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The increased social environmental awareness requires the monitoring of greenhouse gases (GHG). We report on the development of two sampling devices (which can be mounted to a drone) and the subsequent measurement setup to analyse these gases. The functionality of the presented system was tested in the field and the results emphasized the functionality of the sampling and measurement setup described, demonstrating that it a viable tool for monitoring GHG and identifying their emission sources.

Monitoring and assessment of ozone-depleting substances and fluorinated greenhouse gases are required under the control of the Montreal and Kyoto Protocols. In this study, the existing commercial laboratory VOCs monitoring system was upgraded to establish a rapid and convenient high-precision monitoring technology.

Arctic sea ice loss might impact the atmospheric circulation outside the Arctic and therefore extremes over mid-latitudes. Here, we analyze model experiments to initially assess the influence of sea ice loss on occurrence frequencies of large-scale circulation patterns. Some of these detected circulation changes can be linked to changes in occurrences of European temperature extremes. Compared to future global temperature increases the sea ice-related impacts are however of secondary relevance.

Here we developed a new burned area detection algorithm between 2001–2019 across Alaska and Canada at 500 m resolution. We estimate 2.37 million hectares burned annually between 2001–2019 over the domain emitting 79.3 Tg C per year, with a mean combustion rate of 3.13 kg C m^-2. We found larger fire years were generally associated with greater mean combustion. The burned area and combustion data sets described here can be used for local to continental-scale applications of boreal fire science.

The climate is altered by greenhouse gases and air pollutant particles, and such emissions are likely to change drastically in the future over Africa. Air pollutants do not travel far, so their climate effect depends on where they are emitted. This study uses a climate model to find the climate impacts of future African pollutant emissions being either high or low. The particles absorb and scatter sunlight, causing the ground nearby to be cooler, but elsewhere the increased heat causes warming.

This work is an extension of what is known about a protocol used to measure the hydraulic properties of the soil. For instance, such properties characterize the ability of water to move through the soil, or the amount of water that is held in the soil in dry or wet conditions. We propose a modified version of the protocol, with which we show (i) how the data obtained with this protocol is influenced by the soil hydraulic properties and (ii) how to use it to estimate these properties.

The climate system is strongly regulated by interactions between the ocean and atmosphere. However, many uncertainties remain in the understanding of these interactions. Our analysis uses a relatively novel approach to quantify causal links between the ocean surface and lower atmosphere based on satellite observations. We find that both the ocean and atmosphere influence each other, but with varying intensity depending on the region, demonstrating the power of causal methods.

The study was performed using continuous measurements of temporal variations in soil saturation plus measurements of the concentration of pesticides along the vadose zone profile and underlying alluvial aquifers at sugarcane fields in the Wet Tropical conditions in Australia. A vadose zone monitoring system was set up to enable the characterization of pesticide (non-PS II herbicides) migration with respect to pesticide application, sugarcane growing period and finally, rainwater infiltration.

Under the joint action of climate and human activities, the use of runoff data whose mathematical properties have changed has become the key to watershed management. To determine whether the data has been changed, the number and location of changes, we proposed a changepoint detection framework. By comparing the accuracy of the wavelet changepoint detection, we also proposed a mother wavelet optimization framework, which can improve the uniqueness and rationality of wavelet transform.

We develop a forecasting system for marine litter concentration (MLC) in the Mediterranean based on a simple statistical method. The idea is that similar meteorological situations yield similar MLC patterns. We train our model with a historical meteorological dataset and MLC from numerical simulations to recognize these situations and patterns, and use them to forecast the future MLC. The results are promising and the approach has potential to become a suitable cost effective forecasting method.

Rainfall is erratic and difficult to predict. Thus random models are often used to describe rainfall events. Since many of these random models are based more on statistics than physical laws, it is desirable to develop connections between the random statistical models and the underlying physics of rain. Here, a physics-based model is shown to converge to a statistics-based model, which helps to provide a physical basis for the statistics-based model.

It is hard for scientists to write efficient code which runs fast on all kinds of supercomputers. They like writing Python because it is easier to read and use. We re-wrote a Fortran code that simulates weather and climate into Python. The Python code re-writes itself to a much faster language to run on either normal processors or graphics cards. On one big computer system, our code is 3.5–4x faster on its graphics cards than the original code is on its processors.

Quantitatively estimating combined hazard provides guidance for disaster prevention, mitigation. The GEV and Gumbel copula function are suitable for fitting the marginal and joint distribution characteristics in this study area. When one variable is constant, the simultaneous, joint, and conditional risk probability tends to decrease as the other variable increases. We can estimate the optimal design criteria for different joint return periods by the constraint condition and objective functions.

