*A*_{γ} |
measured UV absorbance at 254 nm (dimensionless) |

*A*_{254} |
absorbance at 254 nm in units of inverse meters (L^{–}^{1}) |

*a*_{γ} |
absorption coefficient (L^{-1}) |

*C*_{1}, *C*_{2} |
constants of integration (*M*/L^{3}) |

[*DOC*] |
DOC concentration in units of milligrams per liter (mg/L) |

*k* |
first-order removal rate constant (T^{–}^{1}) |

*r* |
Path length (L) |

*SUVA*_{254} |
specific ultraviolet absorbance at 254 nm (dimensionless) |

*t* |
time since recharge event (T) |

*x*(*t*) |
DOC concentrations as a function of time, typically in micromoles per liter (M/L^{3}) |