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
GHOST: Geoscientific Hollow Sphere Tessellation Solid Earth DOI 10.5194/se-9-1169-2018 10 October 2018 I present the GHOST (Geoscientific Hollow Sphere Tessellation) software which allows for the fast generation of computational meshes in hollow sphere geometries counting up to a hundred million cells. Each mesh is composed of concentric spherical shells made of quadrilaterals or triangles. I focus here on three commonly used meshes used in the geodynamics/geophysics community and further benchmark the gravity and gravitational potential procedures in the simple case of a constant density. Read more
Building a Raspberry Pi school magnetometer network in the UK Geoscience Communication DOI 10.5194/gc-1-25-2018 10 October 2018 As computing and geophysical sensor components have become increasingly affordable over the past decade, it is now possible to build a cost-effective system for monitoring the Earth’s natural magnetic field variations, in particular for space weather events, e.g. aurorae. Sensors available to the general public are ~ 100 times less sensitive than scientific instruments but only 1/100th of the price. We demonstrate a system that allows schools to contribute to a genuine scientific sensor network. Read more
Mapping carbon monoxide pollution from space down to city scales with daily global coverage Atmospheric Measurement Techniques DOI 10.5194/amt-11-5507-2018 9 October 2018 On 13 October 2017, the S5-P satellite was launched with TROPOMI as its only payload. One of the primary products is atmospheric CO observed with daily global coverage and spatial resolution of 7 × 7 km2. The new dataset allows the sensing of CO enhancements above cities and industrial areas and can track pollution transport from biomass burning regions. Through validation with ground-based TCCON measurements we show that the CO data product is already well within the mission requirement. Read more
Ice crystal number concentration estimates from lidar–radar satellite remote sensing – Part 1: Method and evaluation Atmospheric Chemistry and Physics DOI 10.5194/acp-18-14327-2018 9 October 2018 The number concentration of ice crystals (Ni) is a key cloud property that remains very uncertain due to difficulties in determining it using satellites. This lack of global observational constraints limits our ability to constrain this property in models responsible for predicting future climate. This pair of papers fills this gap by showing and analyzing the first rigorously evaluated global climatology of Ni, leading to new information shedding light on the processes that control high clouds. Read more
Reviews and syntheses: Carbon use efficiency from organisms to ecosystems – definitions, theories, and empirical evidence Biogeosciences DOI 10.5194/bg-15-5929-2018 9 October 2018 Carbon fixed by plants and phytoplankton through photosynthesis is ultimately stored in soils and sediments or released to the atmosphere during decomposition of dead biomass. Carbon-use efficiency is a useful metric to quantify the fate of carbon – higher efficiency means higher storage and lower release to the atmosphere. Here we summarize many definitions of carbon-use efficiency and study how this metric changes from organisms to ecosystems and from terrestrial to aquatic environments. Read more