Washington, Dec 1 (IANS): Starting 2015, NASA will send five new airborne field campaigns to the skies to investigate how long-range air pollution, warming ocean waters and fires in Africa affect our climate.

This is NASA's second series of "Earth Venture" sub-orbital investigations, as NASA began soliciting bids for these projects in 2007 at the behest of the National Research Council.

The first series of five projects was selected in 2010.

"These new investigations address a variety of key scientific questions critical to advancing our understanding of how Earth works," said Jack Kaye, associate director for research in NASA's Earth Science Division in the US.

"These innovative airborne experiments will let us probe inside processes and locations in unprecedented detail that complements what we can do with our fleet of Earth-observing satellites," he added.

These studies into several incompletely understood Earth system processes were selected as part of NASA's Earth Venture-class projects.

The five selected investigations are: Atmospheric chemistry and air pollution; ecosystem changes in a warming ocean; greenhouse gas sources; African fires and Atlantic clouds; and melting Greenland glaciers.

Each project is funded at a total cost of no more than $30 million over five years.

This funding includes initial development, field campaigns and analysis of data.

Seven NASA centres, 25 educational institutions, three US government agencies and two industry partners are involved in these Earth Venture projects.