What does the symbol indicate on a significant weather chart?

Question

Question ATPL - Airline Transport Pilot license - Meteorology

QuizVDS · Accepted Answer

The center of a tropopause high, where the tropopause is at FL 400.

QuizVDS · Answer

The upper limit of significant weather at FL 400.

QuizVDS · Answer

The lower limit of the tropopause.

QuizVDS · Answer

The center of a high pressure area at 400 hPa.

Id 497 - ATPL - What does the symbol indicate on a significant weather chart?