Machine learning and soil sciences: a review aided by machine learning tools SOIL DOI 10.5194/soil-6-35-2020 13 February 2020 The application of machine learning (ML) has shown an accelerated adoption in soil sciences. It is a difficult task to manually review all papers on the application of ML. This paper aims to provide a review of the application of ML aided by topic modelling in order to find patterns in a large collection of publications. The objective is to gain insight into the applications and to discuss research gaps. We found 12 main topics and that ML methods usually perform better than traditional ones. Read more
Global catchment modelling using World-Wide HYPE (WWH), open data, andstepwise parameter estimation Hydrology and Earth System Sciences DOI 10.5194/hess-24-535-2020 11 February 2020 How far can we reach in predicting river flow globally, using integrated catchment modelling and open global data? For the first time, a catchment model was applied world-wide, covering the entire globe with a relatively high resolution. The results show that stepwise calibration provided better performance than traditional modelling of the globe. The study highlights that open data and models are crucial to advance hydrological sciences by sharing knowledge and enabling transparent evaluation. Read more
Mapping the drivers of uncertainty in atmospheric selenium deposition with global sensitivity analysis Atmospheric Chemistry and Physics DOI 10.5194/acp-20-1363-2020 11 February 2020 The amount of the micronutrient selenium in food largely depends on the amount and form of selenium in soil. The atmosphere acts as a source of selenium to soils through deposition, yet little information is available about atmospheric selenium cycling. Therefore, we built the first global atmospheric selenium model. Through sensitivity and uncertainty analysis we determine that selenium can be transported thousands of kilometers and that measurements of selenium emissions should be prioritized. Read more
An urban ecohydrological model to quantify the effect of vegetation on urban climate and hydrology (UT&C v1.0) Geoscientific Model Development DOI 10.5194/gmd-13-335-2020 6 February 2020 We developed a novel urban ecohydrological model (UT&C v1.0) that is able to account for the effects of different plant types on the urban climate and hydrology, as well as the effects of the urban environment on plant well-being and performance. UT&C performs well when compared against energy flux measurements in three cities in different climates (Singapore, Melbourne, Phoenix) and can be used to assess urban climate mitigation strategies that aim at increasing or changing urban green cover. Read more
Identification of new microbial functional standards for soil quality assessment SOIL DOI 10.5194/soil-6-17-2020 6 February 2020 Soil quality depends on the functioning of soil microbiota. Only a few standardized methods are available to assess this as well as adverse effects of human activities. So we need to identify promising additional methods that target soil microbial function. Discussed are (i) molecular methods using qPCR for new endpoints, e.g. in N and P cycling and greenhouse gas emissions, (ii) techniques for fungal enzyme activities, and (iii) field methods on carbon turnover such as the litter bag test. Read more
A decade of variability on Jakobshavn Isbræ: ocean temperatures pace speedthrough influence on mélange rigidity The Cryosphere DOI 10.5194/tc-14-211-2020 27 January 2020 Jakobshavn Isbræ, considered to be Greenland’s fastest glacier, has varied its speed and thinned dramatically since the 1990s. Here we examine the glacier’s behaviour over the last decade to better understand this behaviour. We find that when the floating ice (mélange) in front of the glacier freezes in place during the winter, it can control the glacier’s speed and thinning rate. A recently colder ocean has strengthened this mélange, allowing the glacier to recoup some of its previous losses. Read more
Electron spin resonance (ESR) thermochronometry of the Hida range of the Japanese Alps: validation and future potential Geochronology DOI 10.5194/gchron-2-1-2020 27 January 2020 Rates of landscape evolution over the past million years are difficult to quantify. This study develops a technique which is able to measure changes in rock cooling rates (related to landscape evolution) over this timescale. The technique is based on the electron spin resonance dating of quartz minerals. Measurement protocols and new numerical models are proposed that describe these data, allowing for their translation into rock cooling rates. Read more
Altitude profiles of cloud condensation nuclei characteristics across the Indo-Gangetic Plainprior to the onset of the Indian summer monsoon Atmospheric Chemistry and Physics DOI 10.5194/acp-20-561-2020 27 January 2020 Concurrent measurements of the altitude profiles of the concentration of cloud condensation nuclei (CCNs), as a function of supersaturation (ranging from 0.2 % to 1.0 %), and aerosol optical properties were carried out aboard an instrumented aircraft across the Indo-Gangetic Plain (IGP) just prior to the onset of the 2016 Indian summer monsoon (ISM). A high CCN concentration is observed up to 2.5 km across the IGP, indicating the significant possibility of aerosol indirect effects. Read more
Why did deep convection persist over four consecutive winters (2015–2018) southeast of Cape Farewell? Ocean Science DOI 10.5194/os-16-99-2020 27 January 2020 The region south of Cape Farewell (SCF) is recognized as a deep convection site. Convection deeper than 1300 m occurred SCF in 2015 and persisted during three additional winters. Extreme air–sea buoyancy fluxes caused the 2015 event. For the following winters, air–sea fluxes were close to the climatological average, but local cooling above 800 m and the advection below 1200 m of a fresh anomaly from the Labrador Sea decreased stratification and allowed for the persistence of deep convection. Read more
ESD Ideas: Why are glaciations slower than deglaciations? Earth System Dynamics DOI 10.5194/esd-11-13-2020 23 January 2020 Here we explore ancient climate transitions from warm periods to ice ages and from ice ages to warm periods of the last 400 000 years. The changeovers from warm to ice age conditions are slower than those from ice age to warm conditions. We propose the presence of strong negative sea–ice feedbacks may be responsible for slowing the transition from warm to full ice age conditions. By improving understanding of past abrupt changes, we may have improved knowledge of future system behavior. Read more
