Monitoring and Modelling of ionospheric disturbances by means of GRACE, GOCE and Swarm in-situ observations

Mapping Intimacies ◽

10.5194/egusphere-egu21-14214 ◽

2021 ◽

Author(s):

Michael Schmidt ◽

Andreas Goss ◽

Eren Erdogan

Keyword(s):

Lower Atmosphere ◽

Ionospheric Disturbances ◽

Tsunami Propagation ◽

Ka Band ◽

Leo Satellites ◽

Vertical Displacements ◽

Grace Satellites ◽

Langmuir Probe Measurements ◽

The University ◽

Chile Tsunami

The main objective of the ESA-funded project COSTO (Contribution of Swarm data to the prompt detection of Tsunamis and other natural hazards) is to better characterize, understand and discover coupling processes and interactions between the ionosphere, the lower atmosphere and the Earth&#8217;s surface as well as sea level vertical displacements. Together with our project partners from the University of Warmia and Mazury (UWM), the National Observatory of Athens (NOA) and the Universitat Politecnica de Catalunya (UPC) we focus in COSTO to tsunamis that are the result of earthquakes (EQ), volcano eruptions or landslides.In the scope of COSTO a roadmap was developed to detect the vertical and horizontal propagation of Travelling Ionospheric Disturbances (TID) in the observations of Low Earth Orbiting (LEO) satellites. Under the assumption that the TIDs triggered by tsunamis behave in approximately the same way for different EQ / tsunami events, this roadmap can be applied also to other events. In this regard, the Tohoku-Oki EQ in 2011 and the Chile EQ in 2015 were studied in detail. The aim of investigating these events is to detect the TIDs in the near vicinity of the propagating tsunami. Thereby, given tsunami propagation models serve as a rough orientation to determine the moments in time and positions for which there is co-location with selected LEO satellites/missions, namely GRACE, GOCE and Swarm. GOCE with an altitude of around 280km and the GRACE satellites with an altitude of around 450km flew over the region where the Tohoku-Oki tsunami was located, about 2.5 hours after the EQ. Using wavelet transform, similar signatures with periods of 10-30 seconds could be detected in the top-side STEC observations of GOCE as well as in the Ka-band observations of GRACE at the time of the overflight. These signatures can be related to the gravity wave originating from the tsunami. Similar signatures were detected in the signals from the GRACE Ka-band observations and in the Swarm Langmuir Probe measurements at an altitude of 450 km for the 2015 Chile tsunami. These roadmap studies provided the first opportunity to observe the vertical and horizontal tsunami induced gravity waves in the ionosphere.

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Benchmark of lens antennas for KA-band global earth observation from leo satellites

2006 First European Conference on Antennas and Propagation ◽

10.1109/eucap.2006.4585020 ◽

2006 ◽

Cited By ~ 5

Author(s):

Jorge R. Costa ◽

Carlos A. Fernandes ◽

Gael Godi ◽

Ronan Sauleau ◽

Herve Legay

Keyword(s):

Earth Observation ◽

Ka Band ◽

Lens Antennas ◽

Leo Satellites

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University of Colorado and Black Swift Technologies RPAS-based measurements of the lower atmosphere during LAPSE-RATE

Earth System Science Data ◽

10.5194/essd-13-2515-2021 ◽

2021 ◽

Vol 13 (6) ◽

pp. 2515-2528

Author(s):

Gijs de Boer ◽

Cory Dixon ◽

Steven Borenstein ◽

Dale A. Lawrence ◽

Jack Elston ◽

...

Keyword(s):

