# Sea ice vignette

#### Scott Chamberlain

#### 2019-11-20

Get sea ice data at ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/shapefiles

    library('rnoaa')
    library('dplyr')
    library('ggplot2')

### Look at data for a series of years for Feb, South pole

    res <- sapply(seq(1986, 1990, 1), function(x)
        sea_ice(x, month = 'Feb', pole = 'S'))
    lapply(res, head)

### Map a single year/month/pole combo

    ggplot(res[[1]], aes(long, lat, group=group)) +
        geom_polygon(fill="steelblue") +
        theme_ice()

### Map all years for April only for North pole

    dat <- sea_ice(year = 1985:1990, month = 'Apr', pole = 'N')
    df <- bind_rows(dat, .id = "x")
    ggplot(df, aes(long, lat, group = group)) +
      geom_polygon(fill = "steelblue") +
      theme_ice() +
      facet_wrap(~ x)