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Sea ice has a large interannual variability, studying its evolution requires long time series of observation. In this paper, we propose the first method to extend Arctic sea ice thickness measurements time series from ERS-2 altimeter. The developed method is based on a neural network to calibrate past missions on the current one by taking advantage of their differences during the mission-overlap periods. Data are available as monthly maps for each winter between 1995 and 2021.

Thunderstorm systems play an important role in the dynamics of the Earth’s atmosphere and some of them form a well organised line: squall lines. Simulations of such squall lines with very small initial perturbations are compared to an unperturbed control simulation. The evolution of perturbations and processes amplifying them are analysed. It is shown that the formation of new secondary thunderstorm cells (after the initial primary cells) directly ahead of the line affects the spread strongly.

Lightning assimilation implemented in the WRF model's Kain-Fritsch convective scheme is updated and applied to simulations from regional to hemispheric scales using observed lightning flashes from ground-based lightning detection networks. Different user-toggled options associated with the Kain-Fritsch scheme on simulations with and without lightning assimilation are assessed. The model's performance is improved significantly by lightning assimilation, but it is sensitive to various factors.

Reactivation of tectonic faults can lead to earthquakes and jeopardize underground operations. The reactivation potential is linked to fault properties and the tectonic stress field. We create 3D geometries for major faults in Germany and use stress data from a 3D geomechanical–numerical model to calculate their reactivation potential and compare it to seismic events. The reactivation potential in general is highest for NNE–SSW- and NW–SE-striking faults and strongly depends on the fault dip.

Trees destruction is often used to back-calculate the air blast impact region and estimate the air blast power. Here we established a novel model to assess the air blast power using the tree destruction information. We find that the dynamic magnification effect makes the trees easier to be damaged by a landslide-induced air blast, but the large tree deformation would weaken the effect. Bending and overturning are two likely failure modes, which depend heavily on the properties of trees.

Employing event synchronization and complex networks analysis, we reveal a cascade of heavy rainfall events, triggered by intense atmospheric rivers (ARs): heavy rainfall events (HREs) in western North America that occur in the aftermath of land-falling ARs are synchronized with HREs in central and eastern Canada with a delay of up to 12 days. Understanding the effects of ARs in the rainfall over NA will lead to better anticipating the evolution of the climate dynamics in the region.

Knowledge of what causes maximum water levels is often key in coastal management. Processes, such as strom surge and atmospheric forcing alter the predicted tide. Whilst most of these processes are modelled in present-day ocean forecasting, still there is a need for better understanding situations where modelled and observed water levels deviate from eachother. Here we will use machine learning to detect such anomalies within a network of sea level observations in the North Sea.

The JES is a mid-latitude “Miniature Ocean” featured by multiscale oceanic dynamical processes and sea ice, which strongly influence the JES SSC. However, the dominant factors that favor and/or restrict SSC and how they influence JES SSC on different time scales are not clear. In this study, these issues are investigated using EOF and PCA methods based on high-resolution satellite-derived SSC data provided by the Copernicus Marine Environment Monitoring Service (CMEMS).

This is an article that focuses on the challenges associated with comparing atmospheric composition models with satellite products such as tropospheric NO₂ columns. The aim is to highlight the methodological difficulties and propose sound ways of doing such comparisons. Building on the comparisons, a new satellite product is proposed and made available, which takes advantage of higher resolution, regional atmospheric modelling to improve estimates of troposheric NO₂ columns over Europe.

Heavy pollution events often occur in cloudy conditions, which is hard to observe. This study introduces a new 3D-Var analysis that can facilitate aerosol-cloud interactions through weakly coupled data assimilation using WRF-Chem/WRFDA.

Coral reefs face increasing pressures from environmental change at present. The coral reef physical framework is formed through the production of calcium carbonate by corals, crustose coralline algae (CCA), and other calcifying algae. The Kimberley bioregion, located in the northern part of Western Australia, has largely escaped land-based anthropogenic impacts and this study provides important data on reef building processes we are lacking from an undisturbed set of marine habitats.

The nesting AGRIF library is implemented in the MARS3D hydrodynamic model. Two applications at regional and coastal scale are introduced. A comparison of the two-nesting to the classic offline one-way approach based on in situ dataset is presented. The two-way nesting is an efficient mean to significantly improve the physical hydrodynamics and bring it biological issues.

Assessing hundreds or thousands of emission scenarios in terms of their global-mean temperature implications requires standardised procedures of infilling, harmonisation and probabilistic temperature assessments. We here present the ‘climate-assessment’ workflow that provides the methodology used in the IPCC Working Group III report.