In this paper we develop a methodology to model the spatial distribution of solar radiation received by land over mountainous terrain. The approach is designed to be used in Earth System Models, where coarse grid cells hinder the description of fine scale land-atmosphere interactions. We adopt a clustering algorithm to partiton land domain in a set of homogeneous sub-grid “tiles”, and for each evaluate solar radiation receive by land based on terrain properties.

We present the OH observation and model simulation results at a coastal site in Hong Kong. The model well predicted the OH concentration in high NO_x conditions and overpredicted in low NO_x conditions. This implies the insufficient understanding of OH chemistry in low NO_x conditions. We show evidence of missing OH sinks as a possible cause of the overprediction.

In the last decades, geochemical investigations at the spring of rock glaciers have been used to estimate their drainage processes, and the continuous frozen layer is typically considered to act as an aquiclude. In this work, we evaluated the hydraulic behavior of a mountain permafrost site by executing a geophysical monitoring experiment. Several hundred liters of water have been injected into the frozen subsoil and geoelectrical measurements have been performed to define the water flow.

Melt from the Greenland ice sheet and sea ice both influence light and nutrient availability in the Arctic coastal ocean. We use a 3D coupled hydrodynamic-biogeochemical model to evaluate the relative importance of these processes for timing, distribution and magnitude of phytoplankton production in Disko Bay, West Greenland. Our study indicates that decreasing sea ice and more freshwater discharge can work synergistically and increase primary productivity of the coastal ocean around Greenland.

Flood risk is expected to increase in many regions worldwide due to rapid urbanization and climate change. The benefits of risk-mitigation measures remain inadequately quantified for potential future events in some multi-hazard-prone areas such as Kathmandu Valley (KV), Nepal, which this paper addresses. The analysis involves modeling two flood-occurrence scenarios and using four residential exposure inventories representing current urban system or near-future development trajectories for KV.

We present two methods to refine the assimilation of satellite sea surface temperatures (SSTs) into a regional ocean model. First, we correct the SSTs for biases and show that this correction reduces the model SST errors. Then, we implement a special observation operator that handles the spatial resolution mismatch between coarse passive microwave SSTs and the high-resolution model. We find that excluding this operator spatially smooths the modeled SST, whereas its inclusion prevents this.

Sodic soil affect ~580 Mha in semi-arid and arid regions of the world. These soils have weak structure. This laboratory study evaluated treatments to overcome the weak aggregate structure in two sodic Vertisols, by applying organic amendments, gypsum and wetting drying cycles. We conclude that sodic soils need to be treated with gypsum to flocculate clay, and organic matter (lucerne or chicken manure) to form aggregates, whereas drying cycles form stable small macroaggregates.

Soils store more carbon (C) than any other terrestrial C reservoir, but the processes that control how much C stays in soil, and for how long, are very complex. Here, we used a recent method that involves heating soil in the lab to measure the range of C ages in soil. We found that most C in soil is decades to centuries old, while some stays for much shorter times (days to months), and some is thousands of years old. Such detail helps to estimate how soil C may react to changing climate.

The percentage contribution of climate change, land use, population and industry to Ganga pollution is quantified using a coupled hydrological-water quality simulation model. Climate change is identified as the prominent driver with a percentage contribution above 70 %. Hence, due to the added pollution load from climate change, land use projections, and industrial growth, the proposed treatment for Ganga in mid 21st century is not sufficient to bring down Ganga pollution.

Aerosol particles with sizes smaller than 50 nm impact cloud formation and precipitation. Representation of this effect is hindered by limited understanding of the properties of liquid water in these particles. Our simulations of aerosol particles containing salt or organic compounds reveal that water becomes a less cohesive phase at droplet sizes below 4 nm. This effect causes important deviations from theoretical predictions of aerosol properties, including phase state and hygroscopic growth.

Ocean acidification is a global perturbation of the ocean carbonate chemistry as a consequence of increased carbon dioxide concentration into the atmosphere. While great progress has been made over the last decade for chemical monitoring, ocean acidification biological monitoring remains anecdotal. This is a consequence of a lack of standards, general methodological framework and overall methodology. This paper presents methodology focusing on sensitive traits and a focus on rate of changes.

Dimethyl sulfide (DMS), emitted from the ocean, is the most abundant biogenic sulfur emission into the atmosphere. OH radicals, among others, can oxidize DMS to sulfuric and methanesulfonic acid, which are relevant for aerosol formation. We quantified DMS and nearly all DMS oxidation products with novel mass spectrometric instruments for gas and particle phase at the high mountain station Chacaltaya (5240 m a.s.l.) in the Bolivian Andes in free tropospheric air after long-range transport.

