README.md

ICOADSDictionary.jl

The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is a compilation of the world’s in situ surface marine observations and represents a culmination of efforts to digitize, assemble, and reconcile information collected over the years by many countries. This package returns a dictionary of symbols and alphanumeric values from an ICOADS IMMA file. The files themselves are available by registering at, and then downloading from, http://rda.ucar.edu/datasets/ds540.0/ but before registering, it is worth taking a look at the historical animation generated from the data and courtesy of the UK Met Office:

https://rda.ucar.edu/OS/web/datasets/ds540.0/docs/ICOADS2.5-HD_Brohan2015.mp4

Is it obvious when the Suez (1869) and Panama (1914) canals opened for business? In spite of a slightly earlier introduction of steam engines and paddle steamers, changes in ship speed seem more impressive once screw propellers took over (around 1855?) Wars invariably impacted shipping, but the Crimean (1853-1856) and American Civil (1861-1865) wars had quite different impacts in the Pacific. When did data coverage seriously improve along the Equatorial Pacific (to watch El Nino develop using arrays of moored buoys) and in the Southern Hemisphere (thanks to drifters following the surface currents)?

Installation

Pkg.add("ICOADSDict")

Quickstart

Given an unpacked ICOADS file, the following script illustrates the use of the dictionary that is returned from the function imma:

using ICOADSDict, Printf
fil = "ICOADS_R3_Beta3_199910.dat"
fpa = open(fil,         "r")
fpb = open(fil*".flux", "w")

for line in eachline(fpa)
  val = imma(rstrip(line))
  if haskey(val,  :YR) && haskey(val,  :MO) && haskey(val,  :DY) &&  haskey(val,  :HR) &&
     haskey(val, :LAT) && haskey(val, :LON) && haskey(val,   :D) &&  haskey(val,   :W) &&
     haskey(val, :SLP) && haskey(val,  :AT) && haskey(val, :SST) &&  haskey(val, :DPT)
    if 0 <= val[:W] < 50 && 880 < val[:SLP] < 1080 && -40 <= val[:AT] < 40 && -40 <= val[:DPT] < 40 && -2 <= val[:SST] < 40 &&
       val[:SF] == 1 && val[:AF] == 1 && val[:UF] == 1 && val[:VF] == 1 && val[:PF] == 1 && val[:RF] == 1
      if haskey(val, :ID)  iden = val[:ID]  else  iden = "MISSING"  end ; iden = replace(strip(iden), ' ' => '_')
      date = @sprintf("%4d%2d%2d%4d", val[:YR], val[:MO], val[:DY], val[:HR]) ; date = replace(date, ' ' => '0')
      form = @sprintf("%9s %14s %7.3f %8.3f %8.2f %8.3f %8.3f %8.2f %8.2f %8.2f\n",
        iden, date, val[:LAT], val[:LON], val[:SLP], val[:D], val[:W], val[:AT], val[:DPT], val[:SST])
      write(fpb, form)
    end
  end
end

close(fpa)
close(fpb)