High-frequency monitoring of anomalous methane point sources with multispectral Sentinel-2 satellite observations Atmospheric Measurement Techniques DOI 10.5194/amt-14-2771-2021 31 May 2021 Satellites can detect methane emissions by measuring sunlight reflected from the Earth’s surface and atmosphere. Here we show that the European Space Agency’s Sentinel-2 twin satellites can be used to monitor anomalously large methane point sources around the world, with global coverage every 2–5 days and 20 m spatial resolution. We demonstrate this previously unreported capability through high-frequency Sentinel-2 monitoring of two strong methane point sources in Algeria and Turkmenistan. Read more
JlBox v1.1: a Julia-based multi-phase atmospheric chemistry box model Geoscientific Model Development DOI 10.5194/gmd-14-2187-2021 28 May 2021 As our knowledge and understanding of atmospheric aerosol particle evolution and impact grows, designing community mechanistic models requires an ability to capture increasing chemical, physical and therefore numerical complexity. As the landscape of computing software and hardware evolves, it is important to profile the usefulness of emerging platforms in tackling this complexity. With this in mind we present JlBox v1.1, written in Julia. Read more
Sudden large-volume detachments of low-angle mountain glaciers – more frequent than thought? The Cryosphere DOI 10.5194/tc-15-1751-2021 26 May 2021 Hardly recognized so far, giant catastrophic detachments of glaciers are a rare but great potential for loss of lives and massive damage in mountain regions. Several of the events compiled in our study involve volumes (up to 100 million m3 and more), avalanche speeds (up to 300 km/h), and reaches (tens of kilometres) that are hard to imagine. We show that current climate change is able to enhance associated hazards. For the first time, we elaborate a set of factors that could cause these events. Read more
African easterly waves in an idealized general circulation model: instability and wave packet diagnostics Weather and Climate Dynamics DOI 10.5194/wcd-2-311-2021 24 May 2021 Using a simple general circulation model, we examine the structure of waves in the mid-tropospheric jet over North Africa. We show that waves occur in near-stationary groups or wave packets. As they are not swept out of the jet, this may provide the opportunity for the packets to amplify via feedback from other energy sources like rain-producing cloud complexes and mineral dust that are known to operate here. Our results address the criticism that the easterly jet is too short to sustain waves. Read more
Medusa–Aqua system: simultaneous measurement and evaluation of novel potential halogenated transient tracers HCFCs, HFCs, and PFCs in the ocean Ocean Science DOI 10.5194/os-17-509-2021 21 May 2021 Observations of transient tracer distribution provide essential information on ocean ventilation. The use of several commonly used transient traces is limited as their atmospheric mole fractions do not monotonically change. Here we explore new potential oceanic transient tracers with an analytical system that simultaneously measures a large range of compounds. Combined with the known atmospheric history and seawater solubility, we discuss the utility of selected HCFCs, HFCs, and PFCs as tracers. Read more
Summary and synthesis of Changing Cold Regions Network (CCRN) research in the interior of western Canada – Part 2: Future change in cryosphere, vegetation, and hydrology Hydrology and Earth System Sciences DOI 10.5194/hess-25-1849-2021 19 May 2021 This article examines future changes in land cover and hydrological cycling across the interior of western Canada under climate conditions projected for the 21st century. Key insights into the mechanisms and interactions of Earth system and hydrological process responses are presented, and this understanding is used together with model application to provide a synthesis of future change. This has allowed more scientifically informed projections than have hitherto been available. Read more
Arctic Ocean acidification over the 21st century co-driven by anthropogenic carbon increases and freshening in the CMIP6 model ensemble Biogeosciences DOI 10.5194/bg-18-2221-2021 17 May 2021 The uptake of carbon, emitted as a result of human activities, results in ocean acidification. We analyse 21st-century projections of acidification in the Arctic Ocean, a region of particular vulnerability, using the latest generation of Earth system models. In this new generation of models there is a large decrease in the uncertainty associated with projections of Arctic Ocean acidification, with freshening playing a greater role in driving acidification than previously simulated. Read more
Airborne measurements of oxygen concentration from the surface to the lower stratosphere and pole to pole Atmospheric Measurement Techniques DOI 10.5194/amt-14-2543-2021 14 May 2021 We describe methods used to make high-precision global-scale airborne measurements of atmospheric oxygen concentrations over a period of 20 years in order to study the global carbon cycle. Our techniques include an in situ vacuum ultraviolet absorption instrument and a pressure- and flow-controlled, cryogenically dried, glass flask sampler. We have deployed these instruments in 15 airborne research campaigns spanning from the Earth’s surface to the lower stratosphere and from pole to pole. Read more
Evaluating stratospheric ozone and water vapour changes in CMIP6 models from 1850 to 2100 Atmospheric Chemistry and Physics DOI 10.5194/acp-21-5015-2021 12 May 2021 Stratospheric ozone and water vapour are key components of the Earth system; changes to both have important impacts on global and regional climate. We evaluate changes to these species from 1850 to 2100 in the new generation of CMIP6 models. There is good agreement between the multi-model mean and observations, although there is substantial variation between the individual models. The future evolution of both ozone and water vapour is strongly dependent on the assumed future emissions scenario. Read more
Diverging land-use projections cause large variability in their impacts on ecosystems and related indicators for ecosystem services Earth System Dynamics DOI 10.5194/esd-12-327-2021 10 May 2021 Many projections of future land-use/-cover exist. We evaluate a number of these and determine the variability they cause in ecosystems and their services. We found that projections differ a lot in regional patterns, with some patterns being at least questionable in a historical context. Across ecosystem service indicators, resulting variability until 2040 was highest in crop production. Results emphasize that such variability should be acknowledged in assessments of future ecosystem provisions. Read more