Midlatitude Ionospheric Trough Boundaries and Minima derived from LP (Langmuir Probe)
Thematic areas: Ionosphere/Magnetosphere
Applicable missions: Swarm
Applicable spacecraft: Swarm-A, Swarm-B, Swarm-C
Midlatitude Ionospheric Trough Boundaries and Minima derived from LP (Langmuir Probe)
N/A
(delivered separately)
| Variable | Units | Description | Dim | Type |
|---|---|---|---|---|
| Timestamp | ms | Time of observation, UTC | 1 | CDF_EPOCH |
| Counter | Swarm orbit counter and quarter orbit (four per Swarm orbit) counter that are based on magnetic coordinates as defined in [AD-2] (Sect. 4.1.2.2) | 2 | CDF_UINT4 | |
| Latitude | deg | Position of the MIT minimum in ITRF - Geocentric latitude | 1 | CDF_DOUBLE |
| Longitude | deg | Position of the MIT minimum in ITRF - Geocentric longitude | 1 | CDF_DOUBLE |
| Radius | m | Position of the MIT minimum in ITRF - Geocentric radius (from the Earth center) | 1 | CDF_DOUBLE |
| Latitude_QD | deg | QD latitude of the MIT minimum | 1 | CDF_DOUBLE |
| Longitude_QD | deg | QD longitude of the MIT minimum | 1 | CDF_DOUBLE |
| MLT | h | Magnetic Local Time of MIT minimum | 1 | CDF_DOUBLE |
| L_value | L-value of the MIT minimum | 1 | CDF_DOUBLE | |
| SZA | deg | Solar zenith angle of the MIT minimum | 1 | CDF_DOUBLE |
| Ne | cm-3 | LP electron densities of the MIT minimum | 1 | CDF_DOUBLE |
| Te | K | LP electron temperatures of the MIT minimum | 1 | CDF_DOUBLE |
| Depth | cm-3 | Depth of the MIT | 1 | CDF_DOUBLE |
| DR | % | Relative change in density within the MIT | 1 | CDF_DOUBLE |
| Width | deg | Width of the MIT calculated from QD latitudes | 1 | CDF_DOUBLE |
| dL | Width of the MIT calculated from L-values | 1 | CDF_DOUBLE | |
| PW_Gradient | log(cm-3)/deg | Change in log electron density at the poleward wall of the MIT divided by QD latitude difference | 1 | CDF_DOUBLE |
| EW_Gradient | log(cm-3)/deg | Change in log electron density at the equatorward wall of the MIT divided by QD latitude difference | 1 | CDF_DOUBLE |
| Quality | Characterizes the detection quality of the MIT as a whole | 8 | CDF_INT1 | |
| Timestamp_ID | Vector of times of observation, UTC | 7 | CDF_EPOCH | |
| Latitude_ID | deg | Vector of Positions in ITRF - Geocentric latitude | 7 | CDF_DOUBLE |
| Longitude_ID | deg | Vector of Positions in ITRF - Geocentric longitude | 7 | CDF_DOUBLE |
| Radius_ID | m | Vector of Positions in ITRF - Geocentric radius (from the Earth centre) | 7 | CDF_DOUBLE |
| Latitude_QD_ID | deg | Vector of QD latitudes | 7 | CDF_DOUBLE |
| Longitude_QD_ID | deg | Vector of QD longitudes | 7 | CDF_DOUBLE |
| MLT_ID | h | Vector of Magnetic Local Times | 7 | CDF_DOUBLE |
| L_value_ID | Vector of L-values in Earth radii | 7 | CDF_DOUBLE | |
| SZA_ID | deg | Vector of solar zenith angles | 7 | CDF_DOUBLE |
| Ne_ID | cm-3 | Vector of LP electron densities | 7 | CDF_DOUBLE |
| Te_ID | K | Vector of LP electron temperatures | 7 | CDF_DOUBLE |
| Position_Quality_ID | Vector of quality indicators characterizing the detection quality of each single positions | 7 | CDF_INT1 |
| Product identifier | MITx_LP_2F |
| Definition | Midlatitude Ionospheric Trough Boundaries and Minima from LP |
| Input data | EFIx_LP_1B1, TECxTMS_2F1, FACxTMS_2F1, AOBxFAC_2F1, AUXxORBCNT |
| Input time span | Up to one year2 |
| Spatial representation | One geographic and QD-latitude/longitude pair, the McIlwain L-value as well as radius for each output position at the nearest LP measurement for each trough crossing, i.e., up to four per orbit. |
| Time representation | Up to four records per orbit (up to one record per orbit quarter) |
| Units | see at Output Data below |
| Resolution | 0.1 degree for coordinates, 0.01 for L-value |
| Uncertainty | ~1 degree for coordinates, ~0.1 for L-value |
| Quality indicator | Quality vector flag values are integers ranging from 3 to -1. Positive values indicate good or acceptable observation, while -1 means a likely false observation. For all flags, a 0 value means that the information needed to derive the flag is not available. In general, greater numbers indicate higher quality. A detailed description of the derivation of these flags is given in Swarm PRISM processing algorithm description (see also related resources) Position_Quality_ID describes the overall quality of the corresponding boundary/position identified by ID. The possible values and their meaning are 3: highest quality; 2: fair quality; 1: uncertain detection; -1: a likely false positive detection; -2: the corresponding boundary/position is not defined. A detailed description of the derivation of these flags is given in Swarm PRISM processing algorithm description (see also related resources) |
| Data volume | Up to 4.2 MB |
| Output data | See file contents |
| Output time span | Up to one year2 |
| Latency | < 5 minutes |
| Update rate | Daily |
| Notes | 1 Version information of Input Data are available in the CDF global attributes.2 Product always contains data from the start of the first boundary crossing of the first day until the end of the last boundary-crossing starting the latest day available for that year, i.e., may contain data from the next day if boundary crossing occurs around midnight.3 The meaning of ID: 1 – LP MIT equatorward edge of the equatorward wall; 2 – LP MIT poleward edge of the equatorward wall; 3 – LP MIT equatorward edge of poleward wall; 4 – LP MIT poleward edge of the poleward boundary; 5 – LP SETE equatorward bounding position; 6 – LP Te peak position; 7 – LP SETE poleward bounding position.4 NaN values: if an ID is not identified Timestamp_ID is set to {the value of} Timestamp and corresponding variable values will be set to NaNs, while the corresponding Position_Quality_ID is set to -2. |
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