Return glider radiosonde for in situ upper-air research measurements Atmospheric Measurement Techniques DOI 10.5194/amt-9-2535-2016 9 June 2016 New radiosonde instruments for humidity-, radiation- and gas-profile measurements were introduced in recent years for atmospheric research and climate monitoring. Such instruments are intended to be reused on multiple flights. Here we introduce the return glider radiosonde (RGR), which enables flying and retrieving valuable in situ upper-air instruments. The RGR is lifted with weather balloons to a preset altitude, and a built-in autopilot flies the glider autonomously back to the launch site. Read more
Causes and systematics of inundations of the Krasnodar territory on the Russian Black Sea coast Natural Hazards and Earth System Sciences DOI 10.5194/nhess-16-1289-2016 8 June 2016 Inundations on the Black Sea coast of the Krasnodar territory of the Russian Federation were analysed for 1945 to 2013. Risks, hazards and damage from inundations here are some of the highest in the country. The large quantity and the extremeness of rainfall, and the intense flood regimes of the rivers are the main contributors. Additionally, anthropogenic impact such as badly planned economic activities in channels, floodplains and on river watersheds strongly enhance the effects. Read more
High spatial resolution imaging of methane and other trace gases with the airborne Hyperspectral Thermal Emission Spectrometer (HyTES) Atmospheric Measurement Techniques DOI 10.5194/amt-9-2393-2016 1 June 2016 Using data from a new airborne Hyperspectral Thermal Emission Spectrometer (HyTES) instrument, we present a technique for the detection and wide-area mapping of emission plumes of methane and other atmospheric trace gas species over challenging and diverse environmental conditions with high spatial resolution, that permits direct attribution to sources in complex environments. Read more
Will a perfect model agree with perfect observations? The impact of spatial sampling Atmospheric Chemistry and Physics DOI 10.5194/acp-16-6335-2016 24 May 2016 We show that evaluating global aerosol model data with observations of very different spatial scales (200 vs. 10 km) can lead to large discrepancies, solely due to different spatial sampling. Strategies for reducing these sampling errors are developed and tested using a set of high-resolution model simulations. Read more
Retrieving atmospheric turbulence information from regular commercial aircraft using Mode-S and ADS-B Atmospheric Measurement Techniques DOI 10.5194/amt-9-2253-2016 23 May 2016 This paper is presenting a feasibility study focused on methods of estimating the turbulence intensity based on a class of navigational messages routinely broadcast by the commercial aircraft (known as ADS-B and Mode-S). Using this kind of information could have potentially significant impact on aviation safety. Three methods have been investigated. Read more
Investigating the impact of land-use land-cover change on Indian summer monsoon daily rainfall and temperature during 1951–2005 using a regional climate model Hydrology and Earth System Sciences DOI 10.5194/hess-20-1765-2016 10 May 2016 Regional climate model (RegCM4) simulations demonstrate that part of the observed decrease in moderate rainfall events during the summer monsoon season over central India from 1951 to 2005 is attributed to anthropogenically induced land-use land-cover change (LULCC). LULCC also partly explains the observed warming trend in the daily mean and maximum temperatures over India. This study demonstrates the importance of LULCC in the context of regional climate change over India. Read more
Alluvial plain dynamics in the southern Amazonian foreland basin Earth System Dynamics DOI 10.5194/esd-7-453-2016 10 May 2016 This paper analyses the behaviour of 12 tributaries of the Río Mamoré and their influence on alluvial plain dynamics. These rivers are extremely active: between 1984 and 2014, 7 of these 12 rivers underwent a total of 41 crevasses and 29 avulsions. Most of the sedimentary load of these rivers is deposited on the alluvial plains before they reach the Mamoré. Crevasses and avulsions are not controlled by ENSO cycles, but rather are the result of intrabasinal processes. Read more
Bayesian statistical ionospheric tomography improved by incorporating ionosonde measurements Atmospheric Measurement Techniques DOI 10.5194/amt-9-1859-2016 28 April 2016 We validate 2-D ionospheric tomography reconstructions against EISCAT incoherent scatter radar measurements. The method is based on Bayesian statistical inversion. We employ ionosonde measurements for the choice of the prior distribution parameters and use a sparse matrix approximation for the computations. This results in a computationally efficient tomography algorithm with clear probabilistic interpretation. We find that ionosonde measurements improve the reconstruction significantly. Read more
Mapping turbulent diffusivity associated with oceanic internal lee waves offshore Costa Rica Ocean Science DOI 10.5194/os-12-601-2016 26 April 2016 Lee waves play a significant role in ocean mixing but are difficult to study with traditional casts, moorings, and tows due to their stationary nature and limited spatial extent. We develop a new method to estimate turbulent diffusivity from seismic data and find elevated levels of turbulence associated with lee waves in the mid-water and around the seafloor that are 5 times greater than surrounding waters and 50 times greater than open-ocean diffusivities. Read more
A Late Pleistocene sea level stack Climate of the Past DOI 10.5194/cp-12-1079-2016 26 April 2016 This study presents an average of seven Late Pleistocene sea level records, which improves the signal-to-noise ratio for estimates of sea level change during glacial cycles of the past 800 000 years. Read more
