TEM diagnostics: typographical errors

[martinjuckes]

• wtem: variable description: "meridional" --> "vertical";
• utendvtem: variable description: "upward" --> "northward";
• utendwtem: variable description: "northward" --> "upward";

[martinjuckes]

The wtem change was missed in 01.00.31beta, but added in 01.00.31