The Exploratorium Embarcadero node sits on the west facing side of the Exploratorium, with direct exposure to the vehicle traffic driving on the Embarcadero, a busy street that runs the along the east side of San Francisco. Comparison to its sister node on the Bay side of the building provides some insight for how quickly emissions decrease as they move away from the street, and give us greater understanding of the magnitude of the emissions by the passing traffic on the Embarcadero.