Observed decline of the Atlantic meridional overturning circulation 2004–2012 Ocean Science DOI 10.5194/os-10-29-2014 6 February 2014 The Atlantic meridional overturning circulation and its component parts are monitored by combining a transatlantic array of moored instruments with submarine-cable-based measurements of the Gulf Stream and satellite derived Ekman transport. The time series has recently been extended to October 2012 and the results show a downward trend since 2004. Read more
Using palaeo-climate comparisons to constrain future projections in CMIP5 Climate of the Past DOI 10.5194/cp-10-221-2014 5 February 2014 We present a selection of methodologies for using the palaeo-climate model component of the Coupled Model Intercomparison Project (Phase 5) to attempt to constrain future climate projections using the same models. Read more
Salinity changes in the Agulhas leakage area recorded by stable hydrogen isotopes of C37 alkenones during Termination I and II Climate of the Past DOI 10.5194/cp-10-251-2014 5 February 2014 We reconstructed sea surface salinity changes using alkenone δD, and paleo-sea surface temperature using TEXH86 and UK’37, from two sediment cores located in the Agulhas leakage area during Termination I and II. Read more
Autonomous thermal camera system for monitoring the active lava lake at Erebus volcano, Antarctica Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-3-13-2014 5 February 2014 In December 2012, the Mount Erebus Volcano Observatory installed a thermal infrared camera system to monitor the volcano’s active lava lake. The new system is designed to be autonomous, and capable of capturing images of the lava lake continuously throughout the year. Read more
China’s dimming and brightening: evidence, causes and hydrological implications Annales Geophysicae DOI 10.5194/angeo-32-41-2014 28 January 2014 In this study, we synthesize reliable results and conclusively address recent advances and insufficiencies in studies on dimming and brightening in China. Read more
Microphysical properties and high ice water content in continental and oceanic mesoscale convective systems and potential implications for commercial aircraft at flight altitude Atmospheric Chemistry and Physics DOI 10.5194/acp-14-899-2014 27 January 2014 Two complementary case studies are conducted to analyse convective system properties in the region where strong cloud-top lidar backscatter anomalies are observed as reported by Platt et al. (2011). Read more
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