A replotting of the recently published NOAA data from the Arctic Report Card 2017

SeaIce.csv

SeaIce.R

# These data appeared in a graph on climate.gov: http://bit.ly/2AFNBJz. 
# Paraphrasing from the website:
# The data are for each November since 1979 to 2017.
# The variable 'area' represents the combined November sea ice 
# area for the Chukchi and Beaufort Seas, the two sub-basins of 
# the Arctic Ocean that touch Alaska’s Arctic (northern) coast. 
# Larger values means more sea ice in the combined basin in square kilometres.
# The variable 'temp' is the November temperature (Fahrenheit) at Utqiaġvik,
# also known as Barrow (71°17′26″N 156°47′19″W).
# The data were digitised using Plot Digitizer 
# (https://sourceforge.net/projects/plotdigitizer). The variable 'years' was added
# manually later.

# Read the sea ice data in
SeaIce <- readr::read_csv("Desktop/SeaIce.csv")

library(ggplot2)
library(magrittr)

# A plot of the temperature on Barrow over the years.  The area of sea ice is 
# included as a colour (and size) gradient of each point. 
# A loess curve is added first.
p <- SeaIce %>%
  ggplot(aes(year, temp)) +
    geom_smooth(method = 'lm')  + 
    geom_point(aes(size = area, color = area)) +
    scale_colour_gradient(low = "Red", high = "Blue",
                        space = "Lab", na.value = "grey50", guide = "colourbar",
                        name = bquote('Sea ice\n(Millions km'^2*")")) +
  scale_radius(breaks = 7) +
  xlab("Year") + 
  ylab("Temperature difference")
ggsave(file="yearXtemp.svg", plot=p, width=5, height=4)


# A plot of the area of sea ice over the years.  The temperature difference is 
# included as a colour gradient of each point. A loess curve is added first.
p <- SeaIce %>%
  ggplot(aes(year, area)) +
  geom_smooth(method = 'loess')  + 
  geom_point(aes(color = temp)) +
  scale_colour_gradient(low = "Blue", high = "Red",
                        space = "Lab", na.value = "grey50", guide = "colourbar",
                        name = "Temperature") +
  xlab("Year") +
  ylab(bquote('Sea ice (Millions km'^2*")"))

ggsave(file="yearXarea.svg", plot=p, width=5, height=4)