Space Weather and Geophysical Alerts from NOAA WWV

:Product: Geophysical Alert Message wwv.txt
:Issued: 2009 Jul 04 0301 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
#
#          Geophysical Alert Message
#
Solar-terrestrial indices for 03 July follow.
Solar flux 67 and mid-latitude A-index 2.
The mid-latitude K-index at 0300 UTC on 04 July was 1 (08 nT).

No space weather storms were observed for the past 24 hours.

No space weather storms are expected for the next 24 hours.


July 04, 2009  @  01:00:02 AM EST  | www.kb3kai.com

Solar Terrestrial Conditions and What They Mean to You

NOAA issues the geophysical alert messages once an hour. This site fetches the WWV data feed each hour and stores it on this page for rapid on-demand display. The alerts display information about our current and forecasted solar conditions, which is directly applicable to HF radio and other long-range communications. Some solar activity can create an aurora in our atmosphere, while severe activity can disrupt communication systems and even disturb our power grid!

What is Space Weather?

NOAA (site) defines space weather as "the conditions in space that affect earth and its technological systems". It is the interaction of solar radiation from our sun (solar winds), the Earth's magnetic field, our atmosphere/ionosphere, and the Earth's position relative to the sun.

Space weather activity is measured by NOAA and defined in a scaled format. High solar activity are described as space weather storms and specific alerts are issued.

Indice Definitions

Solar flux is the intensity of solar radio emissions. They are displayed on a scale from 50 to over 300. They tend to correlate with the 11 year sunspot cycle, with higher flux level averages during sunspot peaks. Long range HF communications become more active during these peaks.

The A index is displayed on a scale of 0 to 400 and describe the range of disturbance in the geomagnetic field.

The K index is displayed on a scale of 0 to 9 and is a measure of change of the horizontal component of the geomagnetic field. Geomagnetic storms are defined from the K index as follows: