A5059983870- Geology and Paleoclimatology Research
- Cryospheric studies and observations
- Climate variability and models
- Methane Hydrates and Related Phenomena
- Arctic and Antarctic ice dynamics
- Climate change and permafrost
- Geological Studies and Exploration
- Atmospheric and Environmental Gas Dynamics
- Tree-ring climate responses
- Meteorological Phenomena and Simulations
- Oceanographic and Atmospheric Processes
- Winter Sports Injuries and Performance
- Landslides and related hazards
- Geological formations and processes
- Pleistocene-Era Hominins and Archaeology
- Marine and environmental studies
- Cellular Automata and Applications
- Advanced Thermodynamics and Statistical Mechanics
- Isotope Analysis in Ecology
- Scientific Research and Discoveries
- Plant Water Relations and Carbon Dynamics
- Ionosphere and magnetosphere dynamics
- Marine and coastal ecosystems
- Paleontology and Stratigraphy of Fossils
- Earth Systems and Cosmic Evolution
Max Planck Institute for Meteorology
2016-2024
Max Planck Society
2021
Universität Hamburg
2018-2020
Stockholm University
2013-2018
Bolin Centre for Climate Research
2013-2018
University of Alaska Fairbanks
2010
Abstract. The Last Glacial Maximum (LGM, ∼ 21 000 years ago) has been a major focus for evaluating how well state-of-the-art climate models simulate changes as large those expected in the future using paleoclimate reconstructions. A new generation of used to generate LGM simulations part Paleoclimate Modelling Intercomparison Project (PMIP) contribution Coupled Model (CMIP). Here, we provide preliminary analysis and evaluation results these experiments (PMIP4, most which are PMIP4-CMIP6)...
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 timing of melt onset affects the surface energy uptake throughout season. Yet processes triggering and causing its large interannual variability are not well understood. Here we show that over Arctic sea ice is initiated by positive anomalies water vapor, clouds, air temperatures increase downwelling longwave radiation (LWD) to surface. earlier occurs; stronger these anomalies. Downwelling shortwave (SWD) smaller than usual at onset, indicating triggered SWD. When occurs early,...
Abstract The last deglaciation was characterized by drastic climate changes, most prominently melting ice sheets. Melting sheets have a significant impact on the atmospheric and oceanic circulation, due to changes in topography meltwater release into ocean. In set of transient simulations with Max Planck Institute for Meteorology Earth System Model we explore differences response that arise from different boundary conditions implementations suggested within Paleoclimate Modeling...
Abstract The Arctic summer sea ice has diminished fast in recent decades. A strong year-to-year variability on top of this trend indicates that is sensitive to short-term climate fluctuations. Previous studies show anomalous atmospheric conditions over the during spring and affect melt September extent (SIE). These are characterized by clouds, humidity, heat anomalies all downwelling shortwave (SWD) longwave (LWD) radiation surface. In general, positive LWD associated with cloudy humid...
Abstract. Heinrich events are among the dominant modes of glacial climate variability. During these events, massive iceberg armadas were released by Laurentide Ice Sheet and sailed across Atlantic where they melted freshwater, as well detritus, that formed characteristic layers on seafloor. known for cold climates in North region global changes. We study a fully coupled complex ice sheet–climate model with synchronous coupling between sheets oceans. The discharges occur an internal...
Abstract. The Greenland Ice Sheet (GrIS) mass loss has been accelerating at a rate of about 20 ± 10 Gt/yr2 since the end 1990's, with around 60 % this directly attributed to enhanced surface meltwater runoff. However, in climate and glaciology communities, different approaches exist on how model balance (SMB) components using: (1) complex physically-based models which are computationally expensive; (2) intermediate complexity energy models; (3) simple fast positive degree day base their...
Abstract Recent studies have shown that atmospheric processes in spring play an important role for the initiation of summer ice melt and therefore may strongly influence September sea concentration (SSIC). Here a simple statistical regression model based on only parameters is applied order to predict SSIC over major part Arctic Ocean. By using anomalies downwelling longwave radiation or water vapor as predictor variables, correlation coefficients between observed predicted up 0.5 are found....
This paper investigates the long‐term variability of specific weather types that are associated with damaging hailstorms in Germany for past (1971–2000) and future (2011–2050) time periods. Forty large‐scale determined by objective type classification scheme German Weather Service. is applied to both reanalyses (ERA‐40) eight different regional climate model (RCM) simulations. It shown RCMs able approximately reproduce distribution occurrences obtained from reference ERA‐40. Using additional...
The declining trend of Arctic September sea ice constitutes a significant change in the climate system. Large year-to-year variations are superimposed on this sea–ice trend, with largest variability observed eastern Ocean. Knowledge processes important for may lead to an improved understanding seasonal and long-term changes. Previous studies suggest that transport heat moisture into during spring enhances downward surface longwave radiation, thereby controlling annual melt onset, setting...
