An overview of the ORACLES (ObseRvations of Aerosols above CLouds and theirintEractionS) project: aerosol–cloud–radiation interactions in the southeastAtlantic basin Atmospheric Chemistry and Physics DOI 10.5194/acp-21-1507-2021 23 February 2021 Southern Africa produces almost a third of the Earth’s biomass burning (BB) aerosol particles, yet the fate of these particles and their influence on regional and global climate is poorly understood. ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) is a 5-year NASA EVS-2 (Earth Venture Suborbital-2) investigation with three intensive observation periods designed to study key atmospheric processes that determine the climate impacts of these aerosols. Read more
Synchronized spatial shifts of Hadley and Walker circulations Earth System Dynamics DOI 10.5194/esd-12-121-2021 22 February 2021 Here, by examining the spatiotemporal relationship between Hadley and Walker cells in observations and climate model experiments, we demonstrate that the seasonally evolving warm-pool sea surface temperature (SST) anomalies in the decay phase of an El Niño event generate a meridionally asymmetric Walker circulation response, which couples the zonal and meridional atmospheric overturning circulations. Read more
A revision of the Combined Drought Indicator (CDI)used in the European Drought Observatory (EDO) Natural Hazards and Earth System Sciences DOI 10.5194/nhess-21-481-2021 19 February 2021 Building on almost 10 years of expertise and operational application of the Combined Drought Indicator (CDI), which is implemented within the European Commission’s European Drought Observatory (EDO) for the purposes of early warning and monitoring of agricultural droughts in Europe, this paper proposes a revised version of the index. Read more
The transient sensitivity of sea level rise Ocean Science DOI 10.5194/os-17-181-2021 18 February 2021 Here, we introduce a similar metric for sea level response. We find that future projections estimated on climate model responses fall below extrapolation based on recent observational records.This comparison suggests that the likely upper level of sea level projections in recent IPCC reports would be too low. Read more
Coordinating an operational data distribution network for CMIP6 data Geoscientific Model Development DOI 10.5194/gmd-14-629-2021 17 February 2021 The distribution of data contributed to the Coupled Model Intercomparison Project Phase 6 (CMIP6) is via the Earth System Grid Federation (ESGF). The ESGF is a network of internationally distributed sites that together work as a federated data archive. Read more
Greenland climate simulations show high Eemian surface meltwhich could explain reduced total air content in ice cores Climate of the Past DOI 10.5194/cp-17-317-2021 16 February 2021 This study presents simulations of Greenland surface melt for the Eemian interglacial period (∼130,000 to 115, 000 years ago) derived from regional climate simulations with a coupled surface energy balance model. Read more
The Eocene–Oligocene transition: a review of marine and terrestrial proxy data, models and model–data comparisons Climate of the Past DOI 10.5194/cp-17-269-2021 15 February 2021 We find that CO2 forcing involving a large decrease in CO2 of ca. 40 % (∼325 ppm drop) provides the best fit to the available proxy evidence,with ice sheet and palaeogeographic changes playing a secondary role. Read more
Macroscopic water vapor diffusion is not enhanced in snow The Cryosphere DOI 10.5194/tc-15-389-2021 12 February 2021 Here we show using theory and numerical simulations of idealized and measured snow microstructures that, although sublimation and deposition of water vapor onto snow crystal surfaces do enhance microscopic diffusion in the pore space, this effect is more than countered by the restriction of diffusion space due to ice. Read more
Experiments on magnetic interference for a portable airborne magnetometry system using a hybrid unmanned aerial vehicle (UAV) Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-10-25-2021 11 February 2021 An experiment concerning the static magnetic interference of the UAV was conducted to assess the severity of the interference of a hybrid vertical take-off and landing (VTOL) UAV. Read more
Last Glacial Maximum (LGM) climate forcing and ocean dynamical feedback and their implications for estimating climate sensitivity Climate of the Past DOI 10.5194/cp-17-253-2021 10 February 2021 Here we conduct a suite of Last Glacial Maximum (LGM) simulations using the Community Earth System Model version 1.2 (CESM1.2) to quantify the forcing and efficacy of land ice sheets (LISs) and greenhouse gases (GHGs) in order to estimate equilibrium climate sensitivity. Read more