Cracking the Aerosol Case

New York City Research Initiative

Team members: (far left) Gerald Rabi, Brooks Rao, Carimaxy Benitez, Jesse Lieman-Sifry and Dr. Carlson

Dr. Carlson's GISS Aerosol Team

Where do aerosol agents' loyalties lie? Are they engaged in activities that cool the climate? Are they working with other atmospheric agents and morphing into a force that is warming our world? Have they worked their way into clouds to change their properties in ways that make them absorb more heat and produce greater global warming and dangerous weather?

The key to cracking the aerosol case is improving how we globally measure these atmospheric agents. Critical to gaining this global perspective is remote sensing observations from space.

While there are lots of aerosol measurements being taken from instrument networks on the ground and orbiting the Earth, significant differences in the data collected tell scientists that great uncertainty still exists about the characteristics of different kinds of aerosols and where they are around the world. One GISS aerosol study by Dr. Carlson's research team provides results that show a "significant" difference between NASA's Multiangle Imaging SpectroRadiometer (MISR) and Moderate Resolution Imaging SpectroRadiometer (MODIS) satellite instruments and data from selected stations of the worldwide ground-based Aerosol Robotic Network (AERONET).

GISS scientists finally got their chance to help solve the aerosol agent problem with a powerful instrument called a polarimeter capable of collecting global measurements aboard a NASA mission, Glory. The space mission launched on March 4, 2011, ended abruptly when it failed to reach its intended Earth orbit for aerosol surveillance. The GISS Glory team is determined to get another instrument into earth orbit and crack the case of aerosol double agents.

Without measurements like those intended to be collected on Glory, we will continue to have only partial information about aerosols. The true extent of aerosol operations may never be known. Certainty about human contributions to aerosols and their role in global warming will continue to elude us.