flux_fitting_exp {fluxible} | R Documentation |
Fitting a model to the gas concentration curve and estimating the slope over time, using the exponential model from Zhao et al (2018)
Description
Fits an exponential expression to the concentration evolution
Usage
flux_fitting_exp(
conc_df,
t_window = 20,
cz_window = 15,
b_window = 10,
a_window = 10,
roll_width = 15,
start_cut = 0,
end_cut = 0,
start_col = "f_start",
end_col = "f_end",
datetime_col = "f_datetime",
conc_col = "f_conc",
fluxid_col = "f_fluxID"
)
Arguments
conc_df |
dataframe of gas concentration over time |
t_window |
enlarge focus window before and after tmin and tmax |
cz_window |
window used to calculate Cz, at the beginning of cut window |
b_window |
window to estimate b. It is an interval after tz where it is assumed that C fits the data perfectly |
a_window |
window at the end of the flux to estimate a |
roll_width |
width of the rolling mean for CO2 when looking for tz, ideally same as cz_window |
start_cut |
time to discard at the start of the measurements (in seconds) |
end_cut |
time to discard at the end of the measurements (in seconds) |
start_col |
column with datetime when the measurement started |
end_col |
column with datetime when the measurement ended |
datetime_col |
column with datetime of each concentration measurement |
conc_col |
column with gas concentration data |
fluxid_col |
column with ID of each flux |
Value
a dataframe with the slope at t zero, modeled concentration over time and exponential expression parameters
References
Zhao, P., Hammerle, A., Zeeman, M., Wohlfahrt, G., 2018. On the calculation of daytime CO2 fluxes measured by automated closed transparent chambers. Agricultural and Forest Meteorology 263, 267–275. https://doi.org/10.1016/j.agrformet.2018.08.022