RainNet v1.0: a convolutional neural network for radar-based precipitation nowcasting Geoscientific Model Development DOI 10.5194/gmd-13-2631-2020 23 June 2020 In this study, we present RainNet, a deep convolutional neural network for radar-based precipitation nowcasting, which was trained to predict continuous precipitation intensities at a lead time of 5 min. RainNet significantly outperformed the benchmark models at all lead times up to 60 min. Yet, an undesirable property of RainNet predictions is the level of spatial smoothing. Obviously, RainNet learned an optimal level of smoothing to produce a nowcast at 5 min lead time. Read more
Changing global cropping patterns to minimize national blue water scarcity Hydrology and Earth System Sciences DOI 10.5194/hess-24-3015-2020 18 June 2020 Previous studies on water saving through food trade focussed either on comparing water productivities among countries or on analysing food trade in relation to national water endowments. Here, we consider, for the first time, both differences in water productivities and water endowments to analyse national comparative advantages. Our study reveals that blue water scarcity can be reduced to sustainable levels by changing cropping patterns while maintaining current levels of global production. Read more
New observations of the distribution, morphology and dissolution dynamics of cryogenic gypsum in the Arctic Ocean The Cryosphere DOI 10.5194/tc-14-1795-2020 16 June 2020 Based on an observed omnipresence of gypsum crystals, we concluded that their release from melting sea ice is a general feature in the Arctic Ocean. Individual gypsum crystals sank at more than 7000 m d −1 , suggesting that they are an important ballast mineral. Previous observations found gypsum inside phytoplankton aggregates at 2000 m depth, supporting gypsum as an important driver for pelagic-benthic coupling in the ice-covered Arctic Ocean. Read more
Induced seismicity risk analysis of the hydraulic stimulation of a geothermal well on Geldinganes, Iceland Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-1573-2020 16 June 2020 This study presents a first-of-its-kind pre-drilling probabilistic induced seismic risk analysis for the Geldinganes (Iceland) deep-hydraulic stimulation. The results of the assessment indicate that the individual risk within a radius of 2 km around the injection point is below the safety limits. However, the analysis is affected by a large variability due to the presence of pre-drilling deep uncertainties. This suggests the need for online risk updating during the stimulation. Read more
Linking economic and social factors to peak flows in an agricultural watershed using socio-hydrologic modeling Hydrology and Earth System Sciences DOI 10.5194/hess-24-2873-2020 11 June 2020 We describe a socio-hydrologic model that couples an agent-based model (ABM) of human decision-making with a hydrologic model. We establish this model for a typical agricultural watershed in Iowa, USA, and simulate the evolution of large discharge events over a 47-year period under changing land use. Using this modeling approach, relationships between seemingly unrelated variables such as crop markets or crop yields and local peak flow trends are quantified. Read more
Comparing Palmer Drought Severity Index drought assessments using the traditional offline approach with direct climate model outputs Hydrology and Earth System Sciences DOI 10.5194/hess-24-2921-2020 11 June 2020 Many previous studies using offline drought indices report that future warming will increase worldwide drought. However, this contradicts observations/projections of vegetation greening and increased runoff. We resolved this paradox by re-calculating the same drought indices using direct climate model outputs and find no increase in future drought as the climate warms. We also find that accounting for the impact of CO 2 on plant transpiration avoids the previous overestimation of drought. Read more
N2O isotopocule measurements using laser spectroscopy: analyzer characterization and intercomparison Atmospheric Measurement Techniques DOI 10.5194/amt-13-2797-2020 10 June 2020 The latest commercial laser spectrometers have the potential to revolutionize N 2 O isotope analysis. However, to do so, they must be able to produce trustworthy data. Here, we test the performance of widely used laser spectrometers for ambient air applications and identify instrument-specific dependencies on gas matrix and trace gas concentrations. We then provide a calibration workflow to facilitate the operation of these instruments in order to generate reproducible and accurate data. Read more
Model-based climatology of diurnal variability in stratospheric ozone as adata analysis tool Atmospheric Measurement Techniques DOI 10.5194/amt-13-2733-2020 10 June 2020 We use the NASA GEOS-GMI chemistry climate model to construct a climatology of stratospheric ozone diurnal variations as a function of latitude, pressure and month, which can be used in a variety of data analysis tasks involving ozone observations made at different times of the day. The climatology compares well with previous modeling simulations and available observations, and to the authors’ knowledge is the first characterization of the diurnal cycle available for general ozone data analyses. Read more
Present and future changes in winter climate indices relevant for access disruptions in Troms, northern Norway Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-1847-2020 9 June 2020 We have studied changes in winter weather known to trigger road closures and isolation of small seaside communities in northern Norway. We find that snow amounts and heavy snowfall events have increased in the past, while future projections for 2040–2100 show a decrease in snow-related indices. Events of heavy water supply and zero crossings are expected to increase. Our results imply fewer dry-snow-related access disruptions in the future, while wet-snow avalanches and slushflows may increase. Read more
Simultaneous measurements of the relative-humidity-dependent aerosol lightextinction, scattering, absorption, and single-scattering albedo with ahumidified cavity-enhanced albedometer Atmospheric Measurement Techniques DOI 10.5194/amt-13-2623-2020 4 June 2020 We report the first demonstration of a humidified cavity-enhanced albedometer (H-CEA) that combines a broadband cavity-enhanced aerosol albedometer with a humidigraph system for simultaneous and accurate measurements of multiple optical hygroscopic parameters ( f (RH)ext,scat,abs,ω) at λ = 532 nm. The instrument is suitable for operating under high RH-conditions and has sampling advantages over independent measurements of different parameters with different instruments. Read more
