Swarm Product Data Handbook

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SW_AEJxPBS_2F

Full product name
Auroral electrojets peaks and boundaries from SECS

Description

This product contains characterization of the auroral electrojets and auroral oval boundaries (by using SECS method).

Data Access

Output variables

VariableUnitsDescriptionDimType
t_Peak Time of WEJ and EEJ peaks in the order as they appear in the satellite flight direction, UTC42CDF_EPOCH
Latitude_PeakdegGeocentric latitude in ITRF of WEJ and EEJ peaks in the order as they appear in the satellite flight direction2CDF_DOUBLE
Longitude_PeakdegGeocentric longitude in ITRF of WEJ and EEJ peaks in the order as they appear in the satellite flight direction2CDF_DOUBLE
Latitude_Peak_QDdegQD latitude of WEJ and EEJ peaks in the order as they appear in the satellite flight direction2CDF_DOUBLE
Longitude_Peak_QDdegQD latitude of WEJ and EEJ peaks in the order as they appear in the satellite flight direction2CDF_DOUBLE
MLT_PeakhourMagnetic Local Time (QD) of WEJ and EEH peaks in the order as they appear in the satellite flight direction2CDF_DOUBLE
J_DFA/kmPeaks (minimum (WEJ) and maximum (EEJ)) of the divergence-free sheet current density in semiQD1 frame in the order as they appear in the satellite flight direction2CDF_DOUBLE
t_EB Time of WEJ and EEJ equatorward boundaries in the order as they appear in the satellite flight direction, UTC42CDF_EPOCH
Latitude_EBdegGeocentric latitude of WEJ and EEJ equatorward boundaries in ITRF in the order as they appear in the satellite flight direction2CDF_DOUBLE
Longitude_EBdegGeocentric longitude of WEJ and EEJ equatorward boundaries in ITRF in the order as they appear in the satellite flight direction2CDF_DOUBLE
Latitude_EB_QDdegQD latitude of WEJ and EEJ equatorward boundaries in the order as they appear in the satellite flight direction2CDF_DOUBLE
Longitude_EB_QDdegQD longitude of WEJ and EEJ equatorward boundaries in the order as they appear in the satellite flight direction2CDF_DOUBLE
MLT_EBhourMagnetic Local Time (QD) of WEJ and EEJ equatorward boundaries in the order as they appear in the satellite flight direction2CDF_DOUBLE
t_PB Time of WEJ and EEJ poleward boundaries in the order as they appear in the satellite flight direction, UTC42CDF_EPOCH
Latitude_PBdegGeocentric latitude of WEJ and EEJ poleward boundaries in ITRF in the order as they appear in the satellite flight direction2CDF_DOUBLE
Longitude_PBdegGeocentric longitude of WEJ and EEJ poleward boundaries in ITRF in the order as they appear in the satellite flight direction2CDF_DOUBLE
Latitude_PB_QDdegQD latitude of WEJ and EEJ poleward boundaries in the order as they appear in the satellite flight direction2CDF_DOUBLE
Longitude_PB_QDdegQD longitude of WEJ and EEJ poleward boundaries in the order as they appear in the satellite flight direction2CDF_DOUBLE
MLT_PBhourMagnetic Local Time (QD) of WEJ and EEJ poleward boundaries in the order as they appear in the satellite flight direction2CDF_DOUBLE
Latitude_BdegGeodetic latitude of peaks (minimum and maximum) in ground magnetic field disturbance in the order as they appear in the satellite flight direction2CDF_DOUBLE
Longitude_BdegGeodetic longitude of peaks (minimum and maximum) in ground magnetic field disturbance in the order as they appear in the satellite flight direction2CDF_DOUBLE
BnTMaximum (first row) and minimum (second row) of ground magnetic field disturbance. First (second) column gives the north (east) component geodetic frame[2, 2]CDF_DOUBLE
Flags Quality indicator1CDF_UINT2

Details

Product identifier AEJxPBS_2F
Definition High-latitude ionospheric sheet current boundary locations, the locations of minimum (WEJ) and maximum (EEJ) eastward current density in semiQD1 frame, the locations of minimum and maximum ground northward magnetic field disturbance (in semiQD1).
Input Data MAGx_LR_1B, Latest CHAOS model2 including, core, lithosphere, magnetosphere and secondary currents.
Input Time Span Up to one year
Spatial representation One geographic and QD latitude/longitude pair for each output value. The Swarm footprints at 110 km altitude have been determined with mapping along the geomagnetic field line.
Time representation One timestamp for each latitude/longitude pair
Units Degrees (locations), A/km (for peak currents) and nT (for ground B)
Resolution Full resolution (Double precision)
Uncertainty c.f. Juusola et al., doi: 10.1002/2016JA022961
Quality indicator Note: Flag values are specified in binary. If two or more situations occurs simultaneously, the Flag value will be a sum of the different Flags values. For more information and examples (see SW-DS-GFZ-GS-001_AEBS_DPA, Swarm-AEBS Description of the Processing Algorithm)
Value Meaning
0000000000000 Both EEJ and WEJ are detected, and their current densities are zero at all boundaries.
0000000000001 No eastward currents detected.
0000000000010 No westward currents detected.
0000000000100 Equatorward EEJ boundary occurs at the edge of the analysis area2, and the density is larger than 20% of peak value.
0000000001000 Poleward EEJ boundary occurs at the edge of the analysis area2, and the density is larger than 20% of peak value.
0000000010000 Equatorward WEJ boundary occurs at the edge of the analysis area2, and the density is larger than 20% of peak value.
0000000100000 Poleward WEJ boundary occurs at the edge of the analysis area2, and the density is larger than 20% of peak value.
0000001000000 Swarm orbit does not fully cover the predefined oval latitude range2. Latitude gap is 2 degrees or larger.
0000010000000 Equatorward EEJ boundary occurs at the edge of the analysis area2.
0000100000000 Poleward EEJ boundary occurs at the edge of the analysis area2.
0001000000000 Equatorward WEJ boundary occurs at the edge of the analysis area2.
0010000000000 Poleward WEJ boundary occurs at the edge of the analysis area2.
0100000000000 Peak value of EEJ occurs at the edge of the analysis area2.
1000000000000 Peak value of WEJ occurs at the edge of the analysis area2.
Data volume Up to 6 MB
Data format CDF
Output time span Up to one year4
Update rate Daily
Latency < 1 day
Notes 1 Horizontal current components will be given both in geographic frame and in a spherical frame whose north pole is defined by the QD frame (SW-DS-GFZ-GS-001_AEBS_DPA, Swarm-AEBS Description of the Processing Algorithm). The latitude and longitude of QD north pole are available in the CDF global attributes LatitudePOLEQD and LongitudePOLEQD respectively. These are vectors of two elements. The 1st (2nd) value is for the case when Swarm is in the northern (southern) hemisphere.
2 Version information of Input Data are available in the CDF global attributes.
3 QD latitudes from 50 to 85 (Northern hemisphere) or -50 to -85 (Southern hemisphere). Note that Swarm orbits does not always cover this area completely.
4 If only eastward current detected timestamps for westward peak and boundaries are set to time of eastward peak and predefined oval boundaries, and vice versa.
5 Ground magnetic field caused by the ionospheric currents is determined in the semiQD frame, where its horizontal part has only the North component. Geodetic vector components are derived from the minimum and maximum of that North component.
6 Product contain data from the start of the first oval crossing of the year up until the end of the last oval crossing starting that year, i.e., may contain data from the next year if oval crossing occurs around midnight on the last day of the year.

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