Latest Permian carbonate carbon isotope variability traces heterogeneous organic carbon accumulation and authigenic carbonate formation Climate of the Past DOI 10.5194/cp-13-1635-2017 22 November 2017 Stratigraphic trends in the carbon isotope composition of calcium carbonate rock can be used as a stratigraphic tool. An important assumption when using these isotope chemical records is that they record a globally universal signal of marine water chemistry. We show that carbon isotope scatter on a confined centimetre stratigraphic scale appears to represent a signal of microbial activity. However, long-term carbon isotope trends are still compatible with a primary isotope imprint. Read more
When probabilistic seismic hazard climbs volcanoes: the Mt. Etna case, Italy – Part 1: Model components for sources parameterization Natural Hazards and Earth System Sciences DOI 10.5194/nhess-17-1981-2017 22 November 2017 The volcanic region of Mt. Etna (Sicily, Italy) represents a perfect lab for testing innovative approaches to seismic hazard assessment. We present here the model components and the procedures adopted for defining seismic sources to be used in a new generation of probabilistic seismic hazard assessment, the first results and maps of which are presented in a companion paper, Peruzza et al. (2017). Read more
When probabilistic seismic hazard climbs volcanoes: the Mt. Etna case, Italy – Part 2: Computational implementation and first results Natural Hazards and Earth System Sciences DOI 10.5194/nhess-17-1999-2017 22 November 2017 It is well known that volcanoes and earthquakes are associated, and some active volcanoes cause damaging earthquakes. Nonetheless, volcanoes usually are not pinpointed on a hazard map, as the effects of shallow, volcanic earthquakes can be overshadowed by stronger tectonic earthquakes in the region, particularly when long exposure periods are considered. In this study we faced some challenges with software implementations and original concept scheme for an original PSHA at Mt. Etna, Italy. Read more
Climate of migration? How climate triggered migration from southwest Germany to North America during the 19th century Climate of the Past DOI 10.5194/cp-13-1573-2017 21 November 2017 This paper presents the extent to which climate, harvest and prices influenced the major migration waves from southwest Germany into North America during the 19th century, a century of dramatic climatic and societal changes. Read more
A multilayer physically based snowpack model simulating direct and indirect radiative impacts of light-absorbing impurities in snow The Cryosphere DOI 10.5194/tc-11-2633-2017 20 November 2017 Light-absorbing impurities deposited on snow, such as soot or dust, strongly modify its evolution. We implemented impurity deposition and evolution in a detailed snowpack model, thereby expanding the reach of such models into addressing the subtle interplays between snow physics and impurities’ optical properties. Model results were evaluated based on innovative field observations at an Alpine site. This allows future investigations in the fields of climate, hydrology and avalanche prediction. Read more
A new diagnostic for tropospheric ozone production Atmospheric Chemistry and Physics DOI 10.5194/acp-17-13669-2017 17 November 2017 Understanding tropospheric ozone chemistry has been at the centre of the field of atmospheric chemistry for the last 30 years. However, our conceptual approach to diagnosing ozone production in global models has not advanced in this time. Our work presents a new and powerful approach for diagnosing tropospheric ozone production, providing a significant enhancement in our ability to understand the processes controlling ozone and how we can validate our assessment of these processes. Read more
Reviews and syntheses: on the roles trees play in building and plumbing the critical zone Biogeosciences DOI 10.5194/bg-14-5115-2017 17 November 2017 This review represents the outcome from an invigorating workshop discussion that involved tree physiologists, geomorphologists, ecologists, geochemists, and hydrologists and developed nine hypotheses that could be tested. We argue these hypotheses point to the essence of issues we must explore if we are to understand how the natural system of the earth surface evolves, and how humans will affect its evolution. This paper will create discussion and interest both before and after publication. Read more
Basin-scale heterogeneity in Antarctic precipitation and its impact on surface mass variability The Cryosphere DOI 10.5194/tc-11-2595-2017 15 November 2017 In this CESM modeling study, we uncover regional relationships in snowfall across Antarctica that are corroborated by regional modeling and ice core records. These relationships are driven by variability in large-scale atmospheric moisture transport and dampen overall Antarctic snowfall variability, with implications for Antarctic-sourced sea level variability and detection of an emergent anthropogenic signal in Antarctic mass trends. Read more
Regional Antarctic snow accumulation over the past 1000 years Climate of the Past DOI 10.5194/cp-13-1491-2017 10 November 2017 Regional Antarctic snow accumulation derived from 79 ice core records is evaluated as part of the PAGES Antarctica 2k working group. Our results show that surface mass balance for the total Antarctic ice sheet has increased at a rate of 7 ± 0.13 Gt dec-1 since 1800 AD, representing a net reduction in sea level of ~ 0.02 mm dec-1 since 1800 and ~ 0.04 mm dec-1 since 1900 AD. The largest contribution is from the Antarctic Peninsula. Read more
Towards representing human behavior and decision making in Earth system models – an overview of techniques and approaches Earth System Dynamics DOI 10.5194/esd-8-977-2017 8 November 2017 Today, human interactions with the Earth system lead to complex feedbacks between social and ecological dynamics. Modeling such feedbacks explicitly in Earth system models (ESMs) requires making assumptions about individual decision making and behavior, social interaction, and their aggregation. In this overview paper, we compare different modeling approaches and techniques and highlight important consequences of modeling assumptions. We illustrate them with examples from land-use modeling. Read more
