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1992-02-19
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USERS MANUAL FOR THE KGRAPH SOFTWARE
------------------------------------
Version 1.00 - Copyright 1992
Solar Terrestrial Dispatch
INTRODUCTION
The daily Solar Geophysical Data Broadcast (SGDB) reports released by
the Solar Terrestrial Dispatch contain a large amount of information
regarding the state of solar and geophysical activity. In the past, the only
software which permitted manipulation of this data was the BCAST software
program. However, this software lacks the ability to chart and track the
geomagnetic K-index information.
The geomagnetic K-index rates geomagnetic activity on a scale between 0
(very quiet) and 9 (very disturbed). The index is based on an open-ended
semi-logarithmic algorithm and is measured once every three hours by magnetic
observatories around the world. Generally, K-indices greater than 5 indicate
major to severe geomagnetic storm conditions. K-indices of 4 or less
indicate active to quiet conditions.
The geomagnetic K-index is very important to persons such as radio
communicators who rely on the geomagnetically-sensitive ionosphere to
transmit and receive radio signals. Quiet levels of geomagnetic activity
usually result in very good and stable radio communications. Active levels
of geomagnetic activity can begin to introduce minor instabilities in radio
communications such as rapid fading or flutter and increased directionality.
Minor geomagnetic storming (K-indices of 5) and particularly major
geomagnetic storming (K-indices of 6) can significantly impair the
propagation of radio signals through the ionosphere. Severe geomagnetic
storming (K-indices of 7 or more) can produce radio blackout conditions for
many middle, high, and polar latitude regions. The level of geomagnetic
activity is therefore a very important parameter which must be considered
when used in conjunction with radio communications.
K-indices are also very important to persons watching for auroral
activity. Major to severe storm level excursions of the geomagnetic K-index
is often associated with visible levels of auroral activity over the lower
latitude regions.
People who are interested in attempting to forecast the level of
geomagnetic activity into the future will find detailed records of K-indices
extremely valuable. Solar phenomena which can influence geomagnetic activity
for several solar rotations (ex. such as stable coronal holes) can be
identified through records of K-index geomagnetic activity. Knowing when
enhanced geomagnetic activity has occurred in the past enables one to
determine when it might occur in the future, since the Sun rotates
approximately once every 27 days.
KGRAPH is a powerful program designed to exploit the detailed K-index
information which is stored in your BCAST database file ("datasets.dat"). It
will examine and display K-index information in useful graphical detail using
the power of your computers VGA graphics system.
KGRAPH will produce three-dimensional graphs of geomagnetic activity in
a variety of formats. It will graph either the geomagnetic Boulder K-Index
(from Boulder, Colorado) or the estimated Planetary K-Index information which
is stored in your database file. The three-dimensional graphs are very
useful for analyzing episodes of activity relative to neighboring periods of
activity. It is also visually impressive and easy to interpret.
KGRAPH will also produce detailed high-density VGA-quality graphical
plots of Boulder or Planetary K-Index data. These graphical plots of
activity let you easily determine the cyclical behavior of geomagnetic
activity. As much as eight solar rotations worth of K-index data can be
viewed on-screen at one time. This is equivalent to 216 days worth of data,
or 1,728 three-hour interval periods. The plots also indicate days in which
major flare activity occurred, to help you determine which episodes of
activity may have been flare-induced. In addition, the plotting method
employed by KGRAPH lets you visually determine, quickly and easily, periods
of activity which were associated with major or severe storming.
All-in-all, KGRAPH is a powerful visual aid package intended to exploit
the large amount of geomagnetic information which has been previously
untapped by the BCAST software. It requires the BCAST-maintained database
file "datasets.dat" to operate. Registration of the BCAST software program
is therefore manditory for anyone who wants to use KGRAPH (see the file
"REGISTER.DOC" for more information). For those who have already registered
the BCAST software, KGRAPH can immediately be used to examine the large base
of K-index information archived in your database file.
SELECTING DATES OF DATA TO GRAPH
Each of the graphical functions supported by KGRAPH first ask you to
type in the date of the last dataset to display on-screen. By default, when
you first start up KGRAPH, the date of the last dataset in your database file
will be displayed. If this is the date you wish to use, simply press ENTER.
If the default date is not what you want to use, type in the appropriate date
(using the given format) and press ENTER. Thereafter, the default date
becomes the last legal date you typed in.
