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Your search keyword '"VAN DEN BROEKE, Michiel R."' showing total 40 results
Start Over Author "VAN DEN BROEKE, Michiel R." Publisher american geophysical union (agu)
40 results on '"VAN DEN BROEKE, Michiel R."'

7. Monsoon Clouds Control the Summer Surface Energy Balance on East Rongbuk Glacier (6,523 m Above Sea Level), the Northern of Mt. Qomolangma (Everest)

Author

Liu, Weigang, Zhang, Dongqi, Qin, Xiang, van den Broeke, Michiel R., Jiang, Youyan, Yang, Diyi, Ding, Minghu, Sub Dynamics Meteorology, Marine and Atmospheric Research, Sub Dynamics Meteorology, and Marine and Atmospheric Research

Subjects
Atmospheric Science, geography, glacier, melting, geography.geographical_feature_category, surface energy balance, Glacier, Monsoon, Surface energy balance, Geophysics, Space and Planetary Science, Climatology, Taverne, Earth and Planetary Sciences (miscellaneous), Tibetan Plateau, Sea level, Geology
Abstract

To identify the atmospheric controls of the summertime glacier surface energy balance in the Himalayas, in situ meteorological data collected at 6,523 m above sea level during May–July 2005 were obtained and analyzed. Our results showed that net shortwave radiation (103 W m−2) and turbulent sensible heat flux (12 W m−2) acted as energy sources, and net longwave radiation (−62 W m−2) and turbulent latent heat flux (−20 W m−2) represented heat sinks. Cloud cover controlled the summer surface energy balance. During the active period of the South Asian Summer Monsoon, the frequent cloud coverage increased the incoming longwave radiation more than it decreased the incident solar radiation. Intensification (weakening) of the South Asian Summer Monsoon strengthened (suppressed) surface melting. The melt energy measured during the nonmonsoon period was small due to the energy consumption associated with glacier volume warming, energy loss from sublimation, and large heat loss through net longwave radiation due to the low amount of incoming longwave radiation caused by the low cloudiness. The comparison of glacier surface energy balances on the Tibetan Plateau shows that on continental glaciers, net radiation is lower and accounts for a smaller contribution to energy sources, and the dominant energy sinks are sublimation and evaporation, rather than melting, which is the primary energy sink for maritime/subcontinental glaciers. This implies an important spatial variability in glacial sensitivity to different climatic conditions on the Tibetan Plateau.

Published
2021
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9. Present‐Day Greenland Ice Sheet Climate and Surface Mass Balance in CESM2

Author

van Kampenhout, Leonardus, Lenaerts, Jan T.M., Lipscomb, William H., Lhermitte, Stef, Noël, Brice, Vizcaíno, Miren, Sacks, William J., van den Broeke, Michiel R., Sub Dynamics Meteorology, Marine and Atmospheric Research, Sub Dynamics Meteorology, and Marine and Atmospheric Research

Subjects
REPRESENTATION, Atmospheric Science, 010504 meteorology & atmospheric sciences, IMPACT, surface mass balance, 21ST-CENTURY, Greenland, ATMOSPHERIC MODEL, Soil Science, Greenland ice sheet, Aquatic Science, Oceanography, Atmospheric sciences, 01 natural sciences, ESM, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Sea ice, Geosciences, Multidisciplinary, TEMPERATURE, MELT, ACCUMULATION, Water Science and Technology, 0105 earth and related environmental sciences, Earth-Surface Processes, geography, Coupled model intercomparison project, Science & Technology, geography.geographical_feature_category, Ecology, ice sheets, Palaeontology, Firn, Geology, Forestry, Future sea level, Albedo, GCM, CLOUD, Geophysics, CESM2, SNOW, Space and Planetary Science, 13. Climate action, Physical Sciences, Environmental science, Climate model, SEA-ICE, Ice sheet
Abstract

