NOAA / Space Weather Prediction Center

D-Region Absorption Prediction

Updated: 2009 Nov 23 1717 UTC       Current Xray Flux:A0.0

World map of D-region frequency degredation Link to NW quadrant Link to NE quadrant Link to SE quadrant Link to SW quadrant

Click on a quadrant of the world map for a zoomed view

October 19 -- This product has been approved for decommissioning.
It will be replaced by the new Global D-Region Absorption product on November 18, 2009.

Conditions in the D-Region of the Ionosphere have a dramatic effect on High Frequency (HF) communications and Low Frequency (LF) navigation systems like Loran. SWPC has developed a new, global, D-Region Absorption Product, depicting the D-region at high latitudes where it is driven by particles as well as low latitudes, where photons cause the prompt changes. This new product merges all latitudes using appropriate displays, and promises to be useful to customers such as commercial aviation and numerous maritime users.
2-hour JavaScript Animation
Documentation Tabular Values Latest X-ray Flux Plot Black Background Monitor

D-Region Major Event Animations

Major X-level X-ray Events since 2000 Smaller M-level X-ray Events

Bastille Day Jul 14, 2000
X5.7

Apr 06, 2001
X5.6

Oct 28, 2003
X17

Nov 04, 2003
X28

Oct 05, 2002
M5.9

Nov 18, 2002
M7.4

Apr 02, 2001
X22

Oct 31, 2002
X1.2

Oct 29, 2003
X10

Jul 16, 2004
X3

Dec 20, 2002
M6.8

Jan 07, 2003
M4.9