VariablesVariables (legacy): Time_GMT Label: Time (GMT) Definition: Time (GMT/UTC) in yymmddhhmmss format Type: Date/time Date format: yymmddhhmmss Missing values: -999 = , Time_EST Label: Time (EST) Definition: Time (EST) in yymmddhhmmss format Type: Date/time Date format: yymmddhhmmss Missing values: -999 = , Time_EDT Label: Time (EDT) Definition: Time (EDT) in yymmddhhmmss format. Type: Date/time Date format: yymmddhhmmss Missing values: -999 = , Concentration Label: Concentration Definition: Type: Physical quantity Unit: moleculePerCubicCentimeter Maximum: Not specified Minimum: Not specified Precision: 1 Missing values: -999 = , Precision Label: Precision Definition: Type: Physical quantity Unit: moleculePerCubicCentimeter Maximum: Not specified Minimum: Not specified Precision: 1 Missing values: -999 = , Flag Label: Flag Definition: Data flag describing data value. Type: Code list Codes: V0 = Valid value V1 = Valid value but below detection limit M1 = Missing value because no value is available or the value was invalidated Missing values: -999 = Methods: SAMPLING INTERVAL AS REPORTED IN MAIN TABLE Variable. Approximately 20-30 min AVERAGING TIME OF DATA IN MAIN TABLE 20 seconds SAMPLING LOCATION Scaffold Tower SAMPLING HEIGHT 3-4 meters