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The Benguela upwelling region off the coast of Namibia supplies cold water from the deep ocean that is transported offshore in finger-like structures called filaments. We investigate one major filament using measurements from a ship that crossed it multiple times and with mutiple buoys that follow the ocean currents. We find that the motions associated with the filament enhance the kinetic energy at small scales and provide a pathway for mixing of water and turbulent dissipation of energy.

We investigated the relationship between PMSE layers and the solar cycle. Our results indicate that PMSE altitude, echo power, and layer thickness are on average higher during solar maximum than solar minimum. Higher electron densities at ionospheric altitudes might be necessary to observe multi-layered PMSE. We observed that the thickness decreases as the number of multi-layers increase. We hypothesized that the thickness of PMSE layers may be related to the vertical wavelength of gravity waves

In this study, we found that photolysis of sodium nitrate leads to a much quicker decay of free amino acids (FAAs, glycine as an example) in the particle phase than ammonium nitrate photolysis, likely due to the molecular interactions between FAAs and different nitrate salts. Since sodium nitrate likely co-exists with FAAs in the coarse mode particles, particulate nitrate photolysis can possibly contribute to a rapid decay of FAAs, and affect atmospheric nitrogen cycling.

Seawater flows from the Pacific to the Indian Oceans through different straits of the South China Sea, forming the South China Sea Throughflow. We present the high-resolution model built for the study of water, heat and salt fluxes involved in this flow. The model is evaluated by comparing with observations. We moreover show that important discards are observed while calculating offline the net heat and salt flux and the inflow and outflow of water, heat and salt.

We propose a new point-prediction DEep Learning WAVe Emulating model (DELWAVE) which successfully emulates the ocean wave model (SWAN) over synoptic to climate timescales. Compared to control climatology over all wind directions, the mismatch between DELWAVE and SWAN is generally small compared to the difference between scenario and control conditions, suggesting that the noise introduced by surrogate modeling is substantially weaker than the climate change signal.

Emissions from aircraft contribute to climate change and degrade air quality. We describe an up-to-date 4D emissions inventory of global aviation from 2019 to 2021 based on actual flown trajectories. In 2019, 40.2 million flights collectively travelled 61 billion kilometres using 283 Tg of fuel. Long-haul flights were responsible for 43 % of CO₂. The emissions inventory is made available for use in future studies to evaluate the negative externalities arising from global aviation.

We show that MethaneAIR, a precursor to the MethaneSAT satellite, demonstrates accurate point source quantification during controlled release experiments and regional observations in 2021. Results from our two independent quantification methods suggest the accuracy of our framework is better than 25 % for sources emitting 200 kg/hr or more. Insights gained from these experiments help refine algorithms for our instruments, further strengthening the capabilities of our instruments.

We analyze the 2022 M_W 6.0 Gölyaka sequence. A high-resolution seismicity catalog revealed no spatio-temporal localization and lack of immediate foreshocks. Aftershock distribution suggests activation of the Karadere and Düzce faults. The preferential energy propagation suggests that mainshock propagated eastwards, in agreement with predictions from models where the velocity in the two sides of the fault is different.

With a comprehensive suite of ground-based and airborne remote sensing measurements during the 2021 Tracking Aerosol Convection Experiment Air Quality (TRACER-AQ) campaign in Houston, this study evaluates the simulation of the planetary boundary layer (PBL) height and the ozone vertical profile by a high-resolution (1.33 km) 3-D photochemical model Weather Research and Forecasting-driven GEOS-Chem (WRF-GC).

Ice mélange is a mixture of sea ice and icebergs, which can have a strong influence on the sea-ice-ocean interaction. So far, ice mélange is not represented in climate models. We include icebergs into the most used sea-ice model by modifying the mathematical equations that describe the material law of sea ice. We show with three test cases that the modification is necessary to represent icebergs. Furthermore we suggest a numerical method to solve the ice mélange equations computational efficient.

This paper shows the potential of a simple and robust radiometer like the ZEN-R52 as a possible alternative for aerosol properties retrieval in remote areas. It assesses the capability from GRASP to retrieve aerosol properties using only ZSR at 440, 500, 675 and 870 nm. The uncertainty and bias found in the retrieval show the limitations of the instrument and inversion strategy, but also demonstrate that the ZEN-R52, together with a developed GRASP-ZEN strategy, can provide useful information.

Oceanic eddies are the structures carrying most of the energy in our oceans. They play an essential role in climate regulation and nutrient transport. This paper prepares for the SWOT mission, studying eddy dynamics in the region south of Africa, where the Indian and Atlantic oceans meet, leveraging models and simulated satellite data. SWOT will provide insights into the structures smaller than what is currently observable, which appear to greatly contribute to eddy kinetic energy and strain.

