A5023386773- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Aeolian processes and effects
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Calibration and Measurement Techniques
- Cryospheric studies and observations
- Air Quality Monitoring and Forecasting
- Arctic and Antarctic ice dynamics
- Remote Sensing in Agriculture
- Precipitation Measurement and Analysis
- Icing and De-icing Technologies
- Solar Radiation and Photovoltaics
- Spacecraft Design and Technology
- Tropical and Extratropical Cyclones Research
- Stellar, planetary, and galactic studies
- Geochemistry and Geologic Mapping
- Spectroscopy and Laser Applications
- Remote Sensing and LiDAR Applications
- Climate variability and models
- Marine and coastal ecosystems
- Astrophysics and Star Formation Studies
- Remote Sensing and Land Use
- Radiative Heat Transfer Studies
Space Research Organisation Netherlands
2005-2025
Goddard Institute for Space Studies
2014-2023
Columbia University
2013-2023
Earth Island Institute
2020
In the atmosphere, microphysics refers to microscale processes that affect cloud and precipitation particles is a key linkage among various components of Earth's atmospheric water energy cycles. The representation microphysical in models continues pose major challenge leading uncertainty numerical weather forecasts climate simulations. this paper, problem treating divided into two parts: (i) how represent population particles, given impossibility simulating all individually within cloud,...
Abstract. The total effect of aerosols, both directly and on cloud properties, remains the biggest source uncertainty in anthropogenic radiative forcing climate. Correct characterization intensive aerosol optical particularly conditions where absorbing is present, a crucial factor quantifying these effects. southeast Atlantic Ocean (SEA), with seasonal biomass burning smoke plumes overlying mixing persistent stratocumulus deck, offers an excellent natural laboratory to make observations...
We present spectra of the 3.3 μm and 11.2 polycyclic aromatic hydrocarbon (PAH) features a large number stellar sources, planetary nebulae, reflection H II regions, galaxies, obtained with Infrared Space Observatory Short Wavelength Spectrometer. Clear variations are in profiles these features. Most sources show symmetric feature peaking at ~3.290 μm, while only very few an asymmetric slightly longer wavelength. The distinctly asymmetric. majority has between 11.20 11.24 steep blue rise low...
Remote sensing of aerosol optical properties is difficult, but multi-angle, multi-spectral, polarimetric instruments have the potential to retrieve sufficient information about aerosols that they can be used improve global climate models. However, complexity these means it difficult intuitively understand relationship between instrument design and retrieval success. We apply a Bayesian statistical technique relates characteristics contained in an observation. Using realistic simulations fine...
We present an optimal-estimation-based retrieval framework, the microphysical aerosol properties from polarimetry (MAPP) algorithm, designed for simultaneous of and ocean color bio-optical parameters using multi-angular total polarized radiances. Polarimetric measurements airborne NASA Research Scanning Polarimeter (RSP) were inverted by MAPP to produce atmosphere products. The RSP results are compared with co-incident lidar made High-Spectral-Resolution Lidar HSRL-1 HSRL-2 instruments....
Abstract. The Twomey effect describes the radiative forcing associated with a change in cloud albedo due to an increase anthropogenic aerosol emissions. It is driven by perturbation droplet number concentration (ΔNd, ant) liquid-water clouds and currently understood exert cooling on climate. key driver effective aerosol–cloud interactions, but rapid adjustments also contribute. These are essentially responses of fraction liquid water path ΔNd, ant thus scale approximately it. While...
Abstract Observations of long-lived mixed-phase Arctic boundary layer clouds on 7 May 1998 during the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE)–Arctic (ACE)/Surface Heat Budget Ocean (SHEBA) campaign provide a unique opportunity to test understanding cloud ice formation. Under microphysically simple conditions observed (apparently negligible aggregation, sublimation, and multiplication), only expected source new crystals is activation...
We demonstrate that multi-angle polarization measurements in the near-UV and blue part of spectrum are very well suited for passive remote sensing aerosol layer height. For this purpose we use simulated with different set-ups (different wavelength ranges, without polarization, polarimetric accuracies) as airborne from Research Scanning Polarimeter (RSP) obtained over continental USA. find good agreement retrieved height RSP Cloud Physics Lidar (CPL) showing a mean absolute difference less...
Abstract. We investigated the importance of spectral range and angular resolution for aerosol retrieval from multiangle photopolarimetric measurements over land. For this purpose, we use an extensive set simulated different ranges resolutions subsets real airborne Research Scanning Polarimeter (RSP) carried out during PODEX SEAC4RS campaigns continental USA. Aerosol retrievals performed RSP show good agreement with ground-based AERONET optical depth (AOD), single scattering albedo (SSA)...
Abstract The Western North Atlantic Ocean (WNAO) and adjoining East Coast of America are great importance for atmospheric research have been extensively studied several decades. This broad region exhibits complex meteorological features a wide range conditions associated with gas particulate species from many sources regionally other continents. As Part 1 2‐part paper series, this work characterizes quantities chemistry, including gases, aerosols, wet deposition, by analyzing available...
