The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate The Cryosphere DOI 10.5194/tc-16-3375-2022 14 November 2022 To overcome internal climate variability, this study uses k-means clustering to combine NAO, GBI and IWV over the Greenland Ice Sheet (GrIS) and names the approach as the North Atlantic influence on Greenland (NAG). With the support of a polar-adapted RCM, spatio-temporal changes on SEB components within NAG phases are investigated. We report atmospheric warming and moistening across all NAG phases as well as large-scale and regional-scale contributions to GrIS mass loss and their interactions. Read more
Invited perspectives: Views of 350 natural hazard community members on key challenges in natural hazards research and the Sustainable Development Goals Natural Hazards and Earth System Sciences DOI 10.5194/nhess-22-2771-2022 11 November 2022 Here we present survey responses of 350 natural hazard community members to key challenges in natural hazards research and step changes to achieve the Sustainable Development Goals. Challenges identified range from technical (e.g. model development, early warning) to governance (e.g. co-production with community members). Step changes needed are equally broad; however, the majority of answers showed a need for wider stakeholder engagement, increased risk management and interdisciplinary work. Read more
Effects of orbital forcing, greenhouse gases and ice sheets on Saharan greening in past and future multi-millennia Climate of the Past DOI 10.5194/cp-18-1897-2022 9 November 2022 Using an Earth system model of intermediate complexity, we quantify contributions of the Earth’s orbit, greenhouse gases (GHGs) and ice sheets to the strength of Saharan greening during late Quaternary African humid periods (AHPs). Orbital forcing is found as the dominant factor, having a critical threshold and accounting for most of the changes in the vegetation response. However, results suggest that GHGs may influence the orbital threshold and thus may play a pivotal role for future AHPs. Read more
TermPicks: a century of Greenland glacier terminus data for use in scientific and machine learning applications The Cryosphere DOI 10.5194/tc-16-3215-2022 7 November 2022 Terminus traces have been used to understand how Greenland’s glaciers have changed over time; however, manual digitization is time-intensive, and a lack of coordination leads to duplication of efforts. We have compiled a dataset of over 39 000 terminus traces for 278 glaciers for scientific and machine learning applications. We also provide an overview of an updated version of the Google Earth Engine Digitization Tool (GEEDiT), which has been developed specifically for the Greenland Ice Sheet. Read more
Bedrock depth influences spatial patterns of summer baseflow, temperature and flow disconnection for mountainous headwater streams Hydrology and Earth System Sciences DOI 10.5194/hess-26-3989-2022 4 November 2022 The geologic structure of mountain watersheds may control how groundwater and streamwater exchange, influencing where streams dry. We measured bedrock depth at 191 locations along eight headwater streams paired with stream temperature records, baseflow separation and observations of channel dewatering. The data indicated a prevalence of shallow bedrock generally less than 3 m depth, and local variation in that depth can drive stream dewatering but also influence stream baseflow supply. Read more
Quantifying methane emissions from the global scale down to point sources using satellite observations of atmospheric methane Atmospheric Chemistry and Physics DOI 10.5194/acp-22-9617-2022 2 November 2022 We review the capability of satellite observations of atmospheric methane to quantify methane emissions on all scales. We cover retrieval methods, precision requirements, inverse methods for inferring emissions, source detection thresholds, and observations of system completeness. We show that current instruments already enable quantification of regional and national emissions including contributions from large point sources. Coverage and resolution will increase significantly in coming years. Read more
MOLISENS: MObile LIdar SENsor System to exploit the potential of small industrial lidar devices for geoscientific applications Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-11-247-2022 31 October 2022 We propose a newly developed modular MObile LIdar SENsor System (MOLISENS) to enable new applications for small industrial light detection and ranging (lidar) sensors. MOLISENS supports both monitoring of dynamic processes and mobile mapping applications. The mobile mapping application of MOLISENS has been tested under various conditions, and results are shown from two surveys in the Lurgrotte cave system in Austria and a glacier cave in Longyearbreen on Svalbard. Read more
Trends in the tropospheric general circulation from 1979 to 2022 Weather and Climate Dynamics DOI 10.5194/wcd-3-777-2022 28 October 2022 This study of changes in temperature and wind since 1979 met its twin aims of (i) increasing confidence in some findings of the latest IPCC assessment and (ii) identifying changes that had received little or no previous attention. It reports a small overall intensification and shift in position of the North Atlantic jet stream and associated storms, and a strengthening of tropical upper-level easterlies. Increases in low-level winds over tropical and southern hemispheric oceans are confirmed. Read more
Soil carbon loss in warmed subarctic grasslands is rapid and restricted to topsoil Biogeosciences DOI 10.5194/bg-19-3381-2022 26 October 2022 In subarctic grassland on a geothermal warming gradient, we found large reductions in topsoil carbon stocks, with carbon stocks linearly declining with warming intensity. Most importantly, however, we observed that soil carbon stocks stabilised within 5 years of warming and remained unaffected by warming thereafter, even after > 50 years of warming. Moreover, in contrast to the large topsoil carbon losses, subsoil carbon stocks remained unaffected after > 50 years of soil warming. Read more
Root-mean-square error (RMSE) or mean absolute error (MAE): when to use them or not Geoscientific Model Development DOI 10.5194/gmd-15-5481-2022 24 October 2022 The task of evaluating competing models is fundamental to science. Models are evaluated based on an objective function, the choice of which ultimately influences what scientists learn from their observations. The mean absolute error (MAE) and root-mean-squared error (RMSE) are two such functions. Both are widely used, yet there remains enduring confusion over their use. This article reviews the theoretical justification behind their usage, as well as alternatives for when they are not suitable. Read more
