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Full product name
Equatorward boundary of SSFACs and the associated midnight PP index


Equatorward boundary of SSFACs and the associated midnight PP index

Output variables

TimestampmsTime of observation, UTC1CDF_EPOCH
Counter Swarm orbit counter and quarter orbit (four per Swarm orbit) counter that are based on magnetic coordinates as defined in Swarm PRISM processing algorithm description (Sect.
LatitudedegPosition of the SSFAC boundary in ITRF - Geocentric latitude1CDF_DOUBLE
LongitudedegPosition of the SSFAC boundary in ITRF - Geocentric longitude1CDF_DOUBLE
RadiusmPosition of the SSFAC boundary in ITRF - Geocentric radius (from the Earth center)1CDF_DOUBLE
Latitude_QDdegQD latitude of the SSFAC boundary1CDF_DOUBLE
Longitude_QDdegQD longitude of the SSFAC boundary1CDF_DOUBLE
MLThMagnetic Local Time of SSFAC boundary1CDF_DOUBLE
L_valueR_EL-value of the SSFAC boundary1CDF_DOUBLE
SZAdegSolar zenith angle of the SSFAC boundary1CDF_DOUBLE
dL Boundary width in Earth radii1CDF_DOUBLE
Sigma Standard deviation of the linear fit of S at the boundary (Heilig, B. and Lühr, H., doi: 10.5194/angeo-31-529-2013)1CDF_DOUBLE
PPIR_EMidnight Plasmapause index1CDF_DOUBLE
Quality Quality indicators of SSFAC boundary detection7CDF_INT1
Timestamp_ID Time vector of observations2CDF_EPOCH
Latitude_IDdegPosition in ITRF - Geocentric latitude2CDF_DOUBLE
Longitude_IDdegPosition in ITRF - Geocentric longitude2CDF_DOUBLE
Radius_IDmPosition in ITRF - Geocentric radius (from the Earth centre)2CDF_DOUBLE
Latitude_QD_IDdegQD latitude2CDF_DOUBLE
Longitude_QD_IDdegQD longitude2CDF_DOUBLE
MLT_IDhMagnetic Local Time2CDF_DOUBLE
L_value_ID L-value in Earth radii2CDF_DOUBLE
SZA_IDdegL-value in Earth radii2CDF_DOUBLE
Position_Quality_ID Vector of quality indicators characterising the detection quality of each single positions2CDF_INT1


Product identifier PPIxFAC_2F
Definition Equatorward boundary of SSFACs and the associated midnight PP index
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 FAC 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. These flags are defined based on the parameter’s sigma and SZA. 3: sig-ma<0.25, 2: 0.25≤sigma<0.5, 1: 0.5≤sigma AND SZA>90°, -1: 0.5≤sigma AND SZA≤90°.
Data volume Up to 1.9 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 – Equatorward edge of SSFAC boundary; 2 – Poleward edge of SSFAC boundary.
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.