The Eastern Pontides are the northmost component of the Anatolian orogen. Its geological development closely associated with the evolution of the Ankara-Erzincan Suture. It exhibits records of the events from the opening to the eliminations of the surrounding oceans. During the Late Paleozoic, the Pontides were located in the north of Gondwana, facing the Paleo-Tethys Ocean. The southward subduction of the Paleo Tethyan oceanic lithosphere generated an active continental margin and opening of the Neo-Tethys Ocean as a back-arc basin during the Early Mesozoic. Throughout the Jurassic-Early Cretaceous, the Pontides remained a passive continental margin facing the Neo-Tethys in the south. Arc reversal occurred as the Neo-Tethys began subducting under the Pontides during the late Early Cretaceous (?)-Late Cretaceous. The Pontides experienced four collisional events throughout the development of the Ankara-Erzincan Suture; (1)- a forearc-arc collision occurred when the accretionary complex, which formed along the southern edge of the Pontides was backthrust over its leading edge during the Late Campanian. (2)- This was followed by a continent-arc collision when the Kırşehir Massif and the underlying NeoTethyan ophiolite nappe collided with and thrust over the Pontides at the end of the Early Eocene, (3)- Following the oceanic lithosphere’s total demise, the remnant basin located between the Pontides, and the Taurus was closed under the northerly advancing Taurus nappes during the Late Eocene. The latest collision is related with the collision of the Arabian Plate with the Anatolian plates. The Arabian Plate’s continuing northward advance after the demise of the NeoTethyan Ocean squeezed and shortened the Eastern Anatolia. From this time onward, the Eastern Pontides were thrust to the north and the south over the surrounding tectonic belts and started to rise as a coherent block.

For over a decade, the Super Dual Auroral Radar Network (SuperDARN) and the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) have been measuring ionospheric convection and field-aligned currents in the high-latitude regions, respectively. Using both, whole hemisphere maps of the magnetosphere-ionosphere energy transfer rate (the Poynting flux) have been generated with a time resolution of two minutes between 2010 and 2017. These uniquely data driven Poynting flux patterns are used in this study to perform a superposed epoch analysis of the northern hemisphere ionospheric response to transitions of the IMF B_z component. We discuss the difference in the distribution of Poynting flux between the magnetosphere-ionosphere Dungey cycle “switching on” and “switching off” to solar wind driving, revealing that they are not symmetric temporally or spatially.

Bays within eastern boundary upwelling systems (EBUS) are ecological hot-spots featuring a diverse range of spatio-temporal dynamics. At the EBUSs’ poleward limit, upwelling occurs in short-lived (<1 week) pulses modulated by synoptic wind variability. The circulations in long, narrow bays can respond to these fluctuations within few hours. The short-term biological response to these pulses was investigated in two of these bays (Rias Baixas, NW-Iberia) with a two-week quasi-synoptic spatio-temporal survey in the summer 2018. A four-day-long upwelling pulse caused deep, nutrient-rich isopycnals to rise into the euphotic zone inside the bays, triggering a rapid (~1.7 days) nutrient uptake and formation of a subsurface chlorophyll maximum (~3.8 days). The phytoplankton biomass was transported rapidly toward deep, offshore waters when the winds weakened. These results suggest that high productivity in narrow bays is controlled by the transient exposure of deep, nutrient-rich waters to light during upwelling pulses.

River flow changes on timescales ranging from minutes to millennia. These variations influence fundamental functions of ecosystems, including biogeochemical fluxes, aquatic habitat, and human society. Efforts to describe temporal variation in river flow—i.e. flow regime—have resulted in hundreds of unique descriptors, complicating interpretation and identification of global drivers of overall flow regime. In this study, we used three analytical approaches to investigate three related questions: 1. how interrelated are flow regime metrics, 2. what catchment characteristics are most associated with flow regime at different timescales globally, and 3. what hydrological processes could explain these associations? To answer these questions, we analyzed a new global database of river discharge from 3,685 stations with coverage from 1987 to 2016. We calculated and condensed 189 traditional flow metrics via principal components analysis (PCA). We then used wavelet analysis to perform a frequency decomposition of each time series, allowing comparison with the flow metrics and characterization of variation in flow at different timescales across sites. Finally, we used three machine learning algorithms to relate flow regime to catchment properties, including climate, land-use, and ecosystem characteristics. For both the PCA and wavelet analysis, just a few catchment properties (catchment size, precipitation, and temperature) were sufficient to predict most aspects of flow regime across sites. The wavelet analysis revealed that variability in flow at short timescales was negatively correlated with variability at long timescales. We propose a hydrological framework that integrates these dynamics across daily to decadal timescales, which we call the Budyko-Darcy hypothesis.

