Detection of large-scale cloud microphysical changes within a major shipping corridor after implementation of the International Maritime Organization 2020 fuel sulfur regulations Atmospheric Chemistry and Physics DOI 10.5194/acp-23-8259-2023 2 August 2023 Fuel sulfur regulations were implemented for ships in 2020 to improve air quality but may also accelerate global warming. We use spatial statistics and satellite retrievals to detect changes in the size of cloud droplets and find evidence for a resulting decrease in cloud brightness within a major shipping corridor after the sulfur limits went into effect. Our results confirm both that the regulations are being followed and that they are having a warming influence via their effect on clouds. Read more
Design and performance of the Hotrod melt-tip ice-drilling system Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-12-121-2023 31 July 2023 We describe a new drill for glaciers and ice sheets. Instead of drilling down into the ice, via mechanical action, our drill melts into the ice. Our goal is simply to pull a cable of temperature sensors on a one-way trip down to the ice–bed interface. Here, we describe the design and testing of our drill. Under laboratory conditions, our melt-tip drill has an efficiency of ~35 % with a theoretical maximum penetration rate of ~12 m h^-1. Under field conditions, our efficiency is just ~15 %. Read more
Continuous weekly monitoring of methane emissions from the Permian Basin by inversion of TROPOMI satellite observations Atmospheric Chemistry and Physics DOI 10.5194/acp-23-7503-2023 28 July 2023 We use TROPOMI satellite observations to quantify weekly methane emissions from the US Permian oil and gas basin from May 2018 to October 2020. We find that Permian emissions are highly variable, with diverse economic and activity drivers. The most important drivers during our study period were new well development and natural gas price. Permian methane intensity averaged 4.6% and decreased by 1% per year. TROPOMI satellite observations">Read more
Brief communication: How deep is the snow on Mount Everest? The Cryosphere DOI 10.5194/tc-17-2625-2023 26 July 2023 There is very strong scientific and public interest regarding the snow thickness on Mountain Everest. Previously reported snow depths derived by different methods and instruments ranged from 0.92 to 3.5 m. Our measurements in 2022 provide the first clear radar image of the snowpack at the top of Mount Everest. The snow thickness at Earth’s summit was averaged to be 9.5 ± 1.2 m. This updated snow thickness is considerably deeper than values reported during the past 5 decades. Read more
All about nitrite: exploring nitrite sources and sinks in the eastern tropical North Pacific oxygen minimum zone Biogeosciences DOI 10.5194/bg-20-2499-2023 24 July 2023 Nitrogen (N) is essential for life; thus, its availability plays a key role in determining marine productivity. Using incubations of seawater spiked with a rare form of N measurable on a mass spectrometer, we quantified microbial pathways that determine marine N availability. The results show that pathways that recycle N have higher rates than those that result in its loss from biomass and present new evidence for anaerobic nitrite oxidation, a process long thought to be strictly aerobic. Read more
Review article: Large fluctuations in non-equilibrium physics Nonlinear Processes in Geophysics DOI 10.5194/npg-30-253-2023 21 July 2023 Non-equilibrium is dominant in geophysical and climate phenomena. Most of the processes that characterize energy flow occur far from equilibrium. These range from very large systems, such as weather patterns or ocean currents that remain far from equilibrium, owing to an influx of energy, to biological structures. In the last decades, progress in non-equilibrium physics has come from the study of very rare fluctuations, and this paper provides an introduction to these theoretical developments. Read more
Dense water formation in the eastern Mediterranean under a global warming scenario Ocean Science DOI 10.5194/os-19-941-2023 19 July 2023 Global warming may strongly affect dense water formation in the eastern Mediterranean, potentially impacting basin circulation and water properties. We find that at the end of the century dense water formation is reduced by 75 % for the Adriatic, 84 % for the Aegean, and 83 % for the Levantine Sea. This reduction is caused by changes in the temperature and salinity of surface and intermediate waters, which strengthen the vertical stratification, hampering deep convection. Read more
Brief communication: Rapid ∼ 335 × 106 m3 bed erosion after detachment of the Sedongpu Glacier (Tibet) The Cryosphere DOI 10.5194/tc-17-2533-2023 17 July 2023 Following the detachment of the 130 × 10^6 m^3 Sedongpu Glacier (south-eastern Tibet) in 2018, the Sedongpu Valley underwent massive large-volume landscape changes. An enormous volume of in total around 330 × 10^6 m^3 was rapidly eroded, forming a new canyon of up to 300 m depth, 1 km width, and almost 4 km length. Such consequences of glacier change in mountains have so far not been considered at this magnitude and speed. Read more
Impact of deoxygenation and warming on global marine species in the 21st century Biogeosciences DOI 10.5194/bg-20-2425-2023 14 July 2023 Ocean temperature and oxygen shape marine habitats together with species’ characteristics. We calculated the impacts of projected 21st-century warming and oxygen loss on the contemporary habitat volume of 47 marine species and described the drivers of these impacts. Most species lose less than 5 % of their habitat at 2 ◦C of global warming, but some species incur losses 2–3 times greater than that. We also calculate which species may be most vulnerable to climate change and why this is the case. Read more
Impact of a strong volcanic eruption on the summer middle atmosphere in UA-ICON simulations Atmospheric Chemistry and Physics DOI 10.5194/acp-23-7001-2023 12 July 2023 Strong volcanic eruptions are able to alter the temperature and the circulation of the middle atmosphere. This study simulates the atmospheric response to an idealized strong tropical eruption and focuses on the impact on the mesosphere. The simulations show a warming of the polar summer mesopause in the first November after the eruption. Our study indicates that this is mainly due to dynamical coupling in the summer hemisphere with a potential contribution from interhemispheric coupling. ICON simulations">Read more
