load and read DIC

[bbest]

Priority: 3P Source: https://calcofi.org/ccdata/dic-data.html
Downloaded to: GDrive calcofi/data/DIC/CalCOFI_DICs_200901-201507_28June2018.csv

In oceano-bottle.Rmd add/modify functions to :

• [x] read DIC data
• [x] plot daily time series for AOI
• [x] map idw raster
• [ ] add screenshots from oceano-bottle.html
• [ ] find alternate variables, if any, for oxygen/pH/DIC after 1950
• [ ] kriging seems pretty pointed, ie IDW isn't great (ie gstat(formula=var_avg~1, locations=p)), so let's use the alternative kriging form (see gstat::gstat() & gstat::krigeST() (see reference: Surface and Field Analysis > Geostatistical Interpolation Methods > Core concepts in Geostatistics)