bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences in physical drivers of diurnal and nocturnal summer heat waves
Authors: Muntjewerf Laura , Rothengatter Siem , Bintanja Richard , Van der Wiel Karin
Published: February 2023

Heat waves place a large burden on society. There are differences in the societal impact between diurnal heatwaves and nocturnal heatwaves. The latter in particular places stress on humans and animals, where exceeding the thermal comfort level may lead to heat-related deaths. Climate change affects not just the mean temperature, but also occurrences of exceptional warmth. We postulate that climate change has a different effect on the occurrence of diurnal and nocturnal heatwaves.Heat waves are extreme events that, by definition, don’t occur frequently. To study extreme events and to be able to robustly do statistical analyses, we use the large ensemble KNMI-LENTIS. This way, we don’t have to rely on statistical interpolation to have enough events to study. KNMI-LENTIS is a time-slice large ensemble generated with the global climate model EC-Earth3. It consists of 2 time slices: the present-day climate and a future climate that is +2K warmer than the present-day. Each time slice consists of 1600 years.We investigate the formation and ending of different types of summer heat waves in north-western Europe. Making the distinction between nocturnal, diurnal and compound heat waves allows us to disentangle the physical processes that drive the different types. Particularly we focus on advection and large-scale processes on the one hand, and local processes based on land-atmosphere coupling feedback mechanisms on the other hand.  
Analysis of rainfall generation process in east Asia by Summer Cold Wave
Authors: Han Kwang-Hee , Ku Ho-Young , Jeong Jee-Hoon , Kim Baek-Min
Published: February 2023

In August 2022, extremely heavy rainfall occurred in the central region of the Korean Peninsula. On August 8, Seoul received 381.5 mm of rain, the most in 115 years. Heavy rain is a phenomenon that accounts for the most significant portion of dangerous weather occurring in Korea, and many studies, including the mechanism of occurrence, have been done on this phenomenon. However, the synoptic pressure pattern that caused heavy rain in August 2022 differed from the rainfall pattern studied in general. The pressure system around the Korean Peninsula also showed a different pattern from the typical summer pressure characteristics. As a result, by reviewing the pressure system specificity of the Korean Peninsula and the Eurasian continent, this study investigated the mechanism and climatological factors of heavy rain in August 2022. In August 2022, strong high pressure developed over the Eurasian continent, the Kamchatka Peninsula, and the Ural Mountains. On August 8, a stationary front crossing the Korean Peninsula from east to west was located. To determine the specificity of the barometric pressure system, the air temperature and barometer of the ground and upper layers were analyzed using ECMWF's ERA-5 reanalysis data. At the surface level, high pressure intensified near the Ural Mountains and Lake Baikal in Siberia in early August. In the case of temperature, the advection of cold air below a -5°C anomaly from high latitudes to the northwest of the Korean Peninsula through Siberia following the flow of lower high pressure is analyzed. At 500 hPa, upper-level blocking was observed in the Ural Mountains and the Kamchatka Peninsula. The blocking over the Eurasian continent reduced zonal flow while increasing meridional flow. Cold air from the high latitudes was transported to East Asia by the increased meridional flow. The cold air that moved toward East Asia met the edge of the North Pacific high pressure and formed a stationary front, causing heavy rain. In this study, the development of a cold continental high pressure in summer affecting the mid-latitude region was defined as the "Summer Cold Wave" (SCW), and the development of the front by the SCW was defined as the "Summer Cold Front" (SCF). In addition, by analyzing cases where SCW occurred in the past, it was determined that the development of Ural blocking in summer influenced the occurrence of SCW, and it was determined that precipitation due to SCF increased in the Korean Peninsula when the North Pacific high pressure occurred strongly.
Ocean remote sensing from meteorological satellites at OSI SAF
Authors: Membrive Olivier , Hernandez Cécile , Roquet Hervé , Saux-Picart Stéphane , Eastwood Steinar , Stoffelen Ad , Verhoef Anton , Howe Eva , Piolle Jean-François
Published: February 2023

The OSI SAF (Ocean and Sea Ice Satellite Application Facility) is a dedicated EUMETSAT centre for processing satellite data at the ocean-atmosphere interface. It’s a consortium constituted of Météo-France, as a leading institute, and four cooperating institutes: MET Norway, DMI (Denmark), Ifremer (France), KNMI (Netherlands). Utilizing specialist expertise the consortium processes and distributes near real-time products related to key parameters of the ocean-atmosphere interface as well as climate data records of these parameters. Main products are: Winds, Sea and Ice Surface Temperature (SST/IST) and Sea Ice Parameters at both poles: Concentration, Edge, Type, Emissivity and Drift.The applications of products are numerous. The most general ones are the assimilation into models, the validation of models, oceanography, research and environmental monitoring. The presentation will showcase OSI SAF ocean remote sensing products from meteorological satellites both from the polar and geostationary orbit.  The presentation will focus on the latest developments.In the next few years, existing Sea Ice, Wind and SST Climate Data records will be improved and extended. It will also be the occasion to discuss the expectations of international colleagues and to describe the plans to exploit the capabilities offered by the future MTG and Metop-SG satellites. 
A first look at the new PolarRES ensemble of polar regional climate model storylines to 2
Authors: Mottram Ruth , Mooney Priscilla , Torres Jose Abraham ,   PolarRES Consortium
Published: February 2023

