A5023721821- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Oceanographic and Atmospheric Processes
- Climate variability and models
- Geological Studies and Exploration
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Soil Moisture and Remote Sensing
- Winter Sports Injuries and Performance
- Ocean Waves and Remote Sensing
- Landslides and related hazards
- Atmospheric and Environmental Gas Dynamics
- Geophysics and Gravity Measurements
- Geology and Paleoclimatology Research
- Underwater Acoustics Research
- Advanced SAR Imaging Techniques
- Scientific Research and Discoveries
- Remote-Sensing Image Classification
- Marine and environmental studies
- Food Industry and Aquatic Biology
- Icing and De-icing Technologies
- Robotics and Sensor-Based Localization
- Satellite Image Processing and Photogrammetry
- Planetary Science and Exploration
Johns Hopkins University Applied Physics Laboratory
2020-2024
University of Washington
2020-2024
New York Medical College
2023
NOAA Physical Sciences Laboratory
2022
National Oceanic and Atmospheric Administration
2022
Jet Propulsion Laboratory
2012-2021
University of Washington Applied Physics Laboratory
2020-2021
Seattle University
2021
California Institute of Technology
2007-2020
Cambridge University Press
2014
The Ice, Cloud, and land Elevation Satellite (ICESat) mission used laser altimetry measurements to determine changes in elevations of glaciers ice sheets, as well sea thickness distribution. These have provided important information on the response cryopshere (Earth's frozen surfaces) atmosphere ocean condition. ICESat operated from 2003 2009 repeat not only cryosphere scientific community but also ocean, terrestrial atmospheric communities. conclusive assessment significant ongoing rapid...
The decline of sea ice thickness in the Arctic Ocean from ICESat (2003–2008) is placed context estimates 42 years submarine records (1958–2000) described by Rothrock et al. (1999, 2008). While earlier 1999 work provides a longer historical record regional changes, latter offers more refined analysis, over sizable portion supported much stronger and richer data set. Within release area (DRA) declassified sonar measurements (covering ∼38% Ocean), overall mean winter 3.64 m 1980 can be compared...
We present our best estimate of the thickness and volume Arctic Ocean ice cover from 10 Ice, Cloud, land Elevation Satellite (ICESat) campaigns that span a 5‐year period between 2003 2008. Derived drafts are consistently within 0.5 m those submarine cruise in mid‐November 2005 4 years draft profiles moorings Chukchi Beaufort seas. Along with more than 42% decrease multiyear (MY) coverage since 2005, there was remarkable thinning ∼0.6 MY over years. In contrast, average seasonal midwinter (∼2...
Satellite records show a decline in ice extent over more than three decades, with record minimum September 2012. Results from the Pan‐Arctic Ice‐Ocean Modelling and Assimilation system (PIOMAS) suggest that has been accompanied by volume, but this not confirmed data. Using new data European Space Agency CryoSat‐2 (CS‐2) mission, validated situ data, we generate estimates of volume for winters 2010/11 2011/12. We compare these current PIOMAS earlier (2003–8) National Aeronautics...
Arctic sea-ice loss is a leading indicator of climate change and can be attributed, in large part, to atmospheric forcing. Here, we show that recent ice reductions, weakening the halocline, shoaling intermediate-depth Atlantic Water layer eastern Eurasian Basin have increased winter ventilation ocean interior, making this region structurally similar western Basin. The associated enhanced release oceanic heat has reduced formation at rate now comparable losses from thermodynamic forcing, thus...
Large-scale changes in Arctic sea ice thickness, volume and multiyear (MYI) coverage with available measurements from submarine sonars, satellite altimeters (ICESat CryoSat-2), scatterometers are summarized. The record spans the period between 1958 2000, altimeter records 2003 2018, scatterometer 1999 2017. Regional thickness (since 1958) within data release area of Ocean, previously reported by Kwok Rothrock (2009 Geophys. Res. Lett. 36 L15501), have been updated to include 8 years...
Abstract Multi-look polarimetric SAR (synthetic aperture radar) data can be represented either in Mueller matrix form or complex covariance form. The latter has a Wishart distribution. A maximum likelihood classifier to segment according terrain types been developed based on the This algorithm also applied multifrequency multi-look data, as well 10 containing only intensity information. procedure is then for unsupervised classification. classification error assessed by using Monte Carlo...
[1] Uncertainty in the Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS) Arctic sea ice volume record is characterized. A range of observations approaches, including situ thickness measurements, ICESat retrieved thickness, model sensitivity studies, yields a conservative estimate for October uncertainty 1.35 × 103 km3 an trend over 1979–2010 period 1.0 decade–1. this −2.8 PIOMAS estimates agree well with retrievals (<0.1 m mean difference) area which submarine data are...
