Melissa Lau spent a month in the tundra ecosystem gathering data using a device called a Greenseeker. This device measures exactly how green a plant is by calculating its NDVI or Normalized Difference Vegetation Index. In this lesson, students will explore light waves, how they interact with plants, and find out how green is green.
Density currents drive 3D movements within the world’s oceans that dwarf surface currents by volume. Density-driven movements due to temperature/salinity differences keep the world’s oceans well mixed & help to re-distribute heat from tropical areas towards polar areas. Resultant upwelling creates some of the world’s richest ocean ecosystems. Density movements known as turbidity currents are the world’s largest