Below is a list of organizations associated with the atmospheric and related sciences.
American Geophysical Union
American Meteorological Society
Earth Observing System [EOS]
Global Change Master Directory
NASA's Earth Science Enterprise
National Center of Atmospheric Research [NCAR]
National Oceanic and Atmospheric Administration [NOAA]
National Science Foundation - Division of Atmospheric Sciences
United States Geological Survey [USGS]
World Meteorological Organization