Space Weather Observations Research Articles

Ionospheric forecasting model using fuzzy logic-based gradient descent method

Space weather phenomena cause satellite to ground or satellite to aircraft transmission outages over the VHF to L-band frequency range, particularly in the low latitude region. Global Positioning System (GPS) is primarily susceptible to this form of space weather. Faulty GPS signals are attributed to ionospheric error, which is a function of Total Electron Content (TEC). Importantly, precise forecasts of space weather conditions and appropriate hazard observant cautions required for ionospheric space weather observations are limited. In this paper, a fuzzy logic-based gradient descent method has been proposed to forecast the ionospheric TEC values. In this technique, membership functions have been tuned based on the gradient descent estimated values. The proposed algorithm has been tested with the TEC data of two geomagnetic storms in the low latitude station of KL University, Guntur, India (16.44°N, 80.62°E). It has been found that the gradient descent method performs well and the predicted TEC values are close to the original TEC measurements.

Geoinformation system for amplitude-frequency analysis of geomagnetic variations and space weather observation data

We present and describe a method to conduct correlation and amplitude-frequency analysis of the observational data of geomagnetic variations and space weather that is based on the combined use of a concept of single information space, models and methods of wavelet and Fourier analysis, and geo-information technologies. The method includes formalized elements of mathematical and methodological support for conducting amplitude-frequency and correlation analysis of the observations of geomagnetic variations and space weather and is verified by means of a prototype in-house platform-independent web-oriented geoinformation system GEOMAGNET (https:// www.geomagnet.ru). The proposed method is verified using data obtained from the magnetic observatories of the INTERMAGNET network and space weather data from the artificial Earth satellite ACE. Results of the observation, automated correlation and amplitude-frequency analysis of signals that provide information on the geomagnetic field and space weather variations at specified time intervals both on the Earth's surface and in near-Earth space are discussed and evaluated.

Becoming a Space Weather-Ready Nation

Becoming a Space Weather-Ready Nation

Simulations and Tests of Prototype Antenna System for Low Frequency Radio Experiment (LORE) Space Payload for Space Weather Observations

Low frequency Radio Experiment (LORE) is a proposed space payload for space weather observations from space, operating between few kHz to 30 MHz. This paper presents preliminary design and practical implementation of LORE antenna systems, which consist of three mutually orthogonal mono-poles. Detailed computational electromagnetic simulations, carried out to study the performance of the antenna systems, are presented followed up by laboratory tests of the antennas as well as radiation tests with a long range test range, designed for this purpose. These tests form the first phase of the design and implementation of the full LORE prototype later in the year.

Statistical characterization of ionosphere anomalies and their relationship to space weather events

The statistical characterization of the relationship between thermosphere-ionosphere anomalies and space weather events, also referred to as space weather anomalies, such as solar coronal mass ejections (CMEs) and geomagnetic storms, is a crucial component in the development of a forecast capability for thermosphere-ionosphere disturbances. This manuscript presents a systematic statistical approach for analyzing historical ionosphere and space weather observations to derive a quantitative characterization of the relationships between the thermosphere-ionosphere anomalies and space weather anomalies. Based on 2 years of historical data, our analysis reveals the complex nature of the relationship between space weather disturbances and ionospheric responses.

Operational Space Weather Services in National Space Science Center of Chinese Academy of Sciences

Operational Space Weather Services in National Space Science Center of Chinese Academy of Sciences

Space weather conditions during the Galaxy 15 spacecraft anomaly

AbstractOn 5 April 2010, the Galaxy 15 spacecraft, orbiting at geosynchronous altitudes, experienced an anomaly near local midnight when it stopped responding to any ground commands. The anomaly has been reported as due to a lockup of the field‐programmable gate array within the spacecraft baseband communications unit during an onboard electrostatic discharge (ESD). This study evaluates the space weather conditions at the time of the Galaxy 15 anomaly. The study also compares the plasma and geomagnetic environments around the anomaly to space weather observations over the operational lifetime of Galaxy 15 up to the anomaly time. On 5 April, the Galaxy 15 spacecraft encountered severe plasma conditions while it was in eclipse and during the subsequent anomaly interval. These conditions included a massive magnetic field dipolarization that injected energetic particles from the magnetotail during a substorm observed by GOES and Time History of Events and Macroscale Interactions during Substorms satellites. Galaxy 15 was located at a near‐optimum position and local time to experience the full impact of the injected energetic particles. During the largest previous storm experienced by Galaxy 15 in December 2006, evidence suggests that it would not have been exposed to the same level of space weather as on 5 April 2010. Hence, while Galaxy 15 was traversing the nightside on 5 April, it likely experienced, for a short period, the most severe local plasma conditions it had encountered since launch. The most likely contributions to the ESD were interactions of the spacecraft with substorm‐injected energetic particles facilitating spacecraft surface charging and deep dielectric charging.