Abstract. In this paper we introduce a Bayesian framework, which is explicit about prior assumptions, for using model ensembles and observations together to constrain future climate change. The emergent constraint approach has seen broad application in recent years, including studies constraining the equilibrium sensitivity (ECS) Last Glacial Maximum (LGM) mid-Pliocene Warm Period (mPWP). Most of these were based on ordinary least squares (OLS) fits between variable state, such as tropical...
Abstract. A realistic simulation of the surface mass balance (SMB) is essential for simulating past and future ice-sheet changes. As most state-of-the-art Earth system models (ESMs) are not capable realistically representing processes determining SMB, studies SMB limited to observations regional climate cover last century near only. Using transient simulations with Max Planck Institute ESM in combination an energy model (EBM), we extend previous research study changes equilibrium line...
Abstract. Heinrich-type ice-sheet surges are one of the prominent signals glacial climate variability. They characterised as abrupt, quasi-periodic episodes instabilities during which large numbers icebergs released from Laurentide ice sheet. The mechanisms controlling timing and occurrence remain poorly constrained to this day. Here, we use a coupled sheet–solid Earth model identify quantify importance boundary forcing for surge cycle length two streams sheet – land-terminating Mackenzie...
Abstract. We analyze the impact of a disintegrated Greenland Ice Sheet (GrIS) on climate through steady-state simulations with global Max Planck Institute for Meteorology Earth System Model (MPI-ESM). This advances our understanding intricate feedbacks between GrIS and full system. Sensitivity experiments enable quantification individual contributions altered surface elevation properties (e.g., land cover) to atmospheric oceanic response. Removing results in reduced mechanical blocking,...
Projections of future climate and especially extreme events depend on the reliable simulation variability. On timescales inaccessible to direct observations, evaluation simulated variability requires comparison proxy-based reconstructions. However, estimates surface temperature disagree locally decadal longer timescales.Here, we expand comparisons in simulations observations with data covering up last 2 Million years. For comparison, compile a multi-proxy database, as well use an ensemble...
Abstract. The Last Glacial Maximum (LGM, ~ 21,000 years ago) has been a major focus for evaluating how well state-of-the-art climate models simulate changes as large those expected in the future using paleoclimate reconstructions. A new generation of have used to generate LGM simulations part Palaeoclimate Modelling Intercomparison Project (PMIP) contribution Coupled Model (CMIP). Here we provide preliminary analysis and evaluation results these experiments (PMIP4-CMIP6) compare them with...
Abstract The evolution of the northern hemispheric climate during last glacial period was beset by quasi-episodic iceberg discharge events from Laurentide ice sheet, known as Heinrich (HEs). paleo record places most HEs into cold stadial Dansgaard-Oeschger cycle. However, not every cycle is associated with a HE, revealing complex interplay between two modes variability. Here, using coupled sheet-solid earth model, we introduce mechanism that explains synchronicity and cycles. Unlike earlier...
Abstract. During the last 20,000 years climate of earth has changed from a state much colder than today with large ice sheets in North America and Northwest Eurasia to its present state. The fully-interactive simulation this transition represents hitherto unsolved challenge for state-of-the-art models. We use novel coupled comprehensive atmosphere–ocean–vegetation– sheet–solid model simulate transient evolution glacial maximum preindustrial times. considers dynamical changes glacier mask,...
Abstract. As of 2023, global mean temperature has risen by about 1.45±0.12 °C with respect to the 1850–1900 pre-industrial (PI) baseline according World Meteorological Organization. This rise constitutes first period substantial warming since Last Deglaciation, when temperatures rose over several millennia 4.0–7.0 proxy reconstructions. Similar levels could be reached in coming centuries considering current and possible future emissions. Such causes widespread changes climate system, which...
During the last 20,000 years, climate of Earth evolved from a state much colder than today with large ice sheets covering North America and Northwest Eurasia to its present state. The fully-interactive simulation this transition represented hitherto unsolved challenge for state-of-the-art models. We use novel coupled comprehensive atmosphere-ocean-vegetation-ice sheet-solid earth model simulate transient evolution, referred as deglaciation. considers dynamical changes (shape extent) well in...
Abstract. During the last 20 000 years climate of earth has changed from a state much colder than today, with large ice sheets over North America and northwest Eurasia, to its present state. The fully interactive simulation this transition represents hitherto unsolved challenge for state-of-the-art models. We use novel coupled comprehensive atmosphere–ocean–vegetation–ice-sheet–solid-earth model simulate transient evolution Last Glacial Maximum pre-industrial times. considers dynamical...
Abstract. To enhance understanding of Earth's climate, numerical experiments are performed contrasting a retrograde and prograde rotating Earth using the Max Planck Institute system model. The show that sense rotation has relatively little impact on globally zonally averaged energy budgets but leads to large shifts in continental climates, patterns precipitation, regions deep water formation. Changes zonal asymmetries climates expected given ideas developed more than hundred years ago....
Abstract. An increasing number of climate model simulations is becoming available for the transition from Last Glacial Maximum to Holocene. Assessing simulations' reliability requires benchmarking against environmental proxy records. To date, no established method exists compare these two data sources in space and time over a period with changing background conditions. Here, we develop new algorithm rank according their deviation reconstructed magnitudes temporal patterns orbital...