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. GHOST: Geoscientific Hollow Sphere Tessellation">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
Why has catchment evaporation increased in the past 40 years? A data-based study in Austria Hydrology and Earth System Sciences DOI 10.5194/hess-22-5143-2018 4 October 2018 We analyze changes in catchment evaporation estimated from the water balances of 156 catchments in Austria over 1977–2014, as well as the possible causes of these changes. Our results show that catchment evaporation increased on average by 29 ± 14 mm yr−1 decade−1. We attribute this increase to changes in atmospheric demand (based on reference and pan evaporation), changes in vegetation (quantified by a satellite-based vegetation index), and changes in precipitation. Read more
Trends in China’s anthropogenic emissions since 2010 as the consequence of clean air actions Atmospheric Chemistry and Physics DOI 10.5194/acp-18-14095-2018 4 October 2018 To tackle the problem of severe air pollution, China has implemented active clean air policies in recent years. We quantified China’s anthropogenic emissions during 2010–2017 and identified the major driving forces of these trends by using a combination of bottom-up emission inventory and index decomposition analysis (IDA) approaches. The major air pollutants have reduced their emissions by 17–62 % during 2010–2017. The IDA results suggest that emission control measures are the main drivers. Read more
Potential for phenol biodegradation in cloud waters Biogeosciences DOI 10.5194/bg-15-5733-2018 28 September 2018 The main objective of this work was to evaluate the potential degradation of phenol, a highly toxic pollutant, by cloud microorganisms. Phenol concentrations measured on five cloud samples collected at the PUY station in France were from 0.15 to 0.74 µg L−1. Metatranscriptomic analysis suggested that phenol could be biodegraded directly in clouds, likely by Gammaproteobacteria. A large screening showed that 93 % of 145 bacterial strains isolated from clouds were able to degrade phenol. Read more