Integrating a mini catchment with mulching for soil water management in a sloping jujube orchard on the semiarid Loess Plateau of China Solid Earth DOI 10.5194/se-7-167-2016 1 February 2016 We integrated fish-scale pits with mulching to test whether this integration could improve soil water conservation. The results showed that integrating fish-scale pits with mulching could conserve significantly more soil water by increasing infiltration and decreasing evaporation, and showed greater soil water storage and degree of soil water compensation compared to fish-scale pits alone. In addition, jujube branches exerted better mulching effects than maize straw. Read more
Does the Budyko curve reflect a maximum-power state of hydrological systems? A backward analysis Hydrology and Earth System Sciences DOI 10.5194/hess-20-479-2016 28 January 2016 We derived mathematical formulations of relations between relative wetness and gradients driving run-off and evaporation for a one-box model such that, when conductances are optimized with the maximum power principle, the model leads exactly to a point on the Budyko curve. With dry spells and dynamics in actual evaporation added, the model compared well with catchment observations without calibrating any parameter. The maximum-power principle may thus be used to derive the Budyko curve. Read more
Efficacy of bedrock erosion by subglacial water flow Earth Surface Dynamics DOI 10.5194/esurf-4-125-2016 27 January 2016 In regions formerly, or currently, covered by glaciers, landscapes have largely been shaped by glaciers. Glaciers erode bedrock through three main mechanisms: abrasion, quarrying, and subglacial meltwater erosion (SME). The latter, however, remains enigmatic. We present the first numerical modelling study of bedrock erosion by subglacial water and find that SME is negligible compared to abrasion and quarrying across the glacier, but its localization can explain the formation of bedrock channels. Read more
Trail impact monitoring in Rocky Mountain National Park, USA Solid Earth DOI 10.5194/se-7-115-2016 26 January 2016 Rocky Mountain National Park is one of the most visited national parks in the United States. 95% of the park is managed as wilderness. This paper examines the impacts of trampling on the vegetation and soil along selected trails. Trail widening and soil loss are the most visible types of trail degradation. Insights into the influence of different factors (use level, topography) can lead to the selection of appropriate management measures to avoid or minimize negative consequences. Read more
CO2 emission and structural characteristics of two calcareous soils amended with municipal solid waste and plant residue Solid Earth DOI 10.5194/se-7-105-2016 26 January 2016 Following the application of organic amendment treatments, the increased organic carbon and total porosity values, as compared to the control treatment, were greater in the loamy sand soil than in the clay loam soil. Moreover, compared to the microbial respiration of control plots, the application of municipal solid waste resulted in higher levels of microbial respiration from the clay loam soil than from the loamy sand soil, whereas the reverse was found for alfalfa residue. Read more
Modeling global water use for the 21st century: the Water Futures and Solutions (WFaS) initiative and its approaches Geoscientific Model Development DOI 10.5194/gmd-9-175-2016 21 January 2016 The Water Futures and Solutions (WFaS) initiative coordinates its work with other ongoing scenario efforts for the sake of establishing a consistent set of new global water scenarios based on the shared socio-economic pathways (SSPs) and the representative concentration pathways (RCPs). The WFaS “fast-track” assessment uses three global water models, H08, PCR-GLOBWB, and WaterGAP, to provide the first multi-model analysis of global water use for the 21st century based on the water scenarios. Read more
Mapping of steady-state electric fields and convective drifts in geomagnetic fields – Part 2: The IGRF Annales Geophysicae DOI 10.5194/angeo-34-67-2016 19 January 2016 The method of electric field mapping along geomagnetic field lines, derived in an accompanying paper, is applied to the International Geomagnetic Reference Field. Formulae for the geomagnetic field gradient tensor are derived and these are used in a software package developed to map the electric field. A number of examples are presented illustrating the method. The method will be of importance in conjugate studies of ionospheric convection when the external magnetic field can be neglected. Read more
Mapping of steady-state electric fields and convective drifts in geomagnetic fields – Part 1: Elementary models Annales Geophysicae DOI 10.5194/angeo-34-55-2016 19 January 2016 This paper introduces a new method for mapping electric fields in the magnetosphere along geomagnetic field lines. This is important for conjugate studies of electric fields measured in the ionosphere by SuperDARN radars, and at spacecraft carrying electric field probes. First elementary methods in a dipole field are reviewed and then the theory of of a new method described for general magnetic field models. The method is tested in a dipole model with a Harris magnetotail field. Read more
Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign Atmospheric Chemistry and Physics DOI 10.5194/acp-16-455-2016 19 January 2016 The aim of this article is to present an experimental campaign over the Mediterranean focused on aerosol-radiation measurements and modeling. Results indicate an important atmospheric loading associated with a moderate absorbing ability of mineral dust. Observations suggest a complex vertical structure and size distributions characterized by large aerosols within dust plumes. The radiative effect is highly variable, with negative forcing over the Mediterranean and positive over northern Africa. Read more
Aggregation in environmental systems – Part 1: Seasonal tracer cycles quantify young water fractions, but not mean transit times, in spatially heterogeneous catchments Hydrology and Earth System Sciences DOI 10.5194/hess-20-279-2016 19 January 2016 Catchment mean transit times have been widely inferred from seasonal cycles of environmental tracers in precipitation and streamflow. Here I show that these cycles yield strongly biased estimates of mean transit times in spatially heterogeneous catchments (and, by implication, in real-world catchments). However, I also show that these cycles can be used to reliably estimate the fraction of “young” water in streamflow, meaning water that fell as precipitation less than roughly 2–3 months ago. Read more
