geotiff_pal_seaice.R

u <- "https://seaice.uni-bremen.de/data/amsr2/asi_daygrid_swath/s6250/2017/nov/Antarctic/asi-AMSR2-s6250-20171109-v5.tif"
f <- basename(u)
download.file(u, f, mode = "wb")

library(raster)

## Loading required package: sp

amsr6 <- raster(f)
amsr6[amsr6 > 100] <- NA_real_
amsr6 <- setValues(raster(amsr6), values(amsr6))
exmon2 <- extent(c(1300000,2000000,-3000000,-1800000 ))
par(mfrow = c(1, 2))
plot(crop(amsr6, exmon2))

## only available on a raadtools server
ice <- raadtools::read_amsr_ice("2017-11-09") 
plot(crop(ice, exmon2))

## small bit of discretization  error
plot(ice - amsr6)

## round the data and it's the same
plot(round(ice) - amsr6)