Regional variability of acidification in the Arctic: a sea of contrasts Biogeosciences DOI 10.5194/bg-11-293-2014 23 January 2014 In this study, we use an ocean-only general circulation model, with embedded biogeochemistry and a comprehensive description of the ocean carbon cycle, to study the response of pH and saturation states of calcite and aragonite to rising atmospheric pCO2and changing climate in the Arctic Ocean. Read more
Weathering by tree-root-associating fungi diminishes under simulated Cenozoic atmospheric CO2decline Biogeosciences DOI 10.5194/bg-11-321-2014 23 January 2014 We report experimental evidence for a negative feedback across a declining Cenozoic [CO2]a range from 1500 to 200 ppm, whereby low [CO2]a curtails mineral surface alteration via trenching and etch pitting by arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungal partners of tree roots. Read more
Ensemble projections of future streamflow droughts in Europe Hydrology and Earth System Sciences DOI 10.5194/hess-18-85-2014 9 January 2014 This paper addresses the issue of future developments in streamflow drought characteristics across Europe. Read more
Seabed topography beneath Larsen C Ice Shelf from seismic soundings The Cryosphere DOI 10.5194/tc-8-1-2014 2 January 2014 Seismic reflection soundings of ice thickness and seabed depth were acquired on the Larsen C Ice Shelf in order to test a sub-ice shelf bathymetry model derived from the inversion of IceBridge gravity data. Read more
The surface temperatures of Earth: steps towards integrated understanding of variability and change Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-2-305-2013 18 December 2013 In a community-based activity in June 2012, the EarthTemp Network brought together 55 researchers from five continents to improve the interaction between scientific communities who focus on surface temperature in particular domains, to exploit the strengths of different observing systems and to better meet the needs of different communities. Read more
Quantifying mesoscale soil moisture with the cosmic-ray rover Hydrology and Earth System Sciences DOI 10.5194/hess-17-5097-2013 17 December 2013 This paper explores the challenges and opportunities for mapping soil moisture over large areas using the cosmic-ray rover. Read more
Statistical analysis to characterize transport of nutrients in groundwater near an abandoned feedlot Hydrology and Earth System Sciences DOI 10.5194/hess-17-4897-2013 6 December 2013 Surface water from a lagoon and groundwater samples from 17 wells within and near an abandoned feedlot in northwestern Minnesota, USA, were analyzed for carbon, nutrients, and field parameters. Read more
A simple explanation for the sensitivity of the hydrologic cycle to surface temperature and solar radiation and its implications for global climate change Earth System Dynamics DOI 10.5194/esd-4-455-2013 5 December 2013 The global hydrologic cycle is likely to increase in strength with global warming, although some studies indicate that warming due to solar absorption may result in a different sensitivity than warming due to an elevated greenhouse effect. Here we show that these sensitivities of the hydrologic cycle can be derived analytically from an extremely simple surface energy balance model that is constrained by the assumption that vertical convective exchange within the atmosphere operates at the thermodynamic limit of maximum power. Read more
Seasonal variations of sea–air CO2 fluxes in the largest tropical marginal sea (South China Sea) based on multiple-year underway measurements Biogeosciences DOI 10.5194/bg-10-7775-2013 29 November 2013 Based upon 14 field surveys conducted between 2003 and 2008, this paper shows that the seasonal pattern of sea surface partial pressure of CO2 (pCO2) and sea–air CO2 fluxes differed among four different physical–biogeochemical domains in the South China Sea proper. Read more
Voyager 2 observation of the multifractal spectrum in the heliosphere and the heliosheath Nonlinear Processes in Geophysics DOI 10.5194/npg-20-1061-2013 28 November 2013 This paper looks in detail at the multifractal scaling of the fluctuations in the interplanetary magnetic field strength as measured onboard Voyager 2 in the entire heliosphere and even in the heliosheath. Read more