Celebrating Accomplishments and Anniversaries of Space Weather Observations and Forecasting

Celebrating Accomplishments and Anniversaries of Space Weather Observations and Forecasting

A comparison of radiation shielding effectiveness of materials for highly elliptical orbits

The Canadian Space Agency (CSA) has proposed a Polar Communications and Weather (PCW) satellite mission, in conjunction with other partners. The PCW will provide essential communications and meteorological services to the Canadian Arctic, as well as space weather observations of in situ ionizing radiation along the orbit. The CSA has identified three potential Highly Elliptical Orbits (HEOs) for a PCW satellite constellation, Molniya, Modified Tundra and Triple Apogee (TAP), each having specific merits, which would directly benefit the performance/longevity of a PCW spacecraft. Radiation shielding effectiveness of various materials was studied for the three PCW orbit options to determine the feasibility of employing materials other than conventional aluminium to achieve a specified spacecraft shielding level with weight savings over aluminium. It was found that, depending on the orbit-specific radiation environment characteristics, the benefits of using polyethylene based materials is significant enough (e.g., 22% in Molniya for PE at 50krad TID) to merit further investigation.

Space weather radiation effects on geostationary satellite solid‐state power amplifiers

AbstractIn order to understand and mitigate the effects of space weather on the performance of geostationary (GEO) communications satellites, we analyze 16 years of archived telemetry data from Inmarsat, the UK‐based telecommunications company. We compare 665,112 operational hours of housekeeping telemetry from two generations of satellites, designated as Fleet A and Fleet B. Each generation experienced 13 solid‐state power amplifier (SSPA) anomalies for a total of 26 anomalies from 1996 to 2012. We compare telemetry from the Inmarsat anomalies with space weather observations, including data from the OMNI2 database, Geostationary Operational Environmental Satellites, the Advanced Composition Explorer Satellite, and Los Alamos National Laboratory (LANL) GEO observations; the evolution of the sunspot number; and the Kp index. Most SSPA anomalies for Fleet A occur as solar activity declines; Fleet B has not yet experienced a full solar cycle. For both fleets, the average value of Kp remained < 2 over time periods of 2 days, 3 days, and 2 weeks around the time of anomaly, which suggests that the anomalies occurred at times of relatively quiet geomagnetic activity and that they were probably not solely caused by surface charging. From 1996 to 2009, the average of the 1.8–3.5 MeV electron flux was 1.98 #/(cm2 s st keV). Five of the 26 anomalies, unfortunately, do not have corresponding science observations (specifically, electron flux data in the LANL data set), so part of this study focuses on the 21 anomalies when science observations were available. Six out of 21 anomalies experienced a high‐energy electron flux greater than 1.5 standard deviations above the mean of the log10 of the flux between 7 and 14 days prior to the anomaly. By contrast, a Monte Carlo simulation finds that on average, only 2.8 out of 21 (13%) of randomly assigned “anomalies” occur between 7 and 14 days after an electron flux greater than 1.5 standard deviations above the mean. Our observations suggest that internal charging from either past elevated radiation belt fluxes or some conditions related to relativistic electron enhancements (either causally or accidentally) is most likely responsible for the SSPA anomalies. We next consider the timing of these anomalies with respect to the local time (LT) and season. Anomalies occur at all LT sectors with 46% (Fleet A) and 38.5% (Fleet B) in the midnight to dawn sector and 54% (Fleet A) and 46% (Fleet B) in the local noon to dusk sector. From the local time distribution, surface charging does not appear to be the sole causative agent of the anomalies. Understanding the connection between the space weather conditions and anomalies on subsystems and specific components on identical and similar geostationary communications satellites for periods of time longer than a solar cycle will help guide design improvements and provide insight on their operation during space weather events.