The eWaterCycle platform for open and FAIR hydrological collaboration Geoscientific Model Development DOI 10.5194/gmd-15-5371-2022 21 October 2022 With the eWaterCycle platform, we are providing the hydrological community with a platform to conduct their research that is fully compatible with the principles of both open science and FAIR science. The eWatercyle platform gives easy access to well-known hydrological models, big datasets and example experiments. Using eWaterCycle hydrologists can easily compare the results from different models, couple models and do more complex hydrological computational research. Read more
Towards a self-sufficient mobile broadband seismological recording system for year-round operation in Antarctica Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-11-235-2022 19 October 2022 We present a mobile and self-sufficient seismometer station concept for operation in polar regions. The energy supply can be adapted as required using the modular cascading of battery boxes, wind generators, solar cells, or backup batteries, which enables optimum use of limited resources. Our system concept is not limited to the applications using seismological stations. It is a suitable system for managing the power supply of all types of self-sufficient measuring systems in polar regions. Read more
A probabilistic framework for quantifying the role of anthropogenic climate change in marine-terminating glacier retreats The Cryosphere DOI 10.5194/tc-16-2725-2022 17 October 2022 Marine-terminating glaciers have recently retreated dramatically, but the role of anthropogenic forcing remains uncertain. We use idealized model simulations to develop a framework for assessing the probability of rapid retreat in the context of natural climate variability. Our analyses show that century-scale anthropogenic trends can substantially increase the probability of retreats. This provides a roadmap for future work to formally assess the role of human activity in recent glacier change. Read more
Stable water isotope signals in tropical ice clouds in the West African monsoon simulated with a regional convection-permitting model Atmospheric Chemistry and Physics DOI 10.5194/acp-22-8863-2022 14 October 2022 The Earth’s water cycle contains the common H2O molecule but also the less abundant, heavier HDO. We use their different physical properties to study tropical ice clouds in model simulations of the West African monsoon. Isotope signals reveal different processes through which ice clouds form and decay in deep-convective and widespread cirrus. Previously observed variations in upper-tropospheric vapour isotopes are explained by microphysical processes in convective updraughts and downdraughts. Read more
Technical note: Conservative storage of water vapour – practical in situ sampling of stable isotopes in tree stems Hydrology and Earth System Sciences DOI 10.5194/hess-26-3573-2022 12 October 2022 We developed a method of sampling and storing water vapour for isotope analysis, allowing us to infer plant water uptake depth. Measurements can be made at high temporal and spatial resolution even in remote areas. We ensured that all necessary components are easily available, making this method cost efficient and simple to implement. We found our method to perform well in the lab and in the field, enabling it to become a tool for everyone aiming to resolve questions regarding the water cycle. Read more
The Great Lakes Runoff Intercomparison Project Phase 4: the Great Lakes (GRIP-GL) Hydrology and Earth System Sciences DOI 10.5194/hess-26-3537-2022 10 October 2022 Model intercomparison studies are carried out to test various models and compare the quality of their outputs over the same domain. In this study, 13 diverse model setups using the same input data are evaluated over the Great Lakes region. Various model outputs – such as streamflow, evaporation, soil moisture, and amount of snow on the ground – are compared using standardized methods and metrics. The basin-wise model outputs and observations are made available through an interactive website. Read more
Stratigraphic templates for ice core records of the past 1.5 Myr Climate of the Past DOI 10.5194/cp-18-1563-2022 7 October 2022 Projects are underway to drill ice cores in Antarctica reaching 1.5 Myr back in time. Dating such cores will be challenging. One method is to match records from the new core against datasets from existing marine sediment cores. Here we explore the options for doing this and assess how well the ice and marine records match over the existing 800 000-year time period. We are able to recommend a strategy for using marine data to place an age scale on the new ice cores. Read more
A physical concept in the press: the case of the jet stream Geoscience Communication DOI 10.5194/gc-5-177-2022 5 October 2022 In this paper, we discuss the instrumental role of the press in informing and educating the public on the subject of climate science and climate change. We illustrate this using an example of a dissemination format called Weather Stories, published daily in one of the most read newspapers in Spain. The particularities of this journalistic format are described using a practical example of a relatively complex physical concept: the jet stream. Read more
Clouds drive differences in future surface melt over the Antarctic ice shelves The Cryosphere DOI 10.5194/tc-16-2655-2022 3 October 2022 Model projections suggest large differences in future Antarctic surface melting even for similar greenhouse gas scenarios and warming rates. We show that clouds containing a larger amount of liquid water lead to stronger melt. As surface melt can trigger the collapse of the ice shelves (the safety band of the Antarctic Ice Sheet), clouds could be a major source of uncertainties in projections of sea level rise. Read more
A tectonic-rules-based mantle reference frame since 1 billion years ago – implications for supercontinent cycles and plate–mantle system evolution Solid Earth DOI 10.5194/se-13-1127-2022 30 September 2022 We have built a community model for the evolution of the Earth’s plate–mantle system. Created with open-source software and an open-access plate model, it covers the last billion years, including the formation, breakup, and dispersal of two supercontinents, as well as the creation and destruction of numerous ocean basins. The model allows us to “see” into the Earth in 4D and helps us unravel the connections between surface tectonics and the “beating heart” of the Earth, its convecting mantle. Read more