Layer Structure ◽

Lower Atmosphere ◽

Lapse Rate ◽

San Luis Valley ◽

University Of Colorado ◽

San Luis ◽

Northern Half ◽

Remotely Piloted Aircraft ◽

In Situ Sensors ◽

The University

Abstract. Between 14 and 20 July 2018, small remotely piloted aircraft systems (RPASs) were deployed to the San Luis Valley of Colorado (USA) together with a variety of surface-based remote and in situ sensors as well as radiosonde systems as part of the Lower Atmospheric Profiling Studies at Elevation – a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE). The observations from LAPSE-RATE were aimed at improving our understanding of boundary layer structure, cloud and aerosol properties, and surface–atmosphere exchange and provide detailed information to support model evaluation and improvement work. The current paper describes the observations obtained using four different types of RPASs deployed by the University of Colorado Boulder and Black Swift Technologies. These included the DataHawk2, the Talon and the TTwistor (University of Colorado), and the S1 (Black Swift Technologies). Together, these aircraft collected over 30 h of data throughout the northern half of the San Luis Valley, sampling altitudes between the surface and 914 m a.g.l. Data from these platforms are publicly available through the Zenodo archive and are co-located with other LAPSE-RATE data as part of the Zenodo LAPSE-RATE community (https://zenodo.org/communities/lapse-rate/, last access: 27 May 2021). The primary DOIs for these datasets are https://doi.org/10.5281/zenodo.3891620 (DataHawk2, de Boer et al., 2020a, e), https://doi.org/10.5281/zenodo.4096451 (Talon, de Boer et al., 2020d), https://doi.org/10.5281/zenodo.4110626 (TTwistor, de Boer et al., 2020b), and https://doi.org/10.5281/zenodo.3861831 (S1, Elston and Stachura, 2020).

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THE EFFECT OF A SUBMARINE CANYON ON TSUNAMI PROPAGATION IN THE GULF OF ARAUCO, CHILE

Coastal Engineering Proceedings ◽

10.9753/icce.v33.currents.5 ◽

2012 ◽

Vol 1 (33) ◽

pp. 5 ◽

Cited By ~ 1

Author(s):

Rafael Aranguiz

Keyword(s):

River Mouth ◽

Submarine Canyon ◽

Eastern Coast ◽

Wave Direction ◽

Tsunami Propagation ◽

Eastern Side ◽

Nested Grids ◽

The 2010 Chile Tsunami ◽

Chile Tsunami ◽

Santa Maria

The 2010 Chile tsunami affected the entire coast of the Biobio Region, where several bays were flooded, and seawater surged hundreds of meters into rivers. However, no inundation occurred in the 2km wide Biobio River, located at the northern entrance of the Gulf of Arauco. Likewise, minimal inundation (less than 2m) was found on the gulf’s eastern coast, just south of the river mouth. The study was done by means of numerical simulation with TUNAMI code. Four (4) nested grids with 81”, 27”, 9” and 3” resolution were defined. Several scenarios were simulated, including the 1730, 1835, 1960 and 2010 events. The first two scenarios considered only a uniform rupture zone, while the others were defined using non-uniform initial condition. Another set of simulations were run without the presence of the island and with a modified bathymetry, so that its effect on tsunami propagation could be studied. It can be concluded that the Biobio canyon is very important in tsunami propagation in the Gulf of Arauco. There is a mitigation effect on the eastern side of the Gulf due to the refraction and dispersion generated by its presence. The change in wave direction is enhanced due to wave diffraction generated by the Santa María Island, causing the wave fronts to move in a north-south direction, preventing severe damage to the eastern side. However a direct impact of the tsunami in the southern end of the Gulf can be observed.

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Ionospheric Induction of Earthquakes: Fitting the Data

10.5194/egusphere-egu21-9614 ◽

2021 ◽

Author(s):

Daniel Helman

Keyword(s):

