A5056043256- Cryospheric studies and observations
- Winter Sports Injuries and Performance
- Arctic and Antarctic ice dynamics
- Climate change and permafrost
- Geology and Paleoclimatology Research
- Climate variability and models
- Landslides and related hazards
- Polar Research and Ecology
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Methane Hydrates and Related Phenomena
- Geophysics and Gravity Measurements
- Atmospheric aerosols and clouds
- Adventure Sports and Sensation Seeking
- Aerospace Engineering and Energy Systems
- Hydrology and Watershed Management Studies
- Oceanographic and Atmospheric Processes
- Marine Biology and Ecology Research
- Paleontology and Stratigraphy of Fossils
- Geological Studies and Exploration
- Aeolian processes and effects
- Climate Change and Geoengineering
- Simulation Techniques and Applications
- Icing and De-icing Technologies
- Atmospheric Ozone and Climate
University of Colorado Boulder
2017-2025
University of Colorado System
2018-2024
NOAA Oceanic and Atmospheric Research
2017-2024
NSF National Center for Atmospheric Research
2022-2023
KU Leuven
2017-2023
NSF NCAR Climate and Global Dynamics Laboratory
2022-2023
National Oceanic and Atmospheric Administration
2021-2022
Utrecht University
2010-2019
Environmental Earth Sciences
2019
Japan External Trade Organization
2015
An overview of the Community Earth System Model Version 2 (CESM2) is provided, including a discussion challenges encountered during its development and how they were addressed. In addition, an evaluation pair CESM2 long preindustrial control historical ensemble simulations presented. These performed using nominal 1° horizontal resolution configuration coupled model with both "low-top" (40 km, limited chemistry) "high-top" (130 comprehensive versions atmospheric component. contains many...
The Community Land Model (CLM) is the land component of Earth System (CESM) and used in several global regional modeling systems. In this paper, we introduce model developments included CLM version 5 (CLM5), which default for CESM2. We assess an ensemble simulations, including prescribed prognostic vegetation state, multiple forcing data sets, CLM4, CLM4.5, CLM5, against a range metrics from International Benchmarking (ILAMBv2) package. CLM5 includes new updated processes parameterizations:...
We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, models surface mass balance glacial isostatic adjustment to estimate the Earth's polar ice sheets. find that there is good agreement between different methods--especially in Greenland West Antarctica--and combining leads greater certainty. Between 1992 2011, sheets Greenland, East Antarctica, Antarctic Peninsula changed by -142 ± 49, +14 43, -65 26, -20...
Ice sheet mass balance estimates have improved substantially in recent years using a variety of techniques, over different time periods, and at various levels spatial detail.Considerable disparity remains between these due to the inherent uncertainties each method, lack detailed comparison independent estimates, effect temporal modulations ice surface balance.Here, we present consistent record for Greenland Antarctic sheets past two decades, validated by techniques last 8 years: one...
Abstract. We evaluate modelled Antarctic ice sheet (AIS) near-surface climate, surface mass balance (SMB) and energy (SEB) from the updated polar version of regional atmospheric climate model, RACMO2 (1979–2016). The referred to as RACMO2.3p2, incorporates upper-air relaxation, a revised topography, tuned parameters in cloud scheme generate more precipitation towards AIS interior modified snow properties reducing drifting sublimation increasing snowmelt. Comparisons model output with several...
Abstract. To estimate the sea level rise (SLR) originating from changes in surface mass balance (SMB) of Greenland ice sheet (GrIS), we present 21st century climate projections obtained with regional model MAR (Modèle Atmosphérique Régional), forced by output three CMIP5 (Coupled Model Intercomparison Project Phase 5) general circulation models (GCMs). Our results indicate that a warmer climate, gain increased winter snowfall over GrIS does not compensate loss through meltwater run-off...
A new, high resolution (27 km) surface mass balance (SMB) map of the Antarctic ice sheet is presented, based on output a regional atmospheric climate model that includes snowdrift physics and forced by most recent reanalysis data from European Centre for Medium‐Range Weather Forecasts (ECMWF), ERA‐Interim (1979–2010). The SMB confirms accumulation zones in western Peninsula (>1500 mm y −1 ) coastal West Antarctica (>1000 ), shows low values large parts interior (<25 ). location...
Abstract This study evaluates the impact of a recent upgrade in physics package regional atmospheric climate model RACMO2 on simulated surface mass balance (SMB) Antarctic ice sheet. The modelled SMB increases, particular over grounded sheet East Antarctica (+44 Gt –1 ), with small change West Antarctica. mainly results from an increase precipitation, which is explained by changes cloud microphysics, including new parameterization for supersaturation, and large-scale circulation patterns,...
