HydroFATE (v1): a high-resolution contaminant fate model for the global river system Geoscientific Model Development DOI 10.5194/gmd-17-2877-2024 16 April 2024 Treated and untreated wastewaters are sources of contaminants of emerging concern. HydroFATE, a new global model, estimates their concentrations in surface waters, identifying streams that are most at risk and guiding monitoring/mitigation efforts to safeguard aquatic ecosystems and human health. Model predictions were validated against field measurements of the antibiotic sulfamethoxazole, with predicted concentrations exceeding ecological thresholds in more than 400 000 km of rivers worldwide. Read more
Rates of palaeoecological change can inform ecosystem restoration Biogeosciences DOI 10.5194/bg-21-1629-2024 12 April 2024 Rate-of-change records based on compositional data are ambiguous as they may rise irrespective of the underlying trajectory of ecosystems. We emphasize the importance of characterizing both the direction and the rate of palaeoecological changes in terms of key features of ecosystems rather than solely on community composition. Past accelerations of community transformation may document the potential of ecosystems to rapidly recover important ecological attributes and functions. Read more
Subglacial valleys preserved in the highlands of south and east Greenland record restricted ice extent during past warmer climates The Cryosphere DOI 10.5194/tc-18-1467-2024 10 April 2024 This study uses airborne radar data and satellite imagery to map mountainous topography hidden beneath the Greenland Ice Sheet. We find that the landscape records the former extent and configuration of ice masses that were restricted to areas of high topography. Computer models of ice flow indicate that valley glaciers eroded this landscape millions of years ago when local air temperatures were at least 4 °C higher than today and Greenland’s ice volume was < 10 % of that of the modern ice sheet. Read more
Minimizing the effects of Pb loss in detrital and igneous U–Pb zircon geochronology by CA-LA-ICP-MS Geochronology DOI 10.5194/gchron-6-89-2024 8 April 2024 Chemical abrasion (CA) is a technique that reduces or eliminates the effects of Pb loss in zircon U–Pb geochronology. However, CA has yet to be applied to large-n detrital zircon (DZ) analyses. We show that CA does not negatively impact or systematically bias U–Pb dates, improves the resolution of age populations defined by 206Pb/238U dates, and increases the percentage of concordant analyses in age populations defined by 207Pb/206Pb dates. Read more
Extreme melting at Greenland’s largest floating ice tongue The Cryosphere DOI 10.5194/tc-18-1333-2024 5 April 2024 The 79° North Glacier in Greenland has experienced significant changes over the last decades. Due to extreme melt rates, the ice has thinned significantly in the vicinity of the grounding line, where a large subglacial channel has formed since 2010. We attribute these changes to warm ocean currents and increased subglacial discharge from surface melt. However, basal melting has decreased since 2018, indicating colder water inflow into the cavity below the glacier. Read more
Solar radiation modification challenges decarbonization with renewable solar energy Earth System Dynamics DOI 10.5194/esd-15-307-2024 3 April 2024 Most solar radiation modification (SRM) simulations assume no physical coupling between mitigation and SRM. We analyze the impact of SRM on photovoltaic (PV) and concentrated solar power (CSP) and find that almost all regions have reduced PV and CSP potential compared to a mitigated or unmitigated scenario, especially in the middle and high latitudes. This suggests that SRM could pose challenges for meeting energy demands with solar renewable resources. Read more
Possible role of anthropogenic climate change in the record-breaking 2020 Lake Victoria levels and floods Earth System Dynamics DOI 10.5194/esd-15-225-2024 27 March 2024 Heavy rainfall in eastern Africa between late 2019 and mid 2020 caused devastating floods and landslides and drove the levels of Lake Victoria to a record-breaking maximum in May 2020. In this study, we characterize the spatial extent and impacts of the floods in the Lake Victoria basin and investigate how human-induced climate change influenced the probability and intensity of the record-breaking lake levels and flooding by applying a multi-model extreme event attribution methodology. Read more
A past and present perspective on the European summer vapor pressure deficit Climate of the Past DOI 10.5194/cp-20-573-2024 25 March 2024 The main aim of this paper is to present the summer vapor pressure deficit (VPD) reconstruction dataset for the last 400 years over Europe based on δ18O records by using a random forest approach. We provide both a spatial and a temporal long-term perspective on the past summer VPD and new insights into the relationship between summer VPD and large-scale atmospheric circulation. This is the first gridded reconstruction of the European summer VPD over the past 400 years. Read more
Distinct oxygenation modes of the Gulf of Oman over the past 43 000 years – a multi-proxy approach Biogeosciences DOI 10.5194/bg-21-1477-2024 22 March 2024 We analyse benthic foraminifera, nitrogen isotopes and lipids in a sediment core from the Gulf of Oman to investigate how the oxygen minimum zone (OMZ) and bottom water (BW) oxygenation have reacted to climatic changes since 43 ka. The OMZ and BW deoxygenation was strong during the Holocene, but the OMZ was well ventilated during the LGM period. We found an unstable mode of oscillating oxygenation states, from moderately oxygenated in cold stadials to deoxygenated in warm interstadials in MIS 3. Read more
Observations of cyanogen bromide (BrCN) in the global troposphere and their relation to polar surface O3 destruction Atmospheric Chemistry and Physics DOI 10.5194/acp-24-3421-2024 20 March 2024 We measured cyanogen bromide (BrCN) in the troposphere for the first time. BrCN is a product of the same active bromine chemistry that destroys ozone and removes mercury in polar surface environments and is a previously unrecognized sink for active Br compounds. BrCN has an apparent lifetime against heterogeneous loss in the range 1–10 d, so it serves as a cumulative marker of Br-radical chemistry. Accounting for BrCN chemistry is an important part of understanding polar Br cycling. Read more