In classical models that track the changes in the elemental composition of phytoplankton, additional state variables are required for each element resolved. In this study, we show how the behavior of such an explicit model can be approximated using an 'instantaneous acclimation' approach, in which the elemental composition of the phytoplankton is assumed to adjust to an optimal value instantaneously. Through rigorous tests, we evaluate the consistency of this scheme.

We construct a new model, OMARE, that can carry out multi-scale ocean simulation through Adaptive Mesh Refinement. OMARE is based on the refactorization of NEMO with a third-party, high-performance middleware. We report the porting process, as well as experiments of an idealized western-boundary current system. The new model simulates turbulent and temporally varying mesoscale and submesoscale processes through adaptive refinement. Related topics and future work with OMARE are also discussed.

Obtaining accurate results from wave models in coastal regions is typically more difficult. This is due to the complex interactions between waves and the local environment characteristics like complex shorelines, sea bottom topography, the presence of strong currents and other processes that include waves’ growth and decay. In the present study we analyze which elements can be adjusted and/or included in order to reduce errors in the modeled output.

The near-surface atmosphere over the Antarctic Plateau is cold and pristine and resembles to a certain extent those of the high-troposphere where cirrus clouds form. In this study, we use innovative humidity measurements at Concordia station to study the formation of ice fogs at temperatures <-40 °C. We provide observational evidence that ice fogs can form through the homogeneous freezing of solution aerosols, a common nucleation pathway for cirrus clouds.

The present study provides the first in-situ observation of secondary ice production at temperatures as low as -27 °C, which is well outside the range of the Hallett-Mossop process (-3 °C to -8 °C). This observation expands our knowledge of the temperature range of initiation of secondary ice in clouds. The obtained results are intended to stimulate laboratory and theoretical studies to develop physically based parameterizations for weather prediction and climate models.

The West African aerosol plume created by oil industry gas flares and biomass burning suppresses convection in West Africa forcing the regional atmospheric circulation to the north and creating anomalous high pressure over southern Europe, the Mediterranean Sea, Iberia and the eastern Atlantic Ocean. This high pressure forces: cold fronts to the north and creates drought in Iberia; and a south westerly atmospheric flow into northern Europe creating higher temperatures and UK floods.

In this study, we benchmark a topography-based model for glacier erosion (OpenLEM) with a well-established process-based model (iSOSIA). Our experiments show that large-scale erosion patterns and, in particular, the transformation of valley length geometry from fluvial to glacial conditions are very similar in both models. This finding enables the application of OpenLEM to study the influence of climate and tectonics on glaciated mountains with reasonable computational effort on standard PCs.

The goal of this study is to understand the uncertainties of different modeling configurations for simulating hydroclimate responses in the mountainous watershed. We run a group of climate models with various configurations and evaluate them against various reference datasets. This paper integrates climate model and hydrology model to have a full understanding of the atmospheric-through-bedrock hydrological processes.

The grain size of snow determines how light is reflected and other physical properties. The IceCube measures snow grain size at the specific near-infrared wavelength of 1320 nm. In our study the preparation of snow samples for the IceCube creates a thin layer of small particles. Comparisons of the grain size with computed tomography, particle counting and numerical simulation confirm the observation. We conclude that snow grain size measurements at this wavelength underestimate the grain size.

We present a simple system to forecast the MJO. We are using atmospheric circulation as input to our system. We found a good skill forecast of the MJO amplitude within 40 days using this methodology. Comparing our results with ECMWF and machine learning forecasts confirmed the good skill of our system.

With this study, we want to highlight the importance of studying both land and ocean together, and water and sediment together, as these systems function as a continuum and determine how organic carbon derived from permafrost is broken down, and its effect on global warming. While on one hand it appears that organic carbon is removed from sediments along the pathway of transport from river to ocean, it also appears to remain relatively ‘fresh’, despite this removal and its very old age.

Recent forest decline requires understanding forest response to multi-seasonal meteorology. We investigate meteorology over 3 years preceding events of low forest greenness in Europe in 2000–2020 in a highly systematic and quantitative way. We identify time periods when meteorological variables and weather systems are significantly anomalous or persistent. Our interdisciplinary results present progress in understanding how changing meteorology will impact forest performance in this century.

Boreal forests, historically a global sink for atmospheric CO₂, store carbon in vast soil reservoirs. To predict how such stores will respond to climate warming we need to understand climate-ecosystem feedbacks. We find boreal forest soil carbon stores are maintained through enhanced nitrogen cycling with climate warming providing direct evidence for a key feedback. Further application of the approach demonstrated here will improve our understanding of the limits of climate-ecosystem feedbacks.