Combining solar science and asteroid science with the space weather observation network (SWON)

The peculiarity of space weather for Earth orbiting satellites, air traffic and power grids on Earth and especially the financial and operational risks posed by damage due to space weather, underline the necessity of space weather observation. The importance of such observations is even more increasing due to the impending solar maximum. In recognition of this importance we propose a mission architecture for solar observation as an alternative to already published mission plans like Solar Probe (NASA) or Solar Orbiter (ESA). Based upon a Concurrent Evaluation session in the Concurrent Engineering Facility of the German Aerospace Center, we suggest using several spacecraft in an observation network. Instead of placing such spacecraft in a solar orbit, we propose landing on several asteroids, which are in opposition to Earth during the course of the mission and thus allow observation of the Sun's far side. Observation of the far side is especially advantageous as it improves the warning time with regard to solar events by about 2 weeks. Landing on Inner Earth Object (IEO) asteroids for observation of the Sun has several benefits over traditional mission architectures. Exploiting shadowing effects of the asteroids reduces thermal stress on the spacecraft, while it is possible to approach the Sun closer than with an orbiter. The closeness to the Sun improves observation quality and solar power generation, which is intended to be achieved with a solar dynamic system. Furthermore landers can execute experiments and measurements with regard to asteroid science, further increasing the scientific output of such a mission. Placing the spacecraft in a network would also benefit the communication contact times of the network and Earth. Concluding we present a first draft of a spacecraft layout, mission objectives and requirements as well as an initial mission analysis calculation.

A new class of long‐term stable lunar resonance orbits: Space weather applications and the Interstellar Boundary Explorer

NASA's Interstellar Boundary Explorer (IBEX) mission was recently maneuvered into a unique long‐term stable Earth orbit, with apogee at ∼50 Earth radii (RE). The Moon's (∼65 RE) gravity disrupts most highly elliptical Earth orbits, leading to (1) chaotic orbital solutions, (2) the inability to predict orbital positions more than a few years into the future, and ultimately (3) mission‐ending possibilities of atmospheric reentry or escape from Earth orbit. By synchronizing the satellite's orbital period to integer fractions of the Moon's sidereal period, PM = 27.3 days (e.g., PM/2 = 13.6 days, PM/3 = 9.1 days), and phasing apogee to stay away from the Moon, very long term stability can be achieved. Our analysis indicates orbital stability for well over a decade, and these IBEX‐like orbits represent a new class of Earth orbits that are stable far longer than typical satellite lifetimes. These orbits provide cost‐effective and nearly ideal locations for long‐term space weather observations from spacecraft that can remotely image the Earth's magnetosphere from outside its boundaries while simultaneously providing external (solar wind or magnetosheath) observation over most of their orbits. Utilized with multiple spacecraft, such orbits would allow continuous and simultaneous monitoring of the magnetosphere in order to help predict and mitigate adverse space weather–driven effects.

South Korea's renewed focus on space weather

South Korea's renewed focus on space weather

Heliophysics: space storms and radiation: causes and effects

Heliophysics is a fast-developing scientific discipline that integrates studies of the Sun’s variability, the surrounding heliosphere, and the environment and climate of planets. Over the past few centuries, our understanding of how the Sun drives space weather and climate on the Earth and other planets has advanced at an ever increasing rate. The Sun is a magnetically variable star and, for planets with intrinsic magnetic fields, planets with atmospheres, or planets like Earth with both, there are profound consequences. This volume, the second in a series of three heliophysics texts, integrates the many aspects of space storms and the energetic radiation associated with them – from their causes on the Sun to their effects in planetary environments. It reviews the physical processes in solar flares and coronal mass ejections, interplanetary shocks, and particle acceleration and transport, and considers many of the space weather responses in geospace. Historical space weather observations, in-situ particle measurement techniques, radiative emissions from energetic particles, and impacts of space weather on people and technology in space are also reviewed. In addition to its utility as a textbook, it also constitutes a foundational reference for researchers in the fields of heliophysics, astrophysics, plasma physics, space physics, solar physics, aeronomy, space weather, planetary science, and climate science. Additional online resources, including lecture presentations and other teaching materials, can be accessed at www.cambridge.org/9780521760515.

