The European 2015 drought from a climatological perspective Hydrology and Earth System Sciences DOI 10.5194/hess-21-1397-2017 8 March 2017 This paper analyses the European summer drought of 2015 from a climatological perspective, including its origin and spatial and temporal development, and how it compares with the 2003 event. It discusses the main contributing factors controlling the occurrence and persistence of the event: temperature and precipitation anomalies, blocking episodes and sea surface temperatures. The results represent the outcome of a collaborative initiative of members of UNESCO’s FRIEND-Water program. Read more
Structural uncertainty in air mass factor calculation for NO2 and HCHO satellite retrievals Atmospheric Measurement Techniques DOI 10.5194/amt-10-759-2017 7 March 2017 Choices and assumptions made to represent the state of the atmosphere introduce an uncertainty of 42 % in the air mass factor calculation in trace gas satellite retrievals in polluted regions. The AMF strongly depends on the choice of a priori trace gas profile, surface albedo data set and the correction method to account for clouds and aerosols. We call for well-designed validation exercises focusing on situations when AMF structural uncertainty has the highest impact on satellite retrievals. Read more
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
