Recently posted  

Seasonal sea ice arch formation in the Nares Strait has shielded the Petermann Glacier Ice Shelf from enhanced basal melting. However, with the sustained decline of the Arctic sea ice predicted to continue, the ice shelf is likely to be exposed to a year round mobile and thin sea ice cover. In such a scenario, our model results show that amplification of thermal driving and friction velocity in the ice shelf cavity driven by the surface forcing modulations amplify the basal melting.

The algorithm that produces the near-real-time data products of the Aura Microwave Limb Sounder has been updated. The new algorithm is based on machine learning techniques and yields data products with much improved accuracy. It is shown that the new algorithm outperforms the previous versions even when it is trained on only a few years of satellite observations. This confirms the potential of applying machine learning to the near-real-time efforts of other current and future mission concepts.

Chlorofluorocarbons were used in Europe pre-1990, before legislation controlled production and use to stop further damage to the stratospheric ozone layer. Global emissions have then decreased sharply, but the rate of decline of CFC-11 recently slowed, which was in part attributed to illegal emission from Eastern China. This four model study concludes that emissions of CFC-11 in Western Europe are unlikely to be the result of new production and that the rate of decline of CFC-11 is as expected.

This paper present the Coastal Ice-Ocean Prediction System implemented operationally at Environment and climate change Canada. The objective is to enhance the numerical guidance in coastal areas to support electronic navigation and response to environmental emergencies in the aquatic environment. Model evaluation against observations shows improvements for most surface ocean variables in the coastal system compared to current coarser-resolution operational systems.

Anthropogenic fugitive dust is causing severe coarse particulate matter (PM) air pollution in East Asia. Due to emission control efforts, coarse PM decreased steadily. We find that the decrease of coarse PM is the major reason for the lack decrease of fine particulate nitrate, as it allows more nitric acid to form fine particulate nitrate. The continuing decrease of coarse PM requires more stringent ammonia and nitrogen oxides emission controls to successfully decrease fine particulate nitrate.

In mountain catchments, damage during floods are generally primarily driven by the supply of massive amount of sediment. Predicting how much sediment can be delivered by frequent and infrequent events is thus important in hazard studies. This paper use data gathered during the maintenance operation of about one hundred debris retention basins to build simple equations aiming at predicting sediment supply from simple parameters describing the upstream catchment.

Through analogue models and field observations, we investigate how inherited platform-basin geometries control strain localisation, style, and orientation of reactivated and new structures during inversion. Our study shows that the style of evolving thrusts and their changes along strike are controlled by pre-existing rheological discontinuities. The results of this study are relevant for understanding inversion structures in general and for the European eastern Southern Alps in particular.

Paleoclimate data assimilation is a useful method that allows researchers to combine climate models with natural archives of past climates. However, it can be difficult to implement in practice. To facilitate this method, we present DASH, a MATLAB toolbox. The toolbox provides routines that implement common steps of paleoclimate data assimilation, and it can be used to implement assimilations for a wide variety of time periods, spatial regions, data networks, and analytical algorithms.

Accretion during subduction, in which one tectonic plate moves under another, forms a wedge where sediments can be transformed into hydrocarbons. We utilised realistic computer models to investigate this, in particular, how accretion affects mobility in the wedge and found that the evolution of the wedge, and the thrusts it develops fundamentally control the thermal maturity of sediments. This can help us better understand the history of subduction and the formation of hydrocarbons in wedges.

Future sea-level rise exhibits multiple forms of uncertainty, all of which must be considered by scientific assessments intended to inform decision making. The Framework for Assessing Changes To Sea-level (FACTS) is a new software package intended to support assessments of global mean, regional, and extreme sea-level rise. An early version of FACTS supported the development of the IPCC Sixth Assessment Report sea level projections.

Stakeholders need high-resolution regional climate data for applications such as assessing water availability, mountain snowpack, etc. This study examines 3- and 24-hr historical precipitation over the contiguous United States in the 12-km WRF version 4.2.1-based dynamical downscaling of the ERA5 reanalysis. WRF improves precipitation characteristics such as the annual cycle and distribution of the precipitation maxima, but it also displays regionally and seasonally varying precipitation biases.

Bottom Water constitutes the lower limb of the ocean’s overturning system and is primarily formed in the Antarctic Weddell and Ross Seas due to interactions between the atmosphere, ocean, sea ice and ice shelves. Here we use a global ocean 1° resolution model with the three large ice shelves important for the formation of the parent waters of Bottom Water explicitly represented and find doing so reduces salinity biases, improves water mass realism, and gives realistic ice shelf melt rates.

