NOAA Geomagnetic Indices
========================
The following geomagnetic indices can be loaded into tplot variables:
["Kp", "ap", "Sol_Rot_Num", "Sol_Rot_Day", "Kp_Sum", "ap_Mean", "Cp", "C9", "Sunspot_Number", "F10.7", "Flux_Qualifier"]
For "Kp" and "ap", there is one data point for every 3 hours.
For all other variables, there is one data point per day.
.. autofunction:: pyspedas.projects.noaa.noaa_load_kp
Example
-------
.. code-block:: python
import pyspedas
from pyspedas import tplot
trange = ["2017-03-23/00:00:00", "2017-04-23/23:59:59"]
noaa_vars = pyspedas.projects.noaa.noaa_load_kp(trange=trange)
print(noaa_vars)
tplot(['Kp','ap','F10.7'])
.. image:: _static/noaa_kp.png
:align: center
:class: imgborder
NOAA and GFZ ftp sites
-----------------------
Data is downloaded either from the NOAA ftp site or the GFZ (Helmholtz Centre Potsdam) ftp site.
NOAA data is available from 1932 to March 2018.
(ftp.ngdc.noaa.gov/STP/GEOMAGNETIC_DATA/INDICES/KP_AP/, filenames: 1932, 1933, ..., 2018)
GFZ data is available from 1932 to present.
(ftp.gfz-potsdam.de/pub/home/obs/kp-ap/wdc/yearly/, filenames: kp1932.wdc, kp1933.wdc, ..., kp2020.wdc)
A single file contains one year of data.
A single line inside a file contains one day of data.
File names are different in the two ftp sites.
Data format is a little different, the NOAA data has 72 characters per line,
while the GFZ data has 62 characters per line (it is missing the last 3 columns).
Example of data from NOAA and from WDC:
NOAA::
1701012502 73337272323302017210 18 22 12 9 9 15 7 6 120.73---070.10
WDC::
17 1 12502 73337272323302017210 18 22 12 9 9 15 7 6 120.73
IDL SPEDAS code loads empty variables for the three missing columns in the GFZ data, python pyspedas code skips these empty variables.
FTP file data format
--------------------
A description of the text file format can be found in the following file:
ftp://ftp.ngdc.noaa.gov/STP/GEOMAGNETIC_DATA/INDICES/KP_AP/kp_ap.fmt
FORMAT FOR RECORDS OF SELECTED GEOMAGNETIC AND SOLAR ACTIVITY INDICES::
-------------------------------------------------------------------------------
COLUMNS FMT DESCRIPTION
-------------------------------------------------------------------------------
1- 2 I2 YEAR
3- 4 I2 MONTH
5- 6 I2 DAY
7-10 I4 BARTELS SOLAR ROTATION NUMBER--a sequence of 27-day intervals
counted continuously from February 8, 1832.
11-12 I2 NUMBER OF DAY within the Bartels 27-day cycle.
13-14 I2 Kp or PLANETARY 3-HOUR RANGE INDEX for 0000 - 0300 UT.
15-16 I2 Kp or PLANETARY 3-HOUR RANGE INDEX for 0300 - 0600 UT.
17-18 I2 Kp or PLANETARY 3-HOUR RANGE INDEX for 0600 - 0900 UT.
19-20 I2 Kp or PLANETARY 3-HOUR RANGE INDEX for 0900 - 1200 UT.
21-22 I2 Kp or PLANETARY 3-HOUR RANGE INDEX for 1200 - 1500 UT.
23-24 I2 Kp or PLANETARY 3-HOUR RANGE INDEX for 1500 - 1800 UT.
25-26 I2 Kp or PLANETARY 3-HOUR RANGE INDEX for 1800 - 2100 UT.
27-28 I2 Kp or PLANETARY 3-HOUR RANGE INDEX for 2100 - 2400 UT.
29-31 I3 SUM of the eight Kp indices for the day expressed to the near-
est third of a unit.
32-34 I3 ap or PLANETARY EQUIVALENT AMPLITUDE for 0000 - 0300 UT.
35-37 I3 ap or PLANETARY EQUIVALENT AMPLITUDE for 0300 - 0600 UT.
38-40 I3 ap or PLANETARY EQUIVALENT AMPLITUDE for 0600 - 0900 UT.
41-43 I3 ap or PLANETARY EQUIVALENT AMPLITUDE for 0900 - 1200 UT.
44-46 I3 ap or PLANETARY EQUIVALENT AMPLITUDE for 1200 - 1500 UT.
47-49 I3 ap or PLANETARY EQUIVALENT AMPLITUDE for 1500 - 1800 UT.
50-52 I3 ap or PLANETARY EQUIVALENT AMPLITUDE for 1800 - 2100 UT.
53-55 I3 ap or PLANETARY EQUIVALENT AMPLITUDE for 2100 - 2400 UT.
56-58 I3 Ap or PLANETARY EQUIVALENT DAILY AMPLITUDE--the arithmetic mean
of the day's eight ap values.
59-61 F3.1 Cp or PLANETARY DAILY CHARACTER FIGURE--a qualitative estimate
of overall level of magnetic activity for the day determined
from the sum of the eight ap amplitudes. Cp ranges, in steps
of one-tenth, from 0 (quiet) to 2.5 (highly disturbed).
62-62 I1 C9--a conversion of the 0-to-2.5 range of the Cp index to one
digit between 0 and 9.
63-65 I3 INTERNATIONAL SUNSPOT NUMBER. Records contain the Zurich num-
ber through December 31, 1980, and the International Brus-
sels number thereafter.
66-70 F5.1 OTTAWA 10.7-CM SOLAR RADIO FLUX ADJUSTED TO 1 AU--measured at
1700 UT daily and expressed in units of 10 to the -22 Watts/
meter sq/hertz. Observations began on February 14, 1947.
From that date through December 31, 1973, the fluxes given
here don't reflect the revisions Ottawa made in 1966. NOTE:
If a solar radio burst is in progress during the observation
the pre-noon or afternoon value is used (as indicated by a
flux qualifier value of 1 in column 71.
71-71 I1 FLUX QUALIFIER. "0" indicates flux required no adjustment;
"1" indicates flux required adjustment for burst in progress
at time of measurement; "2" indicates a flux approximated by
either interpolation or extrapolation; and "3" indicates no
observation.