A5031984162- Climate variability and models
- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Atmospheric Ozone and Climate
- Herpesvirus Infections and Treatments
- Viral Infections and Immunology Research
- Cytomegalovirus and herpesvirus research
- Remote Sensing and Land Use
- Plant responses to elevated CO2
- Arctic and Antarctic ice dynamics
- Tropical and Extratropical Cyclones Research
- Ocean Acidification Effects and Responses
- Reservoir Engineering and Simulation Methods
- Solar Radiation and Photovoltaics
- Toxoplasma gondii Research Studies
- Medical Imaging Techniques and Applications
- Big Data and Business Intelligence
- Climate Change and Geoengineering
- Oceanographic and Atmospheric Processes
- Marine and coastal ecosystems
- Hematological disorders and diagnostics
- Astronomical Observations and Instrumentation
- Carbon Dioxide Capture Technologies
Met Office
2013-2025
Japan Agency for Marine-Earth Science and Technology
2005-2011
ETH Zurich
2009
Max Planck Institute for Meteorology
2009
Laboratory for Atmospheric and Space Physics
2009
National Institute for Environmental Studies
2009
Universität Hamburg
2009
Board of the Swiss Federal Institutes of Technology
2009
Institute for Global Environmental Strategies
2001-2008
United States Global Change Research Program
2006
Abstract A climate data record of global sea surface temperature (SST) spanning 1981–2016 has been developed from 4 × 10 12 satellite measurements thermal infra-red radiance. The spatial area represented by pixel SST estimates is between 1 km 2 and 45 . mean density good-quality observations 13 −2 yr −1 uncertainty evaluated per datum, the median for SSTs being 0.18 K. Multi-annual observational stability relative to drifting buoy within 0.003 K zero with high confidence, despite maximal...
Abstract. The primary objective of CFMIP is to inform future assessments cloud feedbacks through improved understanding cloud–climate feedback mechanisms and better evaluation processes in climate models. However, the approach also increasingly being used understand other aspects change, so a second has now been introduced, improve circulation, regional-scale precipitation, non-linear changes. supporting ongoing model inter-comparison activities by coordinating hierarchy targeted experiments...
The radiative effects from increased concentrations of well‐mixed greenhouse gases (WMGHGs) represent the most significant and best understood anthropogenic forcing climate system. comprehensive tools for simulating past future climates influenced by WMGHGs are fully coupled atmosphere‐ocean general circulation models (AOGCMs). Because importance as agents it is essential that AOGCMs compute these accurately possible. We present results a transfer model intercomparison between forcings...
Key climate feedback due to water vapor and clouds rest largely on how relative humidity ℛ changes in a warmer climate, yet this has not been extensively analyzed models. General circulation models (GCMs) from the CMIP3 archive several higher‐resolution atmospheric GCMs examined here generally predict characteristic pattern of trend with global temperature that reported previously individual models, including increase around tropopause, decrease tropical upper troposphere, midlatitudes. This...
A new radiation scheme has been developed for dynamic general-circulation modeling. An automatic determination of k-distribution parameters and a treatment solar–terrestrial interacting with gaseous particulate matter are incorporated into the by technique that combines discrete ordinate matrix operator methods. accelerated cloud overlap is tested. The resultant accuracy ±0.5 K/day to 70-km height in clear sky better than line-by-line calculation method.
Abstract. A parametric study of the instantaneous radiative impact contrails is presented using three different transfer models for a series model atmospheres and cloud parameters. Contrails are treated as geometrically optically thin plane parallel homogeneous cirrus layers in static atmosphere. The ice water content varied function ambient temperature. include tropical, mid-latitude, subarctic summer winter atmospheres. Optically cause positive net forcing at top At surface negative during...
Abstract Results are presented from a series of sensitivity tests in idealized global warming experiments using the nonhydrostatic model, NICAM, which convection at scales 7–14 km is explicitly resolved. All have strong positive longwave cloud feedback larger than that seen conventional GCMs with parameterized convection. Consequently, mean net outgoing radiation decreases response to increased sea surface temperatures. Large increases high clouds tops between 180 and 50 hPa found, these...
<title>Abstract</title> Models of weather and climate are continuously being developed to improve their reliability and, ultimately, help users make more informed decisions. But they often affected by inadequacies in the physical approximations use, which can lead ‘systematic’ errors. Exposing, understanding, resolving these errors is therefore a key aim model development. One technique that readily expose systematic use perturbed parameter ensembles (PPEs). Here, we show how PPEs be used...