THREE-DIMENSIONAL GRAPHICS FUNCTIONS OF KGRAPH
KGRAPH provides eight three-dimensional graphics functions to display
K-index data in a variety of ways. These eight functions are described
below:
1. KGRAPH can produce a three-dimensional graph of Boulder K-Indices
U with dates descending from the bottom of the screen to the top
B N of the screen. That is, the date of the data at the "front" of
O S the three-dimensional graph would be the most recent date
U O graphed.
L R
D T 2. KGRAPH will generate a three-dimensional graph of Boulder
E E K-Indices with dates ascending from the bottom of the screen to
R D the top of the screen. In this case, the date of the data at the
front of the graph would be the oldest date on-screen. The most
K recent date would be at the "back" of the graph, behind the rest.
I
N 3. KGRAPH will sort the Boulder K-Index data and graph the data in
D three-dimensional format in ascending order. Sorting is done by
E simply summing the eight three-hour K-index values for each day
X S and sorting the summed values. The resulting graph displays the
O quietest days at the front of the graph and the most disturbed
D R days at the end of the graph.
A T
T E 4. KGRAPH will sort the Boulder K-indices and graph the data in
A D descending order. In this case, the graph shows the quietest
days at the end of the graph and the most disturbed days at the
front of the graph.
U 5. KGRAPH will generate three-dimensional graphs of the estimated
P N planetary geomagnetic K-indices in order of descending dates.
L S This graph is identical to #1 above, except the K-indices used
A O are the estimated planetary data as opposed to the Boulder data.
N R
E T 6. KGRAPH will generate graphs of planetary K-indices in order of
T E ascending dates. This graph functions the same as #2 above,
A D except planetary data is used.
R
Y 7. KGRAPH will sort the estimated planetary (global) geomagnetic
S K-indices in ascending order. Graphs of these sorted indices
D O are identical to function #3 given above, except planetary
A R K-indices are used.
T T
A E 8. KGRAPH will sort the estimated planetary K-indices in descending
D order. These three-dimensional graphs are identical to the
graphs produced by function #4, except planetary data is used.
The purpose for producing three-dimensional graphs in order of ascending and
descending dates is to provide a different view of the data. Since the
graphed data is three-dimensional, producing graphs in descending or
ascending order may aid in "unblocking" areas which were previously blocked
from view. For example, a day which has high K-indices will will produce
three-dimensional graph lines which may block out data behind the date with
the high K values. By using these functions to view the data in a different
order, you may be able to see what is behind the three dimensional "wall" of
high K-indices.
While viewing these three-dimensional graphs, you can instruct KGRAPH to
redraw the data in a "slow mode". To accomplish this, press the "S" key to
toggle between the fast and slow modes while viewing graphs of data. While
in the slow mode, KGRAPH will redraw the screen one date at a time, pausing
in-between dates and waiting for a keypress. Using this feature, you can
carefully examine each date of data. To view the next date of data, press
any key on your keyboard. KGRAPH will respond by drawing the next series of
K-indices, pausing after the next group of eight has been drawn. After all
of the indices have been drawn on-screen, you can switch back to the "fast
mode" by pressing "S" again.
To exit back to the main menu, press any key other than "S".
PRODUCING HIGH-DENSITY K-INDEX DATA PLOTS USING KGRAPH
The second and third-last options of the main menu engage powerful
utilities for viewing large quantities of K-index data on-screen at one time.
One option produces a high-density plot of Boulder K-Index data. The other
main menu option generates a high-density plot of estimated Planetary
(global) geomagnetic K-Index data. Both of these functions produce graphs
with identical formats. The only difference is the data which is used.
Boulder K-Index data is generally valid for middle latitude regions near
Boulder Colorado. The Planetary K-indices represent estimated global levels
of geomagnetic activity and may be more reliable characteristics of global
activity.
The high-density plots use the high-resolution of the VGA graphics
system to produce visually pleasing graphs of contiguous activity for as many
as eight consecutive solar rotations. As many as 1,728 data points may be
plotted on-screen at one time for analysis.
The structural format of these high-density graphical plots may be
described as follows. Up to eight horizontal segments of the screen are used
to graph the data. Each horizontal group of graphed K-indices represents one
solar rotation (approximately 27 days). Unfortunately, only 26 days worth of
data can be fit on one horizontal screen segment at a time. As a result,
each horizontal segment contains 26 days worth of data. The 27th day is
not plotted, but will become visible when screen-scrolling of the data occurs
after eight solar rotations of data have been accumulated.
