ETC5521 Worksheet Week 10

Exploring data having a space and time context Part II

Exercise 1: Gridded spatiotemporal data

Conduct a spatiotemporal analysis of ozone measurements over central America, following the analysis of temperature provided in the class lecture notes.

a. Make a single map

Load the nasa data from the GGally package, and make a map of ozone for January 2015, overlaid on a map of the geographic area. What do you learn about the spatial distribution of ozone?

b. Display the map over time

Generate the maps of ozone for all of the time period, by facetting on month and year. Why was the plot organised so that months were in columns and years in rows, do you think? What do you learn about the temporal changes in the spatial distribution of ozone?

c. Glyphmap

Make two glyphmaps of ozone, one with time series at each spatial grid point, scaled globally, and the other using polar coordinates at each spatial grid point, scaled individually. What do you learn about the temporal trend, and seasonal patterns of ozone over this geographic region?