Extract CMEMS level 4 daily chl interpolated product — getCMEMS

Requires global 4km netcdfs downloaded from the CMEMS L4 global ocean color product and stored locally.

Usage

getCMEMS_l4chl(points, desired.diameter = 0.7, func = c("mean", "sd"), nc.path)

Arguments

points: Data frame. Requires an input data frame with columns labeled "lon" (degrees west), "lat", and "date" (formatted as dates).
desired.diameter: Numeric. Default = 0.7. Results in a 0.7 x 0.7 degree box around the central location
func: Character. "mean" or "sd"
nc.path: Character. File path to where daily netCDF's are stored

Value

A five column data frame with chla extracted for lat/lons/dates of interest.

Details

Unlike ROMS, CMEMS chl resolution is defined in km, not degrees. So pixel sizes will vary slightly with latitude. To keep workflow consistent with existing FRD/ESD workflows, we assume that pixel sizes are 0.0416667 X 0.0416667. This may not be accurate at high latitudes!

Examples

points <- data.frame("lon" = c(-130, -125, -124, -130, -125, -124, -130, -125, -124, -180),
"lat" = c(45, 34, 32, 40, 45, 34, 32, 40, 36, 41),
"date" = as.Date("2011-04-04"))
desired.diameter <- 0.7 # Note! This means a 0.7x0.7 degree box
func <- "mean" # mean or sd
nc.path <- "/Users/admin/Downloads"
#getCMEMS_l4chl(points, desired.diameter = 0.7, "mean", nc.path)