The Horizon 2020 project PolarRES is coordinating a large international consortium of regional climate modelling groups in building a new ensemble of regional climate projections out to 2100. The ensemble is built at very high resolution (~12km) and using common domains, and set-ups to give directly comparable model outputs. At the same time, all regional climate models have been upgraded to a next-generation set-up, producing an ensemble of unprecedented sophistication.We use a storyline approach, focused on Arctic amplification and cyclones in the northern hemisphere and Southern Annular Mode variability in Antarctica, to select global climate models for forcing on the boundaries. Each regional climate modelling group will downscale ERA5 and multiple global climate models. The data produced from these simulations will be used to improve process understanding under present and future conditions as well as to identify impacts of climate change in the polar regions.Here, we present the experimental protocol developed in PolarRES and give details of the different regional climate models used, their setup, processes and domains as well as an overview of the outputs and planned applications. We show preliminary analysis of hindcast outputs to assess the performance of the ensemble. We invite other regional climate modelling groups outside the PolarRES consortium to consider using the same CORDEX -compatible model set-up and we are happy to receive suggestions of further spin-off studies or requests for collaboration. 
4D paleomagnetic and rock magnetic properties of the 2021 and 2022 Fagradalsfjall eruption products, Iceland
Authors: Piispa Elisa , Marshall Edward , Mandon Celine
Published: February 2023

Understanding how paleomagnetic and rock magnetic properties vary as a function of time and space is important for acquiring reliable information about the past Earth’s magnetic field. In basalts the magnetic properties are controlled by Fe-Ti oxides precipitating from the magma. The fraction, type, and mineral and magnetic grain size and shape are determined by a complicated multiphase process through the history of the lava or tephra. The deep magmatic conditions with melt composition, temperature, pressure, and oxygen fugacity are the starting point influencing the initial magnetic mineralogy and the matrix surrounding it. The final stage of crystallization is controlled also by syn-eruptive and emplacement conditions such as viscosity, cooling rate, incorporation of water, eruption style and atmospheric oxidation. Lastly, regardless of the natural environment the magnetic mineralogy is bound to further suffer from some degree of chemical alteration and low temperature oxidation. Therefore, the magnetic properties vary considerably even within the same cooling unit, and where one samples can affect the successfulness of paleomagnetic or paleointensity study. Historical eruptions like Fagradalsfjall 2021 and 2022 provide ideal locations for case studies since we know exactly not only the direction and strength of the magnetic field, but also the geochemical properties of the lavas due to near real time analysis of the eruption products. Here we present the magnetic properties of the Fagradalsfjall 2021 and 2022 eruption products. We collected samples during the eruptions as a function of time from the fast cooled materials, such as samples from the naturally fast cooled flow tops, manually quenched samples from the molten lava, and tephra. After eruptions seized and it was safe to work on the lava, we drilled over 100 lava samples from various locations and morphologies. These samples were subjected to a battery of measurements possible at University of Iceland Paleomagnetism Laboratory slightly varying depending on the type of sample such as bulk susceptibility, low field susceptibility vs temperature, hysteresis properties, backfield coercivity distribution, First Order Reversal Curves, alternating field, and thermal demagnetization. With our preliminary results we show how the magnetic properties vary a) between different types of volcanic products, b) across the lava fields and their multiple morphologies, c) as a function of depth, and d) as a function of time from the beginning of the eruption for the rapidly quenched materials.
Next Generation Gravity Mission design activities within the MAGIC - MAss Change and Geoscience International - Constellation
Authors: Massotti Luca , Bulit Alexandra , Daras Ilias , Carnicero Dominguez Bernardo , Carraz Olivier , Hall Kevin , Heliere Arnaud , March Gunther , Marchese Valentina , Martimort Philippe , Palmer Kyle , Rodrigues Gonçalo , Silvestrin Pierluigi , Wallace Neil
Published: February 2023