Our oceans are critical to the health of our planet and its inhabitants. Increasing pressures on our marine environment are triggering an urgent need for continuous and comprehensive monitoring of the oceans and stressors, including anthropogenic activity. Current ocean observational systems are expensive and have limited temporal and spatial coverage. However, there exists a dense network of Fibre-Optic (FO) telecommunication cables, covering

Cratering is a prominent evolutionary process on asteroids. Crater morphologies, regolith generation, bulk fracturing and projectile implantation are all examples of asteroidal surface evolution resulting from impact processes. With the upcoming launch of the Psyche mission in 2022, followed by the spacecraft’s arrival at the 225-km presumed metal-rich asteroid, characterizing impact processes on relevant metal bodies is key for interpreting mission data. Small-scale impact experiments into metals (e.g., iron, aluminum, copper, steel) have shown that crater morphologies into these materials are different than rocky targets — exhibiting notable distinctive features such as raised, sharp rims, and deeper cavities. While several impact codes have been used to simulate and benchmark laboratory scale impacts on rocky targets, it has not yet been shown how well these codes match observed crater shapes in Fe-Ni materials which may constitute the metallic component of Psyche. Here we have used iSALE and CTH shock physics codes to simulate and compare with the observed experimental crater morphologies in Fe-Ni targets. It was found that, when using material strength parameters directly measured in laboratory mechanical tests, at low and high strain-rates and relevant temperatures, it is possible to closely match crater diameters and depths from the impact tests.

GeoHealth as a research paradigm offers the opportunity to re-evaluate common research engagement models and science training practices. GeoHealth challenges are often wicked problems that require both transdisciplinary approaches and the establishment of intimate and long term partnerships with a range of community members. We examine four common modes of community engagement and explore how research projects are launched, who has the power in these relationships, and how projects evolve to become truly transformative for everyone involved.

Perhaps the least ambiguous signal that the mantle is convecting comes from observations of seismic anisotropy---the variation of wave speed with direction---which must arise due to the ordering of material as deformation occurs. Therefore significant effort has been made over many years to infer the direction and nature of mantle flow from these data. Observations have focussed on the boundary layers of the mantle, where deformation is expected to be strongest and where anisotropy is usually present. While prospects for mapping flow seem good, the lack of knowledge of several key issues currently holds progress back. These include the cause of anisotropy in the lowermost mantle, the causative material's response to shear, and the single-crystal or -phase seismic properties of the causative materials. In this chapter we review recent observations of lowermost mantle anisotropy, constraints on mineral elasticity and deformation mechanisms, and challenges in linking geodynamic modelling with seismic observations.

The Moon's bright albedo markings, known as swirls, are defined by broad, bright, on-swirl areas separated by darker off-swirl lanes. Their formation mechanism has long been debated and is key for understanding the processing of the lunar surface, the mobility of the lunar soil particles, and the effects of the space environment on planetary surfaces. Here we present, for the first time, evidence that these features do not necessarily cross the surface without regard to topography or local terrain. Within portions of Mare Ingenii on the lunar far-side, brighter on-swirl areas have statistically lower mean elevations than adjacent, darker, off-swirl lanes. These topographic characteristics provide constraints on the plausible formation mechanisms for the swirls in Mare Ingenii, which in turn provide insight into lunar soil migration and evolution. We believe this correlation with topography argues for highly mobile dust transport across the lunar surface.

A new solution method is given for the general multiple collocation problem formulated in terms of the covariance equations. By a logarithmic transformation, the covariance equations reduce to ordinary linear equations that can be handled using standard methods. Solution by matrix inversion has the advantage that the analytical solutions can be reconstructed. The method can be applied to each determined or overdetermined subset of the covariance equations. It is demonstrated on quintuple collocations of ocean surface vectors winds obtained from buoys, three scatterometers and model forecasts, with representativeness errors estimated from differences in spatial variances. The results are in good agreement with those from quadruple collocation analyses reported elsewhere. The average of the solutions from all determined subsets of the covariance equations equals the least-squares solution of all equations. The standard deviation of all solutions from determined subsets agrees with the accuracy found in earlier triple and quadruple collocation studies, but the difference between minimum and maximum value is much larger. It is shown that this is caused by increased statistical noise in more complex solutions. The averages of the error covariances are close to zero, with a few exceptions that may point at small deficiencies in the underlying error model. Precise accuracy estimates are needed to decide to what extent statistical noise explains the spreading in the results and what is the role of deficiencies in the underlying error model.