The possibilities of polar meteorology, environmental remote sensing, communications and space weather applications from Artificial Lagrange Orbit

The ability to observe meteorological events in the polar regions of the Earth from satellite celebrated an anniversary, with the launch of TIROS-I in a pseudo-polar orbit on 1 April 1960. Yet, after 50 years, polar orbiting satellites are still the best view of the polar regions of the Earth. The luxuries of geostationary satellite orbit including rapid scan operations, feature tracking, and atmospheric motion vectors (or cloud drift winds), are enjoyed only by the middle and tropical latitudes or perhaps only cover the deep polar regions in the case of satellite derived winds from polar orbit. The prospect of a solar sailing satellite system in an Artificial Lagrange Orbit (ALO, also known as “pole sitters”) offers the opportunity for polar environmental remote sensing, communications, forecasting and space weather monitoring. While there are other orbital possibilities to achieve this goal, an ALO satellite system offers one of the best analogs to the geostationary satellite system for routine polar latitude observations. A summary is given of the current on-going activities using composite satellite imagery over both Arctic and Antarctic regions. The use of both polar orbiting and geostationary satellite imagery together currently provide the best continental and hemispheric view of these regions, and provide an analog for what could be possible from an ALO satellite platform. How the composites are made as well as a brief description of applications is discussed. Potential user applications of environmental remote sensing from an ALO satellite platform are outlined along with critical space weather observations. In addition, the increasing need for communication and data relay in the remote polar-regions is reviewed along with an ALO satellite system potential capability to relay data from other satellite constellations. These current efforts foreshadow only a portion of the possibilities that are desired by the user community.

ESA Soon to Unveil Space Weather Services

ESA Soon to Unveil Space Weather Services

The L5 mission for space weather forecasting

We have studied a number of interplanetary space mission scenarios for space weather research and operational forecasting experiments and concluded that a spacecraft should be deployed at the L5 point of the Sun–Earth system to enable remote sensing of the Sun and interplanetary space and in situ measurements of solar wind plasma and high energy solar particle events. The L5 point is an appropriate position for making side-view observations of geo-effective coronal mass ejections and interplanetary plasma clouds. Here, we describe briefly the mission plan and the ongoing BBM development of important subsystems such as the wide field coronal imager (WCI) and the mission processor. The WCI will have a large CCD array with 16-bit sampling, to achieve a dynamic range of several thousand in order to detect very small deviations due to plasma clouds under zodiacal light contaminations a hundred times brighter than the clouds. The L5 mission we propose will surely contribute to the construction of an international space weather observation network.

Nonlinear kinetic Alfven waves associated with saturating nonlinearity: applications to solar wind and coronal heating

The nonlinear equation for the propagation of kinetic Alfven waves has been derived in two-dimensions using the two-fluid model of the plasma. By taking into proper account of the nonlinear electron heating and ponderomotive force driven nonlinearity modification in the background density, the kinetic Alfven wave equation has been derived. The solution of this model equation has been obtained by using analytical and numerical methods to find out the amplitude of the kinetic Alfven wave at a particular distance. The relevance of these investigations has been discussed for the solar wind plasmas and coronal heating. It is seen that the kinetic Alfven wave breaks up into filamentary structures (hot spots) with very high intense magnetic energy. These filaments are separated from each other by a distance of the order of 1 AU in the case of solar winds while it is of the order of 0.6 AU in the case of coronal heating. The effect of these hot spots on other parametric processes which take place in the solar wind plasma and Alfven wave turbulence is also proposed. In the case of the solar corona, rough estimates for additional heating have been made by assuming that the energy of the kinetic Alfven wave is dumped to particles by wave particle interaction. Self-consistent models based on excited wave number spectra of kinetic Alfven waves, calculating the velocity space diffusion coefficient and using this in the Fokker Planck equation is also suggested for coronal heating. The impact of these studies on the Alfven wave turbulence spectrum, space weather and related experimental observation has been pointed out.

Space weather observations using the SOHO CELIAS complement of instruments

The Solar and Heliospheric Observatory (SOHO) spacecraft located at Ll is well outside the Earth's magnetosphere and has been observing the Sun continuously since December 1995, except for relatively brief periods due to spacecraft operational interruptions. While a variety of instruments on the SOHO spacecraft investigate the solar properties important to an improved understanding of the Sun and its effect on space weather, the present work is limited to the observations provided by the Charge, Element, and Isotope Analysis System (CELIAS) proton monitor (PM) and Solar Extreme Ultraviolet Monitor (SEM) instruments and their relationship to other space weather observations. The CELIAS observations consist of particle and EUV/soft X‐ray solar flux measurements. A brief description of the CELIAS instrumentation and examples of the precursor information signaling the possibility of coronal mass ejection events observed by the CELIAS/SEM are presented. In addition, the entire SEM database since commissioning is presented on both expanded and compressed timescales in order to provide both the long‐term weather trends and short‐term storm data. The SEM data presented are full‐disk observations and have a 15 s sampling rate.