Coastal impacts of Storm Gloria (January 2020) over the north-western Mediterranean Natural Hazards and Earth System Sciences DOI 10.5194/nhess-20-1955-2020 28 July 2020 Storm Gloria hit the Mediterranean Spanish coastlines between 20 and 23 January 2020, causing severe damages such as flooding of the Ebro River delta. We evaluate its coastal impacts with a numerical simulation of the wind waves and the accumulated ocean water along the coastline (storm surge). The storm surge that reached values up to 1 m was mainly driven by the wind that also generated wind waves up to 8 m in height. We also determine the extent of the Ebro Delta flooded by marine water. Read more
Mātauranga Māori in geomorphology: existing frameworks, case studies, and recommendations for incorporating Indigenous knowledge in Earth science Earth Surface Dynamics DOI 10.5194/esurf-8-595-2020 28 July 2020 This review highlights potential contributions that Indigenous knowledge can make to geomorphic research. We evaluate several frameworks and models for including Indigenous knowledge in geomorphic research and discuss how they can be adapted for use with Indigenous communities across the world. We propose that weaving Indigenous knowledge with geomorphic science has the potential to create new solutions and understandings that neither body of knowledge could produce in isolation. Read more
Smoke of extreme Australian bushfires observed in the stratosphere over Punta Arenas, Chile, in January 2020: optical thickness, lidar ratios, and depolarization ratios at 355 and 532 nm Atmospheric Chemistry and Physics DOI 10.5194/acp-20-8003-2020 23 July 2020 Unique lidar observations of a strong perturbation in stratospheric aerosol conditions in the Southern Hemisphere caused by the extreme Australian bushfires in 2019–2020 are presented. One of the main goals of this article is to provide the CALIPSO and Aeolus spaceborne lidar science teams with basic input parameters (lidar ratios, depolarization ratios) for a trustworthy documentation of this record-breaking event. Read more
Why does a conceptual hydrological model fail to correctly predict discharge changes in response to climate change? Hydrology and Earth System Sciences DOI 10.5194/hess-24-3493-2020 23 July 2020 We investigate why a conceptual hydrological model failed to correctly predict observed discharge changes in response to increasing precipitation and air temperature in 156 Austrian catchments. Simulations indicate that poor model performance is related to two problems, namely a model structure that neglects changes in vegetation dynamics and inhomogeneities in precipitation data caused by changes in stations density with time. Other hypotheses did not improve simulated discharge changes. Read more
On giant shoulders: how a seamount affects the microbial communitycomposition of seawater and sponges Biogeosciences DOI 10.5194/bg-17-3471-2020 21 July 2020 Seamounts are globally abundant submarine structures that offer great potential to study the impacts and interactions of environmental gradients at a single geographic location. In an exemplary way, we describe potential mechanisms by which a seamount can affect the structure of pelagic and benthic (sponge-)associated microbial communities. We conclude that the geology, physical oceanography, biogeochemistry, and microbiology of seamounts are even more closely linked than currently appreciated. Read more
N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions Biogeosciences DOI 10.5194/bg-17-3511-2020 21 July 2020 Results of the first globally resolved simulations of terrestrial carbon and nitrogen (N) cycling and N 2 O emissions over the past 21 000 years are compared with reconstructed N 2 O emissions. Modelled and reconstructed emissions increased strongly during past abrupt warming events. This evidence appears consistent with a dynamic response of biological N fixation to increasing N demand by ecosystems, thereby reducing N limitation of plant productivity and supporting a land sink for atmospheric CO 2 . Read more
The MOSAiC ice floe: sediment-laden survivor from the Siberian shelf The Cryosphere DOI 10.5194/tc-14-2173-2020 16 July 2020 In October 2019 the research vessel Polarstern was moored to an ice floe in order to travel with it on the 1-year-long MOSAiC journey through the Arctic. Here we provide historical context of the floe’s evolution and initial state for upcoming studies. We show that the ice encountered on site was exceptionally thin and was formed on the shallow Siberian shelf. The analyses presented provide the initial state for the analysis and interpretation of upcoming biogeochemical and ecological studies. Read more
The enigmatic curvature of Central Iberia and its puzzling kinematics Solid Earth DOI 10.5194/se-11-1247-2020 16 July 2020 Pangea was assembled during Devonian to early Permian times and resulted in a large-scale and winding orogeny that today transects Europe, northwestern Africa, and eastern North America. This orogen is characterized by an S shape corrugated geometry in Iberia. This paper presents the advances and milestones in our understanding of the geometry and kinematics of the Central Iberian curve from the last decade with particular attention paid to structural and paleomagnetic studies. Read more
Landfast sea ice material properties derived from ice bridge simulations using the Maxwell elasto-brittle rheology The Cryosphere DOI 10.5194/tc-14-2137-2020 14 July 2020 We study the formation of ice arches between two islands using a model that resolves crack initiation and propagation. This model uses a damage parameter to parameterize the presence or absence of cracks in the ice. We find that the damage parameter allows for cracks to propagate in the ice but in a different orientation than predicted by theory. The results call for improvement in how stress relaxation associated with this damage is parameterized. Read more
Twenty-first century ocean warming, acidification, deoxygenation, and upper-ocean nutrient and primary production decline from CMIP6 model projections Biogeosciences DOI 10.5194/bg-17-3439-2020 14 July 2020 We assess 21st century projections of marine biogeochemistry in the CMIP6 Earth system models. These models represent the most up-to-date understanding of climate change. The models generally project greater surface ocean warming, acidification, subsurface deoxygenation, and euphotic nitrate reductions but lesser primary production declines than the previous generation of models. This has major implications for the impact of anthropogenic climate change on marine ecosystems. Read more
