Coordinated observations of relativistic electron enhancements following an HSS period 

2021 ◽  
Author(s):  
Afroditi Nasi ◽  
Ioannis A. Daglis ◽  
Christos Katsavrias ◽  
Ingmar Sandberg ◽  
Wen Li ◽  
...  
Keyword(s):  
Solar Wind ◽  
Relativistic Electron ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Wind Pressure ◽  
The European Union ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
Wave Measurements ◽  
Substorm Activity

<p>During the second half of 2019, a sequence of solar wind high-speed streams (V<sub>SW</sub> ≥ 600 km/s)  impacted the magnetosphere, resulting in a series of recurrent, relatively weak, geomagnetic storms (Dst<sub>min</sub> ≥ - 80 nT). During one of these storms, a longer-lasting solar wind pressure pulse and intense substorm activity were also recorded (AL ≤ - 1600 nT on August 31 and September 1).</p><p>We use particle measurements from the Van Allen Probes, Arase and Galileo 207, 215 satellites, to investigate this event; all spacecraft observed a significant enhancement of relativistic electron fluxes. We also use ULF and chorus wave measurements, as well as interplanetary parameters, for a detailed investigation of this event and of the acceleration mechanisms involved.</p><p>This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870437 for the SafeSpace project.</p>

scholarly journals A self-consistent simulation of proton acceleration and transport near a high-speed solar wind stream

2021 ◽  
Author(s):  
Nicolas Wijsen ◽  
Evangelia Samara ◽  
Àngels Aran ◽  
David Lario ◽  
Jens Pomoell ◽  
...  
Keyword(s):  
Solar Wind ◽  
Energetic Particle ◽  
High Speed ◽  
Three Dimensional ◽  
Acceleration Process ◽  
Solar Wind Stream ◽  
The European Union ◽  
Horizon 2020 ◽  
Compression Waves ◽  
Research And Innovation

<p>Solar wind stream interaction regions (SIRs)  are often characterised by energetic ion enhancements. The mechanisms accelerating these particles as well as the locations where the acceleration occurs, remains debated. Here, we report the findings of a simulation of a SIR-event observed by Parker Solar Probe at 0.56 au and the Solar Terrestrial Relations Observatory-Ahead at 0.96 au in September 2019 when both spacecraft were approximately radially aligned with the Sun. The simulation reproduces the solar wind configuration and the energetic particle enhancements observed by both spacecraft. Our results show that the energetic particles are produced at the compression waves associated with the SIR and that the suprathermal tail of the solar wind is a good candidate to provide the seed population for particle acceleration. The simulation confirms that the acceleration process does not require shock waves and can already commence within Earth's orbit, with an energy dependence on the precise location where particles are accelerated. The three-dimensional configuration  of the solar wind streams strongly modulates the energetic particle distributions, illustrating the necessity of advanced models to understand  these particle events.</p><p>This research has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870405 (EUHFORIA 2.0).</p><p> </p>

Improving CME evolution and arrival predictions with AMR and grid stretching in EUHFORIA

2021 ◽  
Author(s):  
Tinatin Baratashvili ◽  
Christine Verbeke ◽  
Nicolas Wijsen ◽  
Emmanuel Chané ◽  
Stefaan Poedts
Keyword(s):  
Solar Wind ◽  
Adaptive Mesh Refinement ◽  
Adaptive Mesh ◽  
Mhd Equations ◽  
Efficiency Gain ◽  
The European Union ◽  
Interplanetary Shocks ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
Speed Up

