A5067939391- Climate variability and models
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Atmospheric Ozone and Climate
- Global Energy and Sustainability Research
- Oceanographic and Atmospheric Processes
- Arctic and Antarctic ice dynamics
- Distributed and Parallel Computing Systems
- Advanced Data Storage Technologies
- Algorithms and Data Compression
- Climate Change Policy and Economics
- Atmospheric chemistry and aerosols
- Wind and Air Flow Studies
- demographic modeling and climate adaptation
- Marine and coastal ecosystems
- Geological Studies and Exploration
- Climate change and permafrost
ETH Zurich
2014-2020
Colorado State University
2020
Board of the Swiss Federal Institutes of Technology
2016
Strong future warming in some new climate models is less likely as their recent inconsistent with observed trends.
Abstract The level of agreement between climate model simulations and observed surface temperature change is a topic scientific policy concern. While the Earth system continues to accumulate energy due anthropogenic other radiative forcings, estimates recent evolution fall at lower end projections. Global mean temperatures from are typically calculated using air temperatures, while corresponding observations based on blend sea temperatures. This work quantifies systematic bias in...
Abstract. High-resolution Earth system model simulations generate enormous data volumes, and retaining the from these often strains institutional storage resources. Further, exceedingly large requirements negatively impact science objectives, for example, by forcing reductions in output frequency, simulation length, or ensemble size. To lessen volumes Community System Model (CESM), we advocate use of lossy compression techniques. While does not exactly preserve original (as lossless does),...
Abstract Equilibrium climate sensitivity‐the equilibrium warming per CO 2 doubling‐increases with concentration for 13 of 14 coupled general circulation models 0.5–8 times the preindustrial concentration. In particular, abrupt 4 × is more than twice warming. We identify three potential causes: nonlogarithmic forcing, feedback dependence, and temperature dependence. Feedback dependence explains at least half sensitivity increase, while a smaller share, forcing decreases in as many it...
Recent studies have suggested that significant parts of the observed warming in early and late twentieth century were caused by multidecadal internal variability centered Atlantic Pacific Oceans. Here, a novel approach is used searches for segments unforced preindustrial control simulations from global climate models best match (AMV PMV, respectively). In this way, estimates influence AMV PMV on temperature are consistent both spatially across variables made. Combined impacts surface...
Multidecadal internal climate variability centered in the North Atlantic is evident sea surface temperatures and assumed to be related variations strength of meridional overturning circulation (AMOC). In this study, extent which AMOC may also alter hemispheric global air temperature trends ocean heat content during past century examined. Forty-seven realizations twentieth-century change from two large ensembles using Community Earth System Model (CESM) are analyzed. One shows a much wider...
Abstract Global mean temperature change simulated by climate models deviates from the observed increase during decadal-scale periods in past. In particular, warming ‘global hiatus’ early twenty-first century appears overestimated CMIP5 and CMIP6 multi-model means. We examine role of equatorial Pacific variability these divergences since 1950 comparing 18 studies that quantify contribution to ‘hiatus’ earlier investigating reasons for differing results. During 1992 2012, estimated...
<div>Future global warming estimates have been similar across past assessments, but several climate models of the latest Sixth Coupled Model Intercomparison Project (CMIP6) simulate much stronger warming, apparently inconsistent with assessments. Here we show that projected future is correlated simulated trend during recent decades CMIP5 and CMIP6 models, enabling us to constrain based on consistency observed warming. These findings carry important policy-relevant implications:...
Abstract. High-resolution earth system model simulations generate enormous data volumes, and retaining the from these often strains institutional storage resources. Further, exceedingly large requirements negatively impact science objectives by forcing reductions in output frequency, simulation length, or ensemble size, for example. To lessen volumes Community Earth System Model (CESM), we advocate use of lossy compression techniques. While does not exactly preserve original (as lossless...
Lu (2013) (L13) argued that solar effects and anthropogenic halogenated gases can explain most of the observed warming global mean surface air temperatures since 1850, with virtually no contribution from atmospheric carbon dioxide ( CO 2 ) concentrations. Here we show this conclusion is based on assumptions about saturation -induced greenhouse effect have been experimentally falsified. L13 also confuses equilibrium transient response, relies data sources superseeded due to known...