calc_chla_trichromatic: calc_chla_trichromatic

In aelab: Data Processing for Aquatic Ecology

calc_chla_trichromatic

Description

Calculate chlorophyll-a concentration from trichromatic spectrophotometric absorbance readings using the Jeffrey & Humphrey (1975) equations.

Usage

calc_chla_trichromatic(wl_630, wl_647, wl_664, wl_750)

Arguments

wl_630	Absorbance at 630 nm.
wl_647	Absorbance at 647 nm.
wl_664	Absorbance at 664 nm.
wl_750	Absorbance at 750 nm (turbidity blank).

Details

Absorbance values should be measured in a 1 cm path-length cuvette. The 750 nm reading is used as a turbidity blank correction. Formula: 11.85 \times E_{664} - 1.54 \times E_{647} - 0.08 \times E_{630} where E_{\lambda} = A_{\lambda} - A_{750}.

Value

Chlorophyll-a concentration in µg L^{-1} (assuming a 1 cm path length and standard extraction volume).

Examples

calc_chla_trichromatic(wl_630 = 0.05, wl_647 = 0.08, wl_664 = 0.20, wl_750 = 0.01)

aelab documentation built on Feb. 23, 2026, 5:07 p.m.