Earth Science worksheet
Topic: Dewpoint
Dewpoint
Base your answers to questions 1 on the photographs below and on your knowledge of Earth science. One photograph shows a digital device that recorded several weather variables. The second photograph shows two weather instruments, labeled A and B.

1

Based on the outside air temperature and relative humidity shown on the digital device, what is the approximate dewpoint for the time shown on the device?

(1) 8°C

(2) 12°C

(3) 18°C

(4) 31°C

2

The station model below shows several weather variables recorded at a particular location.

What was the most likely dewpoint at this location?

(1) 32°F

(2) 40°F

(3) 61°F

(4) 70°F

3

What is the dewpoint when the dry-bulb temperature is 8°C and the wet-bulb temperature is 2°C?

(1) 28°C

(2) 6°C

(3) 3°C

(4) −9°C

Base your answers to questions 4 on the weather map below and on your knowledge of Earth science. On the weather map, the location of the center of a high-pressure system (H) and a front are shown. Isobar values are labeled in millibars (mb). Weather station models represent the weather conditions at Atlanta, Georgia, and Tampa, Florida.

4

Describe one piece of evidence shown on the map that indicates that Tampa, Florida, has a high probability of precipitation. [1]

Allow 1 credit. Acceptable responses include, but are not limited to:

• — The dewpoint and air temperature are close together./high relative humidity

• — 100% cloud cover/overcast

• — Tampa is close to a front.

• — The air pressure is low.

Base your answers to questions 5 on the diagram below and on your knowledge of Earth science. The diagram represents a weather balloon as it rises from Earth’s surface to 1000 meters (m). The air temperature and wet-bulb temperature values in degrees Celsius (°C) and the air pressure values in millibars (mb) are given for three altitudes.

5

Determine the dewpoint and the relative humidity of the air at Earth’s surface. [1]

Dewpoint: ______________°C Relative humidity: ________%

Allow 1 credit if both dewpoint and relative humidity are correct.

• Dewpoint: 8°C

• Relative humidity: 40%