Better representation of dust can improve climate models with too weak an African monsoon Atmospheric Chemistry and Physics DOI 10.5194/acp-21-11423-2021 6 September 2021 Earth system models have persistent biases that impinge on our ability to make robust future regional predictions of precipitation. For the last 15 years, there has been little improvement in these biases. This work presents an accurate representation of dust absorption based upon observed dust mineralogical composition and size distribution. The striking result is that this more accurate representation improves tropical precipitations for climate models with too weak an African monsoon. Read more
Characterization of dark current signal measurements of the ACCDs used on board the Aeolus satellite Atmospheric Measurement Techniques DOI 10.5194/amt-14-5153-2021 3 September 2021 This paper reports on dark current signal anomalies of the detectors used on board the ESA’s Earth Explorer satellite Aeolus during the first 1.5 years in orbit. After introducing sophisticated algorithms to classify dark current anomalies according to their characteristics, the impact of the different kinds of anomalies on wind measurements is discussed. In addition, mitigation approaches for the wind retrieval are presented and potential root causes are discussed. ACCDs used on board the Aeolus satellite">Read more
Drought effects on leaf fall, leaf flushing and stem growth in the Amazon forest: reconciling remote sensing data and field observations Biogeosciences DOI 10.5194/bg-18-4445-2021 1 September 2021 Satellite images show that the Amazon forest has greened up during past droughts. Measurements of tree stem growth and leaf litterfall upscaled using machine-learning algorithms show that leaf flushing at the onset of a drought results in canopy rejuvenation and green-up during drought while simultaneously trees excessively shed older leaves and tree stem growth declines. Canopy green-up during drought therefore does not necessarily point to enhanced tree growth and improved forest health. Read more
Steepening of magnetosonic waves in the inner coma of comet 67P/Churyumov–Gerasimenko Annales Geophysicae DOI 10.5194/angeo-39-721-2021 30 August 2021 Plasma waves are an integral part of cometary physics, as they facilitate the transfer of energy and momentum. From intermediate to strong activity, nonlinear asymmetric plasma and magnetic field enhancements dominate the inner coma of 67P/CG. We present a statistical survey of these structures from December 2014 to June 2016, facilitated by Rosetta’s unprecedented long mission duration. Using a 1D MHD model, we show they can be described as a combination of nonlinear and dissipative effects. Read more
Controls on the rates and products of particle attrition by bed-load collisions Earth Surface Dynamics DOI 10.5194/esurf-9-755-2021 27 August 2021 The authors of this paper conducted experiments to investigate the mechanics of sediment attrition due to collisions with the channel bed during downstream transport. During this process, the grains become rounder and smaller, changing the overall distribution of sediment in the river. In this work the authors examine how material properties play a role in the breakdown of sediment due to energetic collisions and the fine particles that are produced when chipped off of larger grains. Read more
fv3gfs-wrapper: a Python wrapper of the FV3GFS atmospheric model Geoscientific Model Development DOI 10.5194/gmd-14-4401-2021 25 August 2021 FV3GFS is a weather and climate model written in Fortran. It uses Fortran so that it can run fast, but this makes it hard to add features if you do not (or even if you do) know Fortran. We have written a Python interface to FV3GFS that lets you import the Fortran model as a Python package. We show examples of how this is used to write “model” scripts, which reproduce or build on what the Fortran model can do. You could do this same wrapping for any compiled model, not just FV3GFS. Read more
Invited perspectives: The ECMWF strategy 2021–2030 challenges in the area of natural hazards Natural Hazards and Earth System Sciences DOI 10.5194/nhess-21-2163-2021 23 August 2021 The European Centre for Medium-Range Weather Forecasts mission is to deliver high-quality global medium‐range (3–15 d ahead of time) weather forecasts and monitoring of the Earth system. We have published a new strategy, and in this paper we discuss what this means for forecasting and monitoring natural hazards. ECMWF strategy 2021–2030 challenges in the area of natural hazards">Read more
Nonstationary weather and water extremes: a review of methods for their detection, attribution, and management Hydrology and Earth System Sciences DOI 10.5194/hess-25-3897-2021 20 August 2021 Weather and water extremes have devastating effects each year. One of the principal challenges for society is understanding how extremes are likely to evolve under the influence of changes in climate, land cover, and other human impacts. This paper provides a review of the methods and challenges associated with the detection, attribution, management, and projection of nonstationary weather and water extremes. Read more
Thaw-driven mass wasting couples slopes with downstream systems, and effects propagate through Arctic drainage networks The Cryosphere DOI 10.5194/tc-15-3059-2021 18 August 2021 Climate-driven landslides are transforming glacially conditioned permafrost terrain, coupling slopes with aquatic systems, and triggering a cascade of downstream effects. Nonlinear intensification of thawing slopes is primarily affecting headwater systems where slope sediment yields overwhelm stream transport capacity. The propagation of effects across watershed scales indicates that western Arctic Canada will be an interconnected hotspot of thaw-driven change through the coming millennia. Read more
Additional carbon inputs to reach a 4 per 1000 objective in Europe: feasibility and projected impacts of climate change based on Century simulations of long-term arable experiments Biogeosciences DOI 10.5194/bg-18-3981-2021 16 August 2021 Increasing soil organic carbon (SOC) stocks is beneficial for climate change mitigation and food security. One way to enhance SOC stocks is to increase carbon input to the soil. We estimate the amount of carbon input required to reach a 4 % annual increase in SOC stocks in 14 long-term agricultural experiments around Europe. We found that annual carbon input should increase by 43 % under current temperature conditions, by 54 % for a 1 °C warming scenario and by 120 % for a 5 °C warming scenario. Read more