A5000477524- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Aeolian processes and effects
- Oceanographic and Atmospheric Processes
- Ocean Waves and Remote Sensing
- Image Enhancement Techniques
- Climate variability and models
- Air Quality Monitoring and Forecasting
- Photoacoustic and Ultrasonic Imaging
- Ionosphere and magnetosphere dynamics
- Air Quality and Health Impacts
- Underwater Acoustics Research
- Optical Wireless Communication Technologies
- Icing and De-icing Technologies
- Physiological and biochemical adaptations
- Adaptive optics and wavefront sensing
- Animal Ecology and Behavior Studies
- Fluid Dynamics and Turbulent Flows
- Wind and Air Flow Studies
- Advanced Image Processing Techniques
- Advanced Image Fusion Techniques
- Chemical and Physical Properties in Aqueous Solutions
NSF National Center for Atmospheric Research
2023-2025
Earth Observing Laboratory
2025
U.S. National Science Foundation
2025
Stratton Park Engineering Company (United States)
2015-2024
Langley Research Center
2022
Environment and Climate Change Canada
2022
University of Miami
2010-2014
United States Naval Research Laboratory
2011-2013
Stennis Space Center
2013
McGill University
1991-2012
Abstract The rapid glaciation of tropical cumulus clouds has been an enigma and debated in the literature for over 60 years. Possible mechanisms responsible freezing have postulated, but until now direct evidence lacking. Recent high-speed photography electrostatically suspended supercooled drops laboratory shown that events produce small secondary ice particles. Aircraft observations from Ice Clouds Experiment–Tropical (ICE-T), strongly suggest drop-freezing production mechanism is...
Abstract. This study presents airborne in situ and satellite remote sensing climatologies of cirrus clouds humidity. The serve as a guide to the properties clouds, with new database providing detailed insights into boreal midlatitudes tropics, while satellite-borne data set offers global overview. To this end, an extensive, quality-checked archive, Cirrus Guide II database, is created from measurements during 150 flights 24 campaigns. archive contains meteorological parameters, ice water...
A central principle in life-history theory is that reproductive effort negatively affects survival. Costs of reproduction are thought to be physiologically based, but the underlying mechanisms remain poorly understood. Using female North American red squirrels (Tamiasciurus hudsonicus), we test hypothesis energetic investment overwhelms antioxidant protection, leading oxidative damage. In support this found highest levels plasma protein damage occurred during energetically demanding period...
Abstract The February–March 2014 deployment of the National Aeronautics and Space Administration (NASA) Airborne Tropical Tropopause Experiment (ATTREX) provided unique in situ measurements western Pacific tropical tropopause layer (TTL). Six flights were conducted from Guam with long-range, high-altitude, unmanned Global Hawk aircraft. ATTREX payload water vapor, meteorological conditions, cloud properties, tracer chemical radical concentrations, radiative fluxes. campaign was partially...
Abstract In situ data collected by three research aircraft in four geographical locations are analyzed to determine the relationship between cloud-base temperature, drop size distribution, and development of supercooled water drops ice strong updraft cores convective clouds. Data were towering cumulus feeder cells Caribbean, over Gulf Mexico, land near Coast, southeastern United States, high plains Colorado Wyoming. Convective clouds Mexico its coast, States all develop millimeter-diameter...
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...
Abstract Refractory black carbon (rBC) is a primary aerosol species, produced through incomplete combustion, that absorbs sunlight and contributes to positive radiative forcing. The overall climate effect of rBC depends on its spatial distribution atmospheric lifetime, both which are impacted by the efficiency with transported or removed convective systems. These processes poorly constrained observations. It especially interesting investigate transport Asian Summer Monsoon (ASM) since this...
It is a well-known fact that the major degradation source on electro-optical imaging underwater from scattering by particles of various origins and sizes. Recent research indicates that, under certain conditions, apparent could also be caused variations index refraction associated with temperature salinity microstructures in ocean lakes. The combined impact has been modeled previously through simple model. current study presents first attempts quantifying level image due to optical...
Abstract The impact of high‐frequency gravity waves on homogeneous‐freezing ice nucleation in cold cirrus clouds is examined using parcel model simulations driven by superpressure balloon measurements temperature variability experienced air parcels the tropical tropopause region. We find that primary influence to generate rapid cooling events drive production numerous crystals. Quenching tendency reversal highest‐frequency does occasionally produce low concentrations, but overall increase...
Abstract Cirrus clouds in the tropical tropopause layer (TTL) and water vapor transported into stratosphere have significant impacts on global radiation budget circulation patterns. Climate models, however, large uncertainties representing dehydration cloud processes TTL, thus their feedback surface climate, prohibiting an accurate projection of future regional climate changes. Here we use unprecedented airborne measurements over Pacific to reveal atmospheric waves as a strong modulator ice...
