This page highlights recent interesting events in the solar wind observed by the Voyager 2 plasma instrument. Voyager was tracked by the Deep Space Network at the time of the shock crossing so we have good data across the shock.
Shocks result from fast solar wind streams running into slower solar wind streams.
Since the solar wind is supersonic a shock forms near stream boundaries. The density and temperature do not change noticeably when the shock passes. This is very different from the inner heliosphere where velocity increases at shock passages are associated with increases in density and pressure. This difference may be because the interstellar pickup ions dominate the pressure in the outer heliosphere.