Meteotsunami are the result of atmospheric disturbances creating water waves which can impact coastlines causing injury and loss to life and assets. This paper introduces a novel intensity index to allow for the quantification of these events at the shoreline which has the potential to assist in the field of natural hazard assessment. Trialled in the UK with a view to global applicability and to becoming a widely accepted standard in coastal planning, meteotsunami forecasting and early warning.

This paper shows how use machine learning methods to for model of small scale atmospherics physics model (large eddy simulation) which cover physics to the 100 m scale and implement that model to global large scale model. Our results shows that the global model is stable and it provides meaningful results. This way we can include physic based presentation of sub-grid (physics which happens in 100 m scale) physics to the global model which resolution is in 100 km scale.

Atmospheric models benefit from idealized tests that assess their accuracy in a simpler simulation. A new test with artificial mountains is developed for models on a spherical earth. The mountains trigger the development of both planetary-scale and small-scale waves. These can be analyzed in dry or moist environments with a simple rainfall mechanism. Four atmospheric models are intercompared. This sheds light on the pros and cons of the model designs and the impact of mountains on the flow.

In this work we looked at the projected change in bottom water oxygen content in an ensemble of ocean climate change models of the North Western European Shelf. What emerged is that, 1. oxygen decreases in all models, 2. in the models with the most warming, a change in circulation patterns is tied to the emergence of low oxygen hotspots in the Eastern North Sea, and, 3. in relatively shallow coastal areas increasing in primary production partially mitigates oxygen decline.

This study provides insights into the complex chemical composition of long-range transported wildfire plumes from Yakutia, which underwent different levels of atmospheric processing. With mass complementary mass spectrometric techniques, we improve our understanding of the chemical processes and atmospheric fate of wildfire plumes. Unprecedented high levels of carbonaceous aerosols crossed the polar circle with implications for the Arctic ecosystem and consequently climate.

The Paris Agreement increased the interest in estimating GHG emissions of individual countries, but top-down emission estimation is not yet considered policy-relevant. It is therefore paramount to reduce the large errors and to build systems that are based on the newest atmospheric transport models (e.g., ICON-ART). In this study, we present the first application of ICON-ART in inverse modelling of GHG fluxes with an Ensemble Kalman Filter and present our results for European CH₄ emissions.

The proposed wind speed correction model (VMD-PCA-RF) demonstrates the highest prediction accuracy and stability in the five southern provinces in nearly a year and at different heights. VMD-PCA-RF evaluation indexes for 10 months remain relatively stable: accuracy rate FA is above 85 %. In future research, the proposed VMD-PCA-RF algorithm can be extrapolated to the 3 km grid points of the five southern provinces to generate a 3 km grid-corrected wind speed product.

The Sunda Strait region is an earthquake-prone zone. The most recent natural catastrophes in 2018 provide evidence that volcanic activity and its consequences might threaten Sunda Strait communities. Strong growth along the coasts of the Sunda Strait, on both Java and Sumatra, required specific preparation for the magnitude and distribution of destructive blazes in this region. Hence, PSHA research may be a foundation for disaster mitigation in the Sunda Strait region.

Statistical postprocessing is necessary to generate good probabilistic forecasts from physical numerical weather prediction models. To allow for more flexibility, there has been a recent shift in postprocessing away from traditional parametric regression models towards modern machine learning methods. By fusing these two distinct approaches, we developed MOS random forests: a new postprocessing method that is highly flexible, but at the same time also very robust and easy to interpret.

Tropical cyclones (TCs) can cause catastrophic damages to coastal regions. We used a numerical model that explicitly simulates aerosol-cloud interaction and atmosphere-ocean coupling. We show that aerosols and ocean coupling work together to make the TC storm bigger but weaker. Moreover, TCs in polluted air have more rainfall and higher sea levels, leading to severer storm surges and flooding. Our research highlights the roles of aerosols and ocean coupling feedbacks in the TC hazard assessment.

Emergent constraints on equilibrium climate sensitivity (ECS) have generally got statistically weaker in the latest set of state-of-the-art climate models (CMIP6) compared to past sets (CMIP5). We look at why this weakening happened for one particular study (Cox et al, 2018) and attribute it to an assumption made in the theory that when corrected for restores a stronger relationship between predictor and ECS.

We conducted a systematic and quantitative study of the effects of plant mixtures on the water cycle. Our results confirmed that plant mixtures help facilitate a positive water cycle through mitigating inefficient water consumption. The positive conclusions we reached, as well as the analyses of the influencing factors, mechanisms, and limitations, are helpful for promoting further in-depth research and encouraging the establishment of more plant mixture systems.

