Earth’s Thermosphere Reaches Highest Temperature in 20 Years

The temperature in Earth’s thermosphere, which is the second-highest layer of the atmosphere, recently reached its highest point in almost 20 years.

This increase in temperature was caused by the energy absorbed from geomagnetic storms that affected our planet this year.

Moreover, experts are concerned that the temperature will continue to rise in the coming years as the sun’s activity intensifies. This could have difficulties for satellites that orbit the Earth.

To give you some perspective, the thermosphere starts at about 53 miles (85 km) above the Earth’s surface, at the top of the mesosphere.

It extends upwards until it reaches the bottom of the exosphere, which begins at nearly 372 miles (600 km) above the ground, according to NASA. Beyond the exosphere lies outer space.

NASA monitoring thermosphere temperature for the past 21 years

NASA has been monitoring the temperature of the thermosphere for over 21 years using a method that involves detecting infrared radiation emitted by carbon dioxide and nitric oxide molecules.

They collect this data through NASA’s Thermosphere, Ionosphere, Mesosphere, Energetics, and Dynamics (TIMED) satellite. Scientists convert it into what is known as the Thermosphere Climate Index (TCI). The TCI is measured in terawatts (TW), where 1 TW is equal to 1 trillion watts.

Earth's thermosphere recently hit a near 20-year temperature peak after soaking up energy from geomagnetic storms that bashed Earth this year. The temperature in the second-highest layer of the atmosphere will likely continue to climb over the next few years as the sun's … 1/ pic.twitter.com/26AoCW3ANn

— Erika  (@ExploreCosmos_) June 23, 2023

Martin Mlynczak, a researcher involved in NASA’s TIMED mission at the Langley Research Center in Virginia and the creator of the TCI, said that the TCI value experienced a notable increase on March 10.

It reached a peak of 0.24 terawatts (TW). Moreover, Mlynczak noted that this is the highest TCI value observed since December 28, 2003.

However, it’s important to note that the data showing the temperature spike has been submitted to a scientific journal, but it has not yet been peer-reviewed, as reported by Live Science.

Cause of the recent temperature spike in the thermosphere

The recent temperature spike in the thermosphere may be due to three geomagnetic storms that occurred in January and February.

These storms are significant disruptions to Earth’s magnetic field and are usually caused by the impact of magnetized plasma called coronal mass ejections (CMEs) and, to a lesser extent, streams of highly charged particles known as the solar wind. Moreover, both CMEs and solar wind are expelled from the sun.

Mlynczak explained that these geomagnetic storms deposit their energy in the thermosphere, leading to its heating.

Consequently, because of this increased heating, there is a rise in the levels of infrared emission from nitric oxide and carbon dioxide in the thermosphere.

Typically, after a storm, the infrared emissions help to cool down the thermosphere. However, when the storms occur consecutively, the temperature remains high without experiencing the usual cooling effect.