We present a new analytical model for collision rates between molecules and clusters of arbitrary sizes, that accounts for long-range interactions. The model is verified against atomistic simulations of typical acid-base clusters participating in atmospheric new particle formation. Results show that accounting for long-range interactions leads to 2–3 times higher collision rates for small clusters, indicating the necessity of including such forces in atmospheric new particle formation modelling.

Tropical forests like Amazon are historically an important carbon sink, helping to mitigate global climate change. Using an atmospheric model and regional and global atmospheric CO₂ observations, we quantified Amazonian carbon emissions between 2010 and 2018. We estimated that Amazon acted as a small carbon source to the atmosphere, mostly due to fire emissions. However, the forest uptake compensated 50 % of these fire emissions. We do not find an increasing time trend of carbon emissions.

Carbon fluxes from agroecosystems change the carbon cycle and the amount of CO₂ in the air. Using the Integrated Science Assessment Model (ISAM), we looked at the carbon cycle in areas where spring wheat is grown. The results showed that fluxes vary a lot between regions, mostly because planting times are different. According to our investigation into which variables have the greatest impact on the carbon cycle, nitrogen fertilizers added to crops have the greatest impact on the carbon cycle.

The role of gravity waves on tropical cirrus clouds and air parcel dehydration was studied using the combination of Lagrangian observations of temperature fluctuations from superpressure balloons and a 1.5 dimension model. A reference simulation of a slow ascent of air parcels in the tropical tropopause layer showed nucleation occurring only below the cold point with a small ice crystals density. Adding gravity waves drastically increases ice crystal number and fits better to observations.

Seagrass meadows are an emblematic coastal habitat. Their sensitivity to environmental change means that it is essential to monitoring their evolution closely. However, high costs make this endeavor a technical challenge. Here, we used machine learning to map seagrass meadows in 148 satellite images in the Venice Lagoon, Italy. We found that adding information like depth of the seabed and known seagrass location improved our capacity to map change in seagrass habitat.

Earthworm invasion in North American forests can alter soil functioning. We investigated how the presence of invasive earthworms affected microbial communities, key drivers of soil biogeochemistry, across the major soil types present in the Canadian boreal forest, a region largely understudied. Although total microbial biomass did not change, community composition shifted in earthworm-invaded mineral soils, where we also found higher fungal biomass and greater microbial species diversity.

We propose an HRBF formulation, AdaHRBF, with an adaptive gradient magnitude for continuous 3D SPF modeling of multiple stratigraphic interfaces. In the linear system of HRBF interpolant constrained by the scattered on-contact attribute points and off-contact attitude points of a set of strata in 3D space, we add a novel optimizing term to iteratively obtain the true gradient magnitude.

Secondary organic aerosols are an important component of PM_2.5, with contributions from anthropogenic, biogenic volatile organic compounds, semi- and intermediate volatility organic compounds. Policy makers need to know which SOA precursors are important. We investigated the role of different SOA precursors and SOA algorithms by applying two commonly used models, CAMx and CMAQ. Suggestions for SOA modelling and control are provided.

The reported below-cloud wet scavenging coefficients (BWSCs) are much higher than the theory, but the reason of it remains unclear. Based on the long-term observation, we find the air masses changing during the rainfall events causes the overestimation of BWSCs. Thus, the discrepancy in BWSCs between observation and theory is not as large as currently believed. To obtain reasonable BWSCs and parameterizations from field observations, the effect of air masses changing needs to be considered.

Equatorial deep jets are ocean currents that flow along the equator in the deep oceans. They are relevant for oxygen transport and tropical surface climate, but their dynamics are not yet entirely understood. We investigate different factors leading to the jets being broader than theory predicts. Mainly using an ocean model, but corroborating the results with shipboard observations, we show that dissipation of momentum is the main factor for the broadening, but that meandering also contributes.

Simulations are performed with an intermediate complexity climate model, PLASIM, to assess the future response of the monsoons to changing concentrations of aerosols and greenhouse gases. The aerosol loading is applied to India, Southeast Asia and East China, both concurrently and independently. The primary effect of increased aerosol loading is a decrease in summer precipitation in the vicinity of the applied forcing, although the regional response varies significantly.

1. Conservation tillage significantly prevents soil loss in spring maize seedling stage. 2. Horizontal ridge rupture caused more runoff and soil loss even with cornstalks mulching. 3. Runoff strength, rather than soil erodibility, was the key factor for soil erosion. 4. Receding runoff velocity, rather than amount, was more effective to control soil loss. 5. Horizontal ridging with mulching is recommended to conserve soil and water.