Rainfall estimation using moving cars as rain gauges – laboratory experiments Hydrology and Earth System Sciences DOI 10.5194/hess-17-4701-2013 28 November 2013 The spatial assessment of short time-step precipitation is a challenging task. Low density of observation networks, as well as the bias in radar rainfall estimation motivated the new idea of exploiting cars as moving rain gauges with windshield wipers or optical sensors as measurement devices. Read more
Arctic stratospheric dehydration – Part 1: Unprecedented observation of vertical redistribution of water Atmospheric Chemistry and Physics DOI 10.5194/acp-13-11503-2013 27 November 2013 This paper presents high-resolution measurements of water vapour, aerosols and clouds in the Arctic stratosphere in January and February 2010 carried out by in situ instrumentation on balloon sondes and high-altitude aircraft combined with satellite observations. Read more
Quantifying aerosol mixing state with entropy and diversity measures Atmospheric Chemistry and Physics DOI 10.5194/acp-13-11423-2013 25 November 2013 This paper presents the first quantitative metric for aerosol population mixing state, defined as the distribution of per-particle chemical species composition. Read more
Paleosols in the Transantarctic Mountains: indicators of environmental change Solid Earth DOI 10.5194/se-4-451-2013 20 November 2013 Paleosols on unconsolidated deposits are emphasized in this study. Examples are given from the McMurdo Dry Valleys (78° S) and two outlet glaciers in the central and southern TAMS, including the Hatherton–Darwin Glacier region (80° S) and the Beardmore Glacier region (85°30’ S). Read more
Inverse streamflow routing Hydrology and Earth System Sciences DOI 10.5194/hess-17-4577-2013 19 November 2013 Here we develop a methodology to invert the routing process, i.e., to derive the spatially distributed runoff from streamflow (e.g., measured at gauge stations) by inverting an arbitrary linear routing model using fixed interval smoothing. Read more
Peak glacial 14C ventilation ages suggest major draw-down of carbon into the abyssal ocean Climate of the Past DOI 10.5194/cp-9-2595-2013 15 November 2013 Here we present a new, though still fragmentary, ocean-wide Δ14C data set showing that during the Last Glacial Maximum (LGM) and Heinrich Stadial 1 (HS-1) the maximum 14C age difference between ocean deep waters and the atmosphere exceeded the modern values by up to 1500 14C yr, in the extreme reaching 5100 14C yr. Read more
Heterogeneous formation of polar stratospheric clouds – Part 2: Nucleation of ice on synoptic scales Atmospheric Chemistry and Physics DOI 10.5194/acp-13-10769-2013 6 November 2013 This paper provides compelling evidence for the importance of heterogeneous nucleation, likely on solid particles of meteoritic origin, and of small-scale temperature fluctuations, for the formation of ice particles in the Arctic stratosphere. Read more
Where to find 1.5 million yr old ice for the IPICS “Oldest-Ice” ice core Climate of the Past DOI 10.5194/cp-9-2489-2013 5 November 2013 The recovery of a 1.5 million yr long ice core from Antarctica represents a keystone of our understanding of Quaternary climate, the progression of glaciation over this time period and the role of greenhouse gas cycles in this progression. Here we tackle the question of where such ice may still be found in the Antarctic ice sheet Read more
Ratios among atmospheric trace gases together with winds imply exploitable information for bird navigation: a model elucidating experimental results Biogeosciences DOI 10.5194/bg-10-6929-2013 4 November 2013 A model of avian goal-oriented navigation is described that is based on two empirical findings building a bridge from ornithology to atmospheric chemistry. Read more
A thermodynamic approach to link self-organization, preferential flow and rainfall–runoff behaviour Hydrology and Earth System Sciences DOI 10.5194/hess-17-4297-2013 1 November 2013 This study investigates whether a thermodynamically optimal hillslope structure can, if existent, serve as a first guess for uncalibrated predictions of rainfall–runoff. Read more