Each horizontal segment of data is divided into 26 days and each of
these days are labelled. The month of the first date encountered on each
horizontal segment is displayed adjacent to the horizontal graph segment.
Each horizontal graph segment is composed of a series of vertical lines which
depict the K-indices being graphed. A sample ASCII representation of one day
(eight vertical lines) of K-index data follows below:
_o__o__o_
F _o__|__|__|_
E _o__|__|__|_*#*
B _o__|__|__|__|_*#* /-<-- Next day of data starts
_o__|__|__|__|_*#**#* / on this boundary
o__|__|__|__|__|_*#**#*_\/_____________________
| 1 4 | 1 5 |
Each vertical line (with a "dot" on top) represents one K-index value.
K-Indices are defined as follows:
_o__o__o__o_*#*
_o__|__|__|_*#**#*
_o__|__|__|_*#**#**#*
_o__|__|__|__|_*#**#**#*
_o__|__|__|__|_*#**#**#**#*
o__|__|__|__|__|_*#**#**#**#*
/\ /\ /\ /\ /\ /\ /\ /\ /\ /\
|| || || || || || || || || ||
|| || || || || || || || || ||
0 1 2 3 4 5 6 7 8 9
K - I N D I C E S
This method of graphing K-indices has several notable advantages over
straight linear graphing. First, the graph line is effectively compressed in
vertical extent, allowing a larger number of horizontal segments to be fit
on-screen at one time. Second, determination of the value of each K-index
point is easily accomplished by counting the horizontal divisions. And
finally, visual determination of major to severe storm periods is easily
accomplished simply by examining which graph lines are "filled in" (see
K-indices 6 through 9 in the graph above).
KGRAPH significantly enhances the visibility of major storm periods by
"filling in" these intervals with the color red. This easily distinguishes
major storm periods from active or quiet periods when viewing the data
on-screen.
In addition, KGRAPH color-codes the dates of the data as follows:
DATE COLOR: RED = One or more Major Flares occurred on this date.
YELLOW = A Sudden Magnetic Impulse (SI) occurred on this date.
MAGENTA = Both a Sudden Magnetic Impulse AND a Major Flare(s)
occurred on this date.
WHITE = No Major Flares or Sudden Magnetic Impulses occurred.
This scheme for identifying days where major flares occurred is useful
when attempting to determine which periods of geomagnetic activity may have
been influenced by major flaring. This is particularly valuable when
searching for recurrent geomagnetic patterns caused by stable coronal holes.
By ignoring the periods of activity which may have been enhanced by major
flaring, you can better identify the recurrent patterns attributed to coronal
holes. When looking for flare-induced enhancements in geomagnetic activity,
keep in mind that increases in geomagnetic activity typically do not occur
until after approximately 24 to 48 hours (up to possibly 72 hours) from the
onset of the major flare. It usually takes this long for the plasma cloud to
traverse the distance from the Sun to the Earth. Also, not all major flares
produce enhancements in geomagnetic activity. In fact, only a relatively
small percentage are geoeffective. However, knowing which dates are
associated with major flares helps to eliminate uncertainties when analyzing
the recurrent patterns of geomagnetic activity.
The identification of days when sudden magnetic impulses occur is very
useful during the analysis of the high-density data plots. Since sudden
magnetic impulses are produced by the arrival of interplanetary shockwaves
(such as those which are spawned by major flares), it is possible to
determine which episodes of activity were produced by the arrival of
interplanetary shocks. Coronal holes are not usually associated with sudden
magnetic impulses. The enhancements in geomagnetic activity produced by well
placed solar coronal holes are most often gradual in nature.
USING THE HIGH-DENSITY DATA PLOTS TO DETERMINE RECURRENCE AND OTHER PHENOMENA
To use the high-density data plots properly, you must keep in mind that
each horizontal row of data represents one solar rotation. Since eight rows
may be stacked on top of one another, searching for recurrent patterns is as
simple as scanning vertically down the rows of data. Periods of recurrent
enhancements in geomagnetic activity will be discerned as consistent
increases in K-indices over periods of between 2 or more solar rotations
(which is displayed on-screen as two or more horizontal rows spaced
vertically above and below each other).
Since many coronal holes are constantly evolving and changing in
structure, shape, and spatial extent, some deviations from the above may be
observed. For example, if a coronal hole which enhances geomagnetic activity
during one solar rotation expands in size or becomes elongated in an
east-west direction, enhancements in geomagnetic activity may be observed a
few days earlier or later than would be expected if the coronal hole remained
in the same position and retained the same spatial characteristics. The
amplitude of the recurrent enhancement may also differ quite considerably
from one solar rotation to the next.