<p>Coronal Mass Ejections (CMEs) are the main drivers of interplanetary shocks and space weather disturbances. Strong CMEs directed towards Earth can cause severe damage to our planet. Predicting the arrival time and impact of such CMEs can enable to mitigate the damage on various technological systems on Earth. </p><p>We model the inner heliospheric solar wind and the CME propagation and evolution within a new heliospheric model based on the MPI-AMRVAC code. It is crucial for such a numerical tool to be highly optimized and efficient, in order to produce timely forecasts. Our model solves the ideal MHD equations to obtain a steady state solar wind configuration in a reference frame corotating with the Sun. In addition, CMEs can be modelled by injecting a cone CME from the inner boundary (0.1 AU).</p><p>Advanced techniques, such as grid stretching and Adaptive Mesh Refinement (AMR) are employed in the simulation. Such methods allow for high(er) spatial resolution in the numerical domain, but only where necessary or wanted. As a result, we can obtain a detailed, highly resolved image at the (propagating) shock areas, without refining the whole domain.</p><p>These techniques guarantee more efficient simulations, resulting in optimised computer memory usage and a significant speed-up. The obtained speed-up, compared to the original approach with a high-resolution grid everywhere, varies between a factor of 45 - 100 depending on the domain configuration. Such efficiency gain is momentous for the mitigation of the possible damage and allows for multiple simulations with different input parameters configurations to account for the uncertainties in the measurements to determine them. The goal of the project is to reproduce the observed results, therefore, the observable variables, such as speed, density, etc., are compared to the same type of results produced by the existing (non-stretched, single grid) EUropean Heliospheric FORecasting Information Asset (EUHFORIA) model and observational data for a particular event on 12th of July, 2012. The shock features are analyzed and the results produced with the new heliospheric model are in agreement with the existing model and observations, but with a significantly better performance. </p><p> </p><p><strong>This research has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870405 (EUHFORIA 2.0).</strong></p>

Modeling the Sun – Earth propagation of solar disturbances for the H2020 SafeSpace project

2021 ◽  
Author(s):  
Benoit Lavraud ◽  
Rui Pinto ◽  
Rungployphan Kieokaew ◽  
Evangelia Samara ◽  
Stefaan Poedts ◽  
...  
Keyword(s):  
Solar Wind ◽  
Interplanetary Space ◽  
Coronal Magnetic Field ◽  
Physical Parameters ◽  
The European Union ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
Reconstruction Methods ◽  
Solar Disturbances ◽  
Magnetic Field Computation

<p>We present the solar wind forecast pipeline that is being implemented as part of the H2020 SafeSpace project. The Goal of this project is to use several tools in a modular fashion to address the physics of Sun – interplanetary space – Earth’s magnetosphere. This presentation focuses on the part of the pipeline that is dedicated to the forecasting – from solar measurements – of the solar wind properties at the Lagrangian L1 point. The modeling pipeline puts together different mature research models: determination of the background coronal magnetic field, computation of solar wind acceleration profiles (1 to 90 solar radii), propagation across the heliosphere (for regular solar wind, CIRs and CMEs), and comparison to spacecraft measurements. Different magnetogram sources (WSO, SOLIS, GONG, ADAPT) can be combined, as well as coronal field reconstruction methods (PFSS, NLFFF), wind (MULTI-VP) and heliospheric propagation models (CDPP 1D MHD, EUHFORIA). We aim at providing a web-based service that continuously supplies a full set of bulk physical parameters of the solar wind at 1 AU several days in advance, at a time cadence compatible with space weather applications. This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870437.</p>

A superposed epoch analysis of geomagnetic storms

1994 ◽  
Vol 12 (7) ◽  
pp. 612-624 ◽  
Author(s):  
J. R. Taylor ◽  
M. Lester ◽  
T. K. Yeoman
Keyword(s):  
Solar Wind ◽  
Wind Speed ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Solar Wind Speed ◽  
Magnetic Activity ◽  
Wind Pressure ◽  
Superposed Epoch Analysis ◽  
Controlling Parameter ◽  
Epoch Analysis

Abstract. A superposed epoch analysis of geomagnetic storms has been undertaken. The storms are categorised via their intensity (as defined by the Dst index). Storms have also been classified here as either storm sudden commencements (SSCs) or storm gradual commencements (SGCs, that is all storms which did not begin with a sudden commencement). The prevailing solar wind conditions defined by the parameters solar wind speed (vsw), density (ρsw) and pressure (Psw) and the total field and the components of the interplanetary magnetic field (IMF) during the storms in each category have been investigated by a superposed epoch analysis. The southward component of the IMF, appears to be the controlling parameter for the generation of small SGCs (-100 nT< minimum Dst ≤ -50 nT for ≥ 4 h), but for SSCs of the same intensity solar wind pressure is dominant. However, for large SSCs (minimum Dst ≤ -100 nT for ≥ 4 h) the solar wind speed is the controlling parameter. It is also demonstrated that for larger storms magnetic activity is not solely driven by the accumulation of substorm activity, but substantial energy is directly input via the dayside. Furthermore, there is evidence that SSCs are caused by the passage of a coronal mass ejection, whereas SGCs result from the passage of a high speed/ slow speed coronal stream interface. Storms are also grouped by the sign of Bz during the first hour epoch after the onset. The sign of Bz at t = +1 h is the dominant sign of the Bz for ~24 h before the onset. The total energy released during storms for which Bz was initially positive is, however, of the same order as for storms where Bz was initially negative.

