Total ozone trends from 1979 to 2016 derived from five merged observational datasets – the emergence into ozone recovery Atmospheric Chemistry and Physics DOI 10.5194/acp-18-2097-2018 14 February 2018 This paper commemorates the 30-year anniversary of the initial signing of the Montreal Protocol (MP) on substances that deplete the ozone layer. The MP is so far successful in reducing ozone-depleting substances, and total ozone decline was successfully stopped by the late 1990s. Total ozone levels have been mostly stable since then. In some regions, barely significant upward trends are observed that suggest an emergence into the expected ozone recovery phase. Read more
Satellite remote sensing reveals a positive impact of living oyster reefs on microalgal biofilm development Biogeosciences DOI 10.5194/bg-15-905-2018 13 February 2018 Using satellite technology and a life-size experiment, we analysed the impact of oyster reefs on mats of microscopic algae that develop within coastal mudflats. We showed that the relationship between microalgae and oysters is not limited to a one-way process where microalgae are a food source to oysters, but that oysters also promote microalgae mats development, presumably by providing nutrients to them. This might yield new insights into coastal ecosystem management. Read more
Evidence for a continuous decline in lower stratospheric ozone offsetting ozone layer recovery Atmospheric Chemistry and Physics DOI 10.5194/acp-18-1379-2018 6 February 2018 Using a robust analysis, with artefact-corrected ozone data, we confirm upper stratospheric ozone is recovering following the Montreal Protocol, but that lower stratospheric ozone (50° S–50° N) has continued to decrease since 1998, and the ozone layer as a whole (60° S–60° N) may be lower today than in 1998. No change in total column ozone may be due to increasing tropospheric ozone. State-of-the-art models do not reproduce lower stratospheric ozone decreases. Read more
Modelling ocean-colour-derived chlorophyll a Biogeosciences DOI 10.5194/bg-15-613-2018 30 January 2018 This study provides a demonstration that a biogeochemical/ecosystem/optical computer model which explicitly captures how light is radiated at the surface of the ocean and can be used as a laboratory to explore products (such as Chla) that are derived from satellite measurements of ocean colour. It explores uncertainties that arise from data input used to derive the algorithms for the products, and issues arising from the interplay between optically important constituents in the ocean. Read more
Aerosol characteristics and particle production in the upper troposphere over the Amazon Basin Atmospheric Chemistry and Physics DOI 10.5194/acp-18-921-2018 25 January 2018 We made airborne measurements of aerosol particle concentrations and properties over the Amazon Basin. We found extremely high concentrations of very small particles in the region between 8 and 14 km altitude all across the basin, which had been recently formed by gas-to-particle conversion at these altitudes. This makes the upper troposphere a very important source region of atmospheric particles with significant implications for the Earth’s climate system. Read more
On the link between stress field and small-scale hydraulic fracture growth in anisotropic rock derived from microseismicity Solid Earth DOI 10.5194/se-9-39-2018 25 January 2018 To characterize the stress field at the Grimsel Test Site (GTS) underground rock laboratory, a series of hydrofracturing and overcoring tests were performed. Our study demonstrates that microseismicity monitoring along with high-resolution event locations provides valuable information for interpreting stress characterization measurements. Read more
Minimum forest cover required for sustainable water flow regulation of a watershed: a case study in Jambi Province, Indonesia Hydrology and Earth System Sciences DOI 10.5194/hess-22-581-2018 24 January 2018 This study is the first to describe the quantitative association between forest and plantation areas and the flow indicators (surface runoff and baseflow) in a watershed; this understanding is required by spatial planners if they are to balance the ecology and socioeconomic functions of a landscape with the rapid expansion of plantation crops. In addition, our study provides data regarding how SWAT input parameters related to tropical plantations such as oil palm and rubber should be adjusted. Read more
Reviews and syntheses: to the bottom of carbon processing at the seafloor Biogeosciences DOI 10.5194/bg-15-413-2018 19 January 2018 Organic carbon processing at the seafloor is studied by geologists to better understand the sedimentary record, by biogeochemists to quantify burial and respiration, by organic geochemists to elucidate compositional changes, and by ecologists to follow carbon transfers within food webs. These disciplinary approaches have their strengths and weaknesses. This award talk provides a synthesis, highlights the role of animals in sediment carbon processing and presents some new concepts. Read more
Response to marine cloud brightening in a multi-model ensemble Atmospheric Chemistry and Physics DOI 10.5194/acp-18-621-2018 19 January 2018 Marine cloud brightening (MCB) has been proposed to help limit global warming. We present here the first multi-model assessment of idealized MCB simulations from the Geoengineering Model Intercomparison Project. While all models predict a global cooling as intended, there is considerable spread between the models both in terms of radiative forcing and the climate response, largely linked to the substantial differences in the models’ representation of clouds. Read more
Can riparian vegetation shade mitigate the expected rise in stream temperatures due to climate change during heat waves in a human-impacted pre-alpine river? Hydrology and Earth System Sciences DOI 10.5194/hess-22-437-2018 18 January 2018 In eastern Austria, where air temperature rise is double that recorded globally, stream temperatures of a human-impacted river were simulated during heat waves, as calculated by regional climate models until 2100. An increase of up to 3 °C was predicted – thus exceeding thresholds of resident cold-adapted species. Vegetation management scenarios showed that adding vegetation can reduce both absolute temperatures and its rate of increase but is not able to fully mitigate the expected rise. Read more
