2.3.0 spase://NASA/Catalog/BS_IMP8 IMP 8 bow shock crossings 2020-07-07T19:17:05Z A complete list of bow shock crossings observed by IMP 8 spacecraft. The shock crossings were manually identified in magnetic field and/or thermal plasma measurements by J. Merka, A. Szabo, K. Paularena, J. Richardson, and T. Narock. Each identified crossing was reviewed by at least two persons from the team. Upstream parameters are as measured by IMP 8 on the solar wind side of the shock, typically over a few-minute interval judged by the IMP field and plasma teams as stable. For multiple-shock records, all upstream parameters are for the first shock crossing. Downstream parameters are as measured by IMP 8 on the magnetosheath side of the shock, typically over a few-minute interval. For a multiple-shock records, all downstream parameters are for the first shock crossing if possible. spase://SMWG/Person/Jan.Merka DataProducer spase://VMO/Catalog/BS_IMP8 spase://VSPO/Catalog/BS_IMP8 spase://SMWG/Repository/NASA/GSFC/VHO-VMO Online Open Download of IMP 8 bow shock crossing list https://vho.nasa.gov/mission/imp8/bowshocks/ Repository of IMP 8 bow shock crossings Text ASCII spase://SMWG/Instrument/IMP8/MAG spase://SMWG/Instrument/IMP8/PLS BowShockCrossing 1973-10-31T07:31:00Z 2000-06-08T16:45:00Z The times are estimated to a minute (truncated). Time Fields 1-4 Time of the bow shock crossing. In general, the minute given is that in/during which the crossing is observed. For "extended" crossings, the minute given is that in which the peak of the shock overshoot occurs. For records recording multiple shock crossings, the minute is the minute of the first shock crossing. Truncated to a minute precision. 4 Year 1 Field 1 Day of year 2 Field 2 Hour 3 Field 3 Minute 4 Field 4 Temporal Orbit number Field 5 Orbit number per IMP project Other Orbit leg Field 6 0 for solarwindward orbit leg, 1 for magnetotailward orbit letg Other Sequence number Field 7 Sequence number of the crossing for this orbit leg (1, 2, ...N; N will be an odd number except for Transdr=2 cases). For multiple-shock records (Flag2 = 6 or 7), this number increments by one for unresolvable shock periods (Flag2=6) or by the number of resolvable shocks plus the number of unresolvable-shock subintervals. Other Transdr Field 8 Direction of crossing transition: 0 - spacecraft passing into solar wind, 1 - spacecraft passing into magnetosheath, 2 - non-resolvable shock(s), same domain (solar wind or magnetosheath) on both sides. See Timespan for duration of the crossing. Other Flag1 Field 9 Observation flag. Flag1 has the following values: 1. Shock observed in field and plasma data 2. Field data missing 3. Plasma data missing 4. Inferred crossing, data gap 5. Inferred crossing, data but no likely shock visible. When a bow shock crossing is inferred to have happened during some time interval, the start time of the interval is given in the record. In addition, if the interval is less than 30 minutes in duration, the location of IMP 8 at the start of the interval is also given in the record. Otherwise the IMP location words have fill values in them. Note that the Timespan parameter is used to give the interval duration in such cases. In general, upstream parameter values are given as fill values for such cases. These intervals typically correspond to data gaps (Flag 1 = 4) with IMP 8 clearly in the solar wind on one side of the gap and in the magnetosheath on the other side. There are rare Flag 1 = 5 cases where IMP 8 is clearly in the solar wind on one side of the interval and in the magnetosheath on the other side and wherein there are data within the interval, yet it is impossible to discern on a finer scale when IMP 8 passed between the solar wind and the magnetosheath. Other Flag2 Field 10 Shock cleanliness flag. Flag 2 has the following values. (Note in particular that values 1-4 are relevant to cases of one shock while 6-8 are relevant to cases of multiple close shocks; note also that some or all of the members of a set of multiple close shocks may be unresolvable from each other and, separately, may be ambiguous in the sense of values 2-4 for individual shocks. In general, where an interval of multiple close shocks ends with a clean shock, there will be a separate record for that shock.) 