Dayside equatorial electric field
Citation: University of Colorado Boulder, Technical University of Denmark. (2020). SW_EEFxTMS_2F. European Space Agency. https://swarmhandbook.earth.esa.int/catalogue/SW_EEFxTMS_2F
Product types: SW_OPER_EEFATMS_2F, SW_OPER_EEFBTMS_2F, SW_OPER_EEFCTMS_2F
Authored by: University of Colorado Boulder - https://ror.org/02ttsq026, Technical University of Denmark - https://ror.org/04qtj9h94
Creation year: 2020
Thematic areas: Ionosphere/Magnetosphere, Space Weather
Applicable missions: Swarm
Applicable spacecraft: Swarm-A, Swarm-B, Swarm-C
Estimate of eastward equatorial electric field component, by using magnetic measurements of the equatorial electrojet (EEJ) current as the satellites fly overhead. Since the magnetic signal of the EEJ current is directly measured by the satellite, this product also provides an estimate of the EEJ current strength.
(delivered separately)
| Variable | Units | Description | Dim | Type |
|---|---|---|---|---|
| Timestamp | - | Time of satellite crossing of the magnetic equator, UTC | 1 | CDF_EPOCH |
| Longitude | degrees | Geographic longitude of satellite crossing of the magnetic equator | 1 | CDF_REAL8 |
| Latitude | degrees | Geographic latitude of satellite crossing of the magnetic equator | 1 | CDF_REAL8 |
| EEF | mV/m | Estimate of the equatorial electric field | 1 | CDF_REAL8 |
| EEJ_meast | A/km | Height-integrated magnetic eastward current profile, spanning [-20:0.5:20] degrees QD latitude | 81 | CDF_REAL8 |
| EEJ_mnorth | A/km | Height-integrated magnetic northward current profile, spanning [-20:0.5:20] degrees QD latitude | 81 | CDF_REAL8 |
| RelErr | - | Quality indicator of EEF estimate; relative error between modeled and observed current profile | 1 | CDF_REAL8 |
| Flags | - | Flags describing data gaps and satellite identification | 1 | CDF_UINT2 |
| Timestamp_Track | - | Timestamps along track, length provided in Length_Track | 3000 | CDF_EPOCH |
| Latitude_Track | degrees | Latitudes along track, length provided in Length_Track | 3000 | CDF_REAL8 |
| Longitude_Track | degress | Longitudes along track, length provided in Length_Track | 3000 | CDF_REAL8 |
| Radius_Track | km | Geocentric radii along track, length provided in Length_Track | 3000 | CDF_REAL8 |
| Ksq_Track | A/km | Surface current of estimated Sq signal, packed in geocentric north,east components,, length 2*Length_Track | 6000 | CDF_REAL8 |
| Keej_Track | A/km | Surface current of estimated EEJ signal, packed in geocentric north,east components,, length 2*Length_Track | 6000 | CDF_REAL8 |
| Length_Track | - | Array of track lengths | 1 | CDF_UINT4 |
| Product Identifier | EEFxTMS_2F |
| Definition | Dayside equatorial electric field |
| Input Data | MCO_SHA_2X, AUX_LIT_2, AUX_IGR_2 |
| Input Time Span | Every dayside equator crossing ±20 minutes |
| Spatial Representation | One longitude/latitude pair (on the magnetic equator) for each output value |
| Time Representation | Single values at time of dayside equator crossing |
| Units | mV/m |
| Resolution | 0.1 mV/m |
| Uncertainty | 0.1 mV/m |
| Quality Indicator | Relative error between modeled and observed current profile |
| Data Volume | < 10 MB |
| Output Data | CDF file with time series |
| Output Time Span | Continuous for entire mission. One value for each day-side equator crossing (90 minute sampling for day-night local time orbits, 45 minutes for dawn-dusk orbits) |
| Update Rate | One output file per day |
| Latency | 30 hours |
| Notes | The EEJ_meast and EEJ_mnorth vectors have length 81 and correspond to quasi-dipole (QD) latitudes ranging from -20° to +20° in steps of 0.5°. So for example, the corresponding QD latitude vector could be constructed using the following MATLAB syntax: qdvec = [-20:0.5:20]. The EEJ_meast profile is the projection of the EEJ current along the QD F1 basis vector. The EEJ_mnorth profile is the projection of the EEJ current along the QD F2 basis vector. The variables with suffix _Track have variable lengths depending upon the value in Length_Track |
Version 0502
Old variables (version 0501):
Timestamp CDF_EPOCH/1 0:[] T/ Latitude CDF_REAL8/1 0:[] T/ Longitude CDF_REAL8/1 0:[] T/ EEJ CDF_REAL8/1 1:[81] T/T EEF CDF_REAL8/1 0:[] T/ RelErr CDF_REAL8/1 0:[] T/ Flags CDF_UINT2/1 0:[] T/
New variables (version 0502):
Timestamp CDF_EPOCH/1 0:[] T/ Latitude CDF_REAL8/1 0:[] T/ Longitude CDF_REAL8/1 0:[] T/ EEJ_meast CDF_REAL8/1 1:[81] T/T EEJ_mnorth CDF_REAL8/1 1:[81] T/T EEF CDF_REAL8/1 0:[] T/ RelErr CDF_REAL8/1 0:[] T/ Flags CDF_UINT2/1 0:[] T/ Timestamp_Track CDF_EPOCH/1 1:[3000] T/T Latitude_Track CDF_REAL8/1 1:[3000] T/T Longitude_Track CDF_REAL8/1 1:[3000] T/T Radius_Track CDF_REAL8/1 1:[3000] T/T Ksq_Track CDF_REAL8/1 1:[6000] T/T Keej_Track CDF_REAL8/1 1:[6000] T/T Length_Track CDF_UINT4/1 0:[] T/