The objective of ESA’s Next Generation Gravity Mission (NGGM) is long-term monitoring of the temporal variations of Earth’s gravity field at high temporal (down to 3 days) and spatial (100 km) resolution. Such variations carry information about mass change induced by the water cycle and the related mass exchange among atmosphere, oceans, cryosphere and land, and will complete our picture of Global Change with otherwise unavailable data. The observable is the variation of the distance between two satellites measured by a laser interferometer; ultra-precise accelerometers measure the non-gravitational accelerations to correct the gravity signal in the data processing. The optimal satellite system comprises two pairs of satellites on low (between 396 and 488 km) circular orbits, at 220 km separation, one pair quasi-polar and the other around 65°-70° inclination. The satellite-to-satellite tracking technique for detecting the temporal variations of gravity was established by GRACE (300-400 km spatial resolution at monthly intervals) using tracking in the microwave band. Today, GRACE is being continued by GRACE-Follow-On, with similar objectives, where the laser interferometry has improved the measurement resolution by a factor of 100 (upper MBW). At 150 km spatial resolution, mass change would become observable in 80% of all significant river basins, against 10% achieved with GRACE. High temporal resolution will reveal large-scale sub-weekly mass variations, with applications in water and emergency management. NGGM is a candidate Mission of Opportunity for ESA-NASA cooperation in the framework of MAGIC (MAss Change and Geosciences International Constellation). The MAGIC constellation will build upon the heritage from the GOCE, GRACE and GRACE-FO missions, the ESA NGGM Phase 0 System studies and past technology pre-developments on laser ranging interferometry, and other key technologies, developed over the years in preparation for NGGM and for the LISA mission. MAGIC will be composed of two pairs of satellites. The first Pair (P1) is to be implemented via a DE-USA fast-paced cooperation programme to ensure continuity of observations with GRACE-FO, with some potential ESA in-kind contributions. The second pair (P2) is to be implemented via a Europe-USA cooperation programme with some potential NASA in-kind contributions with a target launch date compatible to maintain at least 4 years of combined operations.The presentation focusses on the on-going Phase A system design, giving an overview of the activities at system and technology level for NGGM, as currently running at the European Space Agency.
MAX-DOAS, FTIR and direct-sun HCHO vertical columns intercomparison in Xianghe (China)
Authors: Pinardi Gaia , Hendrick François , Friedrich Martina , Vigouroux Corinne , Langerock Bavo , Zhou Minqiang , Hermans Christian , De Smedt Isabelle , Wang Ting , Wang Pucai , Van Roozendael Michel
Published: February 2023

MAX-DOAS, direct-sun and FTIR measurements are considered nowadays as reference data for the validation of HCHO satellite observations. Understanding their strengths and limitations, and assessing their consistency is therefore essential in order to produce robust and consolidated validation results. So far, only a few studies have explored the complementarity between MAX-DOAS and FTIR HCHO measurements.

In the present study, we take the opportunity of the presence of MAX-DOAS spectrometers and an FTIR instrument operating in parallel at the Xianghe station (39.75° N, 116.96° E; ~55 km southeast of Beijing) to compare HCHO vertical column retrievals from both instruments operating in heavily polluted conditions. Moreover, the MAX-DOAS also incorporates a direct-sun viewing mode capability, allowing the comparison of direct-sun measurements in the UV and in the IR, showing high level of agreement (regression slope close to 1). The study addresses the impact of the different vertical sensitivities of the MAX-DOAS and FTIR techniques.

The presence of direct-sun DOAS and FTIR data also allows testing different MAX-DOAS approaches for the retrieval of low-tropospheric profiles and VCD. In addition to the existing HCHO processing with the bePRO Optimal Estimation retrieval code, alternative profiles and column datasets produced with the MMF and MAPA algorithms running within the FRM4DOAS centralized-facility are compared. Several building hypothesis are tested and the different results are explored in term of consistency with the other HCHO measurements.
Transition indicators on a flowline ice sheet model
Authors: Moreno-Parada Daniel , Swierczek-Jereczek Jan , Montoya Marisa , Alvarez-Solas Jorge , Robinson Alexander
Published: February 2023

Marine ice-sheet behaviour and grounding line stability have been fundamental objects of study in the last two decades. In particular, the ice sheet-shelf transition deserves special attention as it determines the outflow of ice from the grounded region and, together with accumulation, governs the global mass balance. Yet, the dynamics of ice flow are strongly coupled to the climate system via surface mass balance, frontal ablation and atmospheric temperature among others. The interplay of such variables combined with the bed geometry determine the equilibrium position of a glacier terminus, which can display bistability due to the marine ice-sheet instability. These variables further define the boundary conditions of an ice-sheet model and are given by the particular climate scenario. However, a realistic representation of the climate must be described as a stochastic process (short-term variability i.e., “noise”) interacting with long-term deterministic dynamics. The response of a multi-stable system to noisy forcing can be used to predict abrupt transitions by means of so-called transition indicators. That is, a direct application of classical slowdown theory to capture the essence of shifts at tipping points. In the present work, we apply some of these indicators to a 1-D flowline model to study whether a glacier collapse can be predicted by critical slowdown theory. A key challenge with transition indicators is to determine when the system can be expected to tip given that a critical slowdown begins to occur. We explore this issue through a large ensemble of simulations.
Challenges for achieving clean air - The case of Barcelona (Spain)
Authors: Rodriguez-Rey Daniel , Guevara Marc , Armengol Jan Mateu , Criado Alvaro , Enciso Santiago , Tena Carles , Benavides Jaime , Soret Albert , Jorba Oriol , Pérez-Garcia Pando Carlos
Published: February 2023