The Weddell Sea is one of the most studied marine ecosystems outside the Antarctic Peninsula in the Southern Ocean. Yet, few studies consider the complexity of the Weddell Sea food web, which comprises 490 species and 16041 predator-prey interactions. Here we analysed a quantitative version of the Weddell Sea food web, where the interactions’ intensity is explicitly considered. We found that only a few species of marine mammals, sea birds, and fishes are important for the food web stability.

The influence of human-produced aerosols on clouds remains one of the uncertainties in radiative forcing of Earth’s climate. Measurements of aerosol chemistry from sources around the Philippines illustrate the linkage between aerosol chemical composition and cloud droplet characteristics. Differences in aerosol chemical composition in the marine layer from biomass burning, industrial and ship-produced, and marine aerosol are shown to impact cloud microphysical structure just above cloud base.

The differences between climate models can be exploited to infer how specific aspects of the climate influence the whole Earth system. This work analyses the effects of a negative temperature anomaly over the Tibetan Plateau on the winter atmospheric circulation. We show that models with a colder-than-average Tibetan Plateau present a reinforced East Asia winter monsoon and we discuss the atmospheric response to the enhanced transport of cold air from the continent toward the Pacific Ocean.

We studied groundwater near outlet glaciers of the main Icelandic icecap. We acquired new data in the field. Two distinct groundwater compartments and their characteristics are identified. We demonstrate the glacial melt recharge impact on the groundwater dynamic. Knowing groundwater systems in glacial context is crucial to forecast the evolution under climate change of water resources and of potential floods and landslides hazards.

The aim of this review is to summarize the current knowledge about mud-volcano-like structures on Mars, address the critical aspects of process of sedimentary volcanism, identify key open questions, and point to areas where further research is needed to understand this phenomenon and its importance for the red planet’s geological evolution.

The utilities of tight rock are critically needed in various emerging fields of energy geosciences such as EGS and CCUS, but its ultra-low-permeability is not easily measurable, with a lack of a theory-based, rigorous, and rapid measurement technique at sub-nano darcy levels. For the first time, we resolve this by providing an integrated technique (termed as gas permeability technique) with coupled theoretical development, experimental procedures, and data interpretation workflow.

The mixed layer depth (MLD) in the Southern Ocean varies significantly with time and location. We found that, while the wind forcing and surface heating induces the mesoscale MLD variability, the oceanic currents counteracts the atmospheric effects. The role of oceanic currents also changes seasonally. This study emphasizes the importance of ocean currents in driving mesoscale MLD variability, and demonstrates how MLD in modulating the effects of intrinsic oceanic variability.

We reconstructed sea ice and organic carbon composition variabilities based on biomarkers and carbon stable isotopes in the northern Chukchi Sea, western Arctic Ocean, over the past 200 years. Under permanent ice cover, organic carbon was dominated by land sources transported by sea ice and ocean currents, while local primary productivity was suppressed by light limitation. Since ice retreated in 20th century, organic carbon from primary production gradually overtook the terrestrial component.

In this study, we compared measurements from CryoSat-2 and ICESat-2 over Arctic summer sea ice, to understand any possible biases between the two satellites. We found that there is a difference when we measure elevation over summer sea ice using CryoSat-2 and ICESat-2 and this is likely due to surface melt ponds. The differences we found were in good agreement with theoretical predictions, and this work will be valuable for summer sea ice thickness measurements from both altimeters.

Long-term temperature measurements are challenging to carry out in mountain permafrost boreholes. The widely used resistance thermistors are highly accurate but prone to drift when they are exposed to moisture or the cable connecting them is stretched. We explore the possibility of supplementing them with digital sensors and analyse the performance of both systems at 15 depths in one mountain permafrost borehole.

This paper assesses the performance of the latest version (DT2021) of global gridded altimetry products distributed through the CMEMS and C3S Copernicus programs on the retrieval of sea level in the coastal zone of the European Seas respect to the previous DT2018 version. This comparison is made using an external independent dataset. DT2021 sea level products better solve the signal in the coastal band.

The present study used several different data sets, conducted a field survey and paired the data with three different machine learning algorithms to construct spatial maps for areas of risk for land degradation for the Lut watershed in Iran. land degradation map, almost the entire study region is at risk. A large fraction of 43 % of the area is prone to both high wind-driven plus water-driven soil erosion.

We present the theoretical basis of the algorithm for estimating the size and water content of cloud and precipitation. The algorithm utilizes the data collected by the Cloud Precipitation Radar that was developed for the upcoming Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) satellite mission. After the satellite launch, the vertical distribution of cloud and precipitation properties will be delivered as C-CLD product.

This study shows a methodological approach using Machine Learning techniques to disentangle the relationships among the variables in a synthetic dataset, to identify the suitable variables that control the hydrologic response of the slopes. It has been found that not only the rainfall is responsible for the water accumulation in the slope; the underground conditions (soil water content and aquifer water level) indicate the activation of natural slope drainage mechanisms.