Abstract The NASA Cloud, Aerosol, and Monsoon Processes Philippines Experiment (CAMP 2 Ex) employed the P-3, Stratton Park Engineering Company (SPEC) Learjet 35, a host of satellites surface sensors to characterize coupling aerosol processes, cloud physics, atmospheric radiation within Maritime Continent’s complex southwest monsoonal environment. Conducted in late summer 2019 from Luzon, Philippines, conjunction with Office Naval Research Propagation Intraseasonal Tropical Oscillations...
In this study, we propose a simple method to derive vertically resolved aerosol particle number concentration ( N ) using combined polarimetric and lidar remote sensing observations. This relies on accurate polarimeter retrievals of the fine-mode column-averaged extinction cross section measurements coefficient such as those provided by multiwavelength high spectral resolution lidar. We compare resulting + product in situ data collected airborne instruments during NASA cloud meteorology...
Abstract. The NASA Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) produced a unique dataset for research into aerosol–cloud–meteorology interactions, with applications extending from process-based studies to multi-scale model intercomparison and improvement as well remote-sensing algorithm assessments advancements. ACTIVATE used two Langley Research Center aircraft, HU-25 Falcon King Air, conduct systematic spatially coordinated flights over northwest...
[1] A modeling study of a low-lying mixed-phase cloud layer observed on 8 April 2008 during the Indirect and Semi-Direct Aerosol Campaign is presented. Large-eddy simulations with size-resolved microphysics were used to test hypothesis that heterogeneous ice nucleus (IN) concentrations measured above top can account for concentrations, while also matching size distributions, radar reflectivities, mean Doppler velocities. The conditions case are favorable hypothesis: springtime IN high in...
In early 2013, three airborne polarimeters were flown on the high altitude NASA ER-2 aircraft in California for Polarimeter Definition Experiment (PODEX). PODEX supported pre-formulation Aerosol-Cloud-Ecosystem (ACE) mission, which calls an imaging polarimeter polar orbit (among other instruments) remote sensing of aerosols, oceans, and clouds. Several concepts exist as prototypes, some deployed during a capabilities test. Two those instruments to date have successfully produced Level 1...
In support of the Copernicus Anthropogenic Carbon Dioxide Monitoring (CO2M) mission, this study evaluates performance Remote sensing Trace gas and Aerosol Product (RemoTAP) algorithm based on synthetic orbit measurements realistic atmospheric geophysical scenes over land. To make use added value multi-angle polarimeter (MAP) aboard CO2M RemoTAP is developed to perform simultaneous retrieval trace aerosol properties from both MAP CO 2 imager (CO2I) measurements. At same time, it has...
Abstract. The cloud drop effective radius (Re) of the size distribution derived from passive satellite sensors is a key variable used in climate research. Validation these products has often taken place under stratiform conditions that favor assumption horizontal homogeneity by retrieval techniques. However, many studies have noted concerns with respect to significant biases retrieved Re arising heterogeneity, for example, cumulus fields. Here, we examine data collected during 2019 “Cloud,...
Abstract. We present a new remote sensing technique to infer the average asymmetry parameter of ice crystals near cloud top from multi-directional polarization measurements. The method is based on previous findings that (a) complex aggregates hexagonal generally have scattering phase matrices resembling those their components; and (b) systematically vary with aspect ratios degree microscale surface roughness. Ice parameters are inferred polarized reflectance measurements by searching for...
Abstract. A new method to retrieve ice cloud asymmetry parameters from multi-directional polarized reflectance measurements is applied of the airborne Research Scanning Polarimeter (RSP) obtained during CRYSTAL-FACE campaign in 2002. The assumes individual hexagonal columns and plates serve as proxies for more complex shapes aggregates. closest fit searched a look-up table simulated reflectances computed layers that contain individual, randomly oriented with virtually continuous selection...
The variation of ice crystal properties in the tops deep convective clouds off north coast Australia is analyzed. Cloud optical thickness, effective radius, aspect ratio components, distortion parameter and asymmetry are simultaneously retrieved from combined measurements Moderate Resolution Imaging Spectroradiometer (MODIS) Polarization Directionality Earth's Reflectances (POLDER) satellite instruments. data divided into periods with alternating weak strong convection. Mostly plate-like...
Abstract. In this paper, an algorithm for the retrieval of aerosol and land surface properties from airborne spectropolarimetric measurements – combining neural networks iterative scheme based on Phillips–Tikhonov regularization is described. The which extension a previously designed ground-based retrievals applied to Research Scanning Polarimeter (RSP) board NASA ER-2 aircraft. A network, trained large data set synthetic measurements, perform real RSP data, network are subsequently used as...
Abstract The sizes and shapes of ice crystals in clouds affect fundamental microphysical processes, such as sedimentation aggregation, well their optical properties. evolution crystal size shape depends on temperature supersaturation, other processes that may lead to various coexisting complex shapes. Here we present a global assessment collocated characteristics shortwave scattering properties at the tops optically thick inferred from space‐borne multiwavelength reflectance measurements...