The Dynamic Time Warping as a means to assess modeled solar wind time series

2021 ◽  
Author(s):  
Evangelia Samara ◽  
Emmanuel Chane ◽  
Brecht Laperre ◽  
Christine Verbeke ◽  
Manuela Temmer ◽  
...  
Keyword(s):  
Time Series ◽  
Solar Wind ◽  
Dynamic Time Warping ◽  
Optimal Alignment ◽  
The European Union ◽  
Time Warping ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
Single Number ◽  
Dynamic Time

&lt;p&gt;In this work, the Dynamic Time Warping (DTW) technique is presented as an alternative method to assess the performance of modeled solar wind time series at Earth (or at any other point in the heliosphere). This method can quantify how similar two time series are by providing a temporal alignment between them, in an optimal way and under certain restrictions. It eventually estimates the optimal alignment between an observed and a modeled series, which we call the warping path, by providing a single number, the so-called DTW cost. A description on the reasons why DTW should be applied as a metric for the assessment of solar wind time series, is presented. Furthermore, examples on how exactly the technique is applied to our modeled solar wind datasets with EUHFORIA, are shown and discussed.&lt;/p&gt;&lt;p&gt;&lt;span&gt;&lt;span&gt;&lt;em&gt;This project has received funding from the European Union&amp;#8217;s Horizon 2020 research and innovation programme under grant agreement No 870437 (SafeSpace).&lt;/em&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;

On the prediction of magnetic field vectors of ICME using data constrained simulation with EUHFORIA

2021 ◽  
Author(s):  
Ranadeep Sarkar ◽  
Jens Pomoell ◽  
Eleanna Asvestari ◽  
Emilia Kilpua ◽  
Marilena Mierla ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Storms ◽  
Flux Rope ◽  
Magnetized Plasma ◽  
The Sun ◽  
The European Union ◽  
Horizon 2020 ◽  
Sheath Region ◽  
Research And Innovation ◽  
Using Data

&lt;p&gt;Coronal mass ejections (CMEs), the most violent eruptive phenomena occurring in the heliosphere, erupt in the form of gigantic clouds of magnetized plasma from the Sun and can reach Earth within several hours to days. If the magnetic field inside an Earth-directed CME or its associated sheath region has a southward directed component (Bz), then it interacts&amp;#160;stronger&amp;#160;with the Earth&amp;#8217;s magnetosphere, leading to severe geomagnetic storms. Therefore, it is crucial to predict the&amp;#160;magnitude&amp;#160;and orientation&amp;#160;of Bz inside an Earth impacting interplanetary CME (ICME) in order to forecast the intensity of the resulting geomagnetic storms. However, due to&amp;#160;lack of realistic inputs and the complexity of the Sun-Earth system in a time-dependent heliospheric context, it is very difficult to perform a reliable forecast of Bz at 1 AU.&amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;In this work, we use&amp;#160;recently developed observational techniques to constrain the kinematic and magnetic properties of CME flux ropes. Using those observational properties as realistic inputs, we construct an&amp;#160;analytical force free flux rope model to mimic the magnetic structure of a CME and simulate its evolution from Sun to Earth&amp;#160;using the &amp;#8220;European heliospheric forecasting information asset&amp;#8221; (EUHFORIA). In order to validate our tool, we simulate an Earth-directed CME event on 2013 April 11 and compare the simulation results with the in-situ observations at 1 AU. Further, we assess the performance of EUHFORIA in forecasting of Bz, using different flux rope models like spheromak and torus.&amp;#160; The results obtained from this study help to improve our understanding to build the steppingstones towards the forecasting of Bz in near real time.&lt;/p&gt;&lt;p&gt;This research has received funding from the European Union&amp;#8217;s Horizon 2020 research and innovation programme under grant agreement No 870405 (EUHFORIA 2.0).&lt;/p&gt;

