Archive for the ‘Aurorae’ Category

Oslo-physicists use 20 new satellites to forecast space weather

The northern lights interfere with radio communications, GPS navigation and satellite communications. Researchers are now going to launch 20 satellites containing world class instruments from the University of Oslo to find out why.

Satellites are becoming increasingly important in communications and navigation. This makes us more vulnerable to the northern lights, especially within offshore and aviation. In a worst case scenario an aircraft can lose contact with its surroundings. Oil tankers can struggle with precise navigation.

In order to more precisely predict when radio communications and navigation will fail, researchers require more information about what happens when violent solar winds hit the Earth and produce the northern lights.

The solar winds consist of charged particles and produce powerful turbulence in the ionosphere, which consists of plasma clouds with electrical particles at an altitude of 80 to 500 km. The turbulence interferes with radio signals. Sometimes they are reflected wrongly. On other occasions the signals are blocked altogether.

“In the northern regions GPS satellites lie low in the sky. This means the signals have to pass through the ionosphere. This reinforces the navigation problems,” says professor Jøran Moen of the Department of Physics at University of Oslo (UiO), Norway.

Full story:

Space Weather Warnings for Earth & Forecasts for Exoplanets

March 29, 2012 Leave a comment

The UK Met Office’s weather and climate model is being adapted to help understand space weather at Earth and the atmospheres of planets orbiting other stars. Two teams of scientists will present their work at the National Astronomy Meeting in Manchester.

The Met Office plans to expand its services to provide operational space weather forecasts for the UK. It is pooling skills with the UK’s space weather research community to extend its ‘Unified Model’ upwards to include the Earth’s thermosphere, a region about 90-600km above the Earth surface. The impact of space weather events is very commonly seen in this region.

“Space weather can affect the aviation and power industries, as well as a whole range of activities that rely on GPS timing and positioning, radio communication or satellite-based observations,” said the Met Office’s Dr David Jackson, who will present the project on Friday 30th March.

“To develop a more accurate and useful advanced-warning system for space weather, we need to develop a system of interconnected models that describe the whole domain – the conditions on the Sun, interplanetary space, the layers of the Earth’s atmosphere, all the way down to the Earth’s surface. The more accurate we can be in representing interactions between the lower atmosphere and thermosphere, the more we can enhance thermospheric forecasts, and thus improve space weather forecast products for users,” Jackson continued.

Full Story:

Cassini Measures Saturn’s Nightside Aurora & Electric Currents

March 27, 2012 Leave a comment

Since the NASA / ESA Cassini-Huygens spacecraft arrived at Saturn in 2004, astronomers and space scientists have been able to study the ringed planet and its moons in great detail. Now, for the first time, a team of planetary scientists have made simultaneous measurements of Saturn’s nightside aurora, magnetic field, and associated charged particles. Together the fields and particle data provide information on the electric currents flowing that produce the emissions. Team leader Dr Emma Bunce of the University of Leicester will present the new work at the National Astronomy Meeting in Manchester on 27 March 2012.

Generally, images of the aurora (equivalent to the terrestrial ‘northern lights’) provide valuable information about the electromagnetic connection between the solar wind, the planet’s magnetic field (magnetosphere) and its upper atmosphere. Variations in the aurora then provide information on changes in the associated magnetosphere. But viewing the aurora (best done at a large distance) at the same time as measuring the magnetic field and charged particles at high latitudes (where the aurora is found, best done close to the planet) is hard

In 2009, Cassini made a crossing of the magnetic field tubes that connect to the aurora on the night side of Saturn. Because of the position of the spacecraft, Dr Bunce and her team were able to obtain ultraviolet images of the aurora (which manifests itself as a complete oval around each pole of the planet) at the same time.

Full Story:

Storms From the Sun

March 12, 2012 Leave a comment

Space weather starts at the sun. It begins with an eruption such as a huge burst of light and radiation called a solar flare or a gigantic cloud of solar material called a coronal mass ejection (CME). But the effects of those eruptions happen at Earth, or at least near-Earth space. Scientists monitor several kinds of space “weather” events — geomagnetic storms, solar radiation storms, and radio blackouts – all caused by these immense explosions on the sun.

One of the most common forms of space weather, a geomagnetic storm refers to any time Earth’s magnetic environment, the magnetosphere, undergoes sudden and repeated change. This is a time when magnetic fields continually re-align and energy dances quickly from one area to another.

Geomagnetic storms occur when certain types of CMEs connect up with the outside of the magnetosphere for an extended period of time. The solar material in a CME travels with its own set of magnetic fields. If the fields point northward, they align with the magnetosphere’s own fields and the energy and particles simply slide around Earth, causing little change. But if the magnetic fields point southward, in the opposite direction of Earth’s fields, the effects can be dramatic. The sun’s magnetic fields peel back the outermost layers of Earth’s fields changing the whole shape of the magnetosphere. This is the initial phase of a geomagnetic storm.

Full Story:

Geomagnetic Storm Strength Increases

Geomagnetic storms due to coronal mass ejections (CMEs) earlier in the week have increased in strength, and are now rated a G3 on a scale from G1 to G5.

This space weather is due to the March 7 activity from the sun that caused rapid changes to the shape of Earth’s magnetosphere – the bubble of protective magnetic fields surrounding the planet — resulting in a geomagnetic storm. As of March 8, the storm was fairly mild since the magnetic fields from the CMEs were partially aligned with Earth’s own and thus slid around the magnetosphere. However, the geomagnetic storm has increased because the magnetic fields of the CMEs have now changed direction such that they can more easily deposit magnetic energy and radiation into Earth’s environment.

Full Story:

Another Major Flare – Class X5

March 7, 2012 2 comments

Big sunspot AR1429 has unleashed another major flare–an X5-class eruption on March 7th at 00:28 UT.   As a result of the blast, a radiation storm is underway and a CME will likely hit Earth’s magnetic field in a day or so. Geomagnetic storms are already in progress at high latitudes due to earlier eruptions from the active sunspot.  Last night, auroras were spotted over several northern-tier US states including Michigan and Wisconsin.  Check for updates and images.

GEOMAGNETIC STORM UPDATE: A CME propelled toward Earth by this morning’s X5-class solar flare is expected to reach our planet on March 8th at 0625 UT (+/- 7 hr). Analysts at the Goddard Space Weather Lab, who prepared the CME’s forecast track, say the impact could spark a strong-to-severe geomagnetic storm. Sky watchers at all latitudes should be alert for auroras. Aurora alerts: text,phone.

A mild geomagnetic storm is already underway, following a lesser CME impact on March 7th around 0400 UT. Shortly after the cloud arrived, a burst of Northern Lights appeared over the US-Canadian border.

Full Story:

Big Sunspot Unleashes X-flare & CME

Solar activity is now high. Big sunspot AR1429, which emerged on March 2nd, is crackling with strong flares. The strongest so far, an X1-class eruption, occured just ths morning, March 5th at 0413 UT. NASA’s Solar Dynamics Observatory recorded the extreme ultraviolet flash:

The explosion also hurled a bright coronal mass ejection (CME) into space: SOHO movie. The expanding cloud will probably deliver a glancing blow to Earth’s magnetic field on March 6th or 7th. (Stay tuned for updates on this possibility as more data arrive.) High-latitude sky watchers should be alert for auroras in the nights ahead.

Auroras alerts: textphone.

Full Story: