A5073890180- Climate variability and models
- Tropical and Extratropical Cyclones Research
- Meteorological Phenomena and Simulations
- nanoparticles nucleation surface interactions
- Astro and Planetary Science
- Oceanographic and Atmospheric Processes
- Freezing and Crystallization Processes
- Atmospheric chemistry and aerosols
- Geochemistry and Geologic Mapping
- Icing and De-icing Technologies
- Marine and environmental studies
- Geological and Geophysical Studies
- Sports, Gender, and Society
- Ancient Mediterranean Archaeology and History
- Astrophysics and Star Formation Studies
- Geology and Paleoclimatology Research
- Atmospheric aerosols and clouds
- Digital Games and Media
- Climate Change Policy and Economics
- Phase-change materials and chalcogenides
- Management and Marketing Education
- Atmospheric Ozone and Climate
- Historical, Religious, and Philosophical Studies
- Geophysics and Gravity Measurements
- Atmospheric and Environmental Gas Dynamics
Johns Hopkins University
2023-2024
Pennsylvania State University
2016-2020
NSF National Center for Atmospheric Research
2019
Bureau of Meteorology
2012-2015
Ames National Laboratory
2013
Iowa State University
2013
Abstract Changes of the Southern Hemisphere Hadley cell over twentieth century are investigated using Twentieth Century Reanalysis (20CR) and coupled model simulations from phase 5 Coupled Model Intercomparison Project (CMIP5). Trends computed on a 30-yr sliding window 20CR dataset reveal statistically significant expansion 1968 forced by an increasing surface global warming. This is strongly associated with intensification poleward shift subtropical dry zone, which potentially explain...
Abstract Models of ice crystal vapor growth require estimates the deposition coefficient α when surface attachment kinetics limit and shape is predicted. Parametric models can be used to calculate for faceted as long characteristic supersaturation values are known. However, previously published measurements limited temperatures higher than −40°C. Estimates at between −40° −70°C provided here through reanalysis data. The estimated follow same functional temperature dependence data taken...
Abstract There are few measurements of the vapor growth small ice crystals at temperatures below −30°C. Presented here mass-growth heterogeneously and homogeneously frozen particles grown within an electrodynamic levitation diffusion chamber between −44° −30°C supersaturations s i 3% 29%. These data analyzed with two methods devised to estimate deposition coefficient α without direct use . Measurements typically uncertain, which has called past estimates into question. We find that ranges...
Abstract A levitation diffusion chamber designed to examine the mass growth from vapor of small ice particles (diameter < 100 μm) at ambient pressure (≃970 hPa) and low temperature (T −30°C) is presented. The unique in that charged are levitated by an opposing voltage on lower copper plate with lateral stability provided button quadrupole electrodes attached upper plate. far particle region, allowing grow free substrate influences. Experiments have been conducted for temperatures −30°...
A comprehensive study of GeTe-based materials where Ge is replaced by 2 at.% Ag, Sb, and additionally 1 or Dy (Ag2Sb2Ge46 − xDyxTe50 alloys) has been conducted using Seebeck coefficient, electrical resistivity, thermal conductivity measurements in the temperature range 300–750 K, X-ray diffraction (XRD) 125Te NMR at 300 K. According to our data, ∼720 GeTe, a self-doping degenerate semiconductor, exhibits highest known power factor (PF) among tellurides, 42 μW cm−1 K−2, but due high...
Abstract Ice clouds in Titan’s polar stratosphere are implicated radiative heating and cooling transporting volatile organic compounds from where they form the upper atmosphere to surface of moon. In early southern fall, Cassini detected a large, unexpected cloud at an altitude 300 km over south pole. The cloud, which was found contain HCN ice, inconsistent with most recent measurements temperature same location suggested that had be 100 K cooler than expected. However, changes Cassini’s...
Early during Titan's southern fall, images captured by Cassini's Imaging Science Subsystem (ISS) revealed the formation of a large cloud above south pole. Subsequent analysis Cassini data contained HCN ice, but cloud's evolution has not been examined. We reviewed imagery pole between 2012 and end mission at Ls=93°. find evidence as early Ls=32° (April 2012), one terrestrial month earlier than previously reported, after which persists until Ls=79° (mid 2016). The top altitude descended from...
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