SW_AOBxFAC_2F

Auroral oval boundaries derived from FACs

Thematic areas: Ionosphere/Magnetosphere, Space Weather

Applicable missions: Swarm

Applicable spacecraft: Swarm-A, Swarm-B, Swarm-C

Description

Auroral oval boundaries, associated with auroral precipitation, estimated from the presence of small-scale (<150 km) field-aligned currents.

Data access

FAST processing

N/A

Preview image

(delivered separately)

File contents

Variable Units Description Dim Type
t Time of observation, UTC 1 CDF_EPOCH
Latitude deg Position in ITRF - Geocentric latitude 1 CDF_DOUBLE
Longitude deg Position in ITRF - Geocentric longitude 1 CDF_DOUBLE
Radius m Position in ITRF - Geocentric radius (from the Earth center) 1 CDF_DOUBLE
Latitude_QD deg Quasi-dipole latitude 1 CDF_DOUBLE
Longitude_QD deg Quasi-dipole longitude 1 CDF_DOUBLE
MLT hour Magnetic Local Time (QD) 1 CDF_DOUBLE
Boundary_Flag nan Indicator for equatorward (=1) or poleward (=2) boundary 1 CDF_UINT1
Quality nan Quality indicator of equatorward/poleward boundary (Pa, Sigma) 2 CDF_DOUBLE
Pair_Indicator nan Indicator of equatorward/poleward boundary of auroral oval. If the auroral oval boundaries are detectable as one pair, the pair indicator represents the record of previous (-1) or next (1) equatorward/poleward boundary within one pair; otherwise, the pair indicator is set to 0 1 CDF_INT1

More details

Product identifier AOBxFAC_2F
Definition Auroral Oval Boundaries using the FAC method
Input Data FACxTMS_2F1
Input Time Span Up to one year
Spatial representation One geographic and quasi-dipole latitude/longitude as well as magnetic local time for each output value at the nearest magnetic-field measurement.
Time representation One timestamp for each boundary represented by the geographic and quasi-dipole latitude/longitude as well as magnetic local time.
Units Degrees
Resolution Full resolution (Double precision)
Uncertainty 3 deg, c.f. Xiong, C. and Lühr, H., doi: 10.5194/angeo-32-623-2014
Quality indicator
Value Meaning
Pa Slop of linear fit of S value. Users are suggested to use boundaries with pa larger than 0.2
Sigma The standard deviation of the linear fit of S value. Users are suggested to use boundaries with σ less than 0.4. See SW-DS-GFZ-GS-001_AEBS_DPA Swarm-AEBS Description of the Processing Algorithm, for the S value definition
Data volume Up to 2.5 MB
Data format CDF
Output time span Up to one year2
Update rate Daily
Latency < 1 day
Notes 1 Version information of Input Data are available in the CDF global attributes.
2 Product always contain data from the start of the first oval crossing of the year 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.

Related resources

Changelog

N/A