Green-Up and Green-Down

Hi,

I'm David Verbyla, a remote sensing scientist. I am excited about working with students and teachers all over the world on the plant phenology investigation. Plant phenology observations around the globe are very important. The seasonal cycle of atmospheric carbon dioxide, a greenhouse gas, follows the seasonal cycle of plant green-up, growth, and green-down. At high latitudes, the pattern of spring green-up is related to the distribution of calving caribou and other animals. In dry regions, the pattern of green-up and senescence or green-down is related to wildfire danger. Green-up and green-down can be estimated from satellite data, but these estimates need to be validated with observations throughout the globe.

Unfortunately, on-the-ground plant phenology observations are rare because they are typically too expensive and time consuming for scientists to take. There is no way that I can do all these ground observations at different places at the same time. However, with your help in the GLOBE schools, important plant stages such as budburst, leaf growth, and plant green-down can be observed and recorded. Such information is important for scientists modeling global carbon budgets, and for me and other remote sensing scientists validating our estimates of worldwide plant activity.

This spring we hope to use GLOBE data to compare an improved vegetation index that has been developed for the new MODIS sensor that was launched on the new TERRA satellite. In theory, the improved vegetation index is better at estimating plant green-up but we need GLOBE data to test this.

Welcome to our research team!

Dr. Dave Verbyla Phenology Investigation