SODANKYLA                                                     1  JANUARY  2021
    GEOPHYSICAL OBSERVATORY             GEOMAGNETIC K INDEX                  K=9: 1500 nT
      UNIVERSITY OF OULU


SODANKYLA GEOMAGNETIC K INDEX UNTIL 31 DEC 2020 WAS PRODUCED BY MANUAL METHOD.
1914-1995 ANALOGICAL REGISTRATION WAS USED AS THE SOURCE DATA.
1996-2020 THE DAILY MAGNETOGRAM PLOTS OF H,D AND Z BASED ON 15s SPOT VALUES(PSM/FG) WERE USED.


SINCE 1 JANUARY 2021 SODANKYLA GEOMAGNETIC K INDEX REPORTED AT SGO IS ADOPTED BY FMI METHOD BASED
ON THE 10S AVERAGES FROM H AND D COMPONENTS.
2021-     SOFTWARE WRITTEN BY L.HAKKINEN, FMI. SOURCE DATA: FG 10s averages.

DIFFERENCE OF THE ADOPTION METHOD IS PRESENTED IN 
Geomagnetic Activity at the Sodankyla Observatory, 1914 - 2010, Geophysica (2011), 47(1-2), 31-42. Available online:
http://www.geophysica.fi/pdf/geophysica_2011_47_1-2_031_nevanlinna.pdf

CHANGES IN AVAILABILITY:
- Kz is not anymore defined
- daily update of SOD Khd files available after 0630UT:
	K_INDEX_2020_2029.txt
	K_IND_2021/K_INDEX_2021.txt
- other files are updated after the verification.

TERO RAITA
18.02.2021