A5000717001- Climate variability and models
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Atmospheric chemistry and aerosols
- Arctic and Antarctic ice dynamics
- Atmospheric aerosols and clouds
- Geology and Paleoclimatology Research
- Atmospheric Ozone and Climate
- Geophysics and Gravity Measurements
- Cryospheric studies and observations
- Tropical and Extratropical Cyclones Research
- Oceanographic and Atmospheric Processes
- Climate change and permafrost
- Global Energy and Sustainability Research
- Solar and Space Plasma Dynamics
- Marine and coastal ecosystems
- Methane Hydrates and Related Phenomena
- Ecosystem dynamics and resilience
- Astro and Planetary Science
- Wind and Air Flow Studies
- Climate Change Policy and Economics
- Species Distribution and Climate Change
- Fluid Dynamics and Turbulent Flows
- Protein Tyrosine Phosphatases
- Medical Imaging Techniques and Applications
Bolin Centre for Climate Research
2020-2024
Stockholm University
2007-2024
National Institute of Meteorology
2020-2024
Uganda National Meteorological Authority
2020-2024
University of Bern
2023
Max Planck Institute for Meteorology
2013-2022
Swedish Meteorological and Hydrological Institute
2020
Universität Hamburg
2018
Max Planck Society
2010-2017
Sorbonne Université
2013
The new Max‐Planck‐Institute Earth System Model (MPI‐ESM) is used in the Coupled Intercomparison Project phase 5 (CMIP5) a series of climate change experiments for either idealized CO 2 ‐only forcing or forcings based on observations and Representative Concentration Pathway (RCP) scenarios. paper gives an overview model configurations, related forcings, initialization procedures presents results simulated changes carbon cycle. It found that feedback depends global warming possibly history....
ECHAM6, the sixth generation of atmospheric general circulation model ECHAM, is described. Major changes with respect to its predecessor affect representation shortwave radiative transfer, height top. Minor have been made tuning and convective triggering. Several configurations, differing in horizontal vertical resolution, are compared. As resolution increased beyond T63, simulated climate improves but incremental; major biases appear be limited by parameterization small‐scale physical...
A new release of the Max Planck Institute for Meteorology Earth System Model version 1.2 (MPI-ESM1.2) is presented. The development focused on correcting errors in and improving physical processes representation, as well computational performance, versatility, overall user friendliness. In addition to radiation aerosol parameterizations atmosphere, several relatively large, but partly compensating, coding model's cloud, convection, turbulence were corrected. representation land was refined...
Abstract The MPI‐ESM1.2 is the latest version of Max Planck Institute Earth System Model and baseline for Coupled Intercomparison Project Phase 6 current seasonal decadal climate predictions. This paper evaluates a coupled higher‐resolution (MPI‐ESM1.2‐HR) in comparison with its lower‐resolved (MPI‐ESM1.2‐LR). We focus on basic oceanic atmospheric mean states selected modes variability, El Niño/Southern Oscillation North Atlantic Oscillation. increase resolution MPI‐ESM1.2‐HR reduces biases...
Abstract The process of parameter estimation targeting a chosen set observations is an essential aspect numerical modeling. This usually named tuning in the climate modeling community. In models, variety and complexity physical processes involved, their interplay through wide range spatial temporal scales, must be summarized series approximate submodels. Most submodels depend on uncertain parameters. Tuning consists adjusting values these parameters to bring solution as whole into line with...
During a development stage global climate models have their properties adjusted or tuned in various ways to best match the known state of Earth's system. These desired are observables, such as radiation balance at top atmosphere, mean temperature, sea ice, clouds and wind fields. The tuning is typically performed by adjusting uncertain, even non‐observable, parameters related processes not explicitly represented model grid resolution. practice has seen an increasing level attention because...
Ocean circulation changes not needed What causes the pattern of sea surface temperature change that is seen in North Atlantic Ocean? This naturally occurring quasi-cyclical variation, known as Multidecadal Oscillation (AMO), affects weather and climate. Some have suggested AMO a consequence variable large-scale ocean circulation. Clement et al. suggest otherwise. They find variability can be produced model does include changes, but only effects air temperatures winds. Science , this issue p. 320
Abstract. On average, airborne aerosol particles cool the Earth's surface directly by absorbing and scattering sunlight indirectly influencing cloud reflectivity, life time, thickness or extent. Here we show that over central Arctic Ocean, where there is frequently a lack of upon which clouds may form, small increase in loading enhance cloudiness thereby likely causing climatologically significant warming at ice-covered surface. Under these low concentration conditions droplets grow to...
In the 1990s, scientists at European Centre for Medium‐Range Weather Forecasts (ECMWF) suggested that artificially enhancing turbulent diffusion in stable conditions improves representation of two important aspects weather forecasts, i.e., near‐surface temperatures and synoptic cyclones. Since then, this practice has often been used tuning large‐scale performance operational numerical prediction (NWP) models, although it is widely recognized to be detrimental an accurate boundary layers....
Abstract ICON‐A is the new icosahedral nonhydrostatic (ICON) atmospheric general circulation model in a configuration using Max Planck Institute physics package, which originates from ECHAM6 model, and has been adapted to account for changed dynamical core framework. The coupling scheme between dynamics employs sequential updating by physics, fixed sequence of physical processes similar ECHAM6. To allow meaningful initial comparison established ECHAM6‐LR setup with similar, low resolution...
Abstract. A simple plume implementation of the second version (v2) Max Planck Institute Aerosol Climatology, MACv2-SP, is described. MACv2-SP provides a prescription anthropogenic aerosol optical properties and an associated Twomey effect. It was created to provide harmonized description post-1850 radiative forcing for climate modeling studies. has been designed be easy implement, change use, thereby enable studies exploring climatic effects different patterns forcing, including formulated...
Abstract Eight atmospheric general circulation models (AGCMs) are forced with observed historical (1871–2010) monthly sea surface temperature and ice variations using the Atmospheric Model Intercomparison Project II data set. The AGCMs therefore have a similar pattern trend to that of climate change. simulate spread in feedback seen coupled simulations response CO 2 quadrupling. However, feedbacks robustly more stabilizing effective sensitivity (EffCS) smaller. This is due effect , whereby...
Abstract. State-of-the-art Earth system models typically employ grid spacings of O(100 km), which is too coarse to explicitly resolve main drivers the flow energy and matter across system. In this paper, we present new ICON-Sapphire model configuration, targets a representation components their interactions with spacing 10 km finer. Through use selected simulation examples, demonstrate that can (i) be run coupled globally on seasonal timescales 5 km, monthly 2.5 daily 1.25 km; (ii) large...
Abstract We investigate the dependence of radiative feedback on pattern sea‐surface temperature (SST) change in 14 Atmospheric General Circulation Models (AGCMs) forced with observed variations SST and sea‐ice over historical record from 1871 to near‐present. find that 1871–1980, Earth warmed feedbacks largely consistent strongly correlated long‐term climate sensitivity (diagnosed corresponding atmosphere‐ocean GCM abrupt‐4xCO2 simulations). Post 1980, however, unusual trends tropical...
Abstract. We present a new reconstruction of surface air temperature and sea for the Last Glacial Maximum. The method blends model fields sparse proxy-based point estimates through data assimilation approach. Our updates that Annan Hargreaves (2013), using full range general circulation (GCM) simulations which contributed to three generations PMIP database, major compilations gridded (SST) (SAT) from proxy data, an improved methodology based on ensemble Kalman filter. has global annual mean...