Numerical version of DMI Arctic temperature dataSeptember 8, 2009
I am providing the DMI arctic temperature data in numerical format as a public service. This data is available in graphical format at the DMI Centre for Ocean and Ice, but I could not figure out a simple way to get the numerical data that was used to make the graphs. So I have extracted it from the graphs myself.
Here it is, for the entire set of DMI images from 1958 to the present. You must go through a slightly convoluted procedure to use it. First, open this word document. Then, select all the text and copy it. Finally, paste it into a spreadsheet.
The left column gives the day of the year. Notice that the days are given in half day increments. The top row shows the year, and each column represents the temperature data for the coresponding year.
You can now plot, average, and compare trends to your heart’s content.
Explanation of Data Handling
This data was acquired by copying all of the yearly graphs from DMI and writing image handling code in LabView to extract the temperature data. The 365 days of data in each graph is distributed through 518 columns of pixels, so about 1.4 columns of pixels per day. I decided to interpolate the data to half days. Since leap years and non-leap years both consisted of 518 columns, I have treated all years as 365.25 days.
All of the data suffers from the uncertainties of my extraction process. So if anybody sees problems with the data please feel free to post your observations as comments here.
I will be showing some results of my analysis in subsequent posts.
Here is the image from DMI for the year 2008, followed by a plot of my version of the data for 2008.