Freshwater (FW) fluxes from river runoff and precipitation minus evaporation for the pan Arctic seas are relatively well documented prescribed in ocean GCMs. Fluxes Greenland on other hand generally ignored altogether, despite their potential impacts circulation marine biology. Here, we present a reconstruction of spatially distributed FW flux 1958–2010. We find modest increase into Ocean during this period. Irminger Basin, however, have increased by fifty percent (6.3 ± 0.5 km 3 yr −2 )...
Abstract. The Antarctic ice sheet mass balance is a major component of the sea level budget and results from difference two fluxes similar magnitude: flow discharging in ocean net snow accumulation on surface, i.e. surface (SMB). Separately modelling dynamics SMB only way to project future trends. In addition, studies frequently use regional climate models (RCMs) outputs as an alternative observed fields because observations are particularly scarce sheet. Here we evaluate new simulations...
Abstract. We evaluate modelled Greenland ice sheet (GrIS) near-surface climate, surface energy balance (SEB) and mass (SMB) from the updated regional climate model RACMO2 (1958–2016). The new version, referred to as RACMO2.3p2, incorporates glacier outlines, topography albedo fields. Parameters in cloud scheme governing conversion of condensate into precipitation have been tuned correct inland snowfall underestimation: snow properties are modified reduce drifting melt production percolation...
Abstract The most recent Intergovernmental Panel on Climate Change assessment report concludes that the Atlantic Meridional Overturning Circulation (AMOC) could weaken substantially but is very unlikely to collapse in 21st century. However, largely neglected Greenland Ice Sheet (GrIS) mass loss, lacked a comprehensive uncertainty analysis, and was limited Here community effort, improved estimates of GrIS loss are included multicentennial projections using eight state‐of‐the‐science climate...
Surface mass balance (SMB) provides input to the surface of Antarctic and Greenland Ice Sheets therefore comprises an important control on ice sheet resulting contribution global sea level change. As SMB varies highly across multiple scales space (meters hundreds kilometers) time (hourly decadal), it is notoriously challenging observe represent in models. In addition, consists components, all which depend complex interactions between atmosphere snow/ice surface, large-scale atmospheric...
Abstract The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. drivers runoff, however, remain poorly understood. Here we show that clouds enhance runoff by about one-third relative clear skies, using a unique combination active satellite observations, climate model data and snow simulations. This impact results from cloud radiative effect 29.5 (±5.2) W m −2 . Contrary conventional wisdom, responds this...
Abstract. Here we present Antarctic snow accumulation variability at the regional scale over past 1000 years. A total of 79 ice core records were gathered and assigned to seven geographical regions, separating high-accumulation coastal zones below 2000 m elevation from dry central Plateau. The composites annual evaluated against modelled surface mass balance (SMB) RACMO2.3p2 precipitation ERA-Interim reanalysis. With exception Weddell Sea coast, low-elevation capture SMB as defined by...
Locally grounded features in ice shelves, called rises and rumples, play a key role buttressing discharge from the Antarctic Ice Sheet regulating its contribution to sea level. typically rise several hundreds of meters above surrounding shelf; shelf flow is diverted around them. On other hand, flows across which only few tens shelf. contain rich histories deglaciation climate that extend back over timescales ranging millennia beyond last glacial maximum. Numerical model results have shown...
Abstract. Observations and models agree that the Greenland Ice Sheet (GrIS) surface mass balance (SMB) has decreased since end of 1990s due to an increase in meltwater runoff this trend will accelerate future. However, large uncertainties remain, partly different approaches for modelling GrIS SMB, which have weigh physical complexity or low computing time, spatial temporal resolutions, forcing fields, ice sheet topographies extents, collectively make inter-comparison difficult. Our SMB model...
Abstract The Antarctic ice sheet (AIS) is sensitive to short‐term extreme meteorological events that can leave long‐term impacts on the continent's surface mass balance (SMB). We investigate of atmospheric rivers (ARs) AIS precipitation budget using an AR detection algorithm and a regional climate model (Modèle Atmosphérique Régional) from 1980 2018. While ARs their associated vapor transport are relatively rare over coastal regions (∼3 days per year), they have significant impact...
To simulate the impact of drifting snow on lower atmosphere, surface characteristics and mass balance (SMB) Antarctic ice sheet regional atmospheric climate model (RACMO2.1/ANT) with horizontal resolution 27 km is coupled to a routine forced by ERA‐Interim fields at its lateral boundaries (1989–2009). This paper evaluates near‐surface RACMO2.1/ANT. Modeled wind speed (squared correlation coefficient R 2 = 0.64) temperature ( 0.93) agree well observations. Wind underestimated in...