Two versions of a coupled atmosphere‐ocean general circulation model (GCM) with different climate sensitivities are tested on global cooling following the Pinatubo volcanic eruption to investigate validity high sensitivities. The higher‐sensitivity version, sensitivity 6.3 K for doubled CO 2 forcing, overestimates due eruption, whereas lower‐sensitivity version (4.0 K) produces results consistent observations. A simple scheme feedback analysis is devised and it found that difference between...
Abstract Using a global nonhydrostatic model with explicit cloud processes, upper-cloud changes are investigated by comparing the present climate condition under perpetual July setting and warming condition, in which sea surface temperature (SST) is raised 2°. The sensitivity of cover ice water path (IWP) through set experiments. responses convective mass flux areas also examined, together those large-scale subsidence relative humidity subtropics. IWP found to be opposite; that is, as SST...
Abstract Idealized climate change simulations with a new physical model, HadGEM3‐GC2 from The Met Office Hadley Centre are presented and contrasted the earlier MOHC HadGEM2‐ES. role of atmospheric resolution is also investigated. Transient Climate Response (TCR) 1.9 K/2.1 K at N216/N96 Effective Sensitivity (ECS) 3.1 K/3.2 N216/N96. These substantially lower than HadGEM2‐ES (TCR: 2.5 K; ECS: 4.6 K) arising combination changes in size feedbacks. While net cloud feedback between HadGEM3...
Abstract A key contribution to the latest generation of climate projections for UK (UKCP18) was a perturbed parameter ensemble (PPE) global coupled models based on HadGEM3-GC3.05. Together with 13 CMIP5 simulations, this PPE provides users dataset that samples modelling uncertainty and is ideal use in impacts studies. Evaluations mean surface temperatures have shown twenty-first century warming rates consistently at top end range. Here we investigate one potential contributory factor lack...
Abstract. The primary objective of CFMIP is to inform future assessments cloud feedbacks through improved understanding cloud-climate feedback mechanisms and better evaluation processes in climate models. However, the approach also increasingly being used understand other aspects change, such as nonlinear change regional changes atmospheric circulation precipitation. supporting ongoing model inter-comparison activities by coordinating a hierarchy targeted experiments for CMIP6, along with...
Abstract A large spread in model estimates of the equilibrium climate sensitivity (ECS), defined as global mean near-surface air-temperature increase following a doubling atmospheric CO 2 concentration, leaves us greatly disadvantaged guiding policy-making for change adaptation and mitigation. In this study, we show that projected ECS latest generation models is highly related to seasonal variations extratropical low-cloud fraction (LCF) historical simulations. Marked reduction LCF from...
Abstract The overall performance of general circulation models is often investigated on the basis synthesis a number scalar metrics individual that measure reproducibility diverse aspects climate. Because physical and dynamic constraints governing climate, model’s in simulating certain aspect climate sometimes related closely to another aspect, which results significant intermodel correlation between metrics. Numerous correlations may cause problem understanding evaluation synthesizing One...
This is the first study to obtain a statistical climate state under perpetual July condition using nonhydrostatic global model with explicit cloud processes. Horizontal grid intervals of approximately 7 and 14 km over globe marginally allowed for general representation meso‐scale circulations associated deep clouds. The fine‐scale precipitation distribution was similar satellite observations, particularly in regions Intertropical Convergence Zone. Realistic distributions cover upper, middle,...
In climate change projections, inter-model differences in cloud feedback have been identified as the largest source of uncertainty. The terms condensate tendency equation (CCTD) are expected to be useful diagnostics better understand different responses a CO2 increase GCMs. To demonstrate idea, analysis CCTD response doubling is presented using two versions model with sensitivities 6.2°C ('HS'version) and 4.1°C ('LS'version). model's characterized marked difference between versions, which...
We compared the climate response of doubled CO2 equilibrium experiments (2 × CO2) by atmosphere—slab ocean coupled general circulation models (ASGCMs) and that 1% per year increase (1%CO2 atmosphere—ocean (AOGCMs) using eight state-of-the-art models. Climate feedback processes in 2 are different from those 1%CO2, sensitivity (T2×) is effective (T2×, eff) 1%CO2. The difference between T2× T2×, eff −1.3 to 1.6 K, a large part which can be explained ice-albedo cloud feedback. largest...