This category covers 16 topics and has 44 questions.

• Layer Order
• Boundaries
• Tropopause Definition
• Tropopause Height
• Tropopause Height Changes
• Tropopause Seasonal Changes
• ISA Calculations
• Layer Separation
• Changes Within Layers
• Tropopause Breaks
• Makeup of Air
• WV Relevance
• WV Amount
• WV Location
• Mass Location
• ISA Conditions