Wednesday, April 14, 2010

Big City Trends

Joseph asked about an analysis for trends in cities over 2M population. I'm not sure that the GHCN database captures this well. I looked up my own big city (Melbourne) and of the 5 stations listed, three were on the city fringe, and may well by climatically similar to any city fringe area.

However, the analysis is easy to do. The instruction I inserted was:
if(tc == "BigCity") i01 = i01[tv$ipop>2000 &tv$urban == "C"];

I also did MedCity, with pop >500,000. Joseph's analysis is here


Trend se0.0073210.007264
Trend se0.051950.05094


1 comment:

  1. The trend of the last 30 years doesn't look too different, that's for sure. Here's the graph I produced of 12-year running averages, comparing cities greater than 2 million, and towns with population less than 15,000.

    To see the most pronounced effect possible, I'd suggest cities bigger than 10 million - in the raw data, of course.

    There should be 35 such stations.