Air pollution affects the economy, the environment, and public health. This is particularly relevant in dense urban areas due to their urban built, high traffic activity, and near-the-source population exposure. In the city of Barcelona, the 40 ug/m3 nitrogen dioxide NO2 annual limit value set up by the 2008/50/EC European Air Quality Directive (AQD) is systematically exceeded in traffic stations mainly due to the contribution of road transport. In the last Urban Mobility Plan (2019-2024), the city hall of Barcelona presented several traffic management strategies aiming to reduce on-road traffic emissions by both renewing and reducing the private motorized transport in the city. These measures include the application of tactical urban actions, green corridors and superblocks along with a Low Emission Zone, which together are expected to reduce the number of private vehicles circulating throughout the city by -25%. In parallel, the Port of Barcelona has recently announced a plan to electrify the docks and reduce emission from hotelling activities by -38%. To properly assess the impact of such measures, the AQD recommends the application of numerical models in combination with monitoring data. Following AQD recommendations, our study runs a coupled transport-emission model able to characterize traffic movement along the city and produce multiple scenarios that quantify the impact of the aforementioned measures on primary emissions. The resulting scenarios are then used to feed a multi-scale air quality modeling system to estimate NO2 concentration values at very high resolution (20m, hourly). To reduce the uncertainty typically associated with modeling results, the estimated values are corrected with a data-fusion methodology using observations from the official monitoring network and several measurement campaigns. Our results show that the implementation of all mobility restrictions and electrification of the Port will allow Barcelona to comply with the current legislated NO2 air quality standards at the traffic monitoring stations, with reductions up to -24.7% and -12 ug/m3. However, the resulting NO2 levels achieved at these locations would still fail to meet the new 2021 WHO guideline (10 ug/m3) and the recent proposal for a revision of the EU AQD (20 ug/m3). Also, despite the estimated NO2 reductions, several areas in the city would still be above the current legal limit of 40 ug/m3, including 16.7% of schools and 19.7% of hospitals and healthcare facilities. All in all, our results suggest the planned measures are steps in the right direction, yet still insufficient to ensure healthy AQ values across the entire city.
Highly sensitive laser heterodyne radiometer based on a balanced photodetector for carbon dioxide measurement in the atmospheric column
Authors: Wei Tingting , Wang Jingjing , Shen Fengjiao , Tan Tu , Cao Zhensong , Gao Xiaoming , Jeseck Pascal , Te Yao-Veng , Plus Stéphane , Dong Lei , Miller Houston , Chen Weidong
Published: February 2023

An all-fiber coupled laser heterodyne radiometer (LHR), using a wideband tunable external cavity diode laser (1500–1640 nm) as local oscillator laser, was developed for ground-based remote sensing of carbon dioxide. Optimal absorption lines and transmission spectra of carbon dioxide in this wavelength range were determined. High sensitivity of the LHR was achieved by using a balanced photodetector to suppress the relative intensity noise of the local oscillator laser. The noise model of the highly sensitive LHR was analyzed and compared with the traditional LHR using single photodetector [1-2]. Finally, field campaigns were performed on the roof of the platform of IRENE building in Dunkerque (51.05°N/2.34°E). The measured LHR spectra in the atmospheric column are compared, in good agreement, with referenced Fourier-transform infrared spectra from the TCCON observation network and with the simulation spectra resulting from an atmospheric transmission modeling. Experimental details including noise analysis and LHR spectra will be discussed and presented. AcknowledgmentsThe authors thank the ﬁnancial supports from the LABEX CaPPA project (ANR-10-LABX005), the CPER ECRIN program, the EU H2020-ATMOS project as well as the funding from China Scholarship Council (CSC). References[1] T. G. Blaney. "Signal-to-noise ratio and other characteristics of heterodyne radiation receivers", Space Science Reviews 17 (1975) 691-702.[2] F. Shen, G. Wang, J. Wang, T. Tan, G. Wang, P. Jeseck, Y.-V. Te, X. Gao, W. Chen. "A transportable mid-infrared laser heterodyne radiometer operating in the shot-noise dominated regime", Opt. Lett.46 (2021) 3171-3174.
Serpentinite dehydration as a multiscale process
Authors: Huber Konstantin , Vrijmoed Johannes C. , John Timm
Published: February 2023

