High-resolution spatial patterns and drivers of terrestrial ecosystem carbon dioxide, methane, and nitrous oxide fluxes in the tundra Biogeosciences DOI 10.5194/bg-21-335-2024 12 January 2024 Arctic greenhouse gas (GHG) fluxes of CO2, CH4, and N2O are important for climate feedbacks. We combined extensive in situ measurements and remote sensing data to develop machine-learning models to predict GHG fluxes at a 2 m resolution across a tundra landscape. The analysis revealed that the system was a net GHG sink and showed widespread CH4 uptake in upland vegetation types, almost surpassing the high wetland CH4 emissions at the landscape scale. Read more
Toward generalized Milankovitch theory (GMT) Climate of the Past DOI 10.5194/cp-20-151-2024 10 January 2024 Despite significant progress in modelling Quaternary climate dynamics, a comprehensive theory of glacial cycles is still lacking. Here, using the results of model simulations and data analysis, I present a framework of the generalized Milankovitch theory (GMT), which further advances the concept proposed by Milutin Milankovitch over a century ago. The theory explains a number of facts which were not known during Milankovitch time’s, such as the 100 kyr periodicity of the late Quaternary. Read more
The additionality problem of ocean alkalinity enhancement Biogeosciences DOI 10.5194/bg-21-261-2024 8 January 2024 Ocean alkalinity enhancement (OAE) is a widely considered marine carbon dioxide removal method. OAE aims to accelerate chemical rock weathering, which is a natural process that slowly sequesters atmospheric carbon dioxide. This study shows that the addition of anthropogenic alkalinity via OAE can reduce the natural release of alkalinity and, therefore, reduce the efficiency of OAE for climate mitigation. However, the additionality problem could be mitigated via a variety of activities. Read more
Geomorphological and hydrological controls on sediment export in earthquake-affected catchments in the Nepal Himalaya Earth Surface Dynamics DOI 10.5194/esurf-12-135-2024 5 January 2024 Using satellite images, we show that, unlike other examples of earthquake-affected rivers, the rivers of central Nepal experienced little increase in sedimentation following the 2015 Gorkha earthquake. Instead, a catastrophic flood occurred in 2021 that buried towns and agricultural land under up to 10 m of sediment. We show that intense storms remobilised glacial sediment from high elevations causing much a greater impact than flushing of earthquake-induced landslides. Read more
Opinion: The importance of historical and paleoclimate aerosol radiative effects Atmospheric Chemistry and Physics DOI 10.5194/acp-24-533-2024 3 January 2024 Estimating past aerosol radiative effects and their uncertainties is an important topic in climate science. Aerosol radiative effects propagate into large uncertainties in estimates of how present and future climate evolves with changing greenhouse gas emissions. A deeper understanding of how aerosols interacted with the atmospheric energy budget under past climates is hindered in part by a lack of relevant paleo-observations and in part because less attention has been paid to the problem. Read more
Quantifying particulate matter optical properties and flow rate in industrial stack plumes from the PRISMA hyperspectral imager Atmospheric Measurement Techniques DOI 10.5194/amt-17-57-2024 1 January 2024 We propose analyzing the aerosol composition of plumes emitted by different industrial stacks using PRISMA satellite hyperspectral observations. Three industrial sites have been observed: a coal-fired power plant in South Africa, a steel plant in China, and gas flaring at an oil extraction site in Algeria. Aerosol optical thickness and particle radius are retrieved within the plumes. The mass flow rate of particulate matter is estimated in the plume using the integrated mass enhancement method. Read more
Geochronological and geochemical effects of zircon chemical abrasion: insights from single-crystal stepwise dissolution experiments Geochronology DOI 10.5194/gchron-6-1-2024 29 December 2023 Acid leaching is used to remove radiation-damaged portions of zircon crystals prior to U–Pb dating to improve the accuracy of datasets. We test how the temperature and duration of acid leaching affect geochronological and geochemical outcomes. We build a framework that relates radiation damage, zircon solubility, and Pb loss. Read more
Reviews and syntheses: expanding the global coverage of gross primary production and net community production measurements using Biogeochemical-Argo floats Biogeosciences DOI 10.5194/bg-21-13-2024 27 December 2023 This paper provides an overview of the capacity to expand the global coverage of marine primary production estimates using autonomous ocean-going instruments, called Biogeochemical-Argo floats. We review existing approaches to quantifying primary production using floats, provide examples of the current implementation of the methods, and offer insights into how they can be better exploited. This paper is timely, given the ongoing expansion of the Biogeochemical-Argo array. Read more
Cost estimation for the monitoring instrumentation of landslide early warning systems Natural Hazards and Earth System Sciences DOI 10.5194/nhess-23-3913-2023 25 December 2023 A new approach for the deployment of landslide early warning systems (LEWSs) is proposed. We combine data-driven landslide susceptibility mapping and population maps to identify exposed locations. We estimate the cost of monitoring sensors and demonstrate that LEWSs could be installed with a budget ranging from EUR 5 to EUR 41 per person in Medellín, Colombia. We provide recommendations for stakeholders and outline the challenges and opportunities for successful LEWS implementation. Read more
The Framework for Assessing Changes To Sea-level (FACTS) v1.0: a platform for characterizing parametric and structural uncertainty in future global, relative, and extreme sea-level change Geoscientific Model Development DOI 10.5194/gmd-16-7461-2023 22 December 2023 Future sea-level rise projections exhibit multiple forms of uncertainty, all of which must be considered by scientific assessments intended to inform decision-making. The Framework for Assessing Changes To Sea-level (FACTS) is a new software package intended to support assessments of global mean, regional, and extreme sea-level rise. An early version of FACTS supported the development of the IPCC Sixth Assessment Report sea-level projections. Read more
The Indonesian Throughflow circulation under solar geoengineering Earth System Dynamics DOI 10.5194/esd-14-1317-2023 20 December 2023 The Indonesia Throughflow is an important pathway connecting the Pacific and Indian oceans and is part of a wind-driven circulation that is expected to reduce under greenhouse gas forcing. Solar dimming and sulfate aerosol injection geoengineering may reverse this effect. But stratospheric sulfate aerosols affect winds more than simply ``shading the sun’‘; they cause a reduction in water transport similar to that we simulate for a scenario with unabated greenhouse gas emissions. Read more
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