Net CO2 exchange, evaporation and heat flux data from Alice Holt plantation tower (1999-2012)

Net CO2, evaporation and heat flux data have been collected at the Alice Holt Flux tower since 1999, these data are used in combination with the data set ‘Meteorological and climatological data from the Alice Holt plantation tower (1999-2013)’ to examine the main drivers in inter-annual variation in CO2 fluxes at an oak forest in the south of England. See also: Wilkinson, M., Eaton, E.L., Broadmeadow, M.S.J. and Morison, J.I.L. (2012). Inter-annual variation of carbon uptake by a plantation oak woodland in south-eastern England. Biogeosciences 9: 5373-5389. The columns have the following definitions: Label Units, Format, or Range Description filename,-,Name of the raw file (or the first of a set) from which the dataset for the current averaging interval was extracted date,yyyy-mm-dd,Date of the end of the averaging period time,HH:MM,Time of the end of the averaging period file_records,#,Number of valid records found in the raw file (or set of raw files) used_records,#,Number of valid records used for current the averaging period Tau,kg m-1 s-2,Corrected momentum flux qc_Tau,#,Quality flag for momentum flux rand_err_Tau,kg m-1 s-2,Random error for momentum flux, if selected H,W m-2,Corrected sensible heat flux qc_H,#,Quality flag for sensible heat flux rand_err_H,W m-2,Random error for momentum flux, if selected LE,W m-2,Corrected latent heat flux qc_LE,#,Quality flag latent heat flux rand_err_LE,W m-2,Random error for latent heat flux, if selected gas_flux,µmol m-2 s-1(†),Corrected gas flux qc_gas_flux,#,Quality flag for gas flux rand_err_gas_flux,µmol s-1 m-2(†),Random error for gas flux, if selected H_strg,W m-2,Estimate of storage sensible heat flux LE_strg,W m-2,Estimate of storage latent heat flux gas_strg,µmol s-1 m-2(†),Estimate of storage gas flux gas_v-adv,µmol s-1 m-2(†),Estimate of vertical advection flux gas_molar_density,mmol m-3,Measured or estimated molar density of gas gas_mole_fraction,µmol mol-1(†),Measured or estimated mole fraction of gas gas_mixing_ratio,µmol mol-1(†),Measured or estimated mixing ratio of gas gas_time_lag,s,Time lag used to synchronize gas time series gas_def_timelag,T/F,Flag: whether the reported time lag is the default (T) or calculated (F) sonic_temperature,K,Mean temperature of ambient air as measured by the anemometer air_temperature,K,Mean temperature of ambient air, either calculated from high frequency air temperature readings, or estimated from sonic temperature air_pressure,Pa,Mean pressure of ambient air, either calculated from high frequency air pressure readings, or estimated based on site altitude (barometric pressure) air_density,kg m-3,Density of ambient air air_heat_capacity,J K-1 kg-1,Specific heat at constant pressure of ambient air air_molar_volume,m3 mol-1,Molar volume of ambient air ET,mm hour-1,Evapotranspiration flux water_vapor_density,kg m-3,Ambient mass density of water vapor e,Pa,Ambient water vapor partial pressure es,Pa,Ambient water vapor partial pressure at saturation specific_humidity,kg kg-1,Ambient specific humidity on a mass basis RH,%,Ambient relative humidity VPD,Pa,Ambient water vapor pressure deficit Tdew,K,Ambient dew point temperature u_unrot,m s-1,Wind component along the u anemometer axis v_unrot,m s-1,Wind component along the v anemometer axis w_unrot,m s-1,Wind component along the w anemometer axis u_rot,m s-1,Rotated u wind component (mean wind speed) v_rot,m s-1,Rotated v wind component (should be zero) w_rot,m s-1,Rotated w wind component (should be zero) wind_speed,m s-1,mean wind speed max_wind_speed,m s-1,Maximum instantaneous wind speed wind_dir,° (degrees),Direction from which the wind blows, with respect to Geographic or Magnetic north yaw,° (degrees),First rotation angle pitch,° (degrees),Second rotation angle u*,m s-1,Friction velocity TKE,m-2 s-1,Turbulent kinetic energy L,M,Monin-Obukov length (z-d)/L,#,Monin-Obukhov stability parameter bowen_ratio,#,Sensible heat flux to latent heat flux ratio T*,K,Scaling temperature (footprint) model,-,Model for footprint estimation x_offset,m,Along-wind distance providing <1% contribution to turbulent fluxes x_peak,m,Along-wind distance providing the highest (peak) contribution to turbulent fluxes x_10%,m,Along-wind distance providing 10% (cumulative) contribution to turbulent fluxes x_30%,m,Along-wind distance providing 30% (cumulative) contribution to turbulent fluxes x_50%,m,Along-wind distance providing 50% (cumulative) contribution to turbulent fluxes x_70%,m,Along-wind distance providing 70% (cumulative) contribution to turbulent fluxes x_90%,m,Along-wind distance providing 90% (cumulative) contribution to turbulent fluxes un_Tau,kg m-1 s-2,Uncorrected momentum flux Tau_scf,#,Spectral correction factor for momentum flux un_H,W m-2,Uncorrected sensible heat flux H_scf,#,Spectral correction factor for sensible heat flux un_LE,W m-2,Uncorrected latent heat flux LE_scf,#,Spectral correction factor for latent heat flux un_gas_flux,µmol s-1 m-2(†),Uncorrected gas flux gas_scf,#,Spectral correction factor for gas flux spikes,HFu/v/w/ts/co2 /h2o/ch4/n2,Hard flags for individual variables for spike test amp_res,HFu/v/w/ts/co2 /h2o/ch4/n2,Hard flags for individual variables for amplitude resolution drop_out,HFu/v/w/ts/co2 /h2o/ch4/n2,Hard flags for individual variables for drop-out test abs_lim,HFu/v/w/ts/co2 /h2o/ch4/n2,Hard flags for individual variables for absolute limits skw_kur,HFu/v/w/ts/co2 /h2o/ch4/n2,Hard flags for individual variables for skewness and kurtosis skw_kur,HFu/v/w/ts/co2 /h2o/ch4/n2,Soft flags for individual variables for skewness and kurtosis test discontinuities,HFu/v/w/ts/co2 /h2o/ch4/n2,Hard flags for individual variables for discontinuities test discontinuities,HFu/v/w/ts/co2 /h2o/ch4/n2,Soft flags for individual variables for discontinuities test time_lag,HFu/v/w/ts/co2 /h2o/ch4/n2,Hard flags for gas concentration for time lag test time_lag,HFu/v/w/ts/co2 /h2o/ch4/n2,Soft flags for gas concentration for time lag test attack_angle,HFu/v/w/ts/co2 /h2o/ch4/n2,Hard flag for attack angle test non_steady_wind,HFu/v/w/ts/co2 /h2o/ch4/n2,Hard flag for non-steady horizontal test var_spikes,#,Number of spikes detected and eliminated for variable var AGC,#,Mean value of AGC for LI 7500RS or LI 7200RS RSSI,#,Mean value of RSSI for LI 7700, if present var_var,-(‡),Variance of variable var w/var_cov,-(‡),Covariance between w and variable var extravar_mean,(‡),Mean value of extravar The quality flags (e.g. qc_Tau) used are described on the following link. They range from 0 to 2; 0 is the best quality data and 2 the worst. https://www.licor.com/env/help/eddypro/topics_eddypro/Flux_Quality_Flags.html?Highlight=quality%20flag Missing values are denoted with a -9999 Attribution statement: