Climate sensitivity estimates – sensitivity to radiative forcing time series and observational data Earth System Dynamics DOI 10.5194/esd-9-879-2018 21 June 2018 A key question in climate science is how the global mean surface temperature responds to changes in greenhouse gases. This dependency is quantified by the climate sensitivity, which is determined by the complex feedbacks in the climate system. In this study observations of past climate change are used to estimate this sensitivity. Our estimate is consistent with values for the equilibrium climate sensitivity estimated by complex climate models but sensitive to the use of uncertain input data. Read more
The seismogenic fault system of the 2017 Mw 7.3 Iran–Iraq earthquake: constraints from surface and subsurface data, cross-section balancing, and restoration Solid Earth DOI 10.5194/se-9-821-2018 20 June 2018 A balanced cross section across the hypocentre of the 2017 Iran–Iraq Mw7.3 earthquake is presented. The structural style of the area is characterised by inversion tectonics with partial decoupling between the basement and the 10 km thick sedimentary cover. The main shock is located along a low-dipping lateral ramp of the Mountain Front Fault. The balanced cross section indicates that the Mountain Front Fault is the only fault where an Mw7.3 earthquake may occur. Read more
Reviews and syntheses: Carbonyl sulfide as a multi-scale tracer for carbon and water cycles Biogeosciences DOI 10.5194/bg-15-3625-2018 18 June 2018 Measurements of the trace gas carbonyl sulfide (OCS) are helpful in quantifying photosynthesis at previously unknowable temporal and spatial scales. While CO2 is both consumed and produced within ecosystems, OCS is mostly produced in the oceans or from specific industries, and destroyed in plant leaves in proportion to CO2. This review summarizes the advancements we have made in the understanding of OCS exchange and applications to vital ecosystem water and carbon cycle questions. Read more
Field-warmed soil carbon changes imply high 21st-century modeling uncertainty Biogeosciences DOI 10.5194/bg-15-3659-2018 18 June 2018 The temperature sensitivity of soil carbon loss is a critical parameter for projecting future CO2. Isolating soil temperature response in the field is challenging due to difficulties isolating root and microbial respiration. We use a database of direct-warming soil carbon changes to generate a new global temperature sensitivity. Incorporating this into Earth system models reduces projected soil carbon. But it also shows that variation due to this parameter is as high as all other causes. Read more
Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations Atmospheric Chemistry and Physics DOI 10.5194/acp-18-8409-2018 15 June 2018 We analyse simulations from the Chemistry-Climate Model Initiative (CCMI) to estimate the return dates of the stratospheric ozone layer from depletion by anthropogenic chlorine and bromine. The simulations from 20 models project that global column ozone will return to 1980 values in 2047 (uncertainty range 2042–2052). Return dates in other regions vary depending on factors related to climate change and importance of chlorine and bromine. Column ozone in the tropics may continue to decline. Read more
On the social dynamics of moisture recycling Earth System Dynamics DOI 10.5194/esd-9-829-2018 14 June 2018 Moisture recycling is the atmospheric branch of the water cycle, including evaporation and precipitation. While the physical water cycle is well-understood, the social links among the recipients of precipitation back to the sources of evaporation are not. In this work, we develop a method to determine how these social connections unfold, using a mix of quantitative and qualitative methods, finding that there are distinct types of social connections with corresponding policy and management tools. Read more
Hazards of decreasing marine oxygen: the near-term and millennial-scale benefits of meeting the Paris climate targets Earth System Dynamics DOI 10.5194/esd-9-797-2018 13 June 2018 Human-caused, climate change hazards in the ocean continue to aggravate over a very long time. For business as usual, we project the ocean oxygen content to decrease by 40 % over the next thousand years. This would likely have severe consequences for marine life. Global warming and oxygen loss are linked, and meeting the warming target of the Paris Climate Agreement effectively limits related marine hazards. Developments over many thousands of years should be considered to assess marine risks. Read more
Surface impacts of the Quasi Biennial Oscillation Atmospheric Chemistry and Physics DOI 10.5194/acp-18-8227-2018 13 June 2018 A major phenomenon in the stratosphere is the Quasi Biennial Oscillation (QBO). Although a feature of the equatorial stratosphere, its influence extends to surface weather at both equatorial and mid latitudes. Improved knowledge of mechanisms of influence should help to improve weather forecasts. In this paper, QBO impacts at the surface are characterized and dominant mechanisms explored. Three pathways are identified, referred to as the tropical, subtropical and polar routes. Read more
On the Holocene evolution of the Ayeyawady megadelta Earth Surface Dynamics DOI 10.5194/esurf-6-451-2018 12 June 2018 Here we provide the first results on the evolution of the Ayeyarwady delta, the last unstudied megadelta of Asia. In addition to its intrinsic value as a founding study on the Holocene development of this region, we advance new ideas on the climate control of monsoonal deltas as well as describe for the first time a feedback mechanism between tectonics and tidal hydrodynamics that can explain the peculiarities of the Ayeyarwady delta. Read more
Airborne wind lidar observations over the North Atlantic in 2016 for the pre-launch validation of the satellite mission Aeolus Atmospheric Measurement Techniques DOI 10.5194/amt-11-3297-2018 11 June 2018 This work reports airborne wind lidar observations performed in a recent field campaign. The deployed lidar system serves as a demonstrator for the satellite instrument ALADIN on board Aeolus, which is scheduled for launch in 2018 and will become the first wind lidar in space. After presenting the measurement principle, operation procedures and wind retrieval algorithm, the obtained wind results are validated and discussed, providing valuable information in preparation for the satellite mission. Read more