Explore using units in calculations with the Leaf Area Index (LAI). LAI is a ratio that describes the number of square meters of leaves per square meter of available land surface. Because of the units in the ratio, it is dimensionless.

Explore using units for calculations with Normalized Difference Vegetation Index (NDVI). NDVI is a ratio of different light wavelength reflectance which can be used to map the density of green vegetation.

The fires in Greece during the summer of 2007 devastated large tracks of forest and ground cover in this Mediterranean region. Students analyze these data to determine the scale, area, and percentage of the forest impacted by of these fires.

This story map allows students to explore the formation and impacts of ash and aerosols from volcanic eruptions around the world in a 5 E-learning cycle.

This story map allows students to explore the formation and impacts of ash and aerosols from volcanic eruptions around the world in a 5 E-learning cycle. They will investigate how ash and aerosols produced from volcanic eruptions are hazardous to the human ecosystem, and will analyze concentrations of aerosols from a volcanic eruption over time. 

Students learn how to estimate the "energy efficiency" of photosynthesis, or the amount of energy that plants absorb for any given location on Earth. This is the ratio of the amount of energy stored to the amount of light energy absorbed and is used to evaluate and model photosynthesis efficiency.

The Earth System Satellite Images help students observe and analyze global Earth and environmental data, understand the relationship among different environmental variables, and explore how the data change seasonally and over longer timescales.