We conducted burning experiments to simulate various types of solid fuel combustion, including residential burning, wildfires, agricultural burning, cow dung, and plastic bags burning. The chemical composition of the particles was characterized using mass spectrometers, and new potential markers for different fuels were identified using statistical analysis. This work improves our understanding of emissions from solid fuel burning and offers support for refined source apportionment.

We apply a previously developed remote calibration framework to a network of PM sensors deployed in the Southern California regions. Our results show that a remote calibration can improve the accuracy of PM data, which was particularly visible for PM₁₀. We highlight that sensor drift was mostly due to differences in particle composition rather than monitor operational factors. Thus, PM sensors may require frequent calibration if PM sources vary with different wind conditions or seasons.

A new metric, snow water storage (SwS), is used to characterize the natural reservoir function of snowpacks. In recent decades, there has been more spatially widespread decreases in annual SwS than increases and the greatest losses in monthly SwS occur early in the snow season. The mountainous regions that play an inordinate role in annual SwS have declined by 22 %. Flexible snow metrics such as SwS may become more valuable as we move into a future of increased climate variability.

We measured cyanogen bromide (BrCN) in the troposphere for the first time as part of a series of survey flights around the globe. BrCN is found to be a product of the same active bromine chemistry that destroys ozone and removes mercury in polar surface environments, and so is a previously unrecognized participant in this chemistry. Accounting for BrCN chemistry is an important part of understanding polar Br cycling.

Combining hydrodynamic simulations and annotated videos, we separated which hydrodynamic variables that determine reef cover are engineered by cold-water corals and which not, which is typically difficult. Around coral mounds hydrodynamic zones create a typical reef zonation, restricting corals from moving deeper (the expected response to climate warming). But non-engineered downward velocities in winter (e.g., deep winter mixing) seem more important for coral reef growth than coral engineering.

The Mt. Samalas eruption had global-scale impacts on climate and has been linked to historical events throughout later half of the 13th Century. Using model simulations and proxy data we constrain the year and season of the eruption to Summer 1257 and investigate the regional-scale variability in surface cooling following the eruption. We also re-evaluate evidence from ice core records, including their limitations when applied to historical eruptions such as Mt. Samalas.

The physical pump transporting atmospheric CO₂ to ocean consists of two parts: The first absorbs CO₂ to the upper mixed layer by rise of atmospheric CO₂. This amount of anthropogenic carbon is calculated. From this, its capacity at present is 1.3 Gtons/year declining to 0.4 for CO₂ above 600 ppm. The second sink transports anthropogenic DIC by thermohaline circulation. This pump increases from 1.9 at present to 5 Gtons/year at 800 ppm , The total pump is not switched off by acidification.

The study focuses on three medicanes, tropical-like cyclones that form in the Mediterranean Sea, studied by mean of ensemble forecasting. This involved multiple simulations of the same event by varying initial conditions and model physics parameters, especially related to convection, which showed comparable results. It is found that medicanes development is influenced by the model's ability to predict precursor events and the interaction upper and lower atmosphere dynamics and thermodynamics.

A new federative chronology for five deep polar ice cores retrieves 800 000 years of past climate variations with an improved accuracy. Precise ice core timescales are key to study the mechanisms linking changes in the Earth’s orbit to the diverse climatic responses (temperature and atmospheric greenhouse gas concentrations). To consruct the chronology, new measurements from the oldest continuous ice core as well as glaciological modeling estimates were combined in a statistical model.

Ammonia (NH₃) is an important air pollutant which, as precursor of fine particulate matter, raises public health issues. Models have difficulty predicting events of pollution associated with NH₃ since ground-based observations of this gas are still relatively sparse and difficult to implement. We present the first relatively long (2.5-years) and continuous record of hourly NH₃ concentrations in Paris to determine its temporal variabilities at different scales to unravel emission sources.

In the paper, we explored the impact of the Madden-Julian Oscillation on East China summer rainfall variability and its sensitivity to the QBO phase. It is novel to find that the combined impact of MJO and QBO is not maximized when the QBO and MJO are in phase to enhance (or suppress) the tropical convection.

The effects of AMV on the distribution of rainfall or the timing of the West African Monsoon is not well known. Through the analysis of atmosphere-ocean coupled model outputs we find that a positive AMV enhances the number of wet days, daily rainfall intensity and extremes over the Sahel, and tends to prolong monsoon length through later demise. Heavy rainfall (moderate) events increase over all (the north of) the Sahel. Model biases affect their skills to simulate the effects of AMV.