01/29/03


  The NOAA/POES Hemispheric Power Index Data directory is being
  developed and filled.
  
  Check this file for the latest information....
  
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  CHANGES DUE TO THE SWITCH TO NOAA-15:
  
  The power files that were updating in near realtime for the current day
  and the previous day, that is, p14_1day and p14_1day.bak, have been replaced
  by pwr_1day and pwr_1day.bak, when NOAA-15 became the data source.  This
  is so that the filenames are satellite independent.  The files are no
  longer at the top of the list, due to the name change.  They are at the
  bottom.
  
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The activity.dat file is updated whenever a new polar pass of the NOAA-12 POES 
satellite is completed and a new hemispheric power index is calculated.  It 
contains a UT date/time string followed by a space followed by the hemispheric 
power index (activity level), a number from 1 to 10.  

As of January 29, 2003, the normalization factor (n) appears after the activity
level.  The format used for 'n' is F4.2.

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The NOAA POES Hemispheric Power Data lists provide information about the 
estimated power in gigawatts deposited in the polar regions by energetic 
particles during transits over the poles by the NOAA POES (formerly called 
TIROS) satellites.  

The files are organized by year, and each line contains day-of-year and 
universal time at the center of the polar pass.  Data are collected from 45 
degrees poleward to 45 degrees equatorward.  Other information provided in each 
record (line of the file) includes the NOAA POES satellite number, the 
hemisphere, an activity level index (1..10) related to the power in gigawatts, 
and a "normalizing factor", usually in the neighborhood of 1.0.

The latter can serve as an indicator of the reliability of the power and 
activity level data--values of the normalizing factor which depart very much 
from 1.0 are indicators of the data being not very reliable.  This would occur 
when the path of the satellite during the measurement does not pass through a 
region which provides a good statistical base of data by which the power 
calculation can be made.

Power data was not collected for the years 1989 and 1990.  Otherwise, there are 
files for all the years from 1978 through the current year.

***********
Format:
***********

The first line of data in each file contains the four-digit year of the data.
Each following line is formatted as in this example--please note the Fortran-
style format listed below. There is no space between Day of year and UT hour
and minute:

NOAA-12(S)  10031     9.0  4    .914

A7    NOAA POES Satellite number
A3    (S) or (N) - hemisphere
I3    Day of year
I4    UT hour and minute
F8.1  Estimated Hemispheric Power in gigawatts
I3    Hemispheric Power Index (activity level)
F8.3  Normalizing factor

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Sample NOAA POES Power File Listing
********************************************************************************
1996
NOAA-12(S)  10031     9.0  4    .914
NOAA-14(N)  10039     9.1  4   1.103
NOAA-12(N)  10121     7.4  4   1.019
NOAA-14(S)  10131     1.3  1   2.033
NOAA-12(S)  10213     5.8  3   1.030
NOAA-14(N)  10223     5.2  3   1.264
NOAA-12(N)  10303     4.3  3   2.033
NOAA-14(S)  10315    13.3  5   1.187
NOAA-12(S)  10355     4.2  3   1.476
NOAA-14(N)  10407     3.8  2   1.086
NOAA-12(N)  10447     2.7  2   2.415
NOAA-14(S)  10457     5.3  3   1.209

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Prepared by the U.S. Dept. of Commerce, NOAA, Space Environment Laboratory.