Solar Activity ◽

Small Sample ◽

Lower Atmosphere ◽

Seismic Events ◽

Petrographic Analysis ◽

Ionospheric Disturbances ◽

Simple Explanation ◽

Total Electron ◽

Ion Concentrations ◽

Large Earthquakes

This discussion assumes that there are ionospheric anomalies in total electron count (TEC) as precursors to major earthquakes. Very careful work by Thomas et al. (2017) and others remove TEC anomalies when correlated with natural events such as geomagnetic or solar activity. Without these data, correlation between ionospheric disturbances and large earthquakes (M &#8805; 7.0) occurs infrequently (~20% of events) and is within the standard error resulting from the small sample size. There are two possibilities: (1) either the mechanism of volatile (including radon) release that occurs in some regions precursory to major seismic events is unrelated to ionospheric disturbances; or (2) the occurrence of these volatiles is related first to geomagnetic and solar activity. The first hypothesis is easily falsified. In addition to careful statistical analysis by Thomas et al. and others, the mechanism for travel through the lower atmosphere of matter arising on the ground as a stable electric signal is not physically plausible. The second hypothesis awaits falsification, as the correlation fits the data. If natural events such as geomagnetic and solar activity are a trigger for large earthquakes, a plausible mechanism ought to be explored. In considering the effects of ionospheric disturbances on ground-based phenomena, geomagnetically induced currents (GIC) are a reasonable model. GIC occur generally at high latitudes and are responsible for the electrocorrosion of bridges and other metal infrastructure. Fluids laden with dissolved ions occur in faults and are a potential conduit for GIC. Electromagnetic fields induced by ionospheric anomalies may be present at depth. Can these types of fields weaken earth materials? One reason dilatancy diffusion models fell out of favor is scale. The microcracks observed are too small to hold the volume of volatiles required to account for observed changes to groundwater. If instead the presence of electric and magnetic fields aid in the liberation of volatiles and dissolution of certain minerals in rock, seismic events may occur. Andre&#769;n et al. (2016), for example, note decreasing groundwater (Si and Na) ion concentrations (ratio 2:1) as well as a small decrease in Ca and an increase in K ion concentrations during a period leading up to two consecutive M > 5 earthquakes in Hafral&#230;kur, Iceland. They took well cuttings for petrographic analysis: The observed groundwater changes are consistent with contemporary replacement of labradorite with analcime and the precipitation of zeolite minerals before and during the seismic activity, respectively, when the cuttings were taken. These observations fit the data well. In some cases, solar and geomagnetic activity cause ionospheric anomalies. These then induce electromagnetic currents in faults. The resulting fields aid in the dissolution of certain minerals and release volatiles, which are then precursory to seismic events. Groundwater changes before and after such events are related to the dissolution and subsequent precipitation of minerals in the rock. This rock weakening hypothesis fits the data, and is a simple explanation for how correlations between ionospheric disturbances caused by solar or geomagnetic events and large seismic events may arise.

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Effect of the solar activity variation on the Global Ionosphere Thermosphere Model (GITM)

Annales Geophysicae ◽

10.5194/angeo-34-725-2016 ◽

2016 ◽

Vol 34 (9) ◽

pp. 725-736 ◽

Cited By ~ 3

Author(s):

Davide Masutti ◽

Günther March ◽

Aaron J. Ridley ◽

Jan Thoemel

Keyword(s):

Solar Activity ◽

Lower Thermosphere ◽

Low Earth Orbit ◽

Atmospheric Models ◽

Space Objects ◽

Density Values ◽

Grace Satellites ◽

The University ◽

Semi Empirical ◽

Gravity Recovery

Abstract. The accuracy of global atmospheric models used to predict the middle/lower thermosphere characteristics is still an open topic. Uncertainties in the prediction of the gas properties in the thermosphere lead to inaccurate computations of the drag force on space objects (i.e. satellites or debris). Currently the lifetime of space objects and therefore the population of debris in low Earth orbit (LEO) cannot be quantified with a satisfactory degree of accuracy. In this paper, the Global Ionosphere Thermosphere Model (GITM) developed at the University of Michigan has been validated in order to provide detailed simulations of the thermosphere. First, a sensitivity analysis has been performed to investigate the effect of the boundary conditions on the final simulations results. Then, results of simulations have been compared with flight measurements from the CHallenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellites and with existing semi-empirical atmospheric models (IRI and MSIS). The comparison shows a linear dependency of the neutral density values with respect to the solar activity. In particular, GITM shows an over-predicting or under-predicting behaviour under high or low solar activity respectively. The reasons for such behaviour can be attributed to a wrong implementation of the chemical processes or the gas transport properties in the model.

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Meteorological Storm Influence on the Ionosphere Parameters

Atmosphere ◽

10.3390/atmos11091017 ◽

2020 ◽

Vol 11 (9) ◽

pp. 1017

Author(s):

Olga Borchevkina ◽

Ivan Karpov ◽

Mikhail Karpov

Keyword(s):