Avaframe – the open avalanche framework – provides open-source tools to simulate and investigate snow avalanches. It is utilized for multiple purposes, the two main applications being hazard mapping and scientific research of snow processes. We present the theory, conversion to a computer model and testing for one of the core modules used for simulations of a particular type of avalanche, the so-called dense flow avalanches. Tests check and confirm the applicability of the utilized method.

Plane strain ductile deformation experiments on rock salt (halite) samples with variable siliciclastic content were conducted. While halite accomodates the strain by the formation of subgrains, deformation in the siliclastic domains was brittle. An increase in the siliclastic content leads to an increase in differential stress of the halite matrix. The results suggest that the barrier properties of rock salt is significantly reduced by larger content of siliciclastic material.

This study shows that mineral aerosols (dust) emission events in high-latitude areas are under-represented in both ground and space detecting methods. This is done through a suite of ground-based data to prove that dust emissions from the proglacial area, Lhù’ààn Mân occur almost daily but are not always recorded at different timescales. Dust has multiple effects on atmospheric process, therefore accurate quantification is important in the calibration and validation of climate models.

Spaceborne thermal infrared sensors with kilometer-scale resolution cannot support adequate parameterization of Arctic leads. For the first time, we applied the 30 m resolution data from the Thermal Infrared Spectrometer (TIS) on the emerging SDGSAT-1 to detect Arctic leads. Validation with Sentinel-2 data shows high accuracy for the three TIS bands. Compared to the MODIS, the TIS presents more narrow leads, demonstrating its great potential for observing previously unresolvable Arctic leads.

Gravity waves (GW) transport energy both in the vertical and horizontal within the atmosphere and thereby can accelerate or decelerate winds in places, that are far from the GW source. We present a model, that identifies orographic GW sources and follows the initialized GWs on their path through the atmosphere. Results of this model are used to explain physical pattern in satellite observations (e.g. little activity above the Himalayas) and to predict seasonal patterns of GW propagation.

The freely available Global Downscaled Projections for Climate Impacts Research (GDPCIR) dataset gives researchers a new tool for studying how future climate will evolve at a local or regional level, corresponding to the latest global climate model simulations prepared as part of the U.N. Intergovernmental Panel on Climate Change’s Sixth Assessment Report. Those CMIP6 simulations represent an enormous advance in quality, detail, and scope that GDPCIR translates to the local level.

This study presents a new model scheme for simulating ice segregation and thaw consolidation in permafrost environments, depending on ground properties and climatic forcing. It is embedded in the CryoGrid Community Model, a land surface model for the terrestrial cryosphere. We describe the model physics and functionalities, followed by a model validation and a sensitivity study of controlling factors.

Louis Morin consistently recorded precipitation intensity and duration between 1665 and 1713. We use these records to reconstruct precipitation totals. This reconstruction is validated by several methods and then presented using precipitation indexes. Exceptional about this dataset is the availability of a subdaily resolution and the few missing data points over the entire measurement/observation period.

There are periods in Earth’s history when huge volumes of magma are erupted at the Earth’s surface. The gases released from volcanic eruptions and from sediments heated by the magma are believed to have caused severe climate changes in the geological past. We use a variety of volcanic and climatic tracers to assess how the North Atlantic Igneous Province (56–54 million years ago) affected the oceans and atmosphere during a period of extreme global warming.

This paper presents time series measurements of pH, dissolved inorganic carbon, and total alkalinity for organic rich estuarine water. The efficacy of sample preservation is examined by comparing results obtained with and without additions of the HgCl₂. Our results show that addition of HgCl₂ affects titration alkalinity and subsequently pH. Accurate analyses can be achieved using improvements in sample preservation techniques for carbonate system measurements in organic-rich estuarine waters.

The El Niño Southern Oscillation (ENSO) has a global influence on weather and climate. Over most of the equatorial Pacific, where ENSO is focused, variations in sea surface height, such as measured by satellite, are strongly influenced by vertical displacements of the ocean thermocline. We show that linearly removing this influence leads to a time series of sea surface height that capture ENSO dynamics in the central Pacific, where ENSO variability has become more active in recent decades.

We present an evaluation of current retrieval techniques in the ice phase applied to polarimetric radar measurements with collocated in situ observations of aircraft conducted over the Olympic Mountains, Washington State during winter 2015. Radar estimates of ice properties most agreed with aircraft observations in regions with pronounced radar signatures, but uncertainties were identified that indicate issues of some retrievals, particularly in warmer temperature regimes.