A5023259851- Climate change and permafrost
- Geology and Paleoclimatology Research
- Arctic and Antarctic ice dynamics
- Fire effects on ecosystems
- Cryospheric studies and observations
- Geological Studies and Exploration
- Atmospheric and Environmental Gas Dynamics
- Hydrology and Watershed Management Studies
- Tree-ring climate responses
- Noise Effects and Management
- Atmospheric chemistry and aerosols
- Methane Hydrates and Related Phenomena
- Rangeland and Wildlife Management
- Air Quality and Health Impacts
- Groundwater and Watershed Analysis
- Flood Risk Assessment and Management
- Atmospheric aerosols and clouds
- Ecology and biodiversity studies
- Land Use and Ecosystem Services
- Forest Management and Policy
- Marine animal studies overview
- Aeolian processes and effects
- Remote Sensing and LiDAR Applications
- Soil Geostatistics and Mapping
- Urban Heat Island Mitigation
Stanford University
2017-2021
University of California, Los Angeles
2008-2016
University of California, Irvine
2006
Jackson State University
2006
Australian Nuclear Science and Technology Organisation
2006
NSF National Center for Atmospheric Research
2006
University of Florida
2006
We report measurements and analysis of a boreal forest fire, integrating the effects greenhouse gases, aerosols, black carbon deposition on snow sea ice, postfire changes in surface albedo. The net effect all agents was to increase radiative forcing during first year (34 +/- 31 Watts per square meter burned area), but decrease when averaged over an 80-year fire cycle (-2.3 2.2 meter) because multidecadal increases albedo had larger impact than fire-emitted gases. This result implies that...
We assessed the multidecadal effects of boreal forest fire on surface albedo using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations within perimeters burn scars in interior Alaska. Fire caused to increase during periods with and without snow cover. Albedo early spring had a mean 0.50 ± 0.03 for first three decades after fire, substantially higher than that observed evergreen conifer forests (0.34 0.04). In older stands between 30 55 years, showed decreasing trend...
ABSTRACT Detailed bathymetric data were collected for 28 thermokarst lakes across the Arctic Coastal Plain (ACP) of northern Alaska from areas with distinctly different surficial sediments and topography. Lakes found in low‐relief coastal area have developed marine silts that are ice‐rich upper 6–10 m. The tend to be shallow (~ 2 m), uniform depth lack prominent littoral shelves. Further inland on ACP, formed relatively ice‐poor aeolian sand deposits. In this hilly terrain, average lake is...
Abstract. Forest fires in Alaska and western Canada represent important sources of aerosols trace gases North America. Among the largest uncertainties when modeling forest fire effects are timing injection height biomass burning emissions. Here we simulate CO over America during 2004 season, using GEOS-Chem chemical transport model. We apply different temporal distributions profiles to emissions, compare model results with satellite-, aircraft-, ground-based measurements. find that averaged...
Regional- to global-scale lake maps can now be produced using existing technology and freely available data serve as powerful tools for a variety of lake- water-related studies. The accuracy these studies depends in part on the map that they use. Mapping lakes remote sensing requires careful study error uncertainty. Errors are caused by sensor-specific, lake-specific, processing-specific factors. These further broken down spatial, spectral/radiometric, temporal In this study, we analyse...
ABSTRACT In summer 2010, water temperature profile measurements were made in 12 thermokarst lakes along a 150‐km long north–south transect across the Arctic Coastal Plain of northern Alaska. shallow lakes, gradual warming column to 1–4°C begins at lake bed during decay ice cover spring. Rapid follows ice‐off, with responding synchronously synoptic weather variations area. Regionally, ice‐off occurs 2–4 weeks later on near coast. Inland are warmer (13°C) mid‐summer than those coast (7°C),...
The Landsat series of satellites provide a nearly continuous, high resolution data record the Earth surface from early 1970s through to present. public release entire archive, free charge, along with modern computing capacity, has enabled monitoring at global scale spatial resolution. With large volume and seasonality varying across globe, image selection is particularly important challenge for regional multitemporal studies remove interference long term trends. This paper presents an...
To investigate preeclampsia etiologies, we examined relationships between greenspace, air pollution, and neighborhood factors. Data were from hospital records geocoded residences of 77,406 women in San Joaquin Valley, California 2000 to 2006. Preeclampsia was divided into mild, severe, or superimposed onto pre-existing hypertension. Greenspace within 100 500 m residential buffers estimated satellite data using normalized difference vegetation index (NDVI). Air quality averaged over pregnancy...
Abstract The coastal plain of Arctic Alaska contains many thousands lakes developed in continuous permafrost, which are ice-free for only 3–4 months each year. spatial pattern lake ice meltout 1870 (>10 ha) a ~9200 km2 study area near Barrow, Alaska, is analyzed using five Landsat scenes spanning 35-year record. For available year, spectra-based clustering algorithm used to differentiate water from during springtime and overlain on common shoreline template determine the percentage covering...
Abstract Antarctic continental shelf waters are the most biologically productive in Southern Ocean. Although satellite‐derived algorithms report peak productivity during austral spring/early summer, recent studies provide evidence for substantial late summer that is associated with green colored frazil ice. Here we analyze daily Moderate Resolution Imaging Spectroradiometer satellite images February and March from 2003 to 2017 identify ice hot spots. Green concentrated 11 of 13 major sea...
We investigated whether residing near more green space might reduce the risk of preeclampsia.Participants were women who delivered a live, singleton birth between 1998 and 2011 in eight counties San Joaquin Valley California. There 7276 cases preeclampsia divided into mild, severe, or superimposed on preexisting hypertension. Controls 197,345 did not have hypertensive disorder 37 41 weeks. Green was estimated from satellite data using Normalized Difference Vegetation Index (NDVI), an index...
Abstract. Forest fires in Alaska and West Canada represent important sources of aerosols trace gases North America. Among the largest uncertainties when modeling forest fire effects are timing injection height biomass burning emissions. Here we simulate CO over America during 2004 season, using GEOS-Chem chemical transport model. We apply different temporal distributions profiles to emissions, compare model results with satellite-, aircraft-, ground-based measurements. find that averaged use...