Flux variables

Table 9‑1. Flux variable definitions. The device for these variables will reflect the analyzer used and gas measured.

Interface variable	Units	Data file variable	Description
Deadband	s	DEADBAND	Deadband length
Stop Time	s	STOP_TIME	Length of data used for the flux computation
Replicate		REPLICATE	Numerical value of R from the chamber's HVR field
Dilution Source		DILUTION_SOURCE	Name of the device that provided the water vapor measurement used for dilution correction (NONE for a dry gas)
Dilution Units		DILUTION_UNIT	Units of water vapor measurement (NONE for a dry gas)
Gas		GAS	Name of the gas species the flux was computed for
Gas Source		GAS_SOURCE	Name of the device that measured the gas for which the flux was computed
Temperature		TEMPERATURE	Label of the temperature measurement used in flux calculation
Temperature Source		T_SOURCE	Device of temperature measurement used in flux calculation

Results - exponential

Table 9‑2. Exponential flux calculation variable definitions. The device for these variables will reflect the analyzer used and gas measured. The nmol units vary depending on the units the gas was measured in (e.g., nmol, μmol, or mmol).

Interface variable	Units	Description
Flux	nmol m-2 s-1	Area-based flux of gas species based on exponential fit
Flux	nmol kg-1 s-1	Mass-based flux of gas species based on exponential fit
dC/dt	nmol mol-1 s-1	Slope used to compute flux
R2		Regression coefficient of fit to accumulation curve
CV		Coefficient of variation for flux calculation
C0	nmol mol-1	Gas concentration at time zero
Cx	nmol mol-1	Asymptotic gas concentration
a		Curvature parameter of exponential fit
T0	s	Time zero for fitting accumulation curve
SEI		Standard error for the intercept
SES		Standard error for the slope

Results - linear

Table 9‑3. Linear flux calculation variable. The device for these variables will reflect the analyzer used and gas measured. The nmol units vary depending on the units the gas was measured in (e.g., nmol, μmol, or mmol).

Interface variable	Units	Description
Flux	nmol m-2 s-1	Area-based flux of gas species based on linear fit
Flux	nmol kg-1 s-1	Mass-based flux of gas species based on linear fit
dC/dt	nmol mol-1 s-1	Slope used to compute flux
R2		Regression coefficient of fit to accumulation curve
CV		Coefficient of variation for flux calculation
SE		Standard error
SSN		Normalized sum of squares