Phys.org December 23, 2024 To understand the impact of mesoscale variability, including gravity waves (GWs), on atmospheric circulation, a team of researchers in the US (Stanford University, Oak Ridge National Laboratory) extracted data from four months of an integrated data at 1 km resolution (XNR1K) using the Integrated Forecast System (IFS) model. They computed zonal and meridional flux of vertical momentum from ~1.5 petabytes of data. The fluxes were validated using ERA5 reanalysis, both during the first week after initialization and over the boreal winter period from November 2018 to February 2019. The agreement between reanalysis and IFS demonstrated its […]
Tag Archives: Climatology
Longer records bring climate change’s impact on atmospheric circulation to light
Phys.org December 23, 2024 The effects of climate change on atmospheric circulation are more complex because the atmosphere is noisy and chaotic and thermodynamic changes can generate effects that make circulation changes difficult to decipher. According to an international team of researchers (USA – University of Chicago, NOAA, Boulder CO, University of Virginia, Germany, Australia, Switzerland, Israel, Finland) the circulation signals are an opportunity for improving our understanding of dynamical mechanisms, testing our theories and reducing uncertainties. The signals have also presented puzzles that represent an opportunity for better understanding the circulation response to climate change, its contribution to climate […]
Solar geoengineering could save 400,000 lives a year
Phys.org December 23, 2024 Decisions about solar geoengineering (SG) entail risk–risk tradeoffs between the direct risks of SG and SG’s ability to reduce climate risks. Quantitative comparisons between these risks are needed to inform public policy. A team of researchers in the US (Georgia Institute of Technology, Princeton University, University of Chicago) evaluated SG’s effectiveness in reducing deaths from warming. They found that temperature-attributable mortality is uneven with decreases for hotter, poorer regions and increases in cooler, richer regions. There was no evidence that the mortality reduction achieved by SG was smaller than the reduction from equivalent cooling by emissions […]
Climate scientists argue that 1000-year sequestration strategies must be used to meet climate goals
Phys.org November 13, 2024 The scientifically recognized definition of Carbon Dioxide Removal requires removed atmospheric CO2 to be stored “durably”; however, it remains unclear what is meant by durably, and interpretations have varied from decades to millennia. An international team of researchers (Switzerland, USA – UC Berkeley) used a reduced-complexity climate model to examine the effect of Carbon Dioxide Removal with varying CO2 storage durations. They found that storage duration substantially affects whether net zero emissions achieve the desired temperature outcomes. With a typical 100-year storage duration, net zero CO2 emissions with 6 GtCO2 per year residual emissions would result […]
Experts warn of political risks in Antarctic curtain geoengineering proposal
Phys.org November 18, 2024 Should current unmitigated emissions continue, there is a growing chance of collapse of the West Antarctic Ice Sheet, one of the planetary climate tipping points at the greatest risk of being crossed. Such a collapse would subject the world to an increase of several metres in average global sea-level rise over just a few centuries. There is an academic debate about the potential of supporting glacial stability through artificial infrastructures such as an undersea ‘curtain’. However, this ‘ice sheet conservation’ would come with significant yet unforeseeable technical and environmental risks. Researchers in the UK argued that […]
Study warns of ‘irreversible’ climate impacts from overshooting 1.5C
Phys.org October 9, 2024 An international team of researchers (Austria, Germany, France, UK, Switzerland, Australia, Norway) found that achieving declining global temperatures could limit long-term climate risks compared with a mere stabilization of global warming, including for sea-level rise and cryosphere changes. However, the possibility that global warming could be reversed many decades into the future might be of limited relevance for adaptation planning today. Temperature reversal could be undercut by strong Earth-system feedback resulting in high near-term and continuous long-term warming. To protect against high-risk outcomes, they identified the geophysical need for a preventive carbon dioxide removal capacity of […]
Climate models predict abrupt intensification of northern wildfires due to permafrost thawing
Phys.org September 24, 2024 Climate change will accelerate Arctic-Subarctic permafrost thaw which can intensify microbial degradation of carbon-rich soils, methane emissions, and global warming. To better understand the impact of permafrost thaw on future Arctic-Subarctic wildfires and the associated release of greenhouse gases and aerosols an international team of researchers (South Korea, Japan, Norway, USA – National Center for Atmospheric Research, University of Colorado) presented a comprehensive analysis of the effect of future permafrost thaw on land surface processes in the Arctic-Subarctic region using large ensemble forced by the SSP3-7.0 greenhouse gas emission scenario. Analyzing 50 greenhouse warming simulations, which […]
Simple equations clarify cloud climate conundrum
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 […]
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 […]