Combined Aerosol Trajectory Tool, CATT Illustrated Instruction Manual Supported by: MARAMA contract on behalf of Mid-Atlantic/Northeast Visibility Union (MANE-VU) for the Inter-RPO Workgroup for Data Analysis Supplemental funding from Environmental Protection Agency, OAQPS, Agreement # National Science Foundation, Grant # Performed by the Center for Air Pollution Impact and Trend Analysis (CAPITA, Washington University In collaboration with Cooperative Institute for Research in the Atmosphere, CIRA-VIEWS Program January 10, 2004

CATT Software Components and Data Flow The CATT software consists of two rather independent components: 1.Chemical filter component. This component is accomplished through queries to chemical data sets. The output of this step is a list of “qualified” dates for a specific receptor location. 2.Trajectory aggregator component. This component receives the list of dates for a specific location and performs the trajectory aggregation, residence time calculation and other spatial operations to yield a transport pattern for specific receptor location and chemical conditions.

The CATT Browser Web Page The CATT program is a standard web page accessible through a URL by any user. The CATT browser has two data views, the Map and Time views. Each view serves double purpose: to display data as maps or time series and to accept user input (clicking on Map/Time view) for navigation (browsing) To the left of each view are view-specific controls to change either the content or form of the view. The top group of controls, ViewControls relate to the entire view, the bottom group of buttons are the LayerControls and the changes depend on which active (current) layer is in the view. The general map view settings include setting the overall image size, geographic zoom rectangle (latitude-longitude), image margins and axis labels. The form, accessible through the magnifying glass – button, is considered self-explanatory. The ‘T button allows the entry of user-specified title on the map image.

View Controls and Settings

Status and Navigation Bar The File menu item is for the design of new applications. It should only be used by developers and not by routine browsers of CATT. Traj_Point which shows the value of the species at different loc and time. Trajj_Line depicts the ensamble trajectories as lines. Traj_Grid shows the gridded trajectories as shaded contours. The Layer menu, highlighted in a yellow box, is an important navigational control of CATT. It displays and allows the selection of the ‘current layer’. Most of the user interaction is confined to the current layer. In CATT, the three layers are: