Tracking our planet from above

By James Dacey

Advances in satellite technology are giving us fresh opportunities to monitor the Earth’s geography and track changes over time. During a recent visit to San Francisco, I got the chance to meet a few of the scientists who use such data to develop a better understanding of global processes. I met them alongside a giant screen, which was part of a NASA exhibition at the annual meeting of the American Geophysical Union.

In this first video interview, I meet NASA scientist Compton Tucker, who is interested in deforestation in the Amazon rainforest. He uses the screen to show me images of a region in north-west Brazil as captured by satellites from the Landsat Program, which has been collecting images since 1972. Tucker explains how he uses these images to identify where deforestation has increased over time and why these changes have occurred.

Tucker says that this information is useful for a number of reasons, including climate studies, because it can help to quantify the amount of carbon dioxide released as a result of deforestation. He explained that scientists collect the data and integrate them with scientific observations obtained on the ground. It was also interesting to hear about Tucker’s adventures in the jungle, particularly his experiences meeting the locals.

In this second video interview, I meet another NASA scientist, Eric Lindstrom, who uses the screen to show me an animation from NASA’s ECCO2 project. This project is designed to create an accurate model of the world’s oceans and sea-ice based on data collected by a whole fleet of satellites. He showed me how the model can identify the extent of turbulence in the oceans in the form of eddy currents.

If you enjoy these videos, then you may also be interested in one of the articles in the March issue of Physics World. It features a series of images focusing on different aspects of planet Earth, including the varying sea-surface temperatures and the elevation of the land surface. You can download a free PDF of this special earth-science issue via this link.