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
First data set of H2O/HDO columns from the Tropospheric Monitoring Instrument (TROPOMI) Atmospheric Measurement Techniques DOI 10.5194/amt-13-85-2020 23 January 2020 This paper presents a new H 2 O/HDO data set from TROPOMI short-wave infrared measurements. It is validated against recent ground-based FTIR measurements from the TCCON network. A bias in TCCON HDO (which is not verified) is corrected by fitting a correction factor for the HDO column to match MUSICA δD for common observations. The use of the new TROPOMI data set is demonstrated using a case study of a blocking anticyclone over Europe in July 2018. Read more
Can subduction initiation at a transform fault be spontaneous? Solid Earth DOI 10.5194/se-11-37-2020 17 January 2020 We propose a new exploration of the concept of “spontaneous” lithospheric collapse at a transform fault (TF) by performing a large study of conditions allowing instability of the thicker plate using 2-D thermomechanical simulations. Spontaneous subduction is modelled only if extreme mechanical conditions are assumed. We conclude that spontaneous collapse of the thick older plate at a TF evolving into mature subduction is an unlikely process of subduction initiation at modern Earth conditions. Read more
Terrestrial ion escape and relevant circulation in space Annales Geophysicae DOI 10.5194/angeo-37-1197-2019 17 January 2020 Terrestrial ion transport and total escape are synthesized, with stress on the high-latitude polar region and the inner magnetosphere where Custer significantly improved knowledge. After estimating the outflow flux and destinations, complicated ion dynamics in the inner magnetosphere was classified and summarized, through which more than half the O+ is finally lost to space. Together with direct escapes, total O+ escape is high enough to influence the evolution of the biosphere. Read more
