How Does Earth's Dynamics To Space Work? This Gold Bird's Eye Reveals How

The surprising behavior of a band of charged particles across the Earth's equator is shown in recent research based on data from NASA's Global Observation (GOLD) mission of limbs and disks.

Geosynchronous orbit is where gold resides. It orbits Earth at the same rate that the planet spins, "hovering" in the same spot overhead. This allows GOLD to track the longitude and latitude of the same region over time. Most satellites investigating the upper atmosphere are unable to do so.

Since GOLD is on a geostationary satellite, researchers could record the 2D temporal development of these processes.

Florida News Times said GOLD examines portions of Earth's upper atmosphere that range in height from 50 to 400 miles (80.47 to 643.74 kilometers), including a neutral layer known as the thermosphere and electrically charged particles known as the ionosphere. The particles in the ionosphere react to the electric and magnetic forces that go through the atmosphere and near-Earth space. However, because the charged and neutral particles are mingled together, anything that affects one population might affect the other as well.

This implies that the ionosphere and upper atmosphere are affected by various complicated variables, such as space weather conditions (such as solar-driven geomagnetic storms) and terrestrial weather. Many of our communications and navigation signals go via these areas. Radio and GPS signals can be muddled by changes in the density and composition of the ionosphere.

GOLD performs hemisphere-wide measurements of the ionosphere every 30 minutes from its vantage position aboard a commercial communications satellite in geostationary orbit. Scientists are learning new things about how this region evolves thanks to this unparalleled bird's-eye view.

Weird Movement

Phys.org said twin bands of concentrated charged particles on each side of Earth's magnetic equator are the most recognizable aspects of the nighttime ionosphere. The Equatorial Ionization Anomaly (EIA) is a set of bands that can fluctuate in size, shape, and strength depending on ionosphere conditions.

The bands can also be moved around. Until previously, scientists relied on data collected by satellites flying over the region. They had observations for months to determine how the bands may vary over time. Short-term changes, on the other hand, were more difficult to track.

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Prior to discovering GOLD, scientists assumed that any rapid changes in the bands would be symmetrical. When the northern band goes north, the southern band moves south in the opposite direction. GOLD saw something that contradicted this theory one night in November 2018: the southern band of particles moved southward in less than two hours, while the northern band stayed stable.

This isn't the first time scientists have seen the bands move in this way, but it was the first time, and it could only have been seen by GOLD. The event lasted only about two hours, compared to the usual six or eight hours.

Rising air draws charged particles along with it, causing these bands to drift symmetrically. Warmer pockets of air rise when the temperature drops and the night falls. Magnetic field lines bind the charged particles transported inside these warmer air pockets. Earth's magnetic field structure implies that upward motion also pulls the charged particles horizontally for those pockets near the magnetic equator. The two charged particle bands move symmetrically northward and southward as a result of this.

The specific reason for GOLD's asymmetric drift is unknown. However, researchers believe it's a mix of the various variables that affect electron mobility in the ionosphere. These include active chemical processes, electric fields, and high-altitude winds sweeping across the area.

These discoveries, however startling, can aid scientists in peering behind the curtain of the ionosphere to understand better what drives its fluctuations. Because it's hard to monitor every activity using a satellite or ground-based sensor, scientists study the ionosphere using computer models, similar to how meteorologists use models to forecast weather on the ground. Scientists code what they think are the fundamental physics at action then compare the model's predictions to observable data to produce these simulations.

Scientists used to get the information from passing satellites and a few ground-based observations before GOLD. GOLD now provides scientists with a bird's-eye view.

The study's findings are detailed in "Observation of Postsunset OI 135.6 nm Radiance Enhancement Over South America by the GOLD Mission," published in the Journal of Geophysical Research: Space Physics on December 29, 2020.