Fluid release from hydrated oceanic lithosphere in subduction zones is a key process in the deep earth water cycle. During prograde metamorphism a channelized vein network forms in the dehydrating rock that allows efficient fluid release from the slab into the mantle wedge. The formation of such a vein network is a multiscale process that occurs over a wide range of time and length scales. Previous studies as well as field observations of exhumed meta-serpentinites suggest that the processes governing rock dehydration shift from chemical to mechanical processes going from small to large scales.To investigate the behavior of a dehydrating slab over this wide range of scales we present a multiscale dataset that includes field-based observations from m to sub-µm scale of a representative serpentinite from the Mirdita ophiolite (Albania). This ophiolite has experienced seafloor alteration, but has not been metamorphosed at conditions that would cause any dehydration. We use these data as input for thermodynamic equilibrium calculations to investigate the effect of chemical heterogeneities in the bulk rock composition while the PT-conditions will be increased following a typical subduction zone geothermal gradient.For upscaling we perform the calculations at various effective thermodynamic domain sizes (20-100 µm), showing that anisotropic chemical heterogeneities lead to heterogeneous porosity formation on all scales. Bloch et al. (2018) found that for vein-like porosity structures the percolation threshold of an effective bulk media may be reached at a porosity as low as 10-3. Therefore, the anisotropic porosity structure formed by chemical heterogeneities leads to a high connectivity even at low porosities and thus allows efficient fluid flow. Accordingly, going to even larger scales we can use these findings to describe the lithologies found in the field as effective bulk media with an effective fluid flow. This allows us to investigate fluid release from the dehydrating slab on the km-scale by reactive porosity waves using a numerical model.Bloch, W., John, T., Kummerow, J., Salazar, P., Krüger, O. S., & Shapiro, S. A. (2018). Watching Dehydration: Seismic Indication for Transient Fluid Pathways in the Oceanic Mantle of the Subducting Nazca Slab. Geochemistry, Geophysics, Geosystems, 19(9), 3189–3207. https://doi.org/10.1029/2018GC007703
From satellite data and Sustainable Development Goals to interactive tools and better territorial decision making
Authors: Plantec Maël , Castel Fabien
Published: February 2023

As human activities continue to expand and evolve, their impact on the planet is becoming more evident. These past years Murmuration has been studying one of the most recent and destructive trends that has taken off: mass tourism. In Malta, tourism has been on the rise since before the Covid-19 pandemic. Now that travel restrictions are beginning to lift, it's likely that this trend will go back to increasing in the coming years. While Malta’s economy is mostly based on tourism, it's essential that this activity does not alter the areas in which it takes place. To address these issues and ensure sustainable development, governments and organizations have developed a set of guidelines called Sustainable Development Goals (SDG). SDGs are a set of 17 goals adopted by the United Nations in 2015 to provide a framework to help countries pursue sustainable economic, social and environmental development. They include objectives for mitigating climate change, preventing water pollution and degradation of biodiversity, as well as providing economic benefits to local communities.In order to help territories like the islands of Malta to cope with these environmental issues, Murmuration carries out studies on various ecological, human and economic indicators. Using the Sentinel satellites of the European Copernicus program for earth imagery data makes possible the collection of geolocated, hourly values on air quality indicators such as NO2, CO and other pollutants but also water quality and vegetation through the analysis of the vegetation health. Other data sources give access to land cover values at meter resolution, tourism infrastructures locations and many more human activity variables. This information is processed into understandable indicators, aggregated indexes which take international standards and SDGs in their design and usage. An example of these standards are the WHO air quality guidelines providing thresholds quantifying the impact on health of the air pollution in the area of interest. The last step is to gather all the data, maps and correlations computed and design understandable visualizations to make it usable by territory management instances, enabling efficient decision making and risk management. The goal here is to achieve a link between satellite imagery, internationally agreed political commitment  and ground level decision-making.This meaningful aggregation comes in the shape of operational dashboards. A dashboard is an up-to-date, interactive, evolving online tool hosting temporal and geographical linked visualizations on various indicators. This kind of tool allows for a better understanding of the dynamic of a territory in terms of environmental state, human impact and ecological potential.
Stress response and transformation processes initiated by the summer drought 2018 – a multi-scale study from the Hainich forest
Authors: Koebsch Franziska , Mund Martina , Klosterhalfen Anne , Dietenberger Steffen , Donfack Laura , Heidenreich Marius , Markwitz Christian , Montero David , Thiel Christian , Tiedemann Frank , Knohl Alexander
Published: February 2023