Rifting and continental break-up are fundamental tectonic processes, the understanding of which is of prime importance. However, the vast temporal and spatial scales involved pose major limitations to researchers. Analogue tectonic modelling represents a great means to mitigate these limitations, but studying internal deformation in lithospheric-scale models remains a challenge. We therefore present a novel method for lithospheric-scale rifting models that are uniquely monitored in an X-ray CT-scanner. CT-scanning, combined with digital image correlation (DIC) techniques, provides unparalleled insights into model deformation. Our models show that the degree of coupling between competent lithospheric layers, which are separated by a weak lower crustal layer, strongly impacts rift system development. Low coupling isolates the upper crust from the upper lithospheric mantle layer below, preventing an efficient transfer of deformation between both layers. By contrast, fast rifting increases coupling, so that deformation in the mantle is efficiently transferred to the upper crust, inducing either a symmetric or asymmetric (double) rift system. The observation that asymmetric deformation can initiate during the earliest rifting stages challenges the two-phase scenario involving initial symmetric rifting, prior to subsequent asymmetric rifting. Oblique divergence leads to en echelon graben arrangements, and seemingly delays break-up, somewhat in contradiction to concepts of oblique divergence promoting break-up. These insights provide an incentive to further run lithsospheric-scale rifting models, and to apply advanced monitoring techniques to extract as much information as possible from these. There is indeed a broad range of opportunities for follow-up studies within and beyond the field of rift tectonics.

Since mid-2008, automated radio monitoring networks such as the Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) have been observing and logging global amateur radio high frequency (HF, 3-30 MHz) communications. These networks are built and operated by amateur radio operators for amateur radio purposes, but the data are also useful for the study of ionospheric space weather and ionospheric science. Ham Radio Science Citizen Investigation (HamSCI) members will present global observations of over 1.9 billion radio reports on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands. The observations span an 11-year period from 2009-2020. We find a correlation between HF propagation path characteristics and the solar EUV output through the F10.7 index, along with solar cycle effects, seasonal effects, and sporadic E signatures. We will also discuss impacts of operator behavior and sampling effects caused by the distribution of amateur radio transmitting and receiving stations.

The contaminated ground water has now evolved to be a real threat for the public as well as the agricultural growth. Many minerals present in the ground water that needs to be constantly monitored and in case of any discrepancy with the minerals’ levels immediate remedial measures become necessary to make it safe to drink as well as to be used for the agricultural purposes. This study assesses the nine physiochemical parameters of drinking water quality of Lahore city. Three thousand, nine hundred and eighteen drinking water samples were randomly collected from the study area. These samples were physio-chemically analyzed for nine key toxic (in excess) elements such as Depth, Electric conductivity, Calcium-Magnesium, Sodium, Carbonates, Bi-Carbonates, Chlorine, Sodium adsorption ratio and Residual sodium carbonate. Geostatistical techniques such as variogram and kriging were used to investigate the spatial variations of these minerals across the city. Four variogram models were evaluated and most appropriate models were applied for each water quality parameter. The kriging predictions revealed significant concentrations of the above-stated elements at some locations in the study area. While comparing with the World Health Organization, United States Environmental Protection Agency, and Pakistan Environmental Protection Agency standards, the water samples were found to be unsatisfactory for drinking in Lahore City. We conclude that the drinking water in this region is of poor quality and needs proper treatment to make it palatable.

