May 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009agusmsm33a..06g&link_type=abstract
American Geophysical Union, Spring Meeting 2009, abstract #SM33A-06
Physics
2778 Ring Current, 2794 Instruments And Techniques, 7959 Models, 7984 Space Radiation Environment
Scientific paper
The storm-time disturbance index Dst is used widely in the space weather community as a measure of geomagnetic activity and magnetospheric ring-current intensity. The standard Dst is a one-hour index, routinely produced by the World Data Center in Kyoto using data from four magnetic observatories (HON, KAK, SJG, HER). Traditionally, calculation of the standard index is done in the time domain, with estimates of secular and solar-quiet (Sq) variation being removed from the data of each station in order to obtain a local, disturbance time series. The four resultant time series are then weighted by latitude and averaged to produce the Dst index. Here we report on an updated and somewhat simpler method for calculating the Dst index, and the application of this method to one-minute observatory data. Secular variation is subtracted in the time domain using Chebyshev polynomials. Then, through Fourier transformation, the data are taken into the frequency domain. Here, Sq is revealed to be dominated by periodic forcing related to the Earth's rotation, the Moon's orbit around the Earth, the Earth's orbit around the Sun, and, to some extent, the solar cycle. In the time domain, cross- coupling of the associated harmonics gives an Sq time series that is seemingly complicated. In the frequency domain Sq is simply represented as a discrete set of identifiable Fourier terms. These can be removed through band-stop filtering. With inverse Fourier transformation, the disturbance time series for each observatory is obtained. Examples of the 1-minute USGS Dst are presented and comparisons to the Kyoto hourly Dst are made.
Gannon J. L.
Love Jeffrey J.
No associations
LandOfFree
One Minute USGS Dst does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with One Minute USGS Dst, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and One Minute USGS Dst will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1109232