wtr.layer {rLakeAnalyzer}

Exploration of lake water column layers

Description

Extract water column parameters of a given parameter from a profile using the split-and-merge algorithm. The cline is defined as the midpoint of the layer of water where the physical property change in the greatest over a small difference. The exact cline depends on the specification of measure. For example if temperature is specified, then we can expect cline to output the thermocline.

Usage

wtr.layer(data, depth, measure, thres = 0.1, z0 = 2.5, zmax = 150,
  nseg = "unconstrained")

Arguments

data

data supplied as a bare (unquoted) value

depth

depth in metres; should be an increasing vector; supplied as a bare (unquoted) value

measure

parameter measured in the water column profile; supplied as a bare (unquoted) value

thres

error norm; defaults to 0.1

z0

initial depth in metres. Defaults to 2.5m

zmax

maximum depth in metres: defaults to 150m

nseg

optional parameter to define the number of segments a priori; defaults to an unconstrained approach whereby the algorithm determines segmentations by minimzing the error norm over each segment

Value

a dataframes with a list column. This includes: nseg (number of segments), mld (mix layer depth), cline (the midpoint of the segment connecting inflection points that has the maximum slope; thermocline for temperature measures) and segments calculated by the sm algorithm.

References

Thomson, R. and I. Fine. 2003. Estimating Mixed Layer Depth from Oceanic Profile Data. Journal of Atmospheric and Oceanic Technology. 20(2), 319-329.

Examples

data("latesummer")
df1 <- wtr.layer(depth=latesummer$depth, measure = latesummer$temper)
df1$mld
df1$segments

wtr.layer(data = latesummer, depth=depth, measure = temper, nseg=4)