Characteristics and causes of Deep Western Boundary Current transport variability at 34.5∘ S during 2009–2014 Ocean Science DOI 10.5194/os-13-175-2017 2 March 2017 This study investigates the variability of the Deep Western Boundary Current at 34.5° S. This current carries a large part of the cold deep limb of the Meridional Overturning Circulation, which is a crucial part of the ocean system and has impacts on global weather patterns. Study of this current in the South Atlantic has been limited in the past, and this new study provides insights into the strength and variability of the current as well as the causes for the observed changes. Read more
Soil conservation in the 21st century: why we need smart agricultural intensification SOIL DOI 10.5194/soil-3-45-2017 1 March 2017 We discuss pathways towards better soil protection in the 21st century. The efficacy of soil conservation technology is not a fundamental barrier for a more sustainable soil management. However, soil conservation is generally not directly beneficial to the farmer. We believe that the solution of this conundrum is a rapid, smart intensification of agriculture in the Global South. This will reduce the financial burden and will, at the same time, allow more effective conservation. Read more
A record of Neogene seawater δ11B reconstructed from paired δ11B analyses on benthic and planktic foraminifera Climate of the Past DOI 10.5194/cp-13-149-2017 24 February 2017 Understanding the boron isotopic composition of seawater (δ11Bsw) is key to calculating absolute estimates of CO2 using the boron isotope pH proxy. Here we use the boron isotope gradient, along with an estimate of pH gradient, between the surface and deep ocean to show that the δ11Bsw varies by ~ 2 ‰ over the past 23 million years. This new record has implications for both δ11Bsw and CO2 records and understanding changes in the ocean isotope composition of a number of ions through time. Read more
Multi-model simulations of aerosol and ozone radiative forcing due to anthropogenic emission changes during the period 1990–2015 Atmospheric Chemistry and Physics DOI 10.5194/acp-17-2709-2017 22 February 2017 Over the past decades, the geographical distribution of emissions of substances that alter the atmospheric energy balance has changed due to economic growth and pollution regulations. Here, we show the resulting changes to aerosol and ozone abundances and their radiative forcing using recently updated emission data for the period 1990–2015, as simulated by seven global atmospheric composition models. The global mean radiative forcing is more strongly positive than reported in IPCC AR5. Read more
A new device to mount portable energy-dispersive X-ray fluorescence spectrometers (p-ED-XRF) for semi-continuous analyses of split (sediment) cores and solid samples Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-6-93-2017 17 February 2017 This paper introduces a hands-on, low-cost device (German industrial property right no. 20 2014 106 048.0) that uses common adapters to mount p-ED-XRF devices so that these can provide bulk-sedimentary chemistry data from non-destructive measurements at the surface of a split sediment core or from other solid samples. The strength of combining p-ED-XRF analyses with this new sample chamber is demonstrated by exemplary sediment cores from an archaeological research project. Read more
How much can we save? Impact of different emission scenarios on future snow cover in the Alps The Cryosphere DOI 10.5194/tc-11-517-2017 16 February 2017 We simulate the future snow cover in the Alps with the help of a snow model, which is fed by projected temperature and precipitation changes from a large set of climate models. The results demonstrate that snow below 1000 m is probably a rare guest at the end of the century. Moreover, even above 3000 m the simulations show a drastic decrease in snow depth. However, the results reveal that the projected snow cover reduction can be mitigated by 50 % if we manage to keep global warming below 2°. Read more
Brief communication: Glaciers in the Hunza catchment (Karakoram) have been nearly in balance since the 1970s The Cryosphere DOI 10.5194/tc-11-531-2017 15 February 2017 Previous geodetic estimates of glacier mass changes in the Karakoram have revealed balanced budgets or a possible slight mass gain since the year ∼ 2000. We used old US reconnaissance imagery and could show that glaciers in the Hunza River basin (Central Karakoram) experienced on average no significant mass changes also since the 1970s. Likewise the glaciers had heterogeneous behaviour with frequent surge activities during the last 40 years. Read more
Trend of atmospheric mercury concentrations at Cape Point for 1995–2004 and since 2007 Atmospheric Chemistry and Physics DOI 10.5194/acp-17-2393-2017 15 February 2017 Currently the Cape Point GAW GEM record is a very sought-after data record for international modelers and scientist alike, as the data set of 20 years represents the longest record in the Southern Hemisphere (SH). CPT was the only monitoring site on the African continent and one of eight GMOS ground-based monitoring sites located in the SH. The increasing Hg trend observed at CPT is of global importance as treaties such as the Minamata Convention on Mercury is there to combat Hg pollution. Read more
Rapid attribution of the August 2016 flood-inducing extreme precipitation in south Louisiana to climate change Hydrology and Earth System Sciences DOI 10.5194/hess-21-897-2017 14 February 2017 During August 2016, heavy precipitation led to devastating floods in south Louisiana, USA. Here, we analyze the climatological statistics of the precipitation event, as defined by its 3-day total over 12–14 August. Using observational data and high-resolution global coupled model experiments, we find for a comparable event on the central US Gulf Coast an average return period of about 30 years and the odds being increased by at least 1.4 since 1900 due to anthropogenic climate change. Read more
Global scale variability of the mineral dust long-wave refractive index: a new dataset of in situ measurements for climate modeling and remote sensing Atmospheric Chemistry and Physics DOI 10.5194/acp-17-1901-2017 9 February 2017 Modeling the interaction of dust with long-wave (LW) radiation is still a challenge due to the scarcity of information on their refractive index. In this paper, we present a unique dataset of dust refractive indices obtained from in situ measurements in a large smog chamber. Our results show that the dust LW refractive index varies strongly from source to source due to particle composition changes. We recommend taking this variability into account in climate and remote sensing applications. Read more
