Breadcrumb Home Sections ACOM Sections Atmospheric Composition Remote Sensing and Prediction (ACRESP) ACOM has long made significant contributions to the determination of atmospheric composition via remote sensing methodologies. Experimental System Sciences (ESS) ACOM scientists and staff maintain and deploy in-situ instrumentation for use in collaborative field programs. ACOM Modeling (MODELING) ACOM’s atmospheric chemistry modeling activities span the whole extent of the atmosphere from the troposphere up to the mesosphere and cover timescales from minutes to decades.