Critical Frequency ◽

Lower Thermosphere ◽

Lower Atmosphere ◽

Ionospheric Disturbances ◽

Acoustic Gravity Waves ◽

Convective Processes ◽

Standard Deviations ◽

The Baltic ◽

Total Electronic Content ◽

Electronic Content

This paper presents the observations of ionospheric parameters in Kaliningrad (54° N, 20° E) during a meteorological storm in the Baltic Sea during October 2017 and 2018. Analysis of the total electronic content (TEC) during the storm showed that perturbations of the TEC values from the median can reach two standard deviations of the value. For the critical frequency of the F2 layer, it was 1.5–1.6 times the standard deviations. On days of a meteorological storm, significant changes were noted in the dynamics of the E-layer’s critical frequency. The reasons for the occurrence of the observed phenomena were due to the propagation of acoustic-gravity waves generated by convective processes in the lower atmosphere during periods of a meteorological storm. Spectral analysis of TEC variations revealed an increase in the amplitudes of ionospheric variations 10–16 min over the area of a meteorological storm. The analysis allowed us to conclude that ionospheric perturbations during the meteorological perturbation were caused by increased acoustic-gravity wave (AGW) generation processes in the lower atmosphere. The most likely cause of negative ionospheric disturbances were processes associated with the dissipation of AGW propagating from the area of a meteorological storm and increased turbulence in the lower thermosphere.

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NUMERICAL MODELLING OF TSUNAMI INUNUNDATION CONSIDERING THE PRESENCE OF OFFSHORE ISLANDS AND BARRIER REEFS

Coastal Engineering Proceedings ◽

10.9753/icce.v36.currents.72 ◽

2018 ◽

pp. 72

Author(s):

Héctor ColÃ³n-De La Cruz ◽

Peter Rivera-Casillas ◽

Adam Keen ◽

Patrick J. Lynett

Keyword(s):

Numerical Model ◽

Computation Time ◽

University Of Southern California ◽

Tsunami Propagation ◽

Tsunami Waves ◽

Near Shore ◽

Evacuation Routes ◽

The University ◽

The Impact ◽

Average User

Advances in computer programming have permitted researchers to predict and visualize how tsunami waves affect coastline areas. Although itâ€™s possible to use numerical model simulations to predict the inundation of tsunamis, the process has some limitations. In order to solve the Boussinesq-type equations for tsunami propagation in the near-shore, it typically requires hundreds of hours of computation time and/or multiple CPUs. (Tavakkol and Lynett, 2017). Recently the University of Southern California developed a numerical model called Celeris, which can solve the Boussinesq-type equations faster than real time. The numerical model can run with minimum preparations on an average-user laptop and is able to provide results of wave inundation in a matter of seconds (Tavakkol and Lynett, 2017). The purpose of this research is to validate the results of wave inundation provided by Celeris and to study how reefs affect the inundation in the shoreline. If Celeris is validated, it could be used to study how to reduce the impact of tsunamis in the coast, explore the possibilities of using reefs to dissipate the energy of waves, improve evacuation routes, etc.

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In situ observations of the near-shore atmospheric boundary layer during ATOMIC/EUREC4A from small Uncrewed Aircraft Systems

10.5194/egusphere-egu21-12635 ◽

2021 ◽

Author(s):

Gijs de Boer ◽

Radiance Calmer ◽

Steven Borenstein ◽

Christopher Choate ◽

Michael Rhodes ◽

...

Keyword(s):

Boundary Layer ◽

Marine Boundary Layer ◽

Internal Variability ◽

Surface Fluxes ◽

Lower Atmosphere ◽

University Of Colorado ◽

Remotely Piloted Aircraft ◽

Near Shore ◽

Aircraft System ◽

The University

During the 2020 Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign (ATOMIC) and ElUcidating the Role of Cloud- Circulation Coupling in ClimAte (EUREC4A) field campaigns, a team from the University of Colorado Boulder deployed the RAAVEN Remotely-Piloted Aircraft System (RPAS). The RAAVEN RPAS was&#160;equipped with the miniFlux measurement system to observe the marine boundary layer upwind of Morgan Lewis, Barbados.&#160; Over the course of 23 days, the team completed 39 flights covering nearly 80 flight hours.&#160; Flights were conducted in and just above the boundary layer at altitudes between 10 and 1000 m, with a focus on capturing regular thermodynamic and kinematic profiles of the lower atmosphere, along with statistics on vertical transport and spatial variability.&#160; In this presentation, we will give initial details on the observed state of the lower atmosphere.&#160; This includes information on the structure and internal variability of thermodynamic and kinematic properties, turbulence intensity, turbulent surface fluxes and their variability, and details on the structure of vertical velocities in the lower atmosphere.

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