The relationship between the time-average state of the atmosphere and aspects of atmospheric circulation drives general understanding of the atmospheric circulation. Here, we present new techniques to calculate local properties of the time-average atmosphere, and relate those properties to aspects of extratropical circulation with important implication for weather. This relationship should help connect changes to the atmosphere, such as under global warming, to changes in midlatitude weather.

The Nash-Sutcliffe efficiency (NSE) is a widely used score in hydrology but is not common in the other environmental sciences. One of the reasons for its unpopularity is that its scientific meaning is somehow unclear in the literature. This study attempts to establish a solid foundation for NSE from the viewpoint of signal progressing. This approach is shown to yield profound explanations to many open problems related to NSE.

More and more researchers use deep learning models to replace physics-based parameterizations to accelerate weather simulations. However, embedding the DL models within the weather models is difficult as they are implemented in different languages. This work proposes a coupling framework to allow DL-based parameterization to be coupled with the Weather Research and Forecasting (WRF) model. We also demonstrate using the coupler to couple the DL-based radiation schemes with the WRF model.

Oceanic turbulence can be measured from autonomous vehicles such as floats and gliders. The raw data files, however, are too large to be transmitted back via satellite. Some processing to reduce the data must happen onboard. We present a scheme to do just that and test it with existing measurements. Our scheme will make it possible to deploy turbulence platforms without the need for their recovery.

Forward modeling of spaceborne millimeter wave radar composed of nine sub modules is presented. We quantify the uncertainties in radar reflectivity that may be caused by the physical model parameters via a sensitivity analysis. The simulations with optimal and conventional setting are compared with CloudSat data, and the improvement of optimal simulation are evaluated and analyzed. The results are instructive to the optimization in forward modeling and microphysical parameter retrieval.

In this work we present and validate a new flood model for the UK that simulates pluvial, fluvial and coastal flooding. We show that previous UK flood losses based on government data and used in national climate change risk assessments are overestimated by a factor of ~3. These official estimates lie well outside our modelled loss distribution, which is plausibly centred on the observations.

The implementation of the new method, line-average concentration measurement with a closed-path analyzer, will enable measurement of fluxes of multiple gases from different types of sources and evaluate the effects of mitigation strategies on emissions. In addition, this method allows for continuous online measurements that resolve temporal variation in ammonia emissions and the peak emissions of methane.

This work is a theoretical contribution that provides equations for understanding uncertainty prediction applied in air quality where multiple chemical species can interact. A simplified minimal test-bed is introduced that shows the ability our equations to reproduce the statistics estimated from an ensemble of forecast. While the latter estimation is the state of the art, solving equations is numerically less costly, depending on the number of chemical species, and motivates this research.

With the development of satellite altimeters, satellite altimeter technologies have been increasingly used to retrieve Arctic sea ice thicknesses and have achieved rapid application. However, few reports have explored the retrieval of sea ice thickness by Chinese altimeters among recent studies. Therefore, it is of great significance to obtain reliable Arctic sea ice thickness products based on the China HY-2B radar altimeter to provide data support for the study of long-term changes in sea ice.

We present the implementation of neodymium (Nd) isotopes into the ocean model of FAMOUS (ND v1.0). Nd fluxes from seafloor sediment alongside incorporation of Nd onto sinking particles represent the major global sources and sinks. However, model-data mismatch in the North Pacific and northern North Atlantic suggest that certain reactive components of the sediment interact the most with seawater. Our results are important for interpreting Nd isotopes in terms of ocean circulation.

We proposed a methodology to obtain useful and robust probabilistic predictions from computational flood simulators using satellite-borne flood extent observations. We developed a Bayesian framework to obtain the uncertainty in roughness parameters, in observations errors and in simulator deficiencies. We found that it can yield improvements in predictions relative to current methodologies, and can potentially lead to consistent ways of combining data from different sources.

We present our model ChronoLorica. We coupled the original Lorica model, that simulates soil and landscape evolution, with a geochronological module that traces cosmogenic nuclide inventories and particle ages through the simulations. These properties are often measured in the field to determine rates of landscape change. The coupling enables calibration of the model and study how soil, landscapes and the geochronometers change under complex boundary conditions such as intensive land management.

We update the 2010 global deposition budget for nitrogen and sulfur with new regional wet deposition measurements, improving the ensemble results of eleven global chemistry transport models from HTAP-II. Our study demonstrates that a global measurement-model fusion approach can substantially improve N and S deposition model estimates at a regional scale and represents a step forward toward the WMO’s goal of global fusion products for accurately mapping harmful air pollution.

