A comprehensive and cohesive aerosol measurement record with consistent, well-understood uncertainties is a prerequisite to understanding aerosol impacts on long-term climate and environmental variability. Objectives to attaining such an understanding include improving upon the current state-of-the-art sensor calibration and developing systematic validation methods for remotely sensed microphysical properties. While advances in active and passive remote sensors will lead to needed improvements in retrieval accuracies and capabilities, ongoing validation is essential so that the changing sensor characteristics do not mask atmospheric trends. Surface-based radiometer, chemical, and lidar networks have critical roles within an integrated observing system, yet they currently undersample key geographic regions, have limitations in certain measurement capabilities, and lack stable funding. In situ aircraft observations of size-resolved aerosol chemical composition are necessary to provide important linkages between active and passive remote sensing. A planned, systematic approach toward a global aerosol observing network, involving multiple sponsoring agencies and surface-based, suborbital, and spaceborne sensors, is required to prioritize trade-offs regarding capabilities and costs. This strategy is a key ingredient of the Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON) framework. A set of recommendations is presented.
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California
University of Washington, Seattle, Washington
Max-Planck-Institut für Meteorologie, Hamburg, Germany
NASA Goddard Space Flight Center, Greenbelt, Maryland
NASA Langley Research Center, Hampton, Virginia
Brookhaven National Laboratory, Upton, New York
NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, Colorado
Colorado State University, Fort Collins, Colorado
University of Maryland, Baltimore County, Baltimore, Maryland
National Center for Atmospheric Research, Boulder, Colorado
NASA Goddard Institute for Space Studies, New York, New York