1. The shock is clean and unambiguous in all available data 2. The shock is clean in field, ambiguous in plasma data 3. The shock is clean in plasma, ambiguous in field data 4. The shock is ambiguous in all available data 5. Used for inferred crossings (Flag1 = 4 or 5) 6. Multiple unresolvable shocks possibly involving relatively clean shocks at the start and end (Sequence number increments by 1 whether same domain or different domains on two sides) 7. Multiple resolvable shocks with no subinterval(s) of unresolvable shocks. Used on for intervals with no shock pair separated by >15 minutes. Sequence number increments by sum of number of shocks in the interval or one less if the ending shock is also given a separate record of its own. 8. Multiple shocks, mixed resolvable/unresolvable, some resolvable shocks may be ambiguous. Sequence number increments by the number of resolvable shocks in the interval or one less if the ending shock is given a record of its own. Other Flag3 Field 11 Upstream cleanliness flag. Flag 3 has the following values: 1. Upstream values steady and well defined 2. Upstream values unsteady and uncertainly defined 3. Used for inferred crossings (Flag1 = 4) Other Spacecraft position in GSE Field 12-14 Spacecraft positition in GSE. Re 6.378e6>m Cartesian GSE 3 Xgse Component.I 1 Field 12 Ygse Component.J 2 Field 13 Zgse Component.K 3 Field 14 999.9 Positional Spacecraft position in GSM Field 15-16 Spacecraft positition in GSM (components Y and Z only). Re 6.378e6>m Cartesian GSM 2 Ygsm Component.J 1 Field 15 Zgsm Component.K 2 Field 16 999.9 Positional B GSE Field 17-19 Upstream magnetic field components in GSE nT 1e-9>T Cartesian GSE 3 Bx GSE Component.I 1 Field 17 By GSE Component.J 2 Field 18 Bz GSE Component.K 3 Field 19 999.9 Vector Average Magnetic B GSM Field 20-21 Upstream magnetic field components Y and Z in GSM nT 1e-9>T Cartesian GSM 2 By GSE Component.J 1 Field 20 Bz GSE Component.K 2 Field 21 999.9 Component.J Component.K Average Magnetic V GSE Field 22-24 Solar wind velocity upstream of the shock. The components of the velocity vector are negative, i.e. the vector is anti-aligned with the measured velocity vector. km/s 1e3>ms/s Cartesian GSE 3 -Vx GSE Component.I 1 Field 22 -Vy GSE Component.J 2 Field 23 -Vz GSE Component.K 3 Field 24 9999.9 Proton Average Velocity Nu Field 25 Upstream solar wind proton density cm^-3 1e3>m^-3 999.9 Proton Average NumberDensity Nd Field 26 Downstream (magnetosheath) proton density cm^-3 1e3>m^-3 999.9 Proton Average NumberDensity T Field 27 Upstream proton temperature K 9999999 Proton Average Temperature Time span Field 28 The time span gives duration, in minutes, of gaps for inferred crossings (flag 1 = 4 cases) or duration of periods of multiple unresolved or resolved shocks (flag 2 = 6 or 7 cases). For other cases, the time span gives the shock duration. In the majority of cases wherein the shock occurs in a fraction of minute, this field has value 0. minutes 60>s 9999 Temporal Btot Field 29 Upstream magnetic field intensity calculated from magnetic field components. nT 1e-9>T 999.9 Magnitude Average Magnetic Vtot Field 30 Upstream solar wind proton flow speed km/s 1e3>m/s 9999.9 Proton Average FlowSpeed Vs Field 31 Upstream sound speed km/s 1e3>m/s 9999.9 Proton Average SoundSpeed Va Field 32 Upstream Alfven speed km/s 1e3>m/s 9999.9 Average Other Vms Field 33 Upstream magnetosonic speed km/s 1e3>m/s 9999.9 Average Other Ms Field 34 Upstream sonic Mach number 99.9 Proton Average SonicMachNumber Ma Field 34 Upstream Alfven Mach number 999.9 Average Other Mms Field 35 Upstream magnetosonic Mach number 99.9 Average Other Beta Field 36 Upstream plasma beta -999.99 Average Other Psw Field 37 Upstream solar wind flow pressure nPa 1e-9>Pa 99.99 Proton Average Pressure Str Field 38 Shock strength: downstream to upstream density ratio (Nd/Nu). 9.9 Other IMF cone Field 39 IMF cone angle = acos(|Bx|/Bt) deg Spherical GSM 999 DirectionAngle Average Magnetic IMF clock Field 40 IMF clock angle = atan(|By GSM|/Bz GSM) deg Spherical GSM 999 DirectionAngle Average Magnetic