Ceptometer derived light interception data
fd_ceptometer()
A data.frame or tibble. See "Details" for column descriptions.
Call fd_metadata for field metadata.
data on light interception, as faPAR or the fraction of absorbed photosynthetically
available radiation, based on the difference between above and below canopy PAR as measured by
a Decagon LP-80 handheld ceptometer. Units of a_par, above canopy PAR, and b_par, below canopy PAR,
are in units of micromoles per square meter per second while fapar and lai_cept, leaf area index derived
from light data, are ratio-based, unitless data. Entries where the notes column has entries may refer to original values
where the a_par value was replaced with data from the nearby UMBS AmeriFlux tower PAR sensor due to ceptometer instrument
issues with securing clear sky PAR readings. Tower PAR readings were synced in time and then adjusted with the calibration
equation A_par = 1.15x - 187.827, where x = the Tower PAR reading. This is an empirically derived equation from several calibration
readings found in the supplemental section of Atkins et al. (In Prep)--to be updated when submitted.
Data were collected by Jeff W. Atkins and Brandon Alveshare using a Decagon LP-80 Handheld Ceptometer
fd_ceptometer()#> # A tibble: 83 x 10 #> subplot_id replicate plot subplot timestamp a_par b_par fapar #> <chr> <chr> <int> <chr> <dttm> <dbl> <dbl> <dbl> #> 1 D01W D 1 W 2018-07-25 10:45:00 1276. 61.8 0.952 #> 2 D03W D 3 W 2018-07-25 10:56:00 1305. 98.3 0.925 #> 3 D04W D 4 W 2018-07-25 11:07:00 1305. 345. 0.735 #> 4 D02W D 2 W 2018-07-25 11:17:00 1367. 58 0.958 #> 5 C04W C 4 W 2018-07-25 11:24:00 1439. 40.6 0.972 #> 6 C03W C 3 W 2018-07-25 11:34:00 1383. 43.5 0.969 #> 7 C02W C 2 W 2018-07-25 11:45:00 1464. 49.5 0.966 #> 8 C01W C 1 W 2018-07-25 11:52:00 1475. 116 0.921 #> 9 B04W B 4 W 2018-07-25 13:25:00 1708. 61.7 0.964 #> 10 B03E B 3 E 2018-07-25 13:36:00 1768. 110. 0.938 #> # ... with 73 more rows, and 2 more variables: lai_cept <dbl>, notes <chr>