In Earth’s highest atmospheric layers, space weather can really heat things up

Posted: October 20, 2021 by oldbrew in atmosphere, data, Electro-magnetism, Natural Variation, research, solar system dynamics, Temperature

Credit: NASA

Report: ‘With its steady stream of temperature measurements, GOLD is painting a picture of an upper atmosphere much more sensitive to the magnetic conditions around Earth than previously thought.’ Interesting – does this impact climate models?
– – –
New results from NASA satellite data show that space weather—the changing conditions in space driven by the sun—can heat up Earth’s hottest and highest atmospheric layer, says Phys.org.

The findings, published in July in Geophysical Research Letters, used data from NASA’s Global Observations of the Limb and Disk, or GOLD mission. Launched in 2018 aboard the SES-14 communications satellite, GOLD looks down on Earth’s upper atmosphere from what’s known as geosynchronous orbit, effectively “hovering” over the western hemisphere as Earth turns.

GOLD’s unique position gives it a stable view of one entire face of the globe—called the disk—where it scans the temperature of Earth’s upper atmosphere every 30 minutes. GOLD scans the thermosphere from a position in geostationary orbit, which stays over one particular spot on Earth as it orbits and the planet rotates.

“We found results that were not previously possible because of the kind of data that we get from GOLD,” said Fazlul Laskar, who led the research. Dr. Laskar is a research associate at the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder.

From its perch some 22,000 miles (35,400 kilometers) above us, GOLD looks down on the thermosphere, a region of Earth’s atmosphere between about 53 and 373 miles (85 and 600 kilometers) high.

The thermosphere is home to the aurora, the International Space Station, and the highest temperatures in Earth’s atmosphere, up to 2,700 °F (1,500 °C). It reaches such incredible temperatures by absorbing the sun’s high-energy X-rays and extreme ultraviolet rays, heating the thermosphere and stopping these types of light from making it to the ground.

But the new findings point to some heating not driven by sunlight, but instead by the solar wind—the particles and magnetic fields continuously escaping the sun.

The solar wind is always blowing, but stronger gusts can disturb Earth’s magnetic field, inducing so-called geomagnetic activity.

Laskar and his collaborators compared days with more geomagnetic activity to days with less, and found an increase of over 160 °F (90 °C) in thermospheric temperatures.

Magnetic disturbances, driven by the sun, were heating up Earth’s hottest atmospheric layer.

Some amount of heating was expected near Earth’s poles, where a weak point in our magnetic field allows some solar wind to pour into our upper atmosphere. But GOLD’s data showed temperature increases across the whole globe—even near the equator, far from any incoming solar wind.

Laskar and colleagues suggest it has to do with changing circulation patterns.

Full article here.

Comments
  1. tallbloke says:

    When discussing temperatures in the upper atmosphere, we need to be careful to distinguish between the joule heating of individual molecules in this rarified zone, and the bulk temperature of an ‘air parcel’ measured in the troposphere. The effects of changes in the thermosphere on the troposphere may not be caused directly by changes in temperature, but by the effect of joule heating on the chemical composition then affecting the amount of sunlight getting through to the surface.

    Not enough research effort has been devoted to these questions, because the CO2 drama queens holding the climate research purse strings are worried their paymasters may not like the answers.

  2. oldbrew says:

    Open access research:
    Response of GOLD Retrieved Thermospheric Temperatures to Geomagnetic Activities of Varying Magnitudes

    Plain Language Summary

    The thermosphere ionosphere system is influenced by waves from the lower atmosphere and solar and geomagnetic forcing from above. For such a coupled system it is important to decipher the relative influence of the two regimes of forcings. The recently launched Global-scale Observations of Limb and Disk (GOLD) mission provides daytime thermospheric temperatures with unprecedented local time and spatial coverage. The thermospheric temperature over the Earth’s disk visible from geostationary orbit is a first of its kind of measurement, which enables us to investigate the local time behavior over wide latitudinal coverage from 69°S to 69°N. We find that, during active geomagnetic conditions, the thermospheric temperature is enhanced across the whole visible hemisphere, with the largest temperature enhancements at higher mid-latitudes. The local time behavior shows that the pre-noon enhancement in temperature is greater compared to the afternoon, which demonstrates, for the first time, a systematic local time varying response of thermosphere to geomagnetic forcing.

    https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL093905

  3. JB says:

    “magnetic fields continuously escaping the sun”

    ‘SIGH’

    That’s Phys.org for ya

  4. oldbrew says:

    From an earlier Talkshop post…

    “The thermosphere always cools off during Solar Minimum. It’s one of the most important ways the solar cycle affects our planet,” explains Mlynczak, who is the associate principal investigator for SABER.

    When the thermosphere cools, it shrinks, literally decreasing the radius of Earth’s atmosphere.

    The Chill of Solar Minimum

  5. Damian says:

    “When the thermosphere cools, it shrinks, literally decreasing the radius of Earth’s atmosphere.”
    I believe that the Earth’s atmosphere is a plasma sheath born through the potential difference between the surface of the Earth and the interplanetary medium which is essentially part of the Sun’s atmosphere. It would follow that, when this potential difference is greater, Solar maximum, the Earth’s atmosphere would expand, increasing the surface area and reducing the stress on the surface of the planet with the opposite happening at Solar minimum.

  6. pochas94 says:

    This will be a hellluva surprise to Ned Nickolov.

  7. tallbloke says:

    Pochas, Ned says space weather makes around +/- 1C difference to surface t at the centennial timescale. So no surprise to him.

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