Calculating turbulent fluxes level 0 (uncorrected fluxes)

Level 0 fluxes are uncorrected. They are computed according to the following equations:

Ambient sensible heat flux, uncorrected (H, W m^-2)

6‑51

CO₂ flux, uncorrected (F_0,co2, μmol m^-2 s^-1)

If CO₂ is measured as molar density with an open path analyzer:

6‑52

If CO₂ is measured as molar density with a closed path analyzer:

6‑53

If CO₂ is measured as mixing ratio:

6‑54

If CO₂ is measured as mole fraction:

6‑55

H₂O flux, uncorrected (F_0,co2, mmol m^-2 s^-1)

If H₂O is measured as molar density with an open path analyzer:

6‑56

If H₂O is measured as molar density with a closed path analyzer:

6‑57

If H₂O is measured as mixing ratio:

6‑58

If H₂O is measured as mole fraction:

6‑59

CH₄ flux, uncorrected: (F_0,ch4, μmol m^-2 s^-1)

If CH₄ is measured as molar density with an open path analyzer:

6‑60

If CH₄ is measured as molar density with a closed path analyzer:

6‑61

If CH₄ is measured as mixing ratio:

6‑62

If CH₄ is measured as mole fraction:

6‑63

Latent heat flux, uncorrected (LE₀, W m^-2)

6‑64

Evapotranspiration flux, uncorrected: (E₀, kg m^-2 s^-1)

6‑65

Momentum flux, uncorrected: (T₀, kg m^-1 s^-2)

Calculated after van Dijk et al. (2004), eq. 2.85

6‑66

Friction velocity (u*, ms^-1)

Calculated according to its definition as:

6‑67

Potential temperature (T_p, K)

Calculated according to:

6‑68

where P_0,a=10⁵ Pa, and is the reference pressure.

Monin-Obukhov length (L, m)

Calculated according to its definition as:

6‑69

where κ = ~0.41, and is the von Kármán constant; g = ~9.81 m s^-1, and is the gravity.

Monin-Obukhov stability parameter (ζ, non-dimensional)

ζ is calculated as:

6‑70

where h_m is the measurement height above the ground, as measured in the center of the anemometer measurement volume, and d is the displacement height.

Dynamic temperature (T*, K)

Calculated according to its definition (e.g., Foken and Wichura, 1996):

6‑71