Satellite and aircraft observations have revealed that remarkable changes in the Earth's polar ice cover occurred last decade. The impacts of these changes, which include dramatic loss from sheets rapid declines Arctic sea ice, could be quite large terms level rise global climate. NASA's Ice, Cloud Land Elevation Satellite-2 (ICESat-2), currently planned for launch 2015, is specifically intended to quantify amount change provide key insights into their behavior. It will achieve objectives...
Abstract Hydrologic cycle intensification is an expected manifestation of a warming climate. Although positive trends in several global average quantities have been reported, no previous studies documented broad across elements the Arctic freshwater (FWC). In this study, authors examine character and quantitative significance changes annual precipitation, evapotranspiration, river discharge terrestrial pan-Arctic over past decades from observations suite coupled general circulation models...
Starting with retrieved freeboards from four ICESat campaigns (ON05, October/November 2005; FM06, February/March 2006; ON06, and MA07, March/April 2007) we estimate their ice thicknesses using constructed fields of daily snow depth compare them drafts moored upward‐looking sonars. The methodologies, considerations, assumptions used in the conversion freeboard to thickness are discussed. distributions Arctic multiyear seasonal covers contrasted. Broadly, resulting seem seasonally...
[1] We examine the spatial trends in Arctic sea ice drift speed from satellite data and role of wind forcing for winter months October through May. Between 1992 2009, spatially averaged trend within Basin is 10.6% ± 0.9%/decade, ranges between −4% 16%/decade depending on location. The mean dominated by second half period. In fact, five years after a clear break point March 2004, average increased to 46% 5%/decade. Over 1992–2009 period, four atmospheric reanalyses are only 1% 2%/decade....
We examine the basinwide trends in sea ice circulation and drift speed highlight changes between 1982 2009 connection to regional winds, multiyear coverage, export, thinning of cover. The polarity Arctic Oscillation (AO) is used as a backdrop for summarizing variance shifts decadal patterns. 28‐year fields show net strengthening Beaufort Gyre Transpolar Drift, especially during last decade. imprint arctic dipole anomaly on mean summer evident (2001–2009) enhances area export at Fram Strait....
We present our estimates of the thickness and volume Arctic Ocean ice cover from CryoSat-2 data acquired between October 2010 May 2014. Average draft differences are within 0.16 m measurements other sources (moorings, submarine, electromagnetic sensors, IceBridge). The choice parameters that affect conversion freeboard to is discussed. Estimates 2011 2013 suggest moderate decreases in followed by a notable increase more than 2500 km(3) (or 0.34 over basin) 2014, which could be attributed not...
Abstract The loss of Arctic sea ice has emerged as a leading signal global warming. This, together with acknowledged impacts on other components the Earth system, led to term “the new Arctic.” Global coupled climate models predict that will continue through twenty-first century, implications for governance, economics, security, and weather. A wide range in model projections reflects complex, highly interactions between polar atmosphere, ocean, cryosphere, including teleconnections lower...
The surplus heat needed to explain the loss of Arctic sea ice during past few decades is on order 1 W/m2. Observing, attributing, and predicting such a small amount energy remain daunting problems.
Abstract Davis Strait is a primary gateway for freshwater exchange between the Arctic and North Atlantic Oceans including contributions from west Greenland Canadian Archipelago glacial melt. Data six years (2004–10) of continuous measurements collected by full-strait moored array concurrent high-resolution Seaglider surveys are used to estimate volume liquid transports through Strait, with respective annual averages −1.6 ± 0.5 Sverdrups (Sv; 1 Sv ≡ 106 m3 s−1) −93 6 mSv (negative sign...
Abstract We present a first examination of Arctic sea ice snow depth estimates from differencing satellite lidar (ICESat‐2) and radar (CryoSat‐2) freeboards. These cover the period between 14 October 2018 end April 2019. Snow is related to freeboard differences by refractive index/bulk density layer—the only free parameter in approach. Area‐averaged ranges 9 cm (on first‐year ice: 5 cm, multiyear cm) late 19 (first‐year 17 27 April; on average, this thinner over FYI. Spatial patterns...
Abstract National Aeronautics and Space Administration's (NASA's) Ice, Cloud, land Elevation Satellite‐2 (ICESat‐2) mission was launched in September 2018 with the primary goal of monitoring our rapidly changing polar regions. The sole instrument onboard, Advanced Topographic Laser Altimeter System, is now providing routine, very high‐resolution, surface elevation data across globe, including Arctic Southern oceans. In this study, we demonstrate new processing chain for converting...
Abstract Using ICESat‐2 and CryoSat‐2 freeboards, we examine the variability of monthly Arctic sea ice snow depth, thickness volume between October 2018 April 2021. For 3 years, satellite‐derived estimates captured a decrease in mean depth (∼2.50 cm) (∼0.28 m) equivalent to an loss ∼12.5%. Results show greater thinning multiyear with end‐of‐season 2021 that is lower by ∼16.1% (0.50 m), negligible changes over first‐year ice. period, using from climatology result thicker (by up ∼0.22 smaller...