More frequent and intense drought events pose one of the greatest threats to forests under climate change with substantial consequences for tree growth, ecosystem stability, and climate change mitigation. A better understanding of drought-related stress response and adaptation mechanisms is paramount to assess the adaptative capacity of forest ecosystems and deduce supportive management actions.Here, we report on the stress effects and transformation processes initiated by the 2018 summer drought in the Hainich Nationalpark, an old-growth beech-dominated forest in Central Germany (DE-Hai). We deploy a multi-scale approach encompassing long-term eddy covariance measurements for stand-level CO2 exchange, concurrent surveys of tree increments, and satellite imagery that covers the core zone of the National Park. Thus, we can provide a comprehensive picture of the response mechanisms that occur in a mixed old-growth forest in the wake of a severe drought.After a 15-year reference period of relatively stable net CO2 uptake of 535±73 g m2 yr-1 on average, the summer drought 2018 persistently lowered the forest’s CO2 sink function down to 333-395 g m2 yr-1 (2019-2021). The lowered CO2 sequestration was primarily due to a sustained reduction in photosynthetic CO2 uptake and went along with an increase in tree mortality from 1 to 6%. We observed a substantial shift in growth patterns among the surviving trees: Fraxinus excelsior, which in its role as competitor tree had contributed substantially to stand-level growth for a long time, showed significantly lower increments from 2018. At the same time, increments of Fagus sylvatica increased markedly after 2018. Especially younger, suppressed Fagus individuals benefitted in the post-drought period and pushed stand-level growth to a new record in 2021. On larger spatial scale encompassing the National Park core zone, drought response was overprinted by topographic effects that reflect landscape water availability, particularly altitude and routing of waterways.Tree growth response to extreme water stress in a mixed, old-growth forest varies with regard to species-specific drought tolerance levels and/or the tree’s role in the forest structure. The natural growth dynamics emanating from drought events in unmanaged forests are modulated locally by landscape water availability, and can cumulate into profound structural change. At the early stage of transformation captured by our study, a reduction in productivity and climate change mitigation potential must be expected.
Quantifying the contribution of climate change to heat-attributable mortality in Europe: Interfacing epidemiology and Extreme Event Attribution
Authors: Beck Thessa , Gudmundsson Lukas , Seneviratne Sonia I. , Achebak Hicham , Schumacher Dominik , Ballester Joan
Published: February 2023

Extreme Event Attribution (EEA) aims to answer the question of whether and to what extent the intensity and likelihood of an observed extreme weather event have changed due to climate change. This approach has been applied to different types of weather extremes such as heatwaves, droughts, or extreme rainfall, but has only rarely been used to assess the role of climate change on health impacts caused by extreme weather events.In this study, we focus on the short-term effects of extreme heat events on human mortality in Europe. We first apply an epidemiological model to estimate the lagged association between temperatures and mortality counts. We use ERA5-Land temperature data and a mortality database including 92.612.620 counts of death from 823 contiguous regions in 35 European countries, representing a population of over 534 million people. We estimate the number of deaths attributable to heat and then compute the death count caused by climate change by applying EEA methods. Here, we apply a conditional extreme value distribution to estimate how the likelihood of selected heat-attributable mortality events has changed from a pre-industrial climate to present-day conditions (1.2ºC global warming).We show that in all regions of Europe, a climate change signal in heat-attributable mortality can be detected. This climate change contribution to mortality differs between geographical locations in Europe and is also influenced by demographic, and socioeconomic factors, e.g., we identify differences in climate impacts in gender-specific mortality.This study shows that epidemiological models can be combined with EEA methodologies and it opens the door to conducting further EEA studies, including rapid attribution, on other health impacts and beyond.
Tracking coarse sediment in an Alpine subglacial channel using radio-tagged particles
Authors: Lane Stuart N. , Jenkin Matt , Hofmann Margaux , Hubbard Bryn , Mancini Davide , Miesen Floreana M. , Herman Frederic
Published: February 2023

Temperate Alpine glaciers produce substantial quantities of sediment that are exported via active subglacial meltwater channels to their proglacial environments. Measurements of suspended sediment and bedload in proglacial rivers have been used to estimate glacial erosion rates and downstream sediment yields, assuming that eroded sediment is rapidly evacuated by flowing meltwater; that subglacial sediment storage remains constant and that the measurements are unaffected by proglacial filtering effects. Studies generally focus on the suspended sediment fraction of export, due to the challenges involved in monitoring coarse sediment transport. It is not surprising that subglacial sediment transport dynamics are poorly understood, and a limited amount of field and model-based research indicates that subglacial sediment transport may be attenuated in the rapidly thinning and retreating snout marginal zones of many Alpine glaciers. This is likely due to the existence of non-pressurised subglacial channels with highly variable transport competence related to diurnal discharge variability, leading to cycles of alluviation and deposition. The potential attenuation of sediment and the unknown relationship between suspended load and bedload has important consequences for estimates of glacial erosion based on proglacial export measurements. Here, we present results from a proof-of-concept for a method to track radio-tagged bedload particles through meltwater channels under shallow temperate glacier ice (<50 m). Active radio transmitters were inserted into natural pebbles and then deployed directly via boreholes into a 10 m wide snout-marginal subglacial channel at the Glacier d'Otemma, Switzerland. A roving antenna at the surface was used daily to estimate the planimetric point location and downstream transport distance of each tagged particle using Kernel Density Estimation (KDE) as it moved downstream through the subglacial channel. In addition, stationary antennas on the glacier surface monitored the passage of the particles through successive reaches of the subglacial and proglacial channel, constraining the timing of particle transport events. The roving and stationary antenna data were combined to create a transport distance model for each particle, which, when applied at scale, may be used in conjunction with river gauging data to examine the drivers and timescales of coarse subglacial sediment transport. We present results that confirm this method as a highly original means of quantifying subglacial sediment transport using particle tracking.
Low-temperature thermochronology history of the Kyrgyz Range – Western Tien Shan (Kyrgyzstan)
Authors: Mariotti Apolline , Schildgen Taylor , Sobel Ed , Glodny Johannes
Published: February 2023

