The purpose of this activity is to measure the aerosol optical thickness of the atmosphere (how much of the sun's light is scattered or absorbed by particles suspended in the air). Students point a GLOBE sun photometer at the sun and record the largest voltage reading they obtain on a digital voltmeter connected to the photometer. Students observe sky conditions near the sun, perform the Cloud, Optional Barometric Pressure (optional) and Relative Humidity Protocols, and measure current air temperature. Intended outcomes are that students will understand the concept that the atmosphere prevents all of the sun's light from reaching Earth's surface and they learn what causes hazy skies. Supporting background materials for both student and teacher are included.
Intended for grade levels:
Type of resource:
Adobe Acrobat reader
Cost / Copyright:
For science/educational use consistent with the methodologies of the GLOBE Program.
DLESE Catalog ID: GLOBE-9
Resource contact / Creator / Publisher:
Author: UCAR (University Corporation for Atmospheric Research)
The GLOBE Program