Below are description of the format used for the geomagnetic data at SGO Data server. Some of them are old World Data Center and bulletin formats. To access easy numerical data, check Data links or contact to observer in charge.
| Sodankylä 1 min data, daily tables | ||
|---|---|---|
| Column | Format | Description |
| 1 - 8 | F8.1 | X component in nT |
| 9 - 16 | F8.1 | Y component in nT |
| 17 - 24 | F8.1 | Z component in nT |
| 26 - 27 | i2 | year two last digits |
| 28 - 29 | i2 | month (1-12) |
| 30 - 31 | i2 | day (1-31) |
| 33 - 38 | 3i2 | time in UT (hours, minutes, seconds) |
| 40 | i1 | instrument (2 = Polish magnetometer, 4 = Danish magnetometer) |
| Hourly mean values (old WDC-format) | ||
|---|---|---|
| Data is always final data and about one year late. | ||
| Column | Format | Description |
| 1 - 3 | c3 | Observatory code (=SOD) |
| 4 - 5 | i2 | year two last digits |
| 6 - 7 | i2 | month (1-12) |
| 8 | c1 | component (X,Y,Z) |
| 9 - 10 | i2 | day (1-31) |
| 11 - 15 | 5x | empty (spaces) |
| 16 | c1 | character of the day (Q=quiet, D=disturbed) |
| 17 - 20 | i4 | base value (hourly mean value = base value*100) |
| 21 - 116 | 24i4 | hourly mean values (=base value*100 + value) |
| 117 - 120 | i4 | the average value of the day (=base value*100 + value) |
| Daily and monthly mean values, monthly tables | ||
|---|---|---|
| The header lines contain co-ordinates, components, month, year, and the base value. The most recent data is preliminary and that is also mentioned in the header. Data is final when there is no word 'preliminary' in the header. | ||
| Column | Format | Description |
| 1 - 2 | i2 | day |
| 5 | i1 | character of the day, Q is one of the 5 quiest days in the respective month, in the preliminary data we have used the SGO own data, In the final data we used the international character of the days |
| 6 - 125 | 24i5 | 24 hourly values + base value in nT (e.g. X copm. base value can be e.g. 11 000 nT) |
| 128- 132 | i5 | the avearage value of the day |
| The last 3 lines, the same as above, but for all, quiet and disturbed days. | ||
| K(HDZ) index, monthly tables: | ||
|---|---|---|
| Column | Format | Description |
| 2 - 5 | i4 | year (yyyy) |
| 6 - 7 | i2 | month (1-12) |
| 8 - 9 | i2 | day (1-31) |
| 12 - 15 | i4 | 3-hourly K index (4 first), obtained from Z component (=Kz) |
| 17 - 20 | i4 | 3-hourly K index (4 last), obtained from Z component (=Kz) |
| 22 - 25 | i4 | 3-hourly K index (4 first), obtained from H component (=Kh) |
| 27 - 30 | i4 | 3-hourly K index (4 last), obtained from H component (=Kh) |
| 32 - 35 | i4 | 3-hourly K index (4 first), obtained from D component (=Kd) |
| 37 - 40 | i4 | 3-hourly K index (4 first), obtained from D component (=Kd) |
| 42 - 57 | 8i2 | 3-hourly K index, obtained from H and D components (=K(hd)) |
| 60 - 61 | i2 | Daily sum of K(hd) indices , obtained from H and D components |
| 63 - 65 | i3 | Ak index (linearized average of the K(hd) indices |
| 67 - 82 | 8i2 | 3-hourly K index, obtained from Z, H and D components (=K(zhd)) |
| 85 - 86 | i2 | Daily sum of K(zhd) indices , obtained from Z, H and D components |
| 88 - 90 | i3 | Ak index (linearized average of the K(zhd) indices, see below |
The K value scale limits follows the definition by IAGA. The lower limit for the K-value 9 is 1500nT. The limits for the K values 0 to 9 are 15, 30, 60, 120, 210, 360, 600, 990 and 1500 nT.
Ak value is linearized average of daily K values. K values 0 to 9 are first converted ak values 0, 3, 7, 15, 27, 48, 80, 140, 240, 400, respectivility and daily mean of ak is presented as daily Ak value. With small K values average of K correlates well with Ak. Single big K value (7-9) influence to Ak, when the K average does not react to it.
| K(HD) index: | ||
|---|---|---|
| Column | Format | Description |
| 2 - 5 | i4 | year (yyyy) |
| 6 - 7 | i2 | month (1-12) |
| 8 - 9 | i2 | day (1-31) |
| 11 - 18 | 8i1 | 3-hourly K indices, obtained from H and D components (=K(hd)) |
| 22 - 23 | i2 | Daily sum of K(hd) indices , obtained from H and D components |
| 26 - 29 | i3 | Ak index (linearized average of the K(hd) indices, see above) |
| Q index, monthly tables: | ||
|---|---|---|
| Column | Format | Description |
| 3 - 6 | i4 | year, (yyyy) |
| 7 - 8 | i2 | month (1-12) |
| 9 - 10 | i2 | day (1-31) |
| 13 - 42 | 6(i4, 1x) | Q index (first 6 hours, one digit for every 15 min, scale = 0 - 11, T=10, E=11) |
| 44 - 73 | 6(i4,1x) | Q index (next 6 hours) |
| 75 - 104 | 6(i4,1x) | Q index (next 6 hours) |
| 106 - 134 | 5(i4,1x),i4 | Q index the last 6 hours) |
Last updated: 26.10.2016