A simple model to study wave-surge interaction

ABSTRACT. In this paper we have tried to set up a mathematical model that will show the contribution of wind-induced surface waves of the ocean, on surges in shallow basin of Bay of Bengal. For this, the energy balance equation, excluding non-linear forcing term, is considered and solved by Lax-Wendroff integration scheme. Wind is specified over all the grid points following Cardone' s formulation. The hydrodynamic equations in linearised form as used by Jelesnianski have been considered and using Shuman's algorithm, those equations have been solved. In the process of solving these equations, the output of the energy balance equation is included as wave set up term to incorporate energy contribution of wind waves to surges. The estimated surge height is compared with and without considering wave contribution.

A Review of Solar Still Assessment with Various PCM Materials

Solar distillation purifies water by transferring sun's heat to a simple device. A shallow basin with a glass shield makes up the majority of the system, which is usually referred to as a solar even now. Evaporation takes place when the pool water is heated by the sun. Humidity rises, condenses on the shield, and drips into a drip tray, leaving salts, minerals, as well as the majority of contaminants behind. The oceans, that have a high salinity, are now the only nearly inexhaustible source of water supply.Separating salts from seawater, on the other hand, necessitates a huge amount of energy, that also, when derived from fossil fuels, can be destructive to the environment. As a result, desalination of seawater must be done using environmentally friendly energy sources. PCM which are solar, are widely used to store solar radiation during the day and release it in the evening, in a wide range of solar applications

Team Mapping of Oxia Planum for the ExoMars 2022 Rover-Surface Platform Mission

<p>Oxia Planum (OP), located at the transition between the ancient terrain of Arabia Terra and the low lying basin of Chryse Planitia, will be the landing site for the ESA-Roscosmos ExoMars Programme’s 2022 mission [1]. The descent module and landing platform, Kazachock, will transport the Rosalind Franklin Rover to search for signs of past and present life on Mars, and investigate the geochemical environment in the shallow subsurface over a 211-sol nominal mission.</p><p>OP forms a shallow basin, open to the north, characterized by clay-bearing bedrock, and episodic geological activity spans from the ~mid-Noachian to ~early Amazonian in age [2,3,4]. Building a thorough understanding of Oxia Planum prior to operations will provide testable hypotheses that facilitate interpretation of results, and hence provide an effective approach to address the mission’s science objectives. To this end, we have run a detailed group mapping campaign at HiRISE-scale using the Multi-Mission Geographic Information System (MMGIS) [5], co-registered HRSC [6], CaSSIS and HiRISE mosaics [7], and 116 1km<sup>2</sup> quads covering the 1-sigma landing ellipse envelope. Complementary CTX-scale mapping covers the wider area around the landing site and is described elsewhere [8].</p><p>Throughout 2020, 84 mapping volunteers associated with the mission’s Rover Science Operations Working Group followed a pre-formulated programme of training, familiarisation and mapping. With the mapping phase complete, a small sub-team are focused on map reconciliation phase, comprising data cleaning and science decision making. The process will culminate in map finalisation and submission for publication, and use in activities to plan rover science activities.</p><p>This campaign yields important advances for overall science readiness of the ExoMars 2022 mission:</p><ul><li>Team experience working, communicating and learning together, valuable for operations.</li> <li>Building team knowledge of the landing site, and the main scientific interpretations.</li> <li>Curated datasets and software available for team use in ongoing planning.</li> </ul><p>High-resolution map data representing our geologic understanding of Oxia Planum. This is an input to ongoing RSOWG work to construct the mission strategic plan, which provides science traceability from mission objectives to rover activities.</p><p><strong>Acknowledgments:</strong> We thank Fred Calef and Tariq Soliman at JPL for their support regarding MMGIS.</p><p><strong>References:</strong> [1] Vago, J. L. et al., (2017) Astrobiology 17 (6–7), 471–510. [2] Carter, J. et al., (2013) J. Geophys. Res. 118 (4), 831–858. [3] Quantin-Nataf, C. et al., (2021) Astrobiol. 21 (3),  doi:10.1089/ast.2019.2191. [4] Fawdon P. et al., (2019) LPSC50 #2132. [5] Calef, F. J. et al., (2019) in 4th Planet. Data Work., Vol. 2151. [6] Gwinner, K. et al., (2016) Planet. Space Sci. 126, 93–138. [7] Volat, M. et al., (2020), EPSC, #564. [8] Hauber, E. et al. (2021), LPSC52.</p>

