SGP/ECOR/E21 - Intermittent incorrect flux measurements

At various times during the period, the LI-7500 CO2/H2O serial and analog signals from the 
LI-7500 were missing, but usually not at the same time.

When the CO2/H2O serial datastream was missing, the Pressure and Temperature were missing; 
this did not, in itself, result in incorrect fluxes, as default values for pressure and 
temperature are automatically used.

Fluxes were incorrect when the CO2/H2O analog datastream was missing; these
times are identified by the qc checks.

• latent heat flux(lv_e)
• covariance wc(cvar_wc)
• average atmospheric pressure (IGRA internal sensor)(atm_pres)
• covariance wq(cvar_wq)
• CO2 flux(fc)
• average temperature (IGRA internal sensor)(temp_irga)