Highlight articles

Analysis of in situ measurements of electron, ion and neutral temperatures in the lower thermosphere–ionosphere

The relation between electron, ion and neutral temperatures in the lower thermosphere–ionosphere (LTI) is key to understanding the energy balance and transfer between species. However, their simultaneous measurement is rare in the LTI. Based on data from the AE-C, AE-D, AE-E and DE-2 satellites of the 1970s and 1980s, a large number of events where neutrals are hotter than ions are identified and statistically analysed. Potential mechanisms that could trigger these events are proposed.

Calibration of groundwater seepage against the spatial distribution of the stream network to assess catchment-scale hydraulic properties

We propose a model calibration method constraining groundwater seepage in the hydrographic network. The method assesses the hydraulic properties of aquifers in regions where perennial streams are directly fed by groundwater. The estimated hydraulic conductivity appear to be highly sensitive to the spatial extent and density of streams. Such an approach improving subsurface characterization from surface information is particularly interesting for ungauged basins.

Opinion: Atmospheric multiphase chemistry – past, present, and future

With important climate and air quality impacts, atmospheric multiphase chemistry involves gas interactions with aerosol particles and cloud droplets. We summarize the status of the field and discuss potential directions for future growth. We highlight the importance of a molecular-level understanding of the chemistry, along with atmospheric field studies and modelling, and emphasize the necessity for atmospheric multiphase chemists to interact widely with scientists from neighbouring disciplines.

Atmospheric CO2 inversion reveals the Amazon as a minor carbon source caused by fire emissions, with forest uptake offsetting about half of these emissions

The Amazon’s carbon balance may have changed due to forest degradation, deforestation and warmer climate. We used an atmospheric model and atmospheric CO2 observations to quantify Amazonian carbon emissions (2010–2018). The region was a small carbon source to the atmosphere, mostly due to fire emissions. Forest uptake compensated for ~ 50 % of the fire emissions, meaning that the remaining forest is still a small carbon sink. We found no clear evidence of weakening carbon uptake over the period.

Brief communication: The Glacier Loss Day as an indicator of a record-breaking negative glacier mass balance in 2022

The Glacier Loss Day (GLD) is the day on which all mass gained from the accumulation period is lost, and the glacier loses mass irrecoverably for the rest of the mass balance year. In 2022, the GLD was already reached on 23 June at Hintereisferner (Austria), and this led to a record-breaking mass loss. We introduce the GLD as a gross yet expressive indicator of the glacier’s imbalance with a persistently warming climate.

A rise in HFC-23 emissions from eastern Asia since 2015

Based on atmospheric HFC-23 observations, the first estimate of post-CDM HFC-23 emissions in eastern Asia for 2008-2019 shows that these emissions contribute significantly to the global emissions rise. The observation-derived emissions were much larger than the bottom-up estimates expected to approach zero after 2015 due to national abatement activities. These discrepancies could be attributed to unsuccessful factory-level HFC-23 abatement and inaccurate quantification of emission reductions.

HFC-23 emissions from eastern Asia since 2015">Read more

Stagnant ice and age modelling in the Dome C region, Antarctica

We combined a numerical model with radar measurements in order to determine the age of ice in the Dome C region of Antarctica. Our results show that at the current ice core drilling sites on Little Dome C, the maximum age of the ice is almost 1.5 Ma. We also highlight a new potential drill site called North Patch with ice up to 2 Ma. Finally, we explore the nature of a stagnant ice layer at the base of the ice sheet which has been independently observed and modelled but is not well understood.

Widespread slowdown in thinning rates of West Antarctic ice shelves

We report on a slowdown in the rate of thinning and melting of West Antarctic ice shelves. We present a comprehensive assessment of the Antarctic ice shelves, where we analyse at a continental scale the changes in thickness, flow, and basal melt over the past 26 years. We also present a novel method to estimate ice shelf change from satellite altimetry and a time-dependent data set of ice shelf thickness and basal melt rates at an unprecedented resolution.

New ring shear deformation apparatus for three-dimensional multiphase experiments: first results

Geoscientific Instrumentation, Methods and Data Systems
DOI 10.5194/gi-12-141-2023
16 August 2023

Multiple geologic hazards, such as landslides and earthquakes, arise when solids and fluids coexist and deform together. We designed an experimental apparatus that allows us to observe such deformation in 3D. The first results show how fluids and solids deform and break at the same time, allowing us to study the impact of both materials on deformation distribution and speed. Making these processes visible has the potential to improve risk assessments associated with geological hazards.

Potential bioavailability of representative pyrogenic organic matter compounds in comparison to natural dissolved organic matter pools

Intensifying wildfires are increasing pyrogenic organic matter (PyOM) production and its impact on water quality. Recent work indicates that PyOM may have a greater impact on aquatic biogeochemistry than previously assumed, driven by higher bioavailability. We provide a full assessment of the potential bioavailability of PyOM across its chemical spectrum. We indicate that PyOM can be actively transformed within the river corridor and, therefore, may be a growing source of riverine C emissions.

News & press Highlight articles

Highlight articles

Information for

External links