Current glacier recession causes significant rockfall increase: the immediate paraglacial response of deglaciating cirque walls Earth Surface Dynamics DOI 10.5194/esurf-8-729-2020 8 October 2020 Climate warming is causing significant ice surface lowering even in the uppermost parts of alpine glaciers. Using terrestrial lidar, we quantify rockfall in freshly exposed cirque walls. During 6-year monitoring (2011–2017), an extensive dataset was established and over 600 rockfall events identified. Drastically increased rockfall activity following ice retreat can clearly be observed as 60 % of the rockfall volume detached from less than 10 m above the glacier surface. Read more
A Bayesian framework for emergent constraints: case studies of climate sensitivity with PMIP Climate of the Past DOI 10.5194/cp-16-1715-2020 6 October 2020 Interest in past climates as sources of information for the climate system has grown in recent years. In particular, studies of the warm mid-Pliocene and cold Last Glacial Maximum showed relationships between the tropical surface temperature of the Earth and its sensitivity to an abrupt doubling of atmospheric CO 2 . In this study, we develop a new and promising statistical method and obtain similar results as previously observed, wherein the sensitivity does not seem to exceed extreme values. Read more
Vertical profiles of light absorption and scattering associated with black carbon particle fractions in the springtime Arctic above 79∘ N Atmospheric Chemistry and Physics DOI 10.5194/acp-20-10545-2020 6 October 2020 Black carbon is a factor in the warming of the Arctic atmosphere due to its ability to absorb light, but the uncertainty is high and few observations have been made in the high Arctic above 80° N. We combine airborne and ground-based observations in the springtime Arctic, at and above 80° N, with simulations from a global model to show that light absorption by black carbon may be much larger than modelled. However, the uncertainty remains high. Read more
Comparing secondary organic aerosol (SOA) volatility distributions derived from isothermal SOA particle evaporation data and FIGAERO–CIMS measurements Atmospheric Chemistry and Physics DOI 10.5194/acp-20-10441-2020 1 October 2020 We compared the volatility distributions of secondary organic aerosol (SOA) constituents estimated from isothermal evaporation experiments from either particle size change data, by process modelling and global optimization, or from mass spectrometer data with positive matrix factorization analysis. Our results show that, despite the two very different estimation methods, the volatility distributions are comparable if uncertainties are taken into account. Read more
Predicting the morphology of ice particles in deep convection using the super-droplet method:development and evaluation of SCALE-SDM 0.2.5-2.2.0, -2.2.1, and -2.2.2 Geoscientific Model Development DOI 10.5194/gmd-13-4107-2020 1 October 2020 Using the super-droplet method, we constructed a detailed numerical model of mixed-phase clouds based on kinetic description and subsequently demonstrated that a large-eddy simulation of a cumulonimbus which predicts ice particle morphology without assuming ice categories or mass–dimension relationships is possible. Our results strongly support the particle-based modeling methodology’s efficacy for simulating mixed-phase clouds. Read more
A compact QCL spectrometer for mobile, high-precision methane sensing aboard drones Atmospheric Measurement Techniques DOI 10.5194/amt-13-4715-2020 29 September 2020 We describe a lightweight (2 kg) mid-IR laser spectrometer for airborne, in situ atmospheric methane (CH 4 ) measurements. The instrument, based on an open-path circular multipass cell, provides fast response (1 Hz) and sub-parts-per-billion precision. It can easily be mounted on a drone, giving access to highly resolved 4D (spatial and temporal) data. The performance was assessed during field deployments involving artificial CH 4 releases and vertical concentration gradients in the PBL. Read more
Using constructed soils for green infrastructure – challenges andlimitations SOIL DOI 10.5194/soil-6-413-2020 29 September 2020 The goal of this study was to discuss current methods to create soils adapted for various green infrastructure (GI) designs. Investigating these new soils for several design categories of GI will provide technical information for management and design agencies. Moreover, these studies can serve as pioneer experiments to prevent recurring errors and, thus, provide improved plant growth practices. Results show that these constructed soils have a high potential to provide multiple soil functions. Read more
HyLands 1.0: a hybrid landscape evolution model to simulate the impact of landslides and landslide-derived sediment on landscape evolution Geoscientific Model Development DOI 10.5194/gmd-13-3863-2020 24 September 2020 Landslides shape the Earth’s surface and are a dominant source of terrestrial sediment. Rivers, then, act as conveyor belts evacuating landslide-produced sediment. Understanding the interaction among rivers and landslides is important to predict the Earth’s surface response to past and future environmental changes and for mitigating natural hazards. We develop HyLands, a new numerical model that provides a toolbox to explore how landslides and rivers interact over several timescales. Read more
Quantifying burning efficiency in megacities using the NO2/CO ratio fromthe Tropospheric Monitoring Instrument (TROPOMI) Atmospheric Chemistry and Physics DOI 10.5194/acp-20-10295-2020 24 September 2020 Rapid urbanization has increased the consumption of fossil fuel, contributing the degradation of urban air quality. Burning efficiency is a major factor determining the impact of fuel burning on the environment. We quantify the burning efficiency of fossil fuel use over six megacities using satellite remote sensing data. City governance can use these results to understand air pollution scenarios and to formulate effective air pollution control strategies. Read more
Fire Weather Index: the skill provided by the European Centre for Medium-Range Weather Forecasts ensemble prediction system Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-2365-2020 22 September 2020 Forecasting of daily fire weather indices driven by the ECMWF ensemble prediction system is shown to have a good skill up to 10 d ahead in predicting flammable conditions in most regions of the world. The availability of these forecasts through the Copernicus Emergency Management Service can extend early warnings by up to 1–2 weeks, allowing for greater proactive coordination of resource-sharing and mobilization within and across countries. Read more