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