As we continue to decline from the solar maximum toward the solar
minimum, coronal hole stability and geoeffectiveness will increase which will
make identification and prediction of recurrent periods easier using the
high-density plot functions of KGRAPH.
Recurrent phenomena is not limited to enhancements of geomagnetic
activity. Indeed, recurrent quiet intervals are also frequently observed.
In fact, these quiet intervals are often easier to discern than recurrent
enhancements of activity due to coronal holes. The same method of
identifying recurrent enhancements of activity applies to the identification
of recurrent quiet periods. Simply scan the high-density graphs of K-index
data vertically between the horizontal rows of data. Consistent and
consecutive periods of low K-indices are typically associated with recurrent
quiet intervals. These are often the best periods for radio communicators,
since low levels of geomagnetic activity can support very stable and reliable
ionospheric communications.
Since active solar regions responsible for major flares also rotate with
periods of approximately 26-28 days, it is possible to determine potential
future influences of energetic active solar regions on the geomagnetic field.
This is less reliable than determining recurrence for coronal holes since
active regions are much more dynamic and change more rapidly than coronal
holes. Although most solar regions fail to survive two solar rotations, and
still fewer remain energetic enough to affect terrestrial geomagnetic
activity over two rotations, the odd ones do and may be capable of producing
recurrent enhancements in geomagnetic activity if they remain energetic for
that length of time.
Finally, these high-density graphs may also be used to help determine
periods of enhanced auroral activity. Since auroral activity is tied closely
to levels of geomagnetic activity, it is often possible to determine the
potential visibility of future auroral activity simply by determining
recurrent patterns of geomagnetic activity. K-indices of six or more are
typically required before auroral activity becomes visible over widespread
areas. K-indices of 7 or more may produce visible auroral activity over the
lower latitude regions. To be most accurate in making predictions, it is
important to remember the influence of lunar phase on visible levels of
auroral activity. However, since the moon also has a period similar to the
solar rotation period of 27 days, the phase of the moon should be
approximately the same between vertical rows of the high density graphs.
This serves to improve the usefulness of this data, even beyond what has
already been discussed.
FINAL NOTE REGARDING THE FORMAT OF THE HIGH-DENSITY GRAPHS
When displaying the graphs of geomagnetic activity over many solar
rotations, you will notice that the flow of dates from the left to the right
is contiguous (provided you do not have any missing datasets in your
database). You may also notice that the dates between the end of one
horizontal graph segment and the beginning of the next horizontal graph
segment are NOT contiguous. In short, you may notice that one day is skipped
between the end of one graph line and the beginning of the next. This
peculiarity is required in order to ensure that each horizontal graph of data
is properly aligned to coincide with the solar rotation period of 27 days.
One day is skipped because only 26 consecutive days may be graphed
horizontally (approximately one day short of a full solar rotation). If no
date skipping were performed to maintain alignment, each horizontal graph
line would be skewed approximately one day to the right, which would
seriously compromise the ability to determine recurrent periods simply by
scanning vertically down the rows. Instead, one would have to scan diagnally
down the rows in order to account for the skewed nature of the graphs. For
this reason, one date is skipped between the end of one horizontal graph
segment and the beginning of the next.
The dates which are skipped will eventually scroll into view after your
database contains at least eight solar rotations of data (or 216 days of
data). Until this time, the skipped dates will not scroll into view.
After you have accumulated 216 days worth of data in your database,
KGRAPH will begin scrolling through your database, displaying eight full
solar rotations of data each time the high-density graphing functions are
selected.
At the present time (mid February), eight solar rotations of SGDB
reports have not been accumulated. The service of providing the daily SGDB
reports containing the K-index information began on September 4, 1991. The
accumulation of eight full solar rotations of data will not occur until after
early April 1992. Until then, the daily SGDB reports will continue to be
made available on either a monthly basis or a daily basis from the STD BBS
(phone number: 403 756-3008), or from the assigned anonymous FTP sites (ex.
xi.uleth.ca, solar.stanford.edu, nic.funet.fi, etc).
To exit the high-density K-index graphs of geomagnetic activity, simply
press any key.
EXITING KGRAPH AND RETURNING TO DOS
To return to DOS at the main menu of KGRAPH, either select the "Exit
Program" function of KGRAPH, press the associated menu letter ('K'), or press
the ESCape key.