Abstract Pervasive cirrus clouds in the tropical tropopause layer (TTL) play an important role determining composition of stratospheric air through dehydration tropospheric entering stratosphere. This affects Earth's energy budget and climate, yet uncertainties remain regarding microphysical processes that govern TTL cirrus. were sampled with NASA Global Hawk UAV for over 30 hr Western Pacific 2014 during Airborne Tropical TRopopause EXperiment. In situ measurements by a Fast Cloud Droplet...
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 Numerical simulations of cirrus formation in the tropical tropopause layer (TTL) during boreal wintertime are used to evaluate impact heterogeneous ice nuclei (IN) abundance on cold cloud microphysical properties and occurrence frequencies. The model includes homogeneous nucleation, deposition growth/sublimation, sedimentation. Reanalysis temperature wind fields with high-frequency waves superimposed force simulations. results constrained by comparison situ satellite observations...
Abstract. Nucleation in the free troposphere (FT) and subsequent growth of new particles represent a globally important source cloud condensation nuclei (CCN). Whereas particle formation (NPF) has been shown to occur frequently upper over tropical oceans, there have few studies NPF at lower altitudes. In addition, impact urban emissions biomass burning on marine FT remains poorly understood. this study, we examine mid-troposphere (3–8.5 km) ocean coastal region using airborne measurements...
Abstract. Cumulus clouds are common over maritime regions. They important regulators of the global radiative energy budget and hydrologic cycle, as well a key contributor to uncertainty in anthropogenic climate change projections due aerosol–cloud interactions. These interactions regionally specific owing their strong influences on aerosol sources meteorology. Here, our analysis focuses statistical properties marine boundary layer (MBL) chemistry relationships MBL cumulus cloud just above...
Abstract The NASA Airborne Tropical Tropopause Experiment (ATTREX) deployment in January–March 2014 yielded more than 34 h of cirrus cloud sampling the tropical tropopause layer (TTL) over western Pacific. Cirrus were encountered throughout TTL, at temperatures between 185 and 207 K, with ice water content (IWC) ranging from >10 mg m −3 to below instrumental detection limit 1 μg . Geometric optical extinction ( σ ) values determined particle probe measurements ranged 10 −1 <10 −7...
Abstract We use a 1‐D cloud model run using prescribed temperature field to investigate the role of gravity waves in dehydration tropical tropopause layer (TTL). find that play an important TTL process beyond just lowering minimum experienced by air parcels. show more rapid cooling presence significantly increases abundance ice crystals. This increase crystal concentration causes depletion vapor excess saturation, and resultant efficiency is increased. Using spectrum waves, we generate...
Abstract The efficiency of dehydration in the tropical tropopause layer (TTL) determines how closely water vapor will be reduced to lowest saturation mixing ratio encountered along a trajectory stratosphere, thereby strongly influencing stratospheric humidity. NASA Airborne Tropical Tropopause Experiment (ATTREX) provided an unprecedented number and quality situ observations constrain key mechanisms controlling this dehydration. Statistical analyses ATTREX data show that nucleation, growth,...
Abstract The secondary ice process (SIP) is a major microphysical process, which can result in rapid enhancement of particle concentration the presence preexisting ice. SPICULE was conducted to further investigate effect collision–coalescence on rate fragmentation freezing drop (FFD) SIP mechanism cumulus congestus clouds. Measurements were over Great Plains and central United States from two coordinated aircraft, NSF Gulfstream V (GV) SPEC Learjet 35A, both equipped with state-of-the-art...
The Chemistry in the Arctic: Clouds, Halogens, and Aerosols (CHACHA) field project featured a wide collaboration from six universities to enhance scientific understanding of multiphase halogen chemistry Arctic that took place Utqia&#289;vik, Alaska during February-April 2022. This was spurred by pursuit strengthening our how Sea ice loss fossil fuel extraction affects atmospheric chemistry.In this study, cloud flights University Wyoming King Air are evaluated closely assess ambient...
Cold-air outbreaks (CAOs) have an overwhelming influence on global atmospheric and oceanic circulations, yet their cloud regimes remain poorly sampled are therefore not fully understood nor well-represented in weather models. More data the vertical dependence of microphysical macrophysical properties clouds CAOs its variability environmental conditions is crucial for enhancing understanding processes occurring clouds, improving evaluating performance models remote sensing retrievals over...
Summary 1. Despite the central importance of rate energy expenditure in lives animals, major drivers within-species variation remain uncertain, largely because most intraspecific studies focus on one or only a few potential determinants expenditure. 2. Here, we examine daily (DEE) free-ranging female North American red squirrels (Tamiasciurus hudsonicus Erxleben) occupying highly seasonal environment. By relating 260 measurements DEE from 176 individuals to key sources (reproductive and...
Acoustical and optical signal transmission underwater is of vital interest for both civilian military applications. The range to noise during the transmission, as a function system water properties, in terms absorption scattering, determines effectiveness deployed electro-optical (EO) technology. impacts from turbulence have been demonstrated affect performance comparable those particles by recent studies. This paper examines on acoustic scattering EO imaging degradation, establishes...