Climate Model Comparison

Plot monthly maps from different climate model datasets as well as differences between datasets.

Collection: Monthly Reanalysis Datasets

Select Data To Plot
Dataset 1
Dataset 2 (Optional)

This form allows you to plot a single field from a model/experiment or compare one field to itself or another. The instructions below explain each of the sections of the form.


  1. From the Collection, select the Model, Experiment, Ensemble Member and Variable you wish to plot
  2. Optionally, select a second data set you wish to compare with the first.
  3. Click the Select Data button to bring up the options for analyzing and plotting the data you've selected. If you make any changes in the Field(s) section, click the Update Data Selection button to refresh the options below.

Area Statistics

  1. If you are plotting pressure level data, select the Level you wish to use
  2. You can plot either the Average or the Anomaly over the region. Anomalies are computed relative to 1981-2010 average for the ensemble mean. <
  3. For times, depending on the configuration you can either select:
    • Choose a starting and ending month over which to average the data.
    • Choose a starting and ending year over which to average the data. Alternatively, type in a list of years that are separated by commas (e.g. 1983, 1986, 1997)
    • If you are doing a comparison, select the years for the second dataset.


    • Select from a list of pre-defined times.
  4. Select the Region that the data will be averaged over. You can select from a predefined list of regions, or select Custom. If you choose custom, you can draw a region on the map