by Scientists are building a digital model of space around Earth “beyond the state of the art” to improve forecasting of solar storms and their effects on infrastructure.
Nearly seven decades into the space age, scientists’ understanding of space weather It’s still very raw. Unlike Earth weather, which is now forecast by powerful supercomputers with great accuracy and timeliness, space weather predictions are more unpredictable.
Most of the time, an inaccurate space weather forecast just means that someone is elevated dawn-Viewing expectations are not met. But humanity is increasingly reliant on technologies that are vulnerable to the vagaries of space weather. From brief radio blackouts to GPS Due to long-lasting power outages and outages, space weather can disrupt our daily lives, perhaps not as frequently as torrential rains and windstorms, but with similar ferocity.
A new model, developed by a team of researchers led by the Applied Physics Laboratory (APL) at Johns Hopkins University, is a step toward closing the gap between space and ground-based weather predictions. However, scientists admit that it could be decades before space weather forecasts catch up.
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“We cannot predict space weather without first deeply understanding its physics,” Slava Merkin, a space physicist at APL and director of its Center for Geospatial Storms (CGS), told Space.com. “We’re building the model and doing science with the model, and through that, we’re figuring out the physics of geospatial storms.”
Geospace is a term that scientists use to describe the region around our planet that includes LandThe upper atmosphere and surrounding space. With the new model, called Multiscale Atmosphere-Geospatial Environment (MAGE), researchers want to capture processes taking place in geospace up to a distance of 1.2 million miles (2 million kilometers) from Earth, Merkin said. It is a vast region that extends four times farther from the planet than the distance of Moon. But Earth’s influence on the cosmos extends even further. The outer edge of Earth’s magnetosphere, its magnetic tail, can be traced nearly 4 million miles (6.5 million kilometers) from Earth in the opposite direction of Sun.
Generated by the movement of molten metals inside. The core of the Earththe magnetosphere interacts with explosions of solar wind — the streams of charged particles that constantly emanate from the sun. This interaction produces the space weather phenomena we experience on Earth. The process is extremely complex, Merkin said. It involves poorly understood physical interactions that take place in the thermosphere (the second highest level of earth atmosphere) and the ionosphere (an overlapping region containing high concentrations of charged particles created in interactions with ultraviolet light from the sun).
“Our number one challenge is to treat this system holistically,” Merkin said. “But the problem is that each of these domains is governed by different physics. They are populated by different populations of plasma, different gas particles, and they all participate in very complex interactions, particularly during geomagnetic storms“.
The team celebrated a major success in 2020 when their fledgling model provided unprecedented insights into the formation of bead-like structures in the aurora that sometimes appear over Earth’s polar regions before large geomagnetic storms. The MAGE model revealed that these pearls of polar light arise when magnetic lines in the distant magnetic tail move further away from the planet before geomagnetic storms and then shoot bubbles of light plasma toward Earth.
But the discovery also aptly demonstrated the difficulty of forecasting space weather. Like the proverbial wave of a butterfly’s wing, a physical process in a distant region of geospace can produce visible and measurable effects near the Earth’s surface.
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“The computer model we are developing needs to be able to capture processes that occur at very large scales but also at very small scales,” Merkin said. “At the same time, you need to capture all the different problems in physics and understand how the various domains (the middle and lower atmosphere, the ionosphere and the magnetosphere) influence each other.”
Unlike Earth-based weather prediction models, which digest millions of measurements taken daily around the world by hundreds of thousands of weather stations, airplanes and high-altitude balloons, MAGE has to make do with far fewer data points.
“At any given time, we actually have quite a few spacecraft in this huge region,” Merkin said. “Point-to-point measurements can be very accurate, particularly with recent spacecraft, but we don’t have the coverage to really know what’s going on at the system level.”
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Merkin and his colleagues have access to data accumulated since the beginning of the space age. Still, there are important gaps. For example, the lower layer of the thermosphere, located at altitudes between 60 and 120 miles (100 to 200 km) and sometimes called “ignorantosphere“, is poorly understood. Too high for stratospheric balloons to reach but too low for satellites to explore, theignorosphere is where auroras occur. MAGE might be able to fill some of those gaps by taking advantage of powerful supercomputing and the detailed measurements taken by satellites higher in the atmosphere, along with information from radars and other sensors on the ground.
“As we go forward, the model becomes more and more complex,” Merkin said. “We are adding more and more physics to it. The final product will represent geospace at its maximum complexity.”
Merkin admits it could be decades before researchers get there. Modeling space weather is an enormously complicated task. The MAGE collaboration involves dozens of software engineers, computer scientists, physicists and other experts working in research laboratories across the United States. In addition to APL, the National Center for Atmospheric Research, the University of New Hampshire, Rice University, Virginia Tech, UCLA and Syntek. Technologies are contributing to the effort.
