KSEC1 element | Contents | GRIB octet | Recommended GRIB_API keys | Coded GRIB_API keys | Comments
--- | --- | --- | --- | --- | ---
37 |
    ECMWF local GRIB use definition identifier.
    1 = MARS labeling or ensemble forecast data.
| 41 | localDefinitionNumber | localDefinitionNumber |
38 | Class | 42 | class | marsClass |
39 | Type | 43 | type | marsType |
40 | Stream | 44-45 | stream | marsStream |
41 |
    Version number or experiment identifier.
    (4 ASCII characters, right justified)
| 46-49 | expver | experimentVersionNumber |
42 |
    Set to 0 for MARS labeling (simple labeling).
    When element 40 = 1035, this is the ensemble forecast number.
    When element 39 = 10, this is the control forecast number and is set to 0.
    When element 39 = 11, this is the perturbed forecast number in some range 1-nn.
    Positive perturbations have odd numbers and negative have even numbers. They
    go in pairs (1,2), (3,4) etc.
    When element 39 = 17, this is an ensemble mean and the number is set to 0.
    When element 39 = 18, this is an ensemble standard deviation and the number
    is set to 0.
| 50 | number | perturbationNumber |
43 | Set to 0, if not an ensemble forecast. Otherwise, the total number of forecasts in an ensemble; the number includes the control forecast. | 51 | numberOfForecastsInEnsemble | numberOfForecastsInEnsemble |
- | Spare (set to zero). | 52 |  |  |