interdep: Flux Interdependency

In lsigut/openeddy: Post-process eddy covariance data with ease

Flux Interdependency

Description

Interdependency of H, LE and NEE QC flags due to corrections/conversions.

Usage

interdep(qc_LE, qc_H = NULL, IRGA = c("en_closed", "open"))

Arguments

qc_LE	An atomic type containing numeric or NA values. Combination of all available QC flags for LE.
qc_H	An atomic type containing numeric or NA values. Combination of all available QC flags for H. Used only if IRGA = "open".
IRGA	A character string. Specifies the type of IRGA. Allowed values are "en_closed" both for closed and enclosed path systems and "open" for open path systems. Can be abbreviated.

Details

Flux interdependency is an additive QC flag correction. Results follow the QC scheme using QC flag range 0 - 2. Returned data frame follows the 'Naming Strategy' described in extract_QC. Returned QC flags have QC suffix interdep.

To convert buoyancy flux to sensible heat flux (SND or Schotanus correction), reliable measurements of LE must be available. To correct LE and NEE estimated by open-path IRGA (IRGA = "open") for the effects of density fluctuations due to temperature and humidity fluctuations (WPL or Webb correction), reliable measurements of H must be available. To perform WPL correction of NEE estimated with any kind of IRGA, reliable measurements of LE must be available. Thus following set of rules apply:

If IRGA = "en_closed"

• If qc_LE == 2 | is.na(qc_LE) == TRUE: qc_H and qc_NEE flags are increased by 1.

If IRGA = "open"

• if qc_LE == 2 | is.na(qc_LE) == TRUE: qc_H flags are increased by 1.

• If qc_H == 2 | is.na(qc_H) == TRUE: qc_LE flags are increased by 1.

• If qc_H == 2 | is.na(qc_H) == TRUE | qc_LE == 2 | is.na(qc_LE) == TRUE: qc_NEE flags are increased by 1.

Value

A data frame. Each column has attributes "varnames" and "units".

Abbreviations

• QC: Quality Control

• H: Sensible heat flux [W m-2]

• LE: Latent heat flux [W m-2]

• NEE: Net ecosystem exchange [umol m-2 s-1]

• IRGA: Infrared Gas Analyzer

.

References

Mauder, M., Cuntz, M., Drue, C., Graf, A., Rebmann, C., Schmid, H.P., Schmidt, M., Steinbrecher, R., 2013. A strategy for quality and uncertainty assessment of long-term eddy-covariance measurements. Agric. For. Meteorol. 169, 122-135. https://doi.org/10.1016/j.agrformet.2012.09.006

See Also

combn_QC and extract_QC.

lsigut/openeddy documentation built on Aug. 5, 2023, 12:25 a.m.