• Data Set Overview
• =================

+-----------------------------------------------------+
| Data Set Characteristics | Value |

| Instrument P.I. | JOHN D. RICHARDSON |
| Data Supplier | JOHN D. RICHARDSON |
| Data Sampling Rate | 96 SECONDS |
| Data Set Start Time | 1979-07-23T23:42:34.541Z |
| Data Set Stop Time | 1979-08-10T04:04:57.070Z |
+-----------------------------------------------------+

This Data Set contains Plasma Parameters from Voyager 2 outbound from Jupiter from the Magnetotail through the Solar Wind. Fit and Moment Parameters are given; the Fit Parameters assume a single, isotropic convected Proton Maxwellian Distribution. Although Magnetotail Data is provided, these Data are unreliable; the Density can be used as an upper Limit to the actual Density. Solar Wind Data are also provided and are reliable. These M-Mode Data are the best Data to use in most Regions of the Magnetosheath. Magnetotail Data in this Data Set are included mainly to put the Sheath Data in context and to show the magnetopause.

• Parameters

• ==========

• Data Set Parameter ION DENSITY

• ==============================

+----------------------------------------------+
| Parameter Characteristics | Value |

| Data Set Parameter Name | ION DENSITY |
| Data Set Parameter Unit | CM^-3 |
| Sampling Parameter Name | TIME |
| Sampling Parameter Unit | SECOND |
| Minimum Sampling Parameter | UNK |
| Maximum Sampling Parameter | UNK |
| Sampling Parameter Interval | UNK |
| Minimum Available Sampling Int | UNK |
| Noise Level | UNK |
+----------------------------------------------+

A derived Parameter equaling the Number of Ions per Unit Volume over a specified Range of Ion Energy, Energy per Charge, or Energy per Nucleon. Discrimination with regard to Mass and or Charge State is necessary to obtain this Quantity, however, Mass and Charge State are often assumed due to Instrument Limitations.

Many different Forms of Ion Density are derived. Some are distinguished by their Composition (N+, Proton, Ion, etc.) or their Method of Derivation (Maxwellian Fit, Method of Moments). In some cases, more than one Type of Density will be provided in a single Data Set. In general, if more than one Ion Species is analyzed, either by Moment or Fit, a total Density will be provided which is the Sum of the Ion Densities. If a Plasma Component does not have a Maxwellian Distribution the actual Distribution can be represented as the Sum of several Maxwellians, in which case the Density of each Maxwellian is given.

• Data Set Parameter ION THERMAL SPEED
• ====================================

+----------------------------------------------------+
| Parameter Characteristics | Value |

| Data Set Parameter Name | ION THERMAL SPEED |
| Data Set Parameter Unit | KM/S |
| Sampling Parameter Name | TIME |
| Sampling Parameter Unit | SECOND |
| Minimum Sampling Parameter | UNK |
| Maximum Sampling Parameter | UNK |
| Sampling Parameter Interval | UNK |
| Minimum Available Sampling Int | UNK |
| Noise Level | UNK |
+----------------------------------------------------+

A Measure of the Velocity associated with the Temperature of the Ions. It is formally defined as the Ion Thermal Speed squared equals two times K (Boltzmann Constant) times T (Ion Temperature) divided by M (Ion Mass). Each Component of a Plasma has a Thermal Speed associated with it.

• Data Set Parameter ION VELOCITY
• ===============================

+-----------------------------------------------+
| Parameter Characteristics | Value |

| Data Set Parameter Name | ION VELOCITY |
| Data Set Parameter Unit | KM/S |
| Sampling Parameter Name | TIME |
| Sampling Parameter Unit | SECOND |
| Minimum Sampling Parameter | UNK |
| Maximum Sampling Parameter | UNK |
| Sampling Parameter Interval | UNK |
| Minimum Available Sampling Int | UNK |
| Noise Level | UNK |
+-----------------------------------------------+

A derived Parameter giving the average Speed and Direction of Motion of a Plasma or Plasma Component. The Velocity can be obtained by taking the first Moment of the Distribution Function or by simulating the Observations with some known Distribution Function, usually a Maxwellian, to the Distribution. Velocities are given in Heliographic (RTN) Coordinates:

• R is radially away from Sun
• T is in Equatorial Plane of the Sun and positive in the Direction of Solar Rotation
• N completes right-handed System

+-------------------------------------------------+
| Source Instrument Characteristics | Value |

| Instrument Host ID | VG2 |
| Data Set Parameter Name | ION DENSITY |
+-------------------------------------------------+