Using machine learning to identify magnetic reconnection in two-dimensional simulations

2020 ◽  
Author(s):  
Andong Hu ◽  
Jannis Teunissen ◽  
Manuela Sisti ◽  
Francesco Califano ◽  
Jérémy Dargent ◽  
...  
Keyword(s):  
Machine Learning ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Solar Wind Plasma ◽  
Space Physics ◽  
Electron Velocity ◽  
Two Dimensional ◽  
The European Union ◽  
Horizon 2020 ◽  
Research And Innovation

&lt;div&gt;The understanding of fundamental processes at play in a collisionless plasmas such as the solar wind, is a frontier problem in space physics. We investigate here the occurrence of magnetic reconnection in a plasma with parameters corresponding to solar wind plasma and its interplay with a fully-developed turbulent state. Ongoing magnetic reconnection can, at the moment, be accurately identified only by humans. Therefore, as a first step, the goal of this study is to present a new method to automatically recognise reconnection events in the output of two-dimensional HVM (Hybrid Vlasov Maxwell)&amp;#160;simulations&amp;#160;where ions evolve by solving the Vlasov equation and the electrons are treated as a fluid with mass. A large dataset with labelled reconnection events was prepared, including parameters such as the magnetic field, the electron velocity field and the current density. We consider two types of machine learning models: classical approaches using on physics-based features, and convolutional neural networks (CNNs). We will investigate which approach performs better, and which input variables are most relevant. In addition, we will try to categorize magnetic reconnection regions (current sheets). This work has received funding from the European Union&amp;#8217;s Horizon 2020 research and innovation programme under grant agreement No 776262 (AIDA, www.aida-space.eu).&lt;/div&gt;

Monitoring and assessment of an oil spill event with very high resolution tools. 

2021 ◽  
Author(s):  
Ana M. Mancho ◽  
Guillermo García-Sánchez ◽  
Antonio G. Ramos ◽  
Josep Coca ◽  
Begoña Pérez-Gómez ◽  
...  
Keyword(s):  
High Resolution ◽  
Oil Spill ◽  
In Situ Observation ◽  
The European Union ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
Port Authorities ◽  
Different Sources ◽  
Very High

&lt;p&gt;This presentation discusses a downstream application from Copernicus Services, developed in the framework of the IMPRESSIVE project, for the monitoring of &amp;#160;the oil spill produced after the crash of the ferry &amp;#8220;Volcan de Tamasite&amp;#8221; in waters of the Canary Islands on the 21&lt;sup&gt;st&lt;/sup&gt; of April 2017. The presentation summarizes the findings of [1] that describe a complete monitoring of the diesel fuel spill, well-documented by port authorities. Complementary information supplied by different sources enhances the description of the event. We discuss the performance of very high resolution hydrodynamic models in the area of the Port of Gran Canaria and their ability for describing the evolution of this event. Dynamical systems ideas support the comparison of different models performance. Very high resolution remote sensing products and in situ observation validate the description.&lt;/p&gt;&lt;p&gt;Authors acknowledge support from IMPRESSIVE a project funded by the European Union&amp;#8217;s Horizon 2020 research and innovation programme under grant agreement No 821922. SW acknowledges the support of ONR Grant No. N00014-01-1-0769&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;[1] G.Garc&amp;#237;a-S&amp;#225;nchez, A. M. Mancho, A. G. Ramos, J. Coca, B. P&amp;#233;rez-G&amp;#243;mez, E. &amp;#193;lvarez-Fanjul, M. G. Sotillo, M. Garc&amp;#237;a-Le&amp;#243;n, V. J. Garc&amp;#237;a-Garrido, S. Wiggins. Very High Resolution Tools for the Monitoring and Assessment of Environmental Hazards in Coastal Areas. &amp;#160;Front. Mar. Sci. (2021) doi: 10.3389/fmars.2020.605804.&lt;/p&gt;

scholarly journals Aerial Campaigns for Cal/Val purposes in the Context of Copernicus - Survey Results of the Project “Copernicus Cal/Val Solution (CCVS)”

2021 ◽  
Author(s):  
Stefanie Holzwarth ◽  
Martin Bachmann ◽  
Bringfried Pflug ◽  
Aimé Meygret ◽  
Caroline Bès ◽  
...  
Keyword(s):  
Gap Analysis ◽  
Model Development ◽  
Metrological Traceability ◽  
The European Union ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
Wide Range ◽  
Data Policy ◽  
Survey Results ◽  
Essential Contribution

