1. What is the Standard Temperature Lapse Rate?

The standard temperature lapse rate is the rate at which atmospheric temperature decreases with an increase in altitude in the Earth's troposphere. The internationally accepted standard is -6.5°C per 1000 meters (-1.98°C per 1000 ft).

2. How Does the Calculator Work?

The calculator uses the standard lapse rate formula:

Where:

• Altitude Change — Difference in elevation (meters)
• -6.5 — Standard lapse rate (°C per 1000 meters)

Explanation: The formula calculates how much temperature changes when moving up or down in the atmosphere based on the standard lapse rate.

3. Importance of Lapse Rate Calculation

Details: Understanding temperature changes with altitude is crucial for aviation, weather forecasting, mountaineering, and atmospheric studies.

4. Using the Calculator

Tips: Enter the altitude change in meters and the base temperature in °C. Positive altitude values represent increases in elevation.

5. Frequently Asked Questions (FAQ)

Q1: Is the lapse rate always -6.5°C/1000m?
A: No, this is the standard value. Actual lapse rates can vary due to weather conditions, humidity, and atmospheric stability.

Q2: Does this apply to all altitudes?
A: The standard lapse rate applies primarily to the troposphere (up to about 11 km). Different rates apply in other atmospheric layers.

Q3: How does humidity affect the lapse rate?
A: Moist air has a lower lapse rate (about -5°C/1000m) due to latent heat release during condensation.

Q4: What's the difference between environmental and adiabatic lapse rates?
A: Environmental is the actual atmospheric temperature profile, while adiabatic describes temperature changes in rising/descending air parcels.

Q5: Why is this important for aviation?
A: Pilots use lapse rates to calculate density altitude, which affects aircraft performance and safety.