Disclaimer: This material is being kept online for historical purposes. Though accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers. Visit https://espo.nasa.gov for information about our current projects.



The Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) is an airborne field campaign to investigate cirrus cloud properties and the processes that affect their impact on radiation. Utilizing the NASA WB-57 based at Ellington Field, TX, the campaign will take place in the March / April 2011 timeframe. Science flights will focus on central North America vicinity with an emphasis over the DoE ARM SGP site in Oklahoma.

Some of the major science questions to be addressed by MACPEX will include:

  • How prevalent are the smaller crystals in cirrus clouds, and how important are these for extinction, radiative forcing, and radiative heating?
  • How are cirrus microphysical properties (particle size distribution, ice crystal habit, extinction, ice water content) related to the dynamical forcing driving cloud formation?
  • How are cirrus microphysical properties related to aerosol loading and composition, including the abundance of heterogeneous ice nuclei?
  • How do cirrus microphysical properties evolve through the lifecycles of the clouds, and what role do radiatively driven dynamical motions play?

In addition to the in situ measurements, flights will be coordinated with the NASA EOS / A-Train satellite observations for validation, as well as, evaluation of new remote-sensing retrievals for future Earth Science Decadal satellites. The detailed measurements aquired by MACPEX will also be used to improve cloud model parameterizations in Global Climate Models (GCMs).

The MACPEX mission is supported by the NASA Earth Science Research and Analysis Program under the Atmospheric Composition Focus Area. The aircraft and support provided by the NASA Airborne Science Program.