Question 1 of 11intermediate🔧 ApplyMCQ1 mark

If the surface air pressure is 1,000 mb, the air pressure at 1 km above the surface will be:

Exercise: EXERCISES | Q: 1(i) | (Page Page 9)
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Explanation

Option C is correct because the textbook states that in the lower atmosphere, pressure decreases rapidly with height at a rate of approximately 1 mb for each 10 m increase in elevation. For a height of 1 km (which equals 1,000 m), the total decrease amounts to about 100 mb. Starting from 1,000 mb at the surface, the pressure at 1 km would be 1,000 - 100 = 900 mb. This is further validated by Table 9.1 in the textbook, which shows that at 1 km elevation, the standard pressure is 898.76 mb when sea level pressure is 1,013.25 mb (a decrease of approximately 114 mb over 1 km).

Solution Steps

  1. Step 1: Identify the rate of pressure decrease from the context - 1 mb per 10 m increase in elevation.

  2. Step 2: Calculate total decrease for 1 km (1,000 m): 1 mb × (1,000 m / 10 m) = 100 mb.

  3. Step 3: Subtract the decrease from surface pressure: 1,000 mb - 100 mb = 900 mb.

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