The response of the Greenland Ice Sheet (GrIS) to a warmer climate is uncertain on long time scales. Climate models, such as those participating in the Coupled Model Intercomparison Project phase 6 (CMIP6), are used to assess this uncertainty. The Community Earth System Model version 2.1 (CESM2) is a CMIP6 model capable of running climate simulations with either one-way coupling (fixed ice sheet geometry) or two-way coupling (dynamic geometry) to the GrIS. The model features prognostic snow albedo, online downscaling using elevation classes, and a firn pack to refreeze percolating melt water. Here we evaluate the representation of the GrIS surface energy balance and surface mass balance in CESM2 at 1° resolution with fixed GrIS geometry. CESM2 agrees closely with ERA-Interim reanalysis data for key controls on GrIS SMB: surface pressure, sea ice extent, 500 hPa geopotential height, wind speed, and 700 hPa air temperature. Cloudsat-CALIPSO data show that supercooled liquid-containing clouds are adequately represented, whereas comparisons to Moderate Resolution Imaging Spectroradiometer and CM SAF Cloud, Albedo, and Surface Radiation data set from Advanced Very High Resolution Radiometer data second edition data suggest that CESM2 underestimates surface albedo. The seasonal cycle and spatial patterns of surface energy balance and surface mass balance components in CESM2 agree well with regional climate model RACMO2.3p2, with GrIS-integrated melt, refreezing, and runoff bracketed by RACMO2 counterparts at 11 and 1 km. Time series of melt, runoff, and SMB show a break point around 1990, similar to RACMO2. These results suggest that GrIS SMB is realistic in CESM2, which adds confidence to coupled ice sheet-climate experiments that aim to assess the GrIS contribution to future sea level rise.

Published
2020
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13. Greenland Ice Sheet flow response to runoff variability

Author

Woods Hole Oceanographic Institution, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, thomas herring, Stevens, Laura A., Behn, Mark D., Das, Sarah B., Joughin, Ian, Noël, Brice P. Y., van den Broeke, Michiel R., Herring, Thomas A, Woods Hole Oceanographic Institution, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, thomas herring, Stevens, Laura A., Behn, Mark D., Das, Sarah B., Joughin, Ian, Noël, Brice P. Y., van den Broeke, Michiel R., and Herring, Thomas A

Abstract

We use observations of ice sheet surface motion from a Global Positioning System network operating from 2006 to 2014 around North Lake in west Greenland to investigate the dynamical response of the Greenland Ice Sheet's ablation area to interannual variability in surface melting. We find no statistically significant relationship between runoff season characteristics and ice flow velocities within a given year or season. Over the 7 year time series, annual velocities at North Lake decrease at an average rate of −0.9 ± 1.1 m yr⁻², consistent with the negative trend in annual velocities observed in neighboring regions over recent decades. We find that net runoff integrated over several preceding years has a negative correlation with annual velocities, similar to findings from the two other available decadal records of ice velocity in western Greenland. However, we argue that this correlation is not necessarily evidence for a direct hydrologic mechanism acting on the timescale of multiple years but could be a statistical construct. Finally, we stress that neither the decadal slowdown trend nor the negative correlation between velocity and integrated runoff is predicted by current ice‐sheet models, underscoring that these models do not yet capture all the relevant feedbacks between runoff and ice dynamics needed to predict long‐term trends in ice sheet flow. Keywords: Greenland Ice Sheet; ice flow; runoff

Published
2019

14. Application of PROMICE Q-Transect in Situ Accumulation and Ablation Measurements (2000-2017) to Constrain Mass Balance at the Southern Tip of the Greenland Ice Sheet

Author

Hermann, Mauro, primary, Box, Jason E., additional, Fausto, Robert S., additional, Colgan, William T., additional, Langen, Peter L., additional, Mottram, Ruth, additional, Wuite, Jan, additional, Noël, Brice, additional, van den Broeke, Michiel R., additional, and van As, Dirk, additional

Published
2018
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16. The Signature of Southern Hemisphere Atmospheric Circulation Patterns in Antarctic Precipitation

Author

Marshall, Gareth J., Thompson, David W.J., van den Broeke, Michiel R., Sub Dynamics Meteorology, Marine and Atmospheric Research, Sub Dynamics Meteorology, and Marine and Atmospheric Research

Subjects
010504 meteorology & atmospheric sciences, Atmospheric circulation, Baroclinity, Earth and Planetary Sciences(all), Zonal and meridional, Atmospheric model, precipitation, Biogeosciences, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, Decadal Ocean Variability, Meteorology and Climatology, Climate Dynamics, Oceans, Research Letter, Geodesy and Gravity, Global Change, Precipitation, climate, Southern Hemisphere, 0105 earth and related environmental sciences, Climate Change and Variability, Climatology, Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions, Climate Variability, Climate and Interannual Variability, Arctic and Antarctic oceanography, Mode (statistics), Research Letters, Oceanography: General, Geophysics, Atmospheric Processes, Antarctica, circulation, General Earth and Planetary Sciences, Environmental science, Geographic Location, Cryosphere, mass balance, Oceanography: Physical, Teleconnection
Abstract