Constraining the effect of global climatic changes on earth surface’s processes is crucial to our understanding of landscape evolution. One debated question is the impact of the Late Cenozoic cooling and subsequent Quaternary glaciations on the erosion of mountain ranges.Low-temperature bedrock thermochronology is widely used to measure rock exhumation/erosion rates in mountain ranges across the world. Specifically, the (U-Th)/He system measured in apatite (AHe) can record low temperature (<100 ◦C) cooling histories and thus has the sensibility to detect million-year timescale changes in erosion rates in glaciated regions. The Kyrgyz Range, part of the Tien Shan and situated in northwest Kyrgyzstan, spans east-west over 400 km and present strong glacial features in the northern flank. Previous thermochronology studies in the Kyrgyz Range have identified an increase of exhumation rates over the last 3 Ma which could be the result of enhanced glacial erosion (Bullen et al., 2003; Sobel et al., 2006). Furthermore, a global analysis of published thermochronology data found the Kyrgyz Range as one of the few locations with the potential to record the effect of Quaternary glaciations (Schildgen et al., 2018). In this study, we present new AHe ages for 6 samples collected along a vertical profile in the glacial valley of Ala Archa. Samples cover an elevation difference of 1850m and were collected on granite outcrops. These results will build on the previous thermochronology dataset by Bullen et al., 2003 (3 AHe ages) by adding both lower and higher elevation samples. Future work includes apatite fission track ages for the same vertical profile.
A CP conditioned hybrid weather generator
Authors: Pidoto Ross , Haberlandt Uwe
Published: February 2023

Long continuous time series of meteorological variables such as temperature and precipitation are required for applications such as derived flood frequency analyses. Observed time series are however generally too short, too sparse in space, or incomplete, especially at the sub-daily timestep. Stochastic weather generators allow an alternative to using observations, being able to generate time series of arbitrary length which are then used as input to hydrological models.A hybrid hourly space-time weather generator has been developed based on a stochastic alternating renewal rainfall model. Modelling of non-rainfall climate variables is achieved using a non-parametric k-nearest neighbour (k-NN) resampling approach, which is coupled to the space-time rainfall model via rainfall state.Circulation pattern (CP) or weather pattern classifications can be useful as a conditioning variable for stochastic rainfall models and weather generators. One primary use is the downscaling of future climate scenarios. Furthermore, CP conditioned models may better simulate rainfall and other climate variables through a better partitioning of observations into distinct rainfall and weather types.Previous research has shown that the point rainfall model performs better, particularly regarding extremes, if conditioned on an optimised fuzzy-rule based objective weather pattern classification. Appropriate model revisions have now been made to allow the full hybrid space-time weather generator to also be conditioned on this classification.This study assesses the performance of the weather pattern conditioned hybrid weather generator compared to the previous seasonal (summer-winter) conditioned model. For testing, 400 meso-scale catchments across Germany were selected. 
Infrared Radiation Effects of Aerosols in the Atmospheric Window during Wet Growth Process
Authors: Ji Denghui , Palm Mathias , Notholt Justus
Published: February 2023

Aerosols increase the down-welling infrared (IR) radiation flux in the Arctic. The activation of aerosols increases the down-welling IR flux further, depending on the type of the aerosol. A new instrument, NYAEM-FTS has been installed in Ny-Alesund, Spitsbergen to measure the down-welling IR flux. Ny-Alesund is located on the archipelago of Spitsbergen in the most Northern part of the Atlantic Ocean. It is affected by influx of air from Europe and Asia which leads to import of Aerosols from the polluted areas of Europe and Asia.We use the measurements of NYAEM -FTS for observing (non-activated) aerosols in cloud-free conditions. We improved this algorithm that it can be used for determining the type of activated aerosol as well.We present first analysis of the IR measurements to show the dependence of the down-welling infrared radiation on the humidity in the aerosol layer and the chemical composition of the aerosols. This helps to close the gap between the warming effect on the Arctic climate of aerosols on one hand and the warming effect of clouds on the other hand.  
ML-based characterization of PS-InSAR multi-mission point clouds for ground deformation classification
Authors: Masciulli Claudia , Gaeta Michele , Berardo Giorgia , Pantozzi Gianmarco , Stefanini Carlo Alberto , Mazzanti Paolo
Published: February 2023