Revolutions in energy input and material cycling in Earth history and human history Earth System Dynamics DOI 10.5194/esd-7-353-2016 22 April 2016 We identify six past revolutions in energy input and material cycling in Earth and human history. We find that human energy use has now reached a magnitude comparable to the biosphere, and conclude that a prospective sustainability revolution will require scaling up new solar energy technologies and the development of much more efficient material recycling systems. Our work was inspired by recognising the connections between Earth system science and industrial ecology at the “LOOPS” workshop. Read more
Differential climate impacts for policy-relevant limits to global warming: the case of 1.5 ∘C and 2 ∘C Earth System Dynamics DOI 10.5194/esd-7-327-2016 21 April 2016 We present for the first time a comprehensive assessment of key climate impacts for the policy relevant warming levels of 1.5 °C and 2 °C above pre-industrial levels. We report substantial impact differences in intensity and frequency of extreme weather events, regional water availability and agricultural yields, sea-level rise and risk of coral reef loss. The increase in climate impacts is particularly pronounced in tropical and sub-tropical regions. Read more
Effects of wood chip amendments on the revegetation performance of plant species on eroded marly terrains in a Mediterranean mountainous climate (Southern Alps, France) Solid Earth DOI 10.5194/se-7-599-2016 15 April 2016 This paper presents the results of two experiments of revegetation techniques in context of water erosion and mountainous Mediterranean climate. We studied the interest of a wood chip amendment, applied on soil surface (mulch), and its interaction with plant development. The use of different plant species and the monitoring on three growing seasons (with climatic variations) allow us to specify the interest of wood chip mulch to improve revegetation especially in erosion and drought conditions. Read more
The link between marine sediment records and changes in Holocene Saharan landscape: simulating the dust cycle Climate of the Past DOI 10.5194/cp-12-1009-2016 15 April 2016 We demonstrate for the first time the direct link between dust accumulation in marine sediment cores and Saharan land surface by simulating the mid-Holocene and pre-industrial dust cycle as a function of Saharan land surface cover and atmosphere-ocean conditions using the coupled atmosphere-aerosol model ECHAM6-HAM2.1. Mid-Holocene surface characteristics, including vegetation cover and lake surface area, are derived from proxy data and simulations. Read more
Combined fluvial and pluvial urban flood hazard analysis: concept development and application to Can Tho city, Mekong Delta, Vietnam Natural Hazards and Earth System Sciences DOI 10.5194/nhess-16-941-2016 13 April 2016 Many urban areas experience both fluvial and pluvial floods, thus this study aims to analyse fluvial and pluvial flood hazards as well as combined pluvial and fluvial flood hazards. This combined fluvial-pluvial flood hazard analysis is performed in a tropical environment for Can Tho city in the Mekong Delta. The final results are probabilistic hazard maps, showing the maximum inundation caused by floods of different magnitudes along with an uncertainty estimation. Read more
Non-deforestation fire vs. fossil fuel combustion: the source of CO2 emissions affects the global carbon cycle and climate responses Biogeosciences DOI 10.5194/bg-13-2137-2016 13 April 2016 We simulated both fire pulses and stable fire regimes and found the resulting climatic impacts to be irreconcilable with equivalent amounts of CO2 emissions produced by fossil fuel combustion. Consequently, side-by-side comparisons of fire and fossil fuel CO2 emissions—implicitly implying that they have similar effects—should be avoided. Our study calls for the explicit representation of fire in climate models in order to improve our understanding of its impacts in the Earth system. Read more
Early warning signals of tipping points in periodically forced systems Earth System Dynamics DOI 10.5194/esd-7-313-2016 13 April 2016 We find early warnings of abrupt changes in complex dynamical systems such as the climate where the usual early warning indicators do not work. In particular, these are systems that are periodically forced, for example by the annual cycle of solar insolation. We show these indicators are good theoretically in a general setting then apply them to a specific system, that of the Arctic sea ice, which has been conjectured to be close to such a tipping point. We do not find evidence of it. Read more
Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015 Atmospheric Chemistry and Physics DOI 10.5194/acp-16-4605-2016 13 April 2016 We examine changes in SO2 and NO2 over the world’s most polluted regions during the first decade of Aura OMI observations. Over the eastern US, both NO2 and SO2 levels decreased by 40% and 80%, respectively. OMI confirmed large reductions in SO2 over eastern Europe’s largest coal power plants. The North China Plain has the world’s most severe SO2 pollution, but a decreasing trend been observed since 2011, with a 50% reduction in 2012-2014. India’s SO2 and NO2 levels are growing at a fast pace. Read more
Statistical analysis of magnetotail fast flows and related magnetic disturbances Annales Geophysicae DOI 10.5194/angeo-34-399-2016 12 April 2016 This study presents an investigation on the occurrence of fast flows in the magnetotail using the complete available data set of the THEMIS spacecraft for the years 2007 to 2015. First, basic statistical findings concerning velocity distributions, occurrence rates, group structures and key features of 16 000 events are presented using Superposed Epoch and Minimum Variance Analysis techniques. Read more
Kinetic isotope effects of 13CH3D + OH and 13CH3D + OH from 278 to 313 K Atmospheric Chemistry and Physics DOI 10.5194/acp-16-4439-2016 11 April 2016 We present experimental kinetic isotope effects (KIE) for the OH oxidation of CH3D and 13CH3D and their temperature dependence. Our determination of the 13CH3D+OH KIE is novel and we find no “clumped” isotope effect within the experimental uncertainty. Read more