Space weather is a branch of Space physics and aeronomy (the science of the upper region of the earth) or heliophysics (the science of the sun) which is concerned with the conditions on the sun, in the solar wind, and within the Earth’s atmosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health.
One of the importance of understanding space weather is the awareness and avoidance of the consequences attached to space weather events either by system design or by efficient warning and prediction systems. Long-term averages and variability of weather in a region constitute the region’s climate.
A major advance in space weather forecasting will come from our ability to determine the speed at which the phenomenon is moving accurately. This will be achieved with stereoscopic views of the sun from NASA’s Solar Terrestrial Relations Observatory (STEREO) spacecraft. This pair of spacecraft will use 3-D vision to construct a global picture of the sun and its influences. Accurately predicting arrival times on Earth and correctly forecasting the scale of impact of an event would help to avoid costly false alarms.
Magnetic storms produce noticeable effects on and near earth. Examples include Aurora borealis, the northern lights, and aurora australis, the southern lights, Communication disruptions, Radiation hazards to orbiting astronauts and spacecraft, Orbital degradation amongst others. However, phenomena occurring on the surface of the sun allows us to monitor solar activity, but knowing that something is heading towards Earth is a key measurement.
A related subject, the Space environment is a branch of astronautics, aerospace engineering and space physics that seeks to understand and address conditions existing in space that affect the design and operation of spacecraft. Effects on spacecraft can arise from radiation, space debris and meteoroid impact, upper atmospheric drag and spacecraft electrostatic charging.
The closed environment of a spacecraft with a closed-loop or nearly closed-loop life support system will present unique challenges to both scientists and engineers who must manage the quality of the crew’s air and water. It will be necessary to maintain the composition, temperature, feed rates, and operating pressures of the solid, gaseous, and liquid constituents to ensure the mechanical health of the system (i.e. reliability, maintainability) and the health of the human crew. Environmental monitoring and control (EMC) encompass the internal environment of a human-occupied spacecraft, including the atmosphere, water supplies, and all surfaces. Monitoring suggests continuous hawk-eyed oversight of the status of these areas to ensure that conditions are maintained within acceptable limits. This also implies that acceptable limits have been established and that detection methodologies are available.
ISES (International Space Environment Services) aims to improve, coordinate, and to deliver operational space weather services. ISES is organized and operated for the benefit of the international space weather user community. ISES works in close cooperation with the World Meteorological Organization, recognizing the mutual interest in global data acquisition and information exchange, in common application sectors, and understanding and predicting the coupled Earth-Sun environment.
South African National Space Agency (SANSA) Space Science is host to the only Space Weather Regional Warning Centre in Africa which operates as part of the International Space Environment Service (ISES). The Space Weather Centre provides an important service to the nation by monitoring the sun and its activity to provide information, early warnings and forecasts on space weather conditions. The space weather products and services are required primarily for communication and navigation systems, in the defence, aeronautics, navigation and communication sectors.
Other African countries are striving to join ISES because non-members have to rely on the data and observations recorded by the sixteen Regional Warning Centres across the globe, four Associate Warning Centers, and one Collaborative Expert Center (European Space Agency)
Several satellites gather space weather data to help forecasters analyse the space environment. Examples are The Solar and Heliospheric Observatory (SOHO), Advanced Composition Explorer(ACE), Geostationary Operational Environmental Satellite (GEOS), Polar Operational Environmental Satellite (POES) amongst others. The bird’s-eye view that satellites have allows them to see large areas of Earth at once. This ability means satellites can collect more data, rapidly, than instruments on the ground. Satellites also can see into space better than telescopes at Earth’s surface. That’s because satellites fly above the clouds, dust and molecules in the atmosphere that can block the view from ground level.
The modus operandi for the Space Situational Awareness (SSA) Space Weather Network is to collect the required measurement data using ground-based instruments because ground-based instruments are usually less expensive and easier to maintain and upgrade than spaceborne instruments onboard satellites.
However, to gain all the necessary, accurate, realtime data needed for future space-weather warning services, data from instruments in space are absolutely critical.
Examples of European and international observatories and instrument networks that could be utilised in ESA‘s Space Weather are; Solar images in various wavelengths which can be gotten from the use or reuse existing European solar telescopes such as the Kanzelhöhe Observatory for Solar and Environmental Research in Austria, Solar radio bursts which can be gotten from the Solar radio spectrograph network, Vector magnetic field (Magnetograms at Earth’s surface which can be gotten from Vector magnetometers, such as the International Real-time Magnetic Observatory Network (INTERMAGNET) amongst others. Also, images of eruptions in the solar corona from NASA’s SOHO (Solar and Heliospheric Observatory) spacecraft have provided invaluable monitoring capabilities of approaching coronal mass ejections which are energetic eruptions on the sun and primary cause of major geomagnetic storms.
There’s a plan put in place by the ESA’s Space Weather Network plans to obtain ‘in-situ’ measurements from space (but inside Earth’s magnetosphere) by using ‘hosted payload’ instruments, that is, instruments have flown on spacecraft operated by ESA or by other organisations, which is a smart way to boost economic efficiency.
For space weather monitoring and forecasting in Africa, however, we need observations from where these happen, i.e. from space, and this is why we need spaceborne observation systems to complement ground-based observations. There’s an urgent need for other space agencies in Africa to develop their indigenous observation system to stay abreast of changes in space weather and the environment in their region.
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