Drivers controlling black carbon temporal variability in the lower troposphere of the European Arctic Atmospheric Chemistry and Physics DOI 10.5194/acp-23-15589-2023 18 December 2023 Models still fail in reproducing black carbon (BC) temporal variability in the Arctic. Analysis of equivalent BC concentrations in the European Arctic shows that BC seasonal variability is modulated by the efficiency of removal by precipitation during transport towards high latitudes. Short-term variability is controlled by synoptic-scale circulation patterns. The advection of warm air from lower latitudes is an effective pollution transport pathway during summer. Read more
Uncertainty assessment of satellite remote-sensing-based evapotranspiration estimates: a systematic review of methods and gaps Hydrology and Earth System Sciences DOI 10.5194/hess-27-4505-2023 15 December 2023 Satellite data are increasingly used to estimate evapotranspiration (ET) or the amount of water moving from plants, soils, and water bodies into the atmosphere over large areas. Uncertainties from various sources affect the accuracy of these calculations. This study reviews the methods to assess the uncertainties of such ET estimations. It provides specific recommendations for a comprehensive assessment that assists in the potential uses of these data for research, monitoring, and management. Read more
Paul J. Crutzen – a pioneer in Earth system science and a founding member of the journal Atmospheric Chemistry and Physics Atmospheric Chemistry and Physics DOI 10.5194/acp-23-15445-2023 13 December 2023 Paul J. Crutzen was a pioneer in atmospheric sciences and a kind-hearted, humorous person with empathy for the private lives of his colleagues and students. He made fundamental scientific contributions to a wide range of scientific topics in all parts of the atmosphere. Paul was among the founders of the journal Atmospheric Chemistry and Physics. His work will continue to be a guide for generations of scientists and environmental policymakers to come. Read more
Opinion: Tropical cirrus – from micro-scale processes to climate-scale impacts Atmospheric Chemistry and Physics DOI 10.5194/acp-23-15413-2023 11 December 2023 Tropical cirrus clouds are essential for climate, but our understanding of these clouds is limited due to their dependence on a wide range of small- and large-scale climate processes. In this opinion paper, we review recent advances in the study of tropical cirrus clouds, point out remaining open questions, and suggest ways to resolve them. Read more
Climate intervention using marine cloud brightening (MCB) compared with stratospheric aerosol injection (SAI) in the UKESM1 climate model Atmospheric Chemistry and Physics DOI 10.5194/acp-23-15305-2023 8 December 2023 The difficulties in ameliorating global warming and the associated climate change via conventional mitigation are well documented, with all climate model scenarios exceeding 1.5 °C above the pre-industrial level in the near future. There is therefore a growing interest in geoengineering to reflect a greater proportion of sunlight back to space and offset some of the global warming. We use a state-of-the-art Earth-system model to investigate two of the most prominent geoengineering strategies. Read more
Results of a long-term international comparison of greenhouse gas and isotope measurements at the Global Atmosphere Watch (GAW) Observatory in Alert, Nunavut, Canada Atmospheric Measurement Techniques DOI 10.5194/amt-16-5909-2023 6 December 2023 Network compatibility is important for inferring greenhouse gas fluxes at global or regional scales. This study is the first assessment of the measurement agreement among seven individual programs within the World Meteorological Organization community. It compares co-located flask air measurements at the Alert Observatory in Canada over a 17-year period. The results provide stronger confidence in the uncertainty estimation while using those datasets in various data interpretation applications. Read more
Alpine hillslope failure in the western US: insights from the Chaos Canyon landslide, Rocky Mountain National Park, USA Earth Surface Dynamics DOI 10.5194/esurf-11-1251-2023 4 December 2023 In this paper, we investigate the 28 June 2022 collapse of the Chaos Canyon landslide in Rocky Mountain National Park, Colorado, USA. We find that the landslide was moving prior to its collapse and took place at peak spring snow melt; temperature modelling indicates the potential presence of permafrost. We hypothesize that this landslide could be part of the broader landscape evolution changes to alpine terrain caused by a warming climate, leading to thawing alpine permafrost. Read more
Opinion: The strength of long-term comprehensive observations to meet multiple grand challenges in different environments and in the atmosphere Atmospheric Chemistry and Physics DOI 10.5194/acp-23-14949-2023 1 December 2023 To be able to meet global grand challenges, we need comprehensive open data with proper metadata. In this opinion paper, we describe the SMEAR (Station for Measuring Earth surface – Atmosphere Relations) concept and include several examples (cases), such as new particle formation and growth, feedback loops and the effect of COVID-19, and what has been learned from these investigations. The future needs and the potential of comprehensive observations of the environment are summarized. Read more
Simulated hydrological effects of grooming and snowmaking in a ski resort on the local water balance Hydrology and Earth System Sciences DOI 10.5194/hess-27-4257-2023 29 November 2023 Ski resorts are a key socio-economic asset of several mountain areas. Grooming and snowmaking are routinely used to manage the snow cover on ski pistes, but despite vivid debate, little is known about their impact on water resources downstream. This study quantifies, for the pilot ski resort La Plagne in the French Alps, the impact of grooming and snowmaking on downstream river flow. Hydrological impacts are mostly apparent at the seasonal scale and rather neutral on the annual scale. Read more
Constraining an eddy energy dissipation rate due to relative wind stress for use in energy budget-based eddy parameterisations Ocean Science DOI 10.5194/os-19-1669-2023 27 November 2023 The dissipation rate of eddy energy in current energy budget-based eddy parameterisations is still relatively unconstrained, leading to uncertainties in ocean transport and ocean heat uptake. Here, we derive a dissipation rate due to the interaction of surface winds and eddy currents, a process known to significantly damp ocean eddies. The dissipation rate is quantified using seasonal climatology and displays wide spatial variability, with some of the largest values found in the Southern Ocean. Read more