Persistent Scatterer Interferometry (PSI) is a powerful multitemporal A-DInSAR (Advanced Differential Synthetic Aperture Radar Interferometry) technique widely used for monitoring and measuring Earth’s surface displacements over large areas with sub-centimetric precision. The capability to detect ground deformation processes relies on the available PSI spatial density, strictly related to the resolution of the considered sensor and the presence of stable natural and artificial reflectors. A new data fusion approach, developed as part of the “MUSAR” project funded by ASI (Italian Space Agency), integrates multi-band SAR sensors to improve data coverage of PSI data by synthesizing multi-sensor displacement information. The integration of multi-mission PSI generates synthetic measurement points, named Ground Deformation Markers (GD-Markers), featuring vertical (Up-Down) and horizontal (Est-West) components of the displacements. The fusion of PSI data extracted by C-band Sentinel-1 images from the Copernicus initiative and the COSMO-SkyMed constellation in the X-band from ASI contributed to creating a dataset with high information content.Each GD-Markers cluster with displacement measurements identifies a specific deformation process in the region of interest. After selecting the relevant cluster of points, the deformation processes were classified into different categories (e.g., landslide, subsidence) to improve their understanding and evaluation for mitigating natural-related hazards. This study aimed to develop a machine learning-based classification system, starting from GD-Markers point clouds, which support the automatization of ground displacement identification and characterization. The synthetic points were characterized as individual entities or point clouds, formed by a discrete cluster of points in space, to evaluate the advantage of treating each point independently or incorporating local neighborhood information. The structured point data were analyzed using a supervised Random Forest (RF) approach to evaluate the performance of point cloud classification and categorization for identifying the best initial setting. Each point was assigned a label representing a deformation process in point cloud classification, while one label is provided for the entire point cloud dataset with categorization.Comparing models’ performances allowed the definition of the best possible approach for classifying the deformation processes observed by GD-Markers point clouds. The analysis assessed the effectiveness of the classification of single points or clusters to identify the optimal setup that achieves an accurate segmentation between adjacent deformation processes. Identifying this initial setting was essential for selecting and developing advanced deep-learning approaches.
Biogeographical drivers of supraglacial microbial communities
Authors: Mourot Rey , Trivedi Christopher B. , Keuschnig Christoph , Winkel Matthias , Bradley James A. , Larose Catherine , Luks Bartlomiej , Feord Helen , Anesio Alexandre M. , Tranter Martyn , Benning Liane G.
Published: February 2023

Pigment-producing microorganisms are prevalent on glacier surfaces, decreasing the snow and ice albedo. This impacts the absorption of solar radiation and accelerates rates of glacier surface melting. Studying the glacier surface ecosystem is important to understand the effects of anthropogenic climate change, and to further our knowledge of how glacier-dwelling organisms and their evolution impact downstream ecosystems. Recent studies have revealed links between habitat type, seasonality, physicochemical characteristics and the microbial composition of the supraglacial environment. However, these studies are limited in number, time points and locations. Thus, global drivers of supraglacial microbial community composition remain unknown. To fill this gap, we used data produced by our team over the last five years, as well as gathered from public repositories, to investigate the prokaryotic and eukaryotic composition of supraglacial environments worldwide.We used 18S and 16S rRNA gene amplicon sequencing to study the microbial composition and diversity of more than eight hundred surface snow, ice and cryoconite samples from glaciers and snowfields all over the world, including Arctic, Antarctic and temperate glaciers. Results reveal a worldwide core microbiome specific to this environment, composed of generalist, freshwater and cold-adapted taxa. Distance-decay and latitudinal patterns can be identified, but key factors in determining microbial community diversity and composition rest on local to regional biogeographical scales. Habitat biology shows different responses to biogeographical drivers, likely influenced by their structure: cryoconite communities present a higher distance-decay and location specialization than snow and ice communities. In addition, communities of prokaryotes are less location-specific than those of eukaryotes. This study highlights the need for further investigation into the drivers of microbial dissemination onto glaciers and their response to local biogeography.    
A new Max Planck Institute-Grand Ensemble with CMIP6 forcing and high-frequency model output
Authors: Olonscheck Dirk , Brune Sebastian , Suarez-Gutierrez Laura , Beobide-Arsuaga Goratz , Baehr Johanna , Fröb Friederike , Hellmich Lara , Ilyina Tatiana , Kadow Christopher , Krieger Daniel , Li Hongmei , Marotzke Jochem , Plésiat Étienne , Schupfner Martin , Wachsmann Fabian , Wieners Karl-Hermann , Milinski Sebastian
Published: February 2023

We present the CMIP6 version of the Max Planck Institute-Grand Ensemble (MPI-GE CMIP6) with 30 realisations for the historical period and five emission scenarios. The power of MPI-GE CMIP6 goes beyond its predecessor ensemble MPI-GE by providing high-frequency model output, the full range of emission scenarios including the highly policy relevant scenarios SSP1-1.9 and SSP1-2.6, and the opportunity to compare the ensemble to high resolution simulations of the same model version. We demonstrate with six novel application examples how to use the power of MPI-GE CMIP6 to better quantify and understand present and future extreme events in the Earth system, to inform about uncertainty in approaching Paris Agreement global warming limits, and to combine large ensembles and artificial intelligence. For instance, MPI-GE CMIP6 allows us to show that the recently observed Siberian and Pacific North American heat waves are projected to occur every year in 2071-2100 in high-emission scenarios, that the storm activity in most tropical to mid-latitude oceans is projected to decrease, and that the ensemble is sufficiently large to be used for infilling surface temperature observations with artificial intelligence.