We provide the first comprehensive analysis of the relationships between large‐scale patterns of Southern Hemisphere climate variability and the detailed structure of Antarctic precipitation. We examine linkages between the high spatial resolution precipitation from a regional atmospheric model and four patterns of large‐scale Southern Hemisphere climate variability: the southern baroclinic annular mode, the southern annular mode, and the two Pacific‐South American teleconnection patterns. Variations in all four patterns influence the spatial configuration of precipitation over Antarctica, consistent with their signatures in high‐latitude meridional moisture fluxes. They impact not only the mean but also the incidence of extreme precipitation events. Current coupled‐climate models are able to reproduce all four patterns of atmospheric variability but struggle to correctly replicate their regional impacts on Antarctic climate. Thus, linking these patterns directly to Antarctic precipitation variability may allow a better estimate of future changes in precipitation than using model output alone., Key Points The primary Southern Hemisphere extratropical circulation patterns all influence the spatial distribution of Antarctic precipitationThey impact not only the mean but also the incidence of extreme precipitation eventsLocally, extreme precipitation may be associated especially with one polarity of a circulation pattern

Published
2017
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30. Recurring dynamically induced thinning during 1985 to 2010 on Upernavik Isstrøm, West Greenland

Author

Khan, Shfaqat Abbas, primary, Kjaer, Kurt H., additional, Korsgaard, Niels J., additional, Wahr, John, additional, Joughin, Ian R., additional, Timm, Lars H., additional, Bamber, Jonathan L., additional, van den Broeke, Michiel R., additional, Stearns, Leigh A., additional, Hamilton, Gordon S., additional, Csatho, Bea M., additional, Nielsen, Karina, additional, Hurkmans, Ruud, additional, and Babonis, Greg, additional

Published
2013
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31. Improved ice loss estimate of the northwestern Greenland ice sheet

Author

Kjeldsen, Kristian K., primary, Khan, Shfaqat Abbas, additional, Wahr, John, additional, Korsgaard, Niels J., additional, Kjaer, Kurt H., additional, Bjørk, Anders A., additional, Hurkmans, Ruud, additional, van den Broeke, Michiel R., additional, Bamber, Jonathan L., additional, and van Angelen, Jan H., additional

Published
2013
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32. Oceanic controls on the mass balance of Wilkins Ice Shelf, Antarctica

Author

Padman, Laurie, primary, Costa, Daniel P., additional, Dinniman, Michael S., additional, Fricker, Helen A., additional, Goebel, Michael E., additional, Huckstadt, Luis A., additional, Humbert, Angelika, additional, Joughin, Ian, additional, Lenaerts, Jan T. M., additional, Ligtenberg, Stefan R. M., additional, Scambos, Ted, additional, and van den Broeke, Michiel R., additional

Published
2012
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33. Revisiting the Earth's sea-level and energy budgets from 1961 to 2008

Author

Church, John A., primary, White, Neil J., additional, Konikow, Leonard F., additional, Domingues, Catia M., additional, Cogley, J. Graham, additional, Rignot, Eric, additional, Gregory, Jonathan M., additional, van den Broeke, Michiel R., additional, Monaghan, Andrew J., additional, and Velicogna, Isabella, additional

Published
2011
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37. Ground‐based measurements of spatial and temporal variability of snow accumulation in East Antarctica

Author

Eisen, Olaf, primary, Frezzotti, Massimo, additional, Genthon, Christophe, additional, Isaksson, Elisabeth, additional, Magand, Olivier, additional, van den Broeke, Michiel R., additional, Dixon, Daniel A., additional, Ekaykin, Alexey, additional, Holmlund, Per, additional, Kameda, Takao, additional, Karlöf, Lars, additional, Kaspari, Susan, additional, Lipenkov, Vladimir Y., additional, Oerter, Hans, additional, Takahashi, Shuhei, additional, and Vaughan, David G., additional

Published
2008
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