Phys.org April 1, 2024 Changes in anvil clouds with warming remain a leading source of uncertainty in estimating Earth’s climate sensitivity. An international team of researchers (France, UK) developed a feedback analysis that decomposes changes in anvil clouds and creates testable hypotheses for refining their proposed uncertainty ranges with observations and theory. They derived a simple but quantitative expression for the anvil area feedback, which depended on the present-day measurable cloud radiative effects and the fractional change in anvil area with warming. Satellite observations suggested an anvil cloud radiative effect of about ±1 W m−2, which requires the fractional change in anvil […]
Tag Archives: Climatology
Researchers provide unprecedented view into aerosol formation in Earth’s lower atmosphere
Phys.org March 6, 2024 Criegee intermediates are reactive intermediates that are implicated in transforming the composition of Earth’s troposphere and in the formation of secondary organic aerosol, impacting Earth’s radiation balance, air quality and human health. Direct identification of their signatures in the field are not available. An international team of researchers (USA – Argonne National Laboratory, NASA Jet Propulsion Laboratory, Sandia National Laboratory, Caltech, Princeton University, Princeton Plasma Physics Laboratory, UC Davis, UK, Turkey, Brazil, France) has identified sequences of masses consistent with the expected signatures of oligomerization of the CH2OO Criegee intermediate, a process implicated in ozonolysis-driven aerosol […]
The escalating impact of global warming on atmospheric rivers
Phys.org February 13, 2024 Researchers in Hong Kong assessed the performance of atmospheric rivers (ARs) in Phase 6 of the Coupled Model Intercomparison Project (CMIP6) models on both seasonal and interannual timescales within the historical period and investigated the future projection of ARs under different emission scenarios on a global scale. The multi-model mean results obtained using the PanLu detection algorithm consistently exhibited agreement with the observational AR climatology and captured interannual fluctuations as well as the relationships with large-scale drivers. The future projections revealed increased AR frequency, intensity, duration, and spatial extent and decreased landfall intervals with regional variations […]
New study reveals the influence of natural climate drivers on extreme monsoons in Pakistan
Phys.org October 13, 2023 Given this region’s long history of floods and droughts, the role of natural climate variability cannot be rejected without a careful diagnosis. An international team of researchers (USA – Oak Ridge National Laboratory, Princeton, Stanford, University of Tennessee, Washington State University, Northeastern University, Pacific Northwest National Laboratory, Tufts University, Italy, India) examined how oceanic and atmospheric variability has contributed to unusual precipitation distributions in West South Asia. Variations in sea surface temperatures in the tropical Pacific and northern Arabian Sea, and internal atmospheric variability related to the circumglobal teleconnection pattern and the subtropical westerly jet stream, […]
Near-surface permafrost could be nearly gone by 2100, scientists conclude
Phys.org September 19, 2023 Accurate understanding of permafrost dynamics is critical for evaluating and mitigating impacts that may arise as permafrost degrades in the future; however, existing projections have large uncertainties. To better understand how near‐surface permafrost may respond to future warming, an international team of researchers (US – University of Alaska, NCAR, University of Connecticut, Columbia University, — UK, Germany, Japan, Canada, France, the Netherlands, Sweden) combined a surface frost index model with outputs from the second phase of the Pliocene Model Intercomparison Project to simulate the near‐surface (~3 to 4 m depth) permafrost state in the Northern Hemisphere […]
Gloomy climate calculation: Scientists predict a collapse of the Atlantic Ocean current to happen mid-century
Science Daily July 25, 2023 The Atlantic meridional overturning circulation (AMOC) is a major tipping element in the climate system and its collapse would have severe impacts on climate in the North Atlantic region. In recent years weakening in circulation has been reported, but assessments by the Intergovernmental Panel on Climate Change (IPCC), based on the Climate Model Intercomparison Project (CMIP) model simulations suggest that a full collapse is unlikely within the 21st century. Tipping to an undesired state in the climate is a growing concern with increasing greenhouse gas concentrations. Predictions based on observations rely on detecting early-warning signals, […]
Researchers: We’ve Underestimated The Risk of Simultaneous Crop Failures Worldwide
Science Alert July 5, 2023 Concurrent weather extremes driven by a strongly meandering jet stream could trigger simultaneous harvest failures across major crop-producing regions, but so far this has not been quantified. The ability of state-of-the art crop and climate models to adequately reproduce such high impact events is a crucial component for estimating risks to global food security. An international team of researchers (USA – Columbia University, Germany) has found an increased likelihood of concurrent low yields during summers featuring meandering jets in observations and models. While climate models accurately simulate atmospheric patterns, associated surface weather anomalies and negative […]
Tracking raindrops, one molecule at a time
Science Daily October 25, 2022 A team of researchers in the US (U Mass. Amherst, University of Alaska) studied the mechanisms of precipitation deuterium excess (d-excess) seasonality in low-latitudes and mid-latitudes through a new analysis of precipitation isotope databases along with climate reanalysis products and moisture tracking models. The ultimate d-excess signals are produced after complex modulations by several reinforcing or competing processes. They developed a simple seasonal water storage model to show that contributions of previously evaporated residual water storage and higher transpiration fractions may lead to relatively low d-excess in evapotranspiration fluxes during periods of enhanced continental moisture […]
Getting it to stick: Designing optimal core-shell MOFs for direct air capture
Phys.org October 11, 2022 MOFs utilize porous membranes to capture large volumes of gasses and can be designed via computational modeling rather than traditional trial-and-error. However, adsorbents designed to strongly bind CO2 nearly always bind H2O strongly. A team of researchers in the US (University of Pittsburgh, DOE) has a direct air capture (DAC) strategy to remove carbon dioxide from the air using core–shell MOF design, where a high-CO2-capacity MOF “core” is protected from competitive H2O-binding via a MOF “shell” that has very slow water diffusion. They considered a high-frequency adsorption/desorption cycle that regenerates the adsorbents before water can pass […]
Study: Four major climate tipping points close to triggering
Phys.org September 11, 2022 Climate tipping points (CTPs) occur when change in large parts of the climate system become self-perpetuating beyond a warming threshold. Triggering CTPs leads to significant, policy-relevant impacts, including substantial sea level rise from collapsing ice sheets, dieback of biodiverse biomes such as the Amazon rainforest or warm-water corals, and carbon release from thawing permafrost. An international team of researchers (Sweden, UK, Germany) provides a comprehensive reassessment of all the nine policy-relevant tipping elements and their CTPs that were originally identified by Lenton et al. (2008). The team updated assessment of the most important climate tipping elements […]