A modeling framework is presented for hydrological modeling to more accurately describe the water, energy, and carbon cycles and their interactions with participating processes. This framework extends the modeling strategy presented in Luo et al. (2013) by simultaneously using multiple plausible expressions, derived from different perspectives, in representing the same processes, and enforcing them together with an optimality rule and a semi-empirical expression for plant CO2 uptake. The objectives are to reduce unconstrained free variables, mitigate parameter or variable equifinality, reduce result uncertainties, and ultimately increase the model robustness and predictability. For demonstration, the least cost optimality theory from Prentice et al. (2014), after extended to include water-limited conditions, is combined with the updated semi-empirical Ball-Berry-Leuning formulation (Tuzet et al., 2003). These two expressions are combined with other multiple expressions adopted for hydrological modeling. This framework is incorporated into both VIC+ and a modified DHSVM hydrological models with each applied to two different sites. Numerical studies are performed that using three approaches which only differ in the stomatal conductance modeling, namely, one uses the extended Prentice, one the semi-empirical, and the new framework that uses both. Results show that although all three approaches give reasonable estimates of limited measured fluxes, the present modeling framework gives much more reasonable estimates in the stomatal conductance and in other major model variables, and it also results in giving a relationship between carboxylation and transpiration that is consistent with observations. This modeling framework is general and can be adopted for other fields of study.

The total lunar eclipse from October 28, 2004, was observed by AMSU-B (Advanced Microwave Sounding Unit - B) on NOAA-15 during a couple of minutes of each orbit around the Earth. From this unique vantage point in space it could provide disk-integrated, effective lunar temperatures at lower frequencies than employed in most previous observations of eclipses, in intervals of 100 min. The relative changes in brightness temperature were 6.4±2.1% at 89 GHz and 16.6±2.1% at 183 GHz. This trend of stronger temperature drop at higher frequency was expected on the basis of a new radiative transfer model simulating the global brightness temperatures. Our measurements disprove two results published in the past, but they confirm the claim made before that the changes are similar at the center and for the whole disc. In terms of precision they are comparable to those carried out in the past with radio telescopes on ground.

Tsunamis in the Mediterranean Sea have been increasingly investigated in the last decades due to past destructive events. We present a novel approach for evaluating tsunami-induced coastal inundation, based on a generalization of Green’s law and a chain of intermediate and small-scale numerical simulations. At the intermediate level, simulations with a linear solver are made to identify the coastal distribution of a novel parameter, namely α, condensing all nearshore wave transformations other than shoaling. α represents a proxy for coastal susceptibility to the tsunami impact. Small-scale modelling of coastal flooding performed in the southern Italy on a freely available DTM at the Esaro river estuary (Calabria) yields inundation levels that compare well with those obtained via intermediate-scale modelling, with a saving in computational time of about 41%. This demonstrates the helpfulness of α to “scale” the offshore wave input and reduce the computational effort to evaluate flooding at regional scale.

Atmospheric rivers (ARs) are efficient mechanisms for transporting atmospheric moisture from low latitudes to the Antarctic Ice Sheet (AIS). While AR events occur infrequently, they can lead to extreme precipitation and surface melt events on the AIS. Here we estimate the contribution of ARs to total Antarctic precipitation, by combining precipitation from atmospheric reanalyses and an polar-specific AR detection algorithm. We show that ARs contribute substantially to Antarctic precipitation, especially on East Antarctica at elevations below 3000 meters. ARs play a vital role in explaining the substantial year-to-year variability in Antarctic precipitation. Our results highlight that ARs are an important component for understanding present and future Antarctic mass balance trends and variability.

Although zooplankton play a substantial role in the biological carbon pump and serve as a crucial link between primary producers and higher trophic level consumers, the skillful representation of zooplankton is not often a focus of ocean biogeochemical models. Systematic evaluations of zooplankton in models could improve their representation, but so far, ocean biogeochemical skill assessment of Earth system model (ESM) ensembles have not included zooplankton. Here we use a recently developed global, observationally-based map of mesozooplankton biomass to assess the skill of mesozooplankton in six CMIP6 ESMs. We also employ a biome-based assessment of the ability of these models to reproduce the observed relationship between mesozooplankton biomass and surface chlorophyll. The combined analysis found that most models were able to reasonably simulate the large regional variations in mesozooplankton biomass at the global scale. Additionally, three of the ESMs simulated a mesozooplankton-chlorophyll relationship within the observational bounds, which we used as an emergent constraint on future mesozooplankton projections. We highlight where differences in model structure and parameters may give rise to varied mesozooplankton distributions under historic and future conditions, and the resultant wide ensemble spread in projected changes in mesozooplankton biomass. Despite differences, the strength of the mesozooplankton-chlorophyll relationships across all models was related to the projected changes in mesozooplankton biomass globally and in regional biomes. These results suggest that improved observations of mesozooplankton and their relationship to chlorophyll will better constrain projections of climate change impacts on these important animals.