3:30 PM | *First solar images from GOES-16 (formerly GOES-R) and they show a coronal hole*

These images of the sun were captured at the same time on January 29, 2017 by the six channels on the SUVI instrument on board GOES-16 and show a large coronal hole in the sun’s southern hemisphere. Each channel observes the sun at a different wavelength, allowing scientists to detect a wide range of solar phenomena important for space weather forecasting.
Credits: NOAA
 

Overview
GOES-16, the first of NOAA’s next generation of geostationary weather satellites, the GOES-R series, successfully launched on November 19, 2016 and will provide continuous imagery and atmospheric measurements of Earth’s Western Hemisphere, total lightning data, and space weather monitoring.  GOES-16 has now successfully delivered its first images of the sun. The images were captured by the Solar Ultraviolet Imager (SUVI) instrument aboard the weather satellite on January 29, 2017 and they show a large coronal hole.  The sun’s 11-year activity cycle is currently approaching the next solar minimum phase, and during this time, powerful solar flares become less frequent and coronal holes become the primary space weather phenomena.  Solar cycles have been in a general weakening trend since solar cycle 21 peaked around 1980. 
 

Daily observations of the number of sunspots since 1 January 1977 according to Solar Influences Data Analysis Center (SIDC). The thin blue line indicates the daily sunspot number, while the dark blue line indicates the running annual average.  The current solar cycle (#24) is heading towards the next solar minimum phase (circled region at lower right). Courtesy climate4you.com

Discussion
According to NASA, the sun’s upper atmosphere - known as the solar corona - consists of extremely hot plasma which is an ionized gas. This plasma interacts with the sun’s powerful magnetic field, generating bright loops of material that can be heated to millions of degrees. Outside hot coronal loops, there are cool, dark regions called filaments which can erupt and become a key source of space weather when the sun is active. Other dark regions are called coronal holes, which occur where the sun’s magnetic field allows plasma to stream away from the sun at high speed.  The solar corona is so hot that it is best observed with X-ray and extreme-ultraviolet (EUV) cameras. Various elements emit light at specific EUV and X-ray wavelengths depending on their temperature, so by observing in several different wavelengths, a picture of the complete temperature structure of the corona can be made.

The GOES-16 SUVI observes the sun in six EUV channels.  SUVI replaces the GOES Solar X-ray Imager (SXI) instrument in previous GOES satellites and represents a change in both spectral coverage and spatial resolution over SXI.  SUVI will capture full-disk solar images around-the-clock and will be able to see more of the environment around the sun than earlier NOAA geostationary satellites.  Data from SUVI will provide an estimation of coronal plasma temperatures and emission measurements which are important to space weather forecasting. SUVI is essential to understanding active areas on the sun, solar flares and eruptions that may lead to coronal mass ejections which may impact Earth. Depending on the magnitude of a particular eruption, a geomagnetic storm can result that is powerful enough to disturb Earth’s magnetic field. Such an event may impact power grids by tripping circuit breakers, disrupt communication and satellite data collection by causing short-wave radio interference and damage orbiting satellites and their electronics. SUVI will allow the NOAA Space Weather Prediction Center to provide early space weather warnings to electric power companies, telecommunication providers and satellite operators.  

Meteorologist Paul Dorian
Vencore, Inc.
vencoreweather.com