Data Access
Section 4.1 of the text describes our procedure for identifying the locations of x-lines in a map of the neutral surface.
At each value of Y in an interpolated grid, we scan the entire length of the trace of Vx from -10 to -70 Re. A function finds all
intervals of Vx>=250 km/s and Vx less then or equal to -250 km/s. We call these earthward and tailward fast flow intervals. We define
a bifurcation of fast flow as the point at which Vx changes sign from fast earthward to fast tailward flow. In simple cases, this
transition occurs in about 2 Re (20 grid points). The zero crossing is the location of the x-line at this value of Y. As described
in the text, we process the arrays of zero crossings to define a line in the neutral surface. We display this information as lines
parallel to X at fixed Y. Intervals of fast earthward flow are represented by a thick red line. Fast flow is a thick blue line. The
zero crossing is a gray circle. After completion of the plot, we add x-lines as colored ropes (yellow with black stripes). Each map is
in a file and subsequently made into a movie. The movie illustrates the formation and evolution of x-lines.
The movie begins at 04:00 UT with at least five significant x-lines and six earthward flow channels. This is the start of the growth
phase of a substorm. As time advances the locations of the x-lines change as flow channels move away from them. New lines form and
channels merge. When the movie approaches substorm onset at 04:44 UT the x-lines merge into a single long x-line stretching diagonally
across the tail. About 04:35, the nose of the fast earthward flow channel penetrates close to the Earth, and then begins to sweep
westward to earlier local times. At this, time the movie mS02 and the text Figure 13 shows magnetic flux accumulating close to the Earth.
At 04:50 UT, the single channels spawns new channels that flow directly toward Earth rather than along the diagonal channel.
Version:2.3.1
Section 4.1 of the text describes our procedure for identifying the locations of x-lines in a map of the neutral surface.
At each value of Y in an interpolated grid, we scan the entire length of the trace of Vx from -10 to -70 Re. A function finds all
intervals of Vx>=250 km/s and Vx less then or equal to -250 km/s. We call these earthward and tailward fast flow intervals. We define
a bifurcation of fast flow as the point at which Vx changes sign from fast earthward to fast tailward flow. In simple cases, this
transition occurs in about 2 Re (20 grid points). The zero crossing is the location of the x-line at this value of Y. As described
in the text, we process the arrays of zero crossings to define a line in the neutral surface. We display this information as lines
parallel to X at fixed Y. Intervals of fast earthward flow are represented by a thick red line. Fast flow is a thick blue line. The
zero crossing is a gray circle. After completion of the plot, we add x-lines as colored ropes (yellow with black stripes). Each map is
in a file and subsequently made into a movie. The movie illustrates the formation and evolution of x-lines.
The movie begins at 04:00 UT with at least five significant x-lines and six earthward flow channels. This is the start of the growth
phase of a substorm. As time advances the locations of the x-lines change as flow channels move away from them. New lines form and
channels merge. When the movie approaches substorm onset at 04:44 UT the x-lines merge into a single long x-line stretching diagonally
across the tail. About 04:35, the nose of the fast earthward flow channel penetrates close to the Earth, and then begins to sweep
westward to earlier local times. At this, time the movie mS02 and the text Figure 13 shows magnetic flux accumulating close to the Earth.
At 04:50 UT, the single channels spawns new channels that flow directly toward Earth rather than along the diagonal channel.
| Role | Person | StartDate | StopDate | Note | |
|---|---|---|---|---|---|
| 1. | GeneralContact | spase://SMWG/Person/Robert.L.McPherron | |||
| 2. | MetadataContact | spase://SMWG/Person/James.M.Weygand |
Supplimentary movies for JGR publication
Virtual Magnetospheric Observatory
Two dimensional display of this movie of the GSM X component of position is on the original.
Each image is 3840 pixels by 1890 pixels and there are 360 frames in the movie.
Two dimensional display of this movie of the GSM Y component of position is on the original.
Each image is 3840 pixels by 1890 pixels and there are 360 frames in the movie.
Two dimensional display of this movie of the GSM X component of plasma flow velocity is on the original, not interpolated grid. Red means Vx flows earthward and is greater then or equal to 250 km/s, Blue means Vx flows tailward and is less then or equal to 250 km/s, and white means flows are between -250 and 250 km/s.
Each image is 3840 pixels by 1890 pixels and there are 360 frames in the movie.
Two dimensional display of this movie of the GSM plasma flow velocity interpolated grid.
Each image is 3840 pixels by 1890 pixels and there are 360 frames in the movie.