N2O as a regression proxy for dynamical variability in stratospheric trace gas trends Atmospheric Chemistry and Physics DOI 10.5194/acp-23-13283-2023 27 October 2023 This paper presents a technique for understanding the causes of long-term changes in stratospheric composition. By using N2O as a proxy for stratospheric circulation in the model used to calculated trends, it is possible to separate the effects of dynamics and chemistry on observed trace gas trends. We find that observed HCl increases are due to changes in the stratospheric circulation, as are O3 decreases above 30 hPa in the Northern Hemisphere. Read more
Opinion: Recent developments and future directions in studying the mesosphere and lower thermosphere Atmospheric Chemistry and Physics DOI 10.5194/acp-23-13255-2023 25 October 2023 The mesosphere or lower thermosphere region of the atmosphere borders the edge of space. It is subject to extreme ultraviolet photons and charged particles from the Sun and atmospheric gravity waves from below, which tend to break in this region. The pressure is very low, which facilitates chemistry involving species in excited states, and this is also the region where cosmic dust ablates and injects various metals. The result is a unique and exotic chemistry. Read more
Mapping Antarctic crevasses and their evolution with deep learning applied to satellite radar imagery The Cryosphere DOI 10.5194/tc-17-4421-2023 23 October 2023 The presence of crevasses in Antarctica influences how the ice sheet behaves. It is important, therefore, to collect data on the spatial distribution of crevasses and how they are changing. We present a method of mapping crevasses from satellite radar imagery and apply it to 7.5 years of images, covering Antarctica’s floating and grounded ice. We develop a method of measuring change in the density of crevasses and quantify increased fracturing in important parts of the West Antarctic Ice Sheet. Read more
ESD Ideas: Translating historical extreme weather events into a warmer world Earth System Dynamics DOI 10.5194/esd-14-1081-2023 20 October 2023 Adapting to climate change requires an understanding of how extreme weather events are changing. We propose a new approach to examine how the consequences of a particular weather pattern have been made worse by climate change, using an example of a severe windstorm that occurred in 1903. When this storm is translated into a warmer world, it produces higher wind speeds and increased rainfall, suggesting that this storm would be more damaging if it occurred today rather than 120 years ago. Read more
Global observations of aerosol indirect effects from marine liquid clouds Atmospheric Chemistry and Physics DOI 10.5194/acp-23-13125-2023 18 October 2023 Interactions between aerosol pollution and liquid clouds are one of the largest sources of uncertainty in the effective radiative forcing of climate over the industrial era. We use global satellite observations to decompose the forcing into components from changes in cloud-droplet number concentration, cloud water content, and cloud amount. Our results reduce uncertainty in these forcing components and clarify their relative importance. Read more
Technical note: NASAaccess – a tool for access, reformatting, and visualization of remotely sensed earth observation and climate data Hydrology and Earth System Sciences DOI 10.5194/hess-27-3621-2023 16 October 2023 We present an open-source platform in response to the NASA Open-Source Science Initiative for accessing and presenting quantitative remote-sensing earth observation,and climate data. With our platform scientists, stakeholders and concerned citizens can engage in the exploration, modelling, and understanding of data. We envisioned this platform as lowering the technical barriers and simplifying the process of accessing and leveraging additional modelling frameworks for data. Read more
The dehydration carousel of stratospheric water vapor in the Asian summer monsoon anticyclone Atmospheric Chemistry and Physics DOI 10.5194/acp-23-12935-2023 13 October 2023 We studied water vapour in a critical region of the atmosphere, the Asian summer monsoon anticyclone, using rare in situ observations. Our study shows that extremely high water vapour values observed in the stratosphere within the Asian monsoon anticyclone still undergo significant freeze-drying and that water vapour concentrations set by the Lagrangian dry point are a better proxy for the stratospheric water vapour budget than rare observations of enhanced water mixing ratios. Read more
Late Cenozoic sea-surface-temperature evolution of the South Atlantic Ocean Climate of the Past DOI 10.5194/cp-19-1931-2023 11 October 2023 We present two new sea surface temperature (SST) records in comparison with available SST records to reconstruct South Atlantic paleoceanographic evolution. Our results show a low SST gradient in the Eocene–early Oligocene due to the persistent gyral circulation. A higher SST gradient in the Middle–Late Miocene infers a stronger circumpolar current. The southern South Atlantic was the coldest region in the Southern Ocean and likely the main deep-water formation location in the Middle Miocene. Read more
Soil-biodegradable plastic films do not decompose in a lake sediment over 9 months of incubation Biogeosciences DOI 10.5194/bg-20-4213-2023 9 October 2023 Agriculture relies heavily on plastic mulch films, which may be transported to aquatic environments. We investigated the breakdown of soil-biodegradable agricultural mulch films in lake sediments. After 40 weeks, films were intact, and no significant CO2 or CH4 was produced from the biodegradable mulch films. We conclude that the mulch films we used have a low biodegradability in lake sediments. The sediment lacks the microbes needed to break down the biodegradable plastics that were used here. Read more
Linear polarization signatures of atmospheric dust with the SolPol direct-sun polarimeter Atmospheric Measurement Techniques DOI 10.5194/amt-16-4529-2023 6 October 2023 Atmospheric dust particles may present a preferential alignment due to their shape on long range transport. Since dust is abundant and plays a key role to global climate, the elusive observation of orientation will be a game changer to existing measurement techniques and the representation of particles in climate models. We utilize a specifically designed instrument, SolPol, and target the Sun from the ground for large polarization values under dusty conditions, a clear sign of orientation. Read more