Multiple seismic anomalies were reported to be related to the 2015 Nepal earthquake. By investigating sufficiently both the space-time features and the physical models of the seismic anomalies, the coupling mechanisms of these anomalies in 3D space were revealed, and an integrated framework to strictly root the sources of various anomalies were proposed. This study provides a practical solution for screening out the reliable seismic anomalies from diversified earthquake observations.

We investigate the peak temperature of sedimentary rocks of the SW Alps (France), using the Raman Spectroscopy on Carbonaceous Material. This method provides an estimate of the peak temperature achieved by organic-rich rocks. To determine the timing and the tectonic context at the origin of these temperatures we use 1D thermal modelling. We find that the high temperatures up to 300 °C were achieved during pre-collisional extensional events, not during tectonic burial in the Western Alps.

What drives the young water fraction (i.e. the fraction of water in streamflow younger than roughly 2–3 months) variations with elevation? Why is F_yw counterintuitively low in high-elevation catchments, in spite of steeper topography compared with lower elevations? In this paper it is shown how the long duration of the snowpack favors the groundwater contribution to streamflow, thus increasing the streamwater age. A dataset of 27 Swiss and Italian catchments between 472 and 3049 m asl is used.

Using the MAX-DOAS network, we successfully analyzed three typical transport types (regional, dust, and transboundary long-range transport), emphasizing the unique advantages provided by the network in monitoring pollutant transport. We think that our findings provide the public with a thorough understanding of pollutant transport phenomena and a reference for designing collaborative air pollution control strategies.

Nitrogen dioxide (NO₂) is an important trace gas for both air quality and climate. NO₂ affects satellite ocean color products. A new ocean color instrument - OCI (ocean color instrument) - will be launched in 2024 on a NASA satellite. We show that it will be possible to measure NO₂ from OCI even though it was not designed for this. The techniques we developed here, based on machine learning, can also be applied to instruments already in space to speed up algorithms and reduce effects of noise.

In this study, we looked into the regional and global response of planktonic foraminifera, single celled organisms which exhibits the best fossil record available to science, to the paleoclimate over the last 5 million years, when the Earth developed its northern icesheets. We document an increasing abundance of species which occupy cold waters. Moreover, closer analysis of certain species may indicate higher fossil diversity than previously thought, with implications for evolutionary studies.

Increasing the vegetation cover over mid-Holcocene North Africa expands the West African Monsoon ~ 4–5° further north. This northward shift of monsoonal precipitation is caused by interactions of the land surface with the large-scale monsoon circulation and the coupling of soil moisture to precipitation. We highlight the importance to not only consider how soil moisture influences precipitation but also how different precipitation characteristics alter the soil hydrology via runoff generation.

This study created a multi-temporal inventory of glacial lake from 1990 to 2019 throughout the Tibetan Plateau . In here, we demonstrated the quantity and size of glacier lakes have grown by 3285 and 258.82 sq km, respectively. The distribution of glacial lakes across the 17 mountains of TP is uneven, and the pace of area change varies per subregion. Most glacial lakes are distributed in the elevation range of 4400–5400 m above sea level, with an obvious expansion tendency in recent decades.

Scientific understandings of the distribution of coseismic landslides, followed by emergency and medium and long-term risk assessment can reduce the landslide risk. The aim of this study is to propose an improved three-stage spatial prediction strategy and develop a corresponding Hazard assessment software called Mat.LShazard V1.0, which provides a new application tool for coseismic landslide disaster prevention and mitigation in different stages .

Water surface tension is applied widely in current aerosol-cloud models but could be inappropriate in the presence of atmospheric surfactant. With cloud condensation nuclei (CCN) activity and atomic force microscopy (AFM) measurement results of inorganic salt/dicarboxylic acid mixed particles, we concluded that surface tension reduction and phase state should be carefully considered in aerosol-cloud interactions. Our results could help to decease the uncertainties in climate models.

We projected climate change impacts to rain-on-snow melt events in the Great Lakes Basin. Decreases in snowpack limit future rain-on-snow melt. Areas with mean winter/spring air temperatures near freezing are most sensitive to rain-on-snow changes. The projected proportion of total monthly snowmelt from rain-on-snow decreases. Timing for rain-on-snow melt projected to be 2 weeks earlier by mid-21^st century and affects spring streamflow. This could affect management of freshwater resources.

Effective mitigation of greenhouse gas (GHG) emissions relies on an accurate understanding of emissions. Here we integrate inventory- and atmosphere- based approaches for estimating US emissions of SF₆, the most potent GHG known over a 100-year time-horizon. The results suggest a large decline in US SF₆ emissions, shed light on the possible processes causing the differences between the independent estimates, and identify opportunities for substantial additional emission reductions.