&lt;p&gt;The objective of the H2020 project &amp;#8220;Copernicus Cal/Val Solution (CCVS)&amp;#8221; is to define a holistic Cal/Val strategy for all ongoing and upcoming Copernicus Sentinel missions. This includes an improved calibration of currently operational or planned Copernicus Sentinel sensors and the validation of Copernicus core products generated by the payload ground segments. CCVS will identify gaps and propose long-term solutions to address currently existing constraints in the Cal/Val domain and exploit existing synergies between the missions. An overview of existing calibration and validation sources and means is needed before starting the gap analysis. In this context, this survey is concerned with measurement capabilities for aerial campaigns.&lt;/p&gt;&lt;p&gt;Since decades airborne observations are an essential contribution to support Earth-System model development and space-based observing programs, both in the domains of Earth Observation (radar and optical) as well as for atmospheric research. The collection of airborne reference data can be directly related to satellite observations, since they are collected in ideal validation conditions using well calibrated reference sensors. Many of these sensors are also used to validate and characterize postlaunch instrument performance. The variety of available aircraft equipped with different instrumentations ranges from motorized gliders to jets acquiring data from different heights to the upper troposphere. In addition, balloons are also used as platforms, either small weather balloons with light payload (around 3 kg), or open stratospheric balloons with big payload (more than a ton). For some time now, UAVs/drones are also used in order to acquire data for Cal/Val purposes. They offer a higher flexibility compared to airplanes, plus covering a bigger area compared to in-situ measurements on ground. On the other hand, they also have limitations when it comes to the weight of instrumentation and maximum altitude level above ground. This reflects the wide range of possible aerial measurements supporting the Cal/Val activities.&lt;/p&gt;&lt;p&gt;The survey will identify the different airborne campaigns. The report will include the description of campaigns, their spatial distribution and extent, ownership and funding, data policy and availability and measurement frequency. Also, a list of common instrumentation, metrological traceability, availability of uncertainty evaluation and quality management will be discussed. The report additionally deals with future possibilities e.g., planned developments and emerging technologies in instrumentation for airborne and balloon based campaigns.&lt;/p&gt;&lt;p&gt;This presentation gives an overview of the preliminary survey results and puts them in context with the Cal/Val requirements of the different Copernicus Sentinel missions.&lt;/p&gt;&lt;p&gt;This project has received funding from the European Union&amp;#8217;s Horizon 2020 research and innovation programme under the grant agreement No 101004242.&lt;/p&gt;

A neural network-based mid-term prognosis of geomagnetic storms that uses pre-storm effects related to current sheets and magnetic islands

2021 ◽  
Author(s):  
Mikhail Fridman
Keyword(s):  
Solar Wind ◽  
Solar Minimum ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Magnetic Islands ◽  
Solar Wind Density ◽  
Short Term ◽  
Storm Effects ◽  
Term Forecast ◽  
Advance Time

&lt;p&gt;Mid-term prognoses of geomagnetic storms require an improvement since the&amp;#1091; are known to have rather low accuracy which does not exceed 40% in solar minimum. We claim that the problem lies in the approach. Current mid-term forecasts are typically built using the same paradigm as short-term ones and suggest an analysis of the solar wind conditions typical for geomagnetic storms. According to this approach, there is a 20-60 minute delay between the arrival of a geoeffective flow/stream to L1 and the arrival of the signal from the spacecraft to Earth, which gives a necessary advance time for a short-term prognosis. For the mid-term forecast with an advance time from 3 hours to 3 days, this is not enough. Therefore, we have suggested finding precursors of geomagnetic storms observed in the solar wind. Such precursors are variations in the solar wind density and the interplanetary magnetic field in the ULF range associated with crossings of magnetic cavities in front of the arriving geoeffective high-speed streams and flows (Khabarova et al., 2015, 2016, 2018; Adhikari et al., 2019). Despite some preliminary studies have shown that this might be a perspective way to create a mid-term prognosis (Khabarova 2007; Khabarova &amp; Yermolaev, 2007), the problem of automatization of the prognosis remained unsolved.&lt;/p&gt;

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