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Slopes of C(t) for each flux with a 30 seconds cut at the end of each flux.

Usage

slopes30

Format

A tibble with 1251 rows and 28 variables

datetime

Datetime at which CO2 concentration was recorded.

temp_air

Air temperature inside the flux chamber in Celsius.

temp_soil

Ground temperature inside the flux chamber in Celsius.

conc

CO2 concentration in ppm.

PAR

Photosynthetically active radiation inside the chamber in micromol/s/sqm.

turfID

Unique ID of the turf in which the measurement took place.

type

Type of measurement: ecosystems respiration (ER) or net ecosystem exchange (NEE).

start

Datetime at which the measurement was started.

end

Datetime at which the measurement ended.

fluxID

Unique ID for each flux.

n_conc

Number of data point per flux.

ratio

Ratio of n_conc over length of the measurement (in seconds).

flag

Data quality flags.

time

Time variable of the flux in seconds.

cut

Indicating if the measurement should be kept (keep) or discarded (cut).

Cm_est

Estimation of the Cm parameter.

a_est

Estimation of the a parameter.

b_est

Estimation of the b parameter.

tz_est

Estimation of the tz parameter.

Cz

Cz parameter of the C(t) function.

Cm

Cm parameter of the C(t) function, calculated by optim() with Cm_est as starting point.

a

a parameter of the C(t) function, calculated by optim() with a_est as starting point.

b

b parameter of the C(t) function, calculated by optim() with b_est as starting point.

tz

tz parameter of the C(t) function, calculated by optim() with tz_est as starting point.

slope_tz

Slope of C(t) at tz

fit

C(t), modeled CO2 concentration as a function of time.

fit_slope

Output of linear model of CO2 concentration passing by C(tz) and a slope of slope_tz.

start_z

Datetime format of tz

Examples

slopes30
#> # A tibble: 1,251 × 29
#>    f_datetime          temp_air temp_soil f_conc   PAR turfID       type 
#>    <dttm>                 <dbl>     <dbl>  <dbl> <dbl> <chr>        <chr>
#>  1 2022-07-28 23:43:35    NA         NA     447. NA    156 AN2C 156 ER   
#>  2 2022-07-28 23:43:36     7.22      10.9   447.  1.68 156 AN2C 156 ER   
#>  3 2022-07-28 23:43:37    NA         NA     448. NA    156 AN2C 156 ER   
#>  4 2022-07-28 23:43:38    NA         NA     449. NA    156 AN2C 156 ER   
#>  5 2022-07-28 23:43:39    NA         NA     449. NA    156 AN2C 156 ER   
#>  6 2022-07-28 23:43:40    NA         NA     450. NA    156 AN2C 156 ER   
#>  7 2022-07-28 23:43:41    NA         NA     451. NA    156 AN2C 156 ER   
#>  8 2022-07-28 23:43:42    NA         NA     451. NA    156 AN2C 156 ER   
#>  9 2022-07-28 23:43:43    NA         NA     453. NA    156 AN2C 156 ER   
#> 10 2022-07-28 23:43:44    NA         NA     453. NA    156 AN2C 156 ER   
#> # ℹ 1,241 more rows
#> # ℹ 22 more variables: f_start <dttm>, f_end <dttm>, f_fluxID <dbl>,
#> #   n_conc <dbl>, ratio <dbl>, flag <lgl>, f_time <dbl>, f_cut <chr>,
#> #   Cm_est <dbl>, a_est <dbl>, b_est <dbl>, tz_est <dbl>, f_Cz <dbl>,
#> #   time_diff <dbl>, f_Cm <dbl>, f_a <dbl>, f_b <dbl>, f_tz <dbl>,
#> #   f_slope <dbl>, f_fit <dbl>, f_fit_slope <dbl>, f_start_z <dttm>