Tropical Atlantic Aerosols

Grade Level: 7-9


Source: National Aeronautics and Space Administration. Adapted with permission.


 

MY NASA DATA (http://mynasadata.larc.nasa.gov) makes NASA Earth science data accessible to K-12 teachers and students, as well as citizen scientists. You can use the data and lessons with your existing science curriculum. The investigations will help you to practice science inquiry and math or technology skills using real measurements of Earth system variables and processes.

MY NASA DATA microsets are created using data from NASA Earth science satellite missions. They have information on the atmosphere, biosphere, cryosphere, ocean, and land surface. You can find the data online along with support for your teacher like lesson plans, user-friendly documents, computer tools, and an Earth science glossary. You can also find science project starter ideas.

In this 50-minute activity, you can use NASA satellite data to find out where there are the greatest concentrations of aerosols over the course of a year in the tropical Atlantic region, and where these aerosols come from.

Background

Earth’s atmosphere is a mixture of gases that includes nitrogen, oxygen, carbon dioxide and other trace gases. The atmosphere also contains small, suspended liquid and particle matter called aerosols. Aerosols come from a number of sources, both natural and human-made. Some examples of aerosols are volcanic ash, dust, sand, sea salts, industrial pollutants, and smoke from biomass burning.

Aerosols are important to study and monitor because they have direct and indirect effects on regional weather and Earth’s climate. They can also affect how much of the sun’s radiation reaches Earth’s surface (radiation budget). For instance, some aerosols can scatter the sun’s radiation back to space, which causes cooling. Other aerosols can absorb radiation (a warming effect). And some can change cloud particle sizes, start chemical reactions, or even keep clouds from forming. Scientists have strong debates about the global impact of aerosols’ effects.

Several NASA satellite instruments are monitoring Earth’s atmosphere to measure aerosols. These instruments measure “aerosol optical depth.” This is the extent that aerosols keep sunlight from passing through the atmosphere by scattering or absorbing radiation. The larger the optical depth, the less radiation reaches Earth’s surface.

NASA scientists are using data from the Aqua, CloudSat, and CALIPSO satellites to understand the impact that warm, dry, dusty air blowing out of the Sahara Desert might have on hurricane formation in the Atlantic. Does the dry air keep hurricanes from forming, or does dust provide seeds for clouds, helping storms to form? Together, the three satellites track humidity, aerosols (dust), temperature, and cloud structure within the layer of Saharan air. These data allow scientists to map these characteristics in relation to where and when hurricanes form. Scientists can then observe what impact the Saharan air might have on storms (from Hurricanes: The Greatest Storms on Earth, http://earthobservatory.nasa.gov/Features/Hurricanes/).

Materials

Procedure

In this lesson, you can explore NASA data from the Multi-angle Imaging Spectroradiometer (MISR) instrument on the Terra Satellite to examine how desert dust travels from the west coast of Africa. Desert dust warms the atmosphere in regions by absorbing radiation and slowing down storm cloud formation.

Ready to start?  Go to: http://mynasadata.larc.nasa.gov/preview_lesson.php?&passid=56. Have fun!

This lesson plan was contributed to MY NASA DATA by Rex Roettger, a teacher at Ramey School, Aguadilla, Puerto Rico.