Low cost sensors see additional pollution that is not seen with traditional regional air quality monitoring stations. This additional local pollution is sufficient to cause exceedance of the World Health Organization exposure thresholds. Analysis shows that a significant amount of the NO₂ pollution we observe is local, mainly due to road traffic. This article demonstrates how networks of nodes containing low cost pollution sensors can powerfully extend existing monitoring programs.

Oceanic eddies are ubiquitous in the ocean, and their dynamics are key components in the evolution of water column properties. This study combines sea surface height and thermohaline field to understand the seasonal variation of eddy activity and associated heat/salt transport in the Bay of Bengal. Eddy activity in the Bay of Bengal has evident seasonal variation, which has notable impact on the circulation system within the entire bay.

We investigated the impact of the severe 2018–2019 Central European drought on riverine nitrate pollution. We found that under severe drought, catchments can lose part of their nitrogen retention capacity due to decreased denitrification and plant uptake, but the time scale of riverine nitrate export responses to drought can be catchment specific. These results imply that severe and prolonged droughts can intensify nitrate pollution and threaten water quality.

To determine best strategies for geoscience communication on TikTok, we created a TikTok account called “Terra Explore.” We produced 48 educational geoscience videos and evaluated each video’s performance. Our most viewed videos received nearly all of their views from TikTok’s algorithmic recommendation feed, and the videos that went the most viral were related to a recent newsworthy event (e.g., earthquake) or explaining the geology of a recognizable area.

The uppermost oceanic layer was sampled to determine what can explain a potential dimethyl sulfide (DMS) enrichment in this environment. A novel sampling method was used, and the results showed that DMS was not as enriched as expected. Our results showed that the phytoplanktonic composition influenced the DMS concentration, confirming results from another study in this oceanic region. However, additional factors are required to observe a DMS enrichment in the uppermost oceanic layer.

We distinguish fire regimes in Central Portugal and investigate the degree to which they are influenced by a set of biophysical drivers. Results show four fire regimes and indicate these can be differentiated using biophysical drivers, among which land use/land cover type, slope and spring rainfall are the foremost. Our results highlight the relations between vegetation (type, availability, and rate of regeneration) and topography with fire regimes in the study area.

We explore satellite retrievals of snow water equivalent (SWE) along hypothetical ground tracks that would allow estimation of SWE over an entire watershed. Retrieval of SWE from satellites has proved elusive, but there are now technological options that do so along essentially one-dimensional tracks. We use machine learning algorithms as the basis for a track to area (TTA) transformation and show that at least one is robust enough to estimate domain-wide SWE with high accuracy.

To understand how dimethyl sulfide (DMS) enrichment is maintained in the sea surface microlayer (SML) while DMS is lost to the atmosphere, deck-board incubation was carried out to determine DMS sources and sinks. Our results showed that the phytoplankton composition played an essential role in DMS processes in the SML. However, all accumulated DMS processes were lower than the calculated air-sea DMS flux, confirming the results from the companion paper.

This paper outlines the development of a color filter wheel, attached to a broadband CL detector, which allows us to recover spectroscopic information and generate composite color images. The embedded data from the pixels were used to generate 2D and 3D graphs providing multiple visual pathways for comparing relative intensities. The design can be adjusted to accommodate various chamber specifications and expand the capabilities of the broadband CL detectors housed at many institutions.

Why do plants distributional range size vary enormously? This study provides evidence that seed mass, intraspecific seed mass variation, seed dispersal mode and phylogeny contribute to explaining species distribution variation on the geographic scale. Our study clearly shows the importance of including seed life-history traits in modeling and predicting the impact of climate change on species distribution of seed plants.

Precipitation nowcasting refers to the prediction of precipitation intensity in a local region and in a short timeframe up to 6 hours. The increasing possibilities to store and evaluate data combined with the advancements in the developments of artificial intelligence algorithms make it natural to use these methods to improve precipitation nowcasting. The positive effectiveness of finetuning and promising skill scores for a prediction time up to 100 minutes are shown.

This paper explores lake ice in the Old Crow Flats, Yukon, Canada using a novel approach that employs radar imagery and deep learning. Results indicate an 11 % increase in fraction of lake ice that grounds between 1993 and 2021. We believe this to be caused by widespread lake drainage, and fluctuations in water level and snow depth. This transition is likely to have implications for permafrost beneath the lakes, with potential impact on methane ebullition and the regional carbon budget.

