Space Weather Observations, Alerts, and Forecast

3-day Solar-Geophysical Forecast

Product: 3-Day Forecast - Issued: 2023 Dec 09 1230 UTC
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center.

Geomagnetic Activity Observation and Forecast

The greatest observed 3 hr Kp over the past 24 hours was 2 (below NOAA Scale levels). The greatest expected 3 hr Kp for Dec 09-Dec 11 2023 is 3.33 (below NOAA Scale levels).

NOAA Kp index breakdown Dec 09-Dec 11 2023
Dec 09Dec 10Dec 11
00-03UT0.331.672.00
03-06UT0.331.673.33
06-09UT1.001.333.00
09-12UT0.671.333.00
12-15UT1.331.672.33
15-18UT1.331.332.33
18-21UT1.331.332.33
21-00UT1.671.333.00

Rationale: No G1 (Minor) or greater geomagnetic storms are expected. No significant transient or recurrent solar wind features are forecast.

Solar Radiation Activity Observation and Forecast

Solar radiation, as observed by NOAA GOES-16 over the past 24 hours, was below S-scale storm level thresholds.

Solar Radiation Storm Forecast for Dec 09-Dec 11 2023
Dec 09Dec 10Dec 11
S1 or greater5%5%5%

Rationale: No S1 (Minor) or greater solar radiation storms are expected. No significant active region activity favorable for radiation storm production is forecast.

Radio Blackout Activity and Forecast

Radio blackouts reaching the R2 levels were observed over the past 24 hours. The largest was at Dec 08 2023 2307 UTC.

Radio Blackout Forecast for Dec 09-Dec 11 2023
Dec 09Dec 10Dec 11
R1-R240%40%40%
R3 or greater5%5%5%

Rationale: There is a chance for R1-R2 (Minor-Moderate) radio blackouts over 09-11 Dec.


Real Time Images of the Sun


SOHO EIT 304
Click for time-lapse image of the sun
SOHO EIT 284
SOHO EIT 284 image of the sun
SDO/HMI Continuum Image
Latest Mauna Loa image of the Sun

The sun is constantly monitored for sun spots and coronal mass ejections. EIT (Extreme ultraviolet Imaging Telescope) images the solar atmosphere at several wavelengths, and therefore, shows solar material at different temperatures. In the images taken at 304 Angstrom the bright material is at 60,000 to 80,000 degrees Kelvin. In those taken at 171 Angstrom, at 1 million degrees. 195 Angstrom images correspond to about 1.5 million Kelvin, 284 Angstrom to 2 million degrees. The hotter the temperature, the higher you look in the solar atmosphere.

Real Time Solar X-ray and Solar Wind



Latest LASCO Solar Corona
Images of the solar corona
Large Angle and Spectrometric Coronagraph (LASCO).
Real-Time Solar Wind
Graph showing Real-Time Solar Wind
Real-Time Solar Wind data broadcast from NASA's ACE satellite.



Solar X-ray Flux
Graph showing Real-Time Solar X-ray Flux
This plot shows 4-days of 5-minute solar x-ray flux values measured on the SWPC primary and secondary GOES satellites.

Satellite Environment Plot
Graph showing Real-Time Satellite Environment Plot

The Satellite Environment Plot combines satellite and ground-based data to provide an overview of the current geosynchronous satellite environment.

Solar Cycle


Sun Spot Number Progression
Graph showing Sun Spot Number Progression
This plot shows the Solar Cycle Sun Spot Number Progression.
F10.7cm Radio Flux Progression
Graph showing F10.7cm Radio Flux Progression
This plot shows the F10.7cm Radio Flux Progression.

The Solar Cycle is observed by counting the frequency and placement of sunspots visible on the Sun. The forecast comes from the Solar Cycle Prediction Panel representing NOAA, NASA and the International Space Environmental Services (ISES).
The Prediction Panel has predicted Cycle 25 to reach a maximum of 115 occurring in July, 2025.


Auroral Activity Extrapolated from NOAA POES


Northern Hemi Auroral Map
Current Northern hemispheric power input map
Southern Hemi Auroral Map
Current Southern hemispheric power input map

Instruments on board the NOAA Polar-orbiting Operational Environmental Satellite (POES) continually monitor the power flux carried by the protons and electrons that produce aurora in the atmosphere. SWPC has developed a technique that uses the power flux observations obtained during a single pass of the satellite over a polar region (which takes about 25 minutes) to estimate the total power deposited in an entire polar region by these auroral particles. The power input estimate is converted to an auroral activity index that ranges from 1 to 10.


Radio Communications Impact

D-Region Absorption

D-Region Absorption Prediction
Latest D-Region Absorption Prediction Model

The D-Region Absorption Product addresses the operational impact of the solar X-ray flux and SEP events on HF radio communication. Long-range communications using high frequency (HF) radio waves (3 - 30 MHz) depend on reflection of the signals in the ionosphere. Radio waves are typically reflected near the peak of the F2 layer (~300 km altitude), but along the path to the F2 peak and back the radio wave signal suffers attenuation due to absorption by the intervening ionosphere. The D-Region Absorption Prediction model is used as guidance to understand the HF radio degradation and blackouts this can cause.



VHF and HF Band Conditions

HF RADIO COMMUNICATIONS Space weather impacts radio communication in a number of ways. At frequencies in the 1 to 30 mega Hertz range (known as “High Frequency” or HF radio), the changes in ionospheric density and structure modify the transmission path and even block transmission of HF radio signals completely. These frequencies are used by amateur (ham) radio operators and many industries such as commercial airlines. They are also used by a number of government agencies such as the Federal Emergency Management Agency and the Department of Defense. There are several types of space weather that can impact HF radio communication. In a typical sequence of space weather storms, the first impacts are felt during the solar flare itself. The solar x-rays from the sun penetrate to the bottom of the ionosphere (to around 80 km). There the x-ray photons ionize the atmosphere and create an enhancement of the D layer of the ionosphere. This enhanced D-layer acts both as a reflector of radio waves at some frequencies and an absorber of waves at other frequencies. The Radio Blackout associated with solar flares occurs on the dayside region of Earth and is most intense when the sun is directly overhead. Another type of space weather, the Radiation Storm caused by energetic solar protons, can also disrupt HF radio communication. The protons are guided by Earth’s magnetic field such that they collide with the upper atmosphere near the north and south poles. The fast-moving protons have an affect similar to the x-ray photons and create an enhanced D-Layer thus blocking HF radio communication at high latitudes. During auroral displays, the precipitating electrons can enhance other layers of the ionosphere and have similar disrupting and blocking effects on radio communication. This occurs mostly on the night side of the polar regions of Earth where the aurora is most intense and most frequent.





Credits:
Space Weather Images and Information (excluded from copyright) courtesy of:
NOAA / NWS Space Weather Prediction Center
Mauna Loa Solar Observatory (HAO/NCAR)
SOHO (ESA & NASA).

Space Weather links:
3-Day Forecast of Solar and Geophysical Activity
Space Weather Overview
LASCO Coronagraph
Real-Time Solar Wind
Space Weather Advisory Outlooks
Space Weather Forecast Disussions
Space Weather Alerts, Watches and Warnings
Solar and Heliospheric Observatory (SOHO)
The Very Latest SOHO Images