Geomagnetic storm index for the Philippines

by Quirino Sugon Jr.

I am thinking of proposing a geomagnetic storm index for the Philippines using MAGDAS (Magnetic Data Acquisition System) data of Kyushu University’s SERC (Space Environment Research Center).  SERC has 6 stations all over the Philippines: TUG (Tuguegarao), MUN (Muntinlupa), LGZ (Legaspi), CEB (Cebu), CDO (Cagayan de Oro), and DAV (Davao).  SERC provided us with data for 2010 at 1 minute interval.  We shall use this data to identify geomagnetic storms from their magnetic signatures.  But to do this, we need first to make a survey on the magnetic storm indices currently used worldwide.  Note that each place defines its own storm index because geomagnetic storms affect different places differently.  At present, there is still no magnetic storm index for the Philippines.

1.  The ever-reliable Wikipedia has a good article on geomagnetic storms.  Here is one definition in terms of DST:

A geomagnetic storm is defined[4] by changes in the Dst[5] (disturbance – storm time) index. The Dst index estimates the globally averaged change of the horizontal component of the Earth’s magnetic field at the magnetic equator based on measurements from a few magnetometer stations. Dst is computed once per hour and reported in near-real-time.[6] During quiet times, Dst is between +20 and -20 nano-Tesla (nT).

2.  NOAA Space weather prediction Center has made a descriptive scale for geomagnetic storms from G1 to G5.  I need a list of geomagnetic storms for 2010 and how NOAA computes its storm scale from its magnetic data.

3.  Wikipedia says that the K-index is measured from the fluctuations in the horizontal component of magnetic field.  It requires only one magnetometer using data in 3 hours.  In the page is the Boulder Scale.  The Kp index is measured from the average of the K-indices of a network of observatories.  In the A-index, each K-index is rescaled into the equivalent 3 hour range.  The Ap index is the average A index for all the stations.

4. Berkeley has a discussion on the DST index.  This index is made by averaging the horizontal component of the magnetic field from midlatitude to equatorial regions.  A negative DST index corresponds to the ring current.  I think there is a mistake here: it is the horizontal fluctuations that must be averaged and not the horizonotal components themselves.

5.  NOAA has a geomagnetic index bulletin for 2010.  I need this.

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About ateneophysicsnews
Physics News and Features from Ateneo de Manila University

3 Responses to Geomagnetic storm index for the Philippines

  1. Richard King says:

    I’m not certain but I’m guessing there were no geomagnetic storms in 2010… the solar cycle was just coming out of a unusually prolonged minimum. If I recall correctly, there were zero, or almost zero sunspots for most days in 2010! I thought the absence of sunspots would have produced a very calm geomagnetic field. You should check with Dr. Keith Strong on Youtube… he would likely have some suggestions for you.

    • Hi Richard,

      Thanks for the info. I listened to Dr. Keith Strong today in You Tube regarding today’s geomagnetic storm. I’ll check out his other videos.

      • Hi Richard,

        I realized I was subscribed to geomagnetic storms alert in spaceweather.com. There are a handful of storms for 2010: April 6, May 4, August 2 (CME). I guess you are right. If we’re stuck with a lemon, we’ll have to make a lemonade. Maybe fewer storms would allow us to study magnetic field variations for many solar quiet periods. Anyway, I think we can still get 2011 magnetic data next year.

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