The influence of upper-plate advance and erosion on overriding plate deformation in orogen syntaxes Solid Earth DOI 10.5194/se-9-1207-2018 5 November 2018 In this modeling study, we investigate rock uplift at plate corners (syntaxes). These are characterized by a unique bent geometry at subduction zones and exhibit some of the world’s highest rock uplift rates. We find that the style of deformation changes above the plate’s bent section and that active subduction is necessary to generate an isolated region of rapid uplift. Strong erosion there localizes uplift on even smaller scales, suggesting both tectonic and surface processes are important. Read more
Additional global climate cooling by clouds due to ice crystal complexity Atmospheric Chemistry and Physics DOI 10.5194/acp-18-15767-2018 2 November 2018 Using light diffraction it is possible to detect microscopic features within ice particles that have not yet been fully characterized. Here, this technique was applied in airborne measurements, where it was found that majority of atmospheric ice particles have features that significantly change the way ice particles interact with solar light. The microscopic features make ice-containing clouds more reflective than previously thought, which could have consequences for predicting our climate. Read more
Mesoscale fine structure of a tropopause fold over mountains Atmospheric Chemistry and Physics DOI 10.5194/acp-18-15643-2018 30 October 2018 GLORIA observations during two crossings of the polar front jet stream resolve the fine mesoscale structure of a tropopause fold in high detail. Tracer–tracer correlations of H2O and O3 are presented as a function of potential temperature and reveal an active mixing region. Our study confirms conceptual models of tropopause folds, validates the high quality of ECMWF IFS forecasts, and suggests that mountain waves are capable of modulating exchange processes in the vicinity of tropopause folds. Read more
Oblique rifting: the rule, not the exception Solid Earth DOI 10.5194/se-9-1187-2018 26 October 2018 Fragmentation of continents often involves obliquely rifting segments that feature a complex three-dimensional structural evolution. Here we show that more than ~ 70 % of Earth’s rifted margins exceeded an obliquity of 20° demonstrating that oblique rifting should be considered the rule, not the exception. This highlights the importance of three-dimensional approaches in modelling, surveying, and interpretation of those rift segments where oblique rifting is the dominant mode of deformation. Read more
Modelling the water balance of Lake Victoria (East Africa) – Part 1: Observational analysis Hydrology and Earth System Sciences DOI 10.5194/hess-22-5509-2018 25 October 2018 Lake Victoria is the largest lake in Africa and one of the two major sources of the Nile river. The water level of Lake Victoria is determined by its water balance, consisting of lake precipitation and evaporation, inflow from rivers and lake outflow, controlled by two hydropower dams. Here, we present a water balance model for Lake Victoria, which closely represents the observed lake levels. The model results highlight the sensitivity of the lake level to human operations at the dam. Read more
Modelling the water balance of Lake Victoria (East Africa) – Part 2: Future projections Hydrology and Earth System Sciences DOI 10.5194/hess-22-5527-2018 25 October 2018 Lake Victoria is the second largest freshwater lake in the world and one of the major sources of the Nile River, which is controlled by two hydropower dams. In this paper we estimate the potential consequences of climate change for future water level fluctuations of Lake Victoria. Our results reveal that the operating strategies at the dam are the main controlling factors of future lake levels and that regional climate simulations used in the projections encompass large uncertainties. Read more
The internal structure of the Brunt Ice Shelf from ice-penetrating radar analysis and implications for ice shelf fracture The Cryosphere DOI 10.5194/tc-12-3361-2018 24 October 2018 Ice shelves are thick sheets of ice floating on the ocean off the coasts of Antarctica and Greenland. They help regulate the flow of ice off the continent. Ice shelves undergo a natural cycle of seaward flow, fracture, iceberg production and regrowth. The Brunt Ice Shelf recently developed two large cracks. We used ground-penetrating radar to find out how the internal structure of the ice might influence the present crack development and the future stability of the ice shelf. Read more
Contrasting biosphere responses to hydrometeorological extremes: revisiting the 2010 western Russian heatwave Biogeosciences DOI 10.5194/bg-15-6067-2018 16 October 2018 Northern forests enhanced their productivity during and before the 2010 Russian mega heatwave. We scrutinize this issue with a novel type of multivariate extreme event detection approach. Forests compensate for 54 % of the carbon losses in agricultural ecosystems due to vulnerable conditions in spring and better water management in summer. The findings highlight the importance of forests in mitigating climate change, while not alleviating the consequences of extreme events for food security. Read more
The importance of small artificial water bodies as sources of methane emissions in Queensland, Australia Hydrology and Earth System Sciences DOI 10.5194/hess-22-5281-2018 15 October 2018 Artificial water bodies are a major source of methane and an important contributor to flooded land greenhouse gas emissions. Past studies focussed on large water supply or hydropower reservoirs with small artificial water bodies (ponds) almost completely ignored. This regional study demonstrated ponds accounted for one-third of flooded land surface area and emitted over 1.6 million t CO2eq. yr−1(10 % of land use sector emissions). Ponds should be included in regional GHG inventories. Read more
The climate of a retrograde rotating Earth Earth System Dynamics DOI 10.5194/esd-9-1191-2018 12 October 2018 Model experiments show that changing the sense of Earth’s rotation has relatively little impact on the globally and zonally averaged energy budgets but leads to large shifts in continental climates and patterns of precipitation. The retrograde world is greener as the desert area shrinks. Deep water formation shifts from the North Atlantic to the North Pacific with subsequent changes in ocean overturning. Over large areas of the Indian Ocean, cyanobacteria dominate over bulk phytoplankton. Read more