A5011951392- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Winter Sports Injuries and Performance
- Spacecraft and Cryogenic Technologies
- Icing and De-icing Technologies
- Oceanographic and Atmospheric Processes
- Environmental Monitoring and Data Management
- Advanced Optical Sensing Technologies
- Freezing and Crystallization Processes
- Remote Sensing and LiDAR Applications
- Species Distribution and Climate Change
- Scientific Computing and Data Management
- Climate variability and models
- Aerospace Engineering and Energy Systems
- Atmospheric chemistry and aerosols
- Conservation Techniques and Studies
- Arctic and Russian Policy Studies
- Atmospheric and Environmental Gas Dynamics
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
Goddard Space Flight Center
2019-2025
Earth System Science Interdisciplinary Center
2019-2025
University of Maryland, College Park
2019-2025
Technical University of Denmark
2023
University of Mary
2021
Centre for Polar Observation and Modelling
2015-2019
University of Leeds
2017-2019
University College London
2015-2016
Arctic sea ice is a major element of the Earth’s climate system. It acts to regulate regional heat and freshwater budgets subsequent atmospheric oceanic circulation across at lower latitudes. Satellites have observed decline in extent for all months since 1979. However, fully understand how changes cover impact on our global weather climate, long-term accurate observations its thickness distribution are also required. Such were made possible with launch European Space Agency’s (ESA’s)...
Two CryoSat-2 sea ice thickness products derived with independent algorithms are used to initialize a coupled ice-ocean modeling system in which series of reanalysis studies performed for the period March 15, 2014–September 30, 2015. Comparisons against moored upward looking sonar, drifting mass balance buoy, and NASA Operation IceBridge data show that exhibits greatly reduced bias using satellite-derived versus operational model run without these data. The initialized skill simulating from...
Abstract. In this study, we compare eight recently developed snow depth products over Arctic sea ice, which use satellite observations, modeling, or a combination of and modeling approaches. These are further compared against various ground-truth including those from ice mass balance observations airborne measurements. Large mean discrepancies observed the Atlantic Canadian sectors. The differences between climatology early in winter could be part result delaying formation that reduces...
Abstract. Timely observations of sea ice thickness help us to understand the Arctic climate, and have potential support seasonal forecasts operational activities in polar regions. Although it is possible calculate using measurements acquired by CryoSat-2, latency final release data set typically 1 month due time required determine precise satellite orbits. We use a new fast-delivery CryoSat-2 based on preliminary orbits compute near real (NRT), analyse this for one growth season from October...
Abstract Hemisphere‐wide observations of melt ponds on sea ice are needed to understand their influence the surface radiation budget Arctic Ocean and extend satellite thickness data record. Here we present a first assessment NASA's Ice, Cloud, land Elevation Satellite‐2 (ICESat‐2) over individual with different reflective properties. We use coincident high‐resolution imagery from WorldView‐2 Sentinel‐2 topographies show that smooth highly can saturate ICESat‐2 photon detection system....
Abstract. Differential penetration of green laser light into snow and ice has long been considered a possible cause range thus elevation bias in altimeters. Over snow, ice, water, photons can penetrate the surface experience multiple scattering events subsurface volume before being scattered back to subsequently instrument's detector, therefore biasing measurement. Newly formed sea adjacent open-water leads provides an opportunity identify differential without need for absolute reference or...
Major changes are occurring across the North Atlantic climate system, including in atmosphere, ocean and cryosphere, many observed unprecedented instrumental records. As directly affect air quality of surrounding continents, it is important to fully understand how why taking place, not least predict region will change future. To this end, article characterizes recent region, especially period 2005–2016, different aspects system including: atmospheric circulation; composition; clouds...
Abstract Multidecadal observations of sea ice thickness, in addition to those available for extent, are key understanding long‐term variations and trends the amount Arctic ice. The European Space Agency's Envisat (2002–2010) CryoSat‐2 (2010–present) satellite radar altimeter missions provide a continuous 17‐year dataset with potential estimate thickness. However, footprints not equal area so different distributions floes leads sampled by each mission. Here, we compare lead floe sampling from...
Abstract. Estimates of Arctic sea ice thickness have been available from the CryoSat-2 (CS2) radar altimetry mission during growth seasons since 2010. We derive sub-grid-scale distribution (ITD) with respect to five categories used in a component (Community Ice CodE, CICE) climate simulations. This allows us initialize ITD stand-alone simulations CICE and verify simulated cycle thickness. find that default simulation strongly underestimates thickness, despite reproducing inter-annual...