Atmospheric waves that carry momentum from the tropospheric weather systems into the equatorial stratosphere modify the winds there. The 2019 Strateole-2 campaign launched long-duration stratospheric superpressure balloons to measure these equatorial waves. We deployed a GPS receiver on one of the balloons to measure atmospheric temperature profiles beneath the balloon. Temperature variations in the retrieved profiles show planetary-scale waves with a 20 day period and 3–4 day period waves.

Compound events threaten marine ecosystems. Here, we investigate the potentially harmful combination of marine heatwaves with low phytoplankton productivity. Using satellite-based observations, we show that these compound events are frequent in the low latitudes. We then investigate the drivers of these compound events using Earth System models. The models share similar drivers in the low latitudes, but disagree in the high latitudes due to divergent factors limiting phytoplankton production.

Warm water is transported from the tropical Atlantic towards western Europe and the Arctic. It loses heat to the atmosphere on the way, which strongly influences the climate. We construct a dataset encircling the North Atlantic basin north of 47° N. We calculate how and where heat enters and leaves the basin, and how much cooling must happen in the interior. We find that cooling in the North-eastern Atlantic is a crucial step in controlling the conversion of water to higher densities.

We focus on the impact of small-scale orographic gravity waves (OGWs) above the Himalayas. The interaction of GWs with the large-scale circulation in the stratosphere is not still well understood and can have implications on climate projections. We use a chemistry-climate model to show that these strong OGW events are associated with anomalously increased upward planetary-scale waves and in turn affect the circumpolar circulation and have the potential to alter ozone variability as well.

In order to quantify C transport and emission and main environmental factors controlling the C cycle on Siberian rivers, we investigated the largest tributary of the Ob River, the Ket River basin, via measuring spatial and seasonal variations in CO₂ and CH₄ concentrations and emissions, together with hydrochemical analyses. The obtained results are useful for large scale modelling of C emission and export fluxes from permafrost-free boreal rivers of under-represented region of the world.

We present the first mechanistic model LAKE2.3 for prediction of methane emissions from artificial reservoirs. Estimates of CH₄ emissions from the Mozhaysk reservoir (Moscow region) provided by the model are demonstrated. Methane annual emissions through diffusion, ebullition and downstream degassing according to in situ measurements and model simulations are presented. The experiments with the model allowed to determine the most sensitive model parameters for calibration of methane fluxes.

We explore the spatial-temporal characteristics of oceanic bottom mixed layer (BML) in the South China Sea (SCS) and investigated its potential formation mechanisms. We found that the BML in the SCS has significant inhomogeneity. In particular, the BML is thick and unstable over the northern continental slope and is relatively thin and stable over the continental shelf and in deep-sea regions. These findings may enhance our understanding of the BML dynamics in the SCS and other marginal seas.

Fine dust is an important component of PM_2.5 and can be largely modulated by droughts. In contrast to the increase in dust in the southwest USA where major dust sources are located, dust in the southeast USA is affected more by long-range transport from Africa and decreases under droughts. Both the transport and emissions of African dust are weakened when the southeast USA is under droughts, which reveals how regional-scale droughts can influence aerosol abundance through long-range transport.

The present paper reports a detailed analysis of the observed and expected climate conditions over the Campania Region. Campania, as part of the Mediterranean area, is already testing relevant impacts related to climate change.

The analysis of stable carbon and oxygen isotopic ratios, trace element ratios and growth rate from a Spanish speleothem provides quantitative information about past hydrological conditions during the early Holocene in southwestern Europe. Our data show that the cave site experienced increased effective recharge during the 8.2 ka event. Additionally, the oxygen isotopes indicate a change in the isotopic composition of the moisture source, associated with the meltwater flux to the North Atlantic.

There is still no full understanding of the relation between drought impacts and drought indices in the Horn of Africa where water scarcity and arid regions are also present. This study assesses their relation in Kenya. A Random Forest model reveals that each region, aggregated by aridity, has their own set of predictors for every impact category. Water scarcity was not found to be related to aridity. Understanding these relations contributes to the development of drought early warning systems.

Mapping and compiling the attributes of faults capable of hosting earthquakes is important for the next generation of seismic hazard assessment. We document 18 active faults in the Luangwa Rift, Zambia in an active fault database. These faults are between 9 and 207 km long, offset Quaternary sediments, have scarps up to ~30 m high and are capable of causing earthquakes between Mw5.8 and 8.1. We correlate the Molaza fault with surface ruptures from two unatributted M6+ 20th century earthquakes.