budget. Studies focusing on these and other areas of research are often in need of skillful estimation of liquid-bearing cloud-layer boundaries. The bases of these layers are predominantly determined by ground-based lidar instruments. Most studies requiring liquid cloud base height (LCBH) information use either fixed lidar depolarization and/or backscatter cross-section thresholds or cloud base height data products that do not distinguish between ice and liquid, all of which might introduce inconsistencies and errors in the resolved LCBH. This data set contains LCBH data at 1-min temoporal resolution based on an explicit LCBH detection algorithm, which uses the high-spectral-resolution lidar (HSRL) data. Examination of this algorithm in multiple cases and scenarios during numerous days and first-order comparison with microwave-radiometer data show satisfactory results.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2019

HSRL Liquid cloud base height

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2020

Ambient Aerosol Hygroscopic Growth From Combined Raman Lidar and HSRL

Not Available

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2018

HSRL Liquid cloud base height / MPL Liquid cloud base height

This dataset provides a liquid cloud base height (LCBH) data product. Widely used LCBH data products are currently absent in the scientific community.

54 ENVIRONMENTAL SCIENCES↗