Abstract NASA's Ice, Cloud, and Land Elevation Satellite‐2 (ICESat‐2) mission launched in September 2018 is now providing high‐resolution surface elevation profiling across the entire globe, including sea ice cover of Arctic Southern Oceans. For applications, successfully discriminating returns between open water key for accurately determining freeboard (the extension above local level) new information regarding geometry floes leads. We take advantage near‐coincident optical imagery obtained...
Abstract. The feasibility of assimilating sea ice thickness (SIT) observations derived from CryoSat-2 along-track measurements freeboard is successfully demonstrated using a 3D-Var assimilation scheme, NEMOVAR, within the Met Office's global, coupled ocean–sea-ice model, Forecast Ocean Assimilation Model (FOAM). Arctic are produced by Centre for Polar Observation and Modelling (CPOM) converted to SIT FOAM modelled snow depth. This first time have been used in this way, with other centres...
Abstract. In sea-ice-covered areas, the sea ice floe size distribution (FSD) plays an important role in many processes affecting coupled sea–ice–ocean–atmosphere system. Observations of FSD are sparse – traditionally taken via a painstaking analysis surface photography and seasonal inter-annual evolution regionally globally is largely unknown. Frequently, measured FSDs assessed using single number, scaling exponent closest power-law fit to observed data, although absence adequate datasets...
ABSTRACT Increased anthropogenic stressors (e.g., warming, acidification, wildfires, and other extreme events) present complex observational challenges for Earth science, no one sensor can “do it all”. While many remote sensing technologies are available at present, scientific disciplines often trained to use only a specific subset, greatly limiting advancements. Here we open‐source software (icepyx) that lowers the barrier entry two platforms offering vertically‐resolved information about...
Abstract. The feasibility of assimilating SIT (sea ice thickness) observations derived from CryoSat-2 along-track measurements sea freeboard is successfully demonstrated using a 3D-Var assimilation scheme, NEMOVAR, within the Met Office’s global, coupled ocean-sea model, FOAM (Forecast Ocean Assimilation Model). Arctic are produced by CPOM (Centre for Polar Observation and Modelling) converted to modelled snow depth. This first time have been used in this way, with other centres gridded...
Melt ponding on Arctic sea ice is a key indicator of the transition from predominantly perennial to seasonal cover, yet quantitative data pond depth remain limited. Here, we present first analysis melt-pond using ICESat-2’s Advanced Topographic Lidar Altimeter System (ATLAS). The Density-Dimension Algorithm for Bifurcating Sea-Ice Reflectors (DDA-bifurcate-seaice) automatically detects multiple surface returns in ICESat-2 photon and estimates corresponding heights, enabling melt-pond-depth...
Abstract. Estimates of Arctic sea ice thickness are available from the CryoSat-2 (CS2) radar altimetry mission during growth seasons since 2010. We derive sub-grid scale distribution (ITD) with respect to 5 categories used in a component (CICE) climate simulations. This allows us initialize ITD stand-alone simulations CICE and verify simulated cycle thickness. find that default simulation strongly underestimates thickness, despite reproducing inter-annual variability summer extent. can...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Science. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Assessing CryoSat-2 Antarctic snow freeboard retrievals using data from ICESat-2AuthorsStevenFonsiDNathan TimothyKurtzMarcoBagnardiiDAlek AaronPettyiDRachelTillingiDSee all authors Steven...
Abstract. Timely observations of sea ice thickness help us to understand Arctic climate, and can support maritime activities in the Polar Regions. Although it is possible calculate using measurements acquired by CryoSat-2, latency final release dataset typically one month, due time required determine precise satellite orbits. We use a new fast delivery CryoSat-2 based on preliminary orbits compute near real (NRT), analyse this data for growth season from October 2014 April 2015. show that...
Abstract NASA's Ice, Cloud, and land Elevation Satellite‐2 (ICESat‐2) laser altimeter launched in Fall 2018, providing an invaluable addition to the polar altimetry record generated by ESA's CryoSat‐2 radar altimeter. The simultaneous operation of these two satellite altimeters enables unique comparison studies sea ice altimetry, utilizing different frequencies profiling strategies instruments. Here, we use freeboard data from ICESat‐2 assess Antarctic snow retrievals CryoSat‐2. We first...
Abstract. In this study, we compare eight recently developed snow depth products that use satellite observations, modeling or a combination of and approaches. These are further compared against various ground-truth including those from ice mass balance buoys (IMBs), buoys, derived NASA's Operation IceBridge (OIB) flights, as well climatology historical observations. Large discrepancies between the different data sets observed over Atlantic Canadian Arctic sectors. Among evaluated, University...