Specific features of sandstones of Upper Devonian Tayokuyakhinskaya Formation on southeastern slope of the Kanin Kamen range (Kanin Peninsula)

The results of studying the lithological and geochemical characteristics of sandstones of the Upper Devonian Tayaokuyakhinskaya Formation in the southeastern part of the Kanin Nos Peninsula are presented. The accumulation of sandstones of the Tayaokuyakhinskaya Formation occurred in the absence of volcanic activity in a shallow basin with small periodic fluctuations in sea level, which led to a change in the degree of maturity, sorting, and the ratio of clay and sandy components in the rock. The accumulation of the psammitic strata occurred due to the destruction and redeposition of weakly weathered sedimentary rocks in a moderately warm climate. It was established that the formation of the composition of sandstones was influenced by at least two sources of clastic material — garnet-bearing crystalline shales and feldspar-quartz sandstones metamorphosed into the greenschist facies. The latter, most likely, were the source of the indicative gold contents found in the Devonian clastic rocks.

Numerical Simulation of the Solitary Waves Propagation and Run-up in Shallow Water

Purpose. The paper is aimed at investigating the propagation of solitons in a shallow basin, assessing the nonlinear effects resulting from the wave run-up on a gentle coast, and at comparing the estimates obtained using different numerical models with the available analytical dependencies. Methods and Results. The results of numerical simulations carried out using two nonlinear models of long waves (the author's model and the Simulating WAves till SHore (SWASH) one) are represented in the paper. The solitary wave profiles were obtained during its propagation in the part of a basin with constant depth conjugated with the inclined bottom. The process of a wave run-up on the coast was simulated using the algorithm of fluid movement along a dry coast. It is shown that when a soliton propagates in the basin part with constant depth, the nonlinearity effects are manifested in deformation of a wave profile. In other words, increase of the wave initial amplitude and the distance traveled by a wave is accompanied by growth of the wave front slope steepness. This, in its turn, leads to increase of a splash when the waves run-up on the coast. The estimates of the run-up heights resulted from different numerical models are in good agreement. Conclusions. The calculated values of the maximum wave run-up on the coast for the non-deformed waves, the length of which is equal to that of the traversed path, are close to the estimates obtained analytically. For the waves with the deformed profile, the front slope steepness of which increases with propagation over long distances, the run-up heights increase with growth of the wave initial amplitude. In such a case, it is desirable to replace the analytical estimates with the numerical ones. The run-up height of the deformed waves can exceed the wave initial amplitude by four or more times. The results obtained in this study can be useful in projecting the coastal protection constructions with the regard for preserving the coastal ecology and economy.

First Evidence of Peat Domes in the Congo Basin using LiDAR from a Fixed-Wing Drone

The world’s most extensive tropical peatlands occur in the Cuvette Centrale depression in the Congo Basin, which stores 30.6 petagrams of carbon (95% CI, 6.3–46.8). Improving our understanding of the genesis, development and functioning of these under-studied peatlands requires knowledge of their topography and, in particular, whether the peat surface is domed, as this implies a rain-fed system. Here we use a laser altimeter mounted on an unmanned airborne vehicle (UAV) to measure peat surface elevation along two transects at the edges of a peatland, in the northern Republic of Congo, to centimetre accuracy and compare the results with an analysis of nearby satellite LiDAR data (ICESat and ICESat-2). The LiDAR elevations on both transects show an upward slope from the peatland edge, suggesting a surface elevation peak of around 1.8 m over ~20 km. While modest, this domed shape is consistent with the peatland being rainfed. In-situ peat depth measurements and our LiDAR results indicate that this peatland likely formed at least 10,000 years BP in a large shallow basin ~40 km wide and ~3 m deep.