A perspective on the next generation of Earth system model scenarios: towards representative emission pathways (REPs) Geoscientific Model Development DOI 10.5194/gmd-17-4533-2024 24 June 2024 The scientific community is considering new scenarios to succeed RCPs and SSPs for the next generation of Earth system model runs to project future climate change. To contribute to that effort, we reflect on relevant policy and scientific research questions and suggest categories for representative emission pathways. These categories are tailored to the Paris Agreement long-term temperature goal, high-risk outcomes in the absence of further climate policy and worlds “that could have been”. Read more
Opinion: Strengthening research in the Global South – atmospheric science opportunities in South America and Africa Atmospheric Chemistry and Physics DOI 10.5194/acp-24-5757-2024 21 June 2024 To tackle the current pressing atmospheric science issues, as well as those in the future, a robust scientific community is necessary in all regions across the globe. Unfortunately, this does not yet exist. There are many geographical areas that are still underrepresented in the atmospheric science community, many of which are in the Global South. There are also larger gaps in the understanding of atmospheric composition, processes, and impacts in these regions. In this opinion, we focus on two geographical areas in the Global South to discuss some common challenges and constraints, with a focus on our strengths in atmospheric science research. It is these strengths, we believe, that highlight the critical role of Global South researchers in the future of atmospheric science research. Read more
Applying global warming levels of emergence to highlight the increasing population exposure to temperature and precipitation extremes Earth System Dynamics DOI 10.5194/esd-15-589-2024 19 June 2024 Using a special suite of climate simulations, we determine if and when climate change is detectable and translate this to the global warming prevalent in the corresponding year. Our results show that, at 1.5°C warming, >85 % of the global population (>95 % at 2.0° warming) is already exposed to nighttime temperatures altered by climate change beyond natural variability. Furthermore, even incremental changes in global warming levels result in increased human exposure to emerged climate signals. Read more
Synergistic approach of frozen hydrometeor retrievals: considerations on radiative transfer and model uncertainties in a simulated framework Atmospheric Measurement Techniques DOI 10.5194/amt-17-3567-2024 17 June 2024 In cloudy situations, infrared and microwave observations are complementary, with infrared being sensitive to cloud tops and microwave sensitive to precipitation. However, infrared satellite observations are underused. This study aims to quantify if the inconsistencies in the modelling of clouds prevent the use of cloudy infrared observations in the process of weather forecasting. It shows that the synergistic use of infrared and microwave observations is beneficial, despite inconsistencies. Read more
On the importance of middle-atmosphere observations on ionospheric dynamics using WACCM-X and SAMI3 Annales Geophysicae DOI 10.5194/angeo-42-255-2024 14 June 2024 This study shows how middle-atmospheric data (starting at 40 km) affect day-to-day ionospheric variability. We do this by using lower atmospheric measurements that include and exclude the middle atmosphere in a coupled ionosphere–thermosphere model. Comparing the two simulations reveals differences in two thermosphere–ionosphere coupling mechanisms. Additionally, comparison against observations showed that including the middle-atmospheric data improved the resulting ionosphere. Read more
The effect of temperature on photosystem II efficiency across plant functional types and climate Biogeosciences DOI 10.5194/bg-21-2731-2024 12 June 2024 A first-of-its-kind global-scale model of temperature resilience and tolerance of photosystem II maximum quantum yield informs how plants maintain their efficiency of converting light energy to chemical energy for photosynthesis under temperature changes. Our finding explores this variation across plant functional types and habitat climatology, highlighting diverse temperature response strategies and a method to improve global-scale photosynthesis modeling under climate change. Read more
Geomorphic risk maps for river migration using probabilistic modeling – a framework Earth Surface Dynamics DOI 10.5194/esurf-12-691-2024 10 June 2024 In this paper, we propose a framework for generating risk maps that provide the probabilities of erosion due to river migration. This framework uses concepts from probability theory to learn the river migration model’s parameter values from satellite data while taking into account parameter uncertainty. Our analysis shows that such geomorphic risk estimation is more reliable than models that do not explicitly consider various sources of variability and uncertainty. Read more
Opinion: A research roadmap for exploring atmospheric methane removal via iron salt aerosol Atmospheric Chemistry and Physics DOI 10.5194/acp-24-5659-2024 7 June 2024 Rapid reduction in atmospheric methane is needed to slow the rate of global warming. Reducing anthropogenic methane emissions is a top priority. However, atmospheric methane is also impacted by rising natural emissions and changing sinks. Studies of possible atmospheric methane removal approaches, such as iron salt aerosols to increase the chlorine radical sink, benefit from a roadmapped approach to understand if there may be viable and socially acceptable ways to decrease future risk. Read more
Does high-latitude ionospheric electrodynamics exhibit hemispheric mirror symmetry? Annales Geophysicae DOI 10.5194/angeo-42-229-2024 5 June 2024 In studies of the Earth’s ionosphere, a hot topic is how to estimate ionospheric conductivity. This is hard to do for a variety of reasons that mostly amount to a lack of measurements. In this study we use satellite measurements to estimate electromagnetic work and ionospheric conductances in both hemispheres. We identify where our model estimates are inconsistent with laws of physics, which partially solves a previous problem with unrealistic predictions of ionospheric conductances. Read more
Extensive coverage of ultrathin tropical tropopause layer cirrus clouds revealed by balloon-borne lidar observations Atmospheric Chemistry and Physics DOI 10.5194/acp-24-5935-2024 3 June 2024 Upper tropical clouds have a strong impact on Earth’s climate but are challenging to observe. We report the first long-duration observations of tropical clouds from lidars flying on board stratospheric balloons. Comparisons with spaceborne observations reveal the enhanced sensitivity of balloon-borne lidar to optically thin cirrus. These clouds, which have a significant coverage and lie in the uppermost troposphere, are linked with the dehydration of air masses on their way to the stratosphere. Read more