Product distribution, kinetics, and aerosol formation from the OH oxidation of dimethyl sulfide under different RO2 regimes Atmospheric Chemistry and Physics DOI 10.5194/acp-22-16003-2022 20 February 2023 The atmospheric oxidation of dimethyl sulfide (DMS) is a major natural source of sulfate particles in the atmosphere. However, its mechanism is poorly constrained. In our work, laboratory measurements and mechanistic modelling were conducted to comprehensively investigate DMS oxidation products and key reaction rates. We find that the peroxy radical (RO2) has a controlling effect on product distribution and aerosol yield, with the isomerization of RO2 leading to the suppression of aerosol yield. Read more
Quantification of blue carbon in salt marshes of the Pacific coast of Canada Biogeosciences DOI 10.5194/bg-19-5751-2022 17 February 2023 Salt marshes are thought to be important carbon sinks because of their ability to store carbon in their soils. We provide the first estimates of how much blue carbon is stored in salt marshes on the Pacific coast of Canada. We find that the carbon stored in the marshes is low compared to other marshes around the world, likely because of their young age. Still, the high marshes take up carbon at rates faster than the global average, making them potentially important carbon sinks in the future. Read more
Reconstructing Holocene temperatures in time and space using paleoclimate data assimilation Climate of the Past DOI 10.5194/cp-18-2599-2022 15 February 2023 To look at climate over the past 12 000 years, we reconstruct spatial temperature using natural climate archives and information from model simulations. Our results show mild global mean warmth around 6000 years ago, which differs somewhat from past reconstructions. Undiagnosed seasonal biases in the data could explain some of the observed temperature change, but this still would not explain the large difference between many reconstructions and climate models over this period. Read more
Solar wind magnetic holes can cross the bow shock and enter the magnetosheath Annales Geophysicae DOI 10.5194/angeo-40-687-2022 13 February 2023 Magnetic holes are curious localized dropouts of magnetic field strength in the solar wind (the flow of ionized gas continuously streaming out from the sun). In this paper we show that these magnetic holes can cross the bow shock (where the solar wind brake down to subsonic velocity) and enter the region close to Earth’s magnetosphere. These structures may therefore represent a new type of non-uniform solar wind–magnetosphere interaction. Read more
Rapid attribution analysis of the extraordinary heat wave on the Pacific coast of the US and Canada in June 2021 Earth System Dynamics DOI 10.5194/esd-13-1689-2022 10 February 2023 In June 2021, the Pacific Northwest of the US and Canada saw record temperatures far exceeding those previously observed. This attribution study found such a severe heat wave would have been virtually impossible without human-induced climate change. Assuming no nonlinear interactions, such events have become at least 150 times more common, are about 2 ℃ hotter and will become even more common as warming continues. Therefore, adaptation and mitigation are urgently needed to prepare society. Read more
Validation of the Aeolus L2B wind product with airborne wind lidar measurements in the polar North Atlantic region and in the tropics Atmospheric Measurement Techniques DOI 10.5194/amt-15-7049-2022 8 February 2023 In August 2018, the first wind lidar Aeolus was launched into space and has since then been providing data of the global wind field. The primary goal of Aeolus was the improvement of numerical weather prediction. To verify the quality of Aeolus wind data, DLR performed four airborne validation campaigns with two wind lidar systems. In this paper, we report on results from the two later campaigns, performed in Iceland and the tropics. Read more
Estimating emissions of methane consistent with atmospheric measurements of methane and δ13C of methane Atmospheric Chemistry and Physics DOI 10.5194/acp-22-15351-2022 6 February 2023 Atmospheric methane (CH4) has been growing steadily since 2007 for reasons that are not well understood. Here we determine sources of methane using a technique informed by atmospheric measurements of CH₄ and its isotopologue 13CH4. Measurements of 13CH4 provide for better separation of microbial, fossil, and fire sources of methane than CH4 measurements alone. Compared to previous assessments such as the Global Carbon Project, we find a larger microbial contribution to the post-2007 increase. Read more
Size, shape and orientation matter: fast and semi-automatic measurement of grain geometries from 3D point clouds Earth Surface Dynamics DOI 10.5194/esurf-10-1211-2022 3 February 2023 The morphology and size of sediments influence erosion efficiency, sediment transport and the quality of aquatic ecosystem. In turn, the spatial evolution of sediment size provides information on the past dynamics of erosion and sediment transport. We have developed a new software which semi-automatically identifies and measures sediments based on 3D point clouds. This software is fast and efficient, offering a new avenue to measure the geometrical properties of large numbers of sediment grains. Read more
Evidence of localised Amazon rainforest dieback in CMIP6 models Earth System Dynamics DOI 10.5194/esd-13-1667-2022 1 February 2023 Despite little evidence of regional Amazon rainforest dieback, many localised abrupt dieback events are observed in the latest state-of-the-art global climate models under anthropogenic climate change. The detected dieback events would still cause severe consequences for local communities and ecosystems. This study suggests that 7±5 % of the northern South America region would experience abrupt downward shifts in vegetation carbon for every degree of global warming past 1.5 °C. Read more
The evolution and dynamics of the Hunga Tonga–Hunga Ha’apai sulfate aerosol plume in the stratosphere Atmospheric Chemistry and Physics DOI 10.5194/acp-22-14957-2022 30 January 2023 The long-duration atmospheric impact of the Tonga eruption in January 2022 is a plume of water and sulfate aerosols in the stratosphere that persisted for more than 6 months. We study this evolution using several satellite instruments and analyse the unusual behaviour of this plume as sulfates and water first moved down rapidly and then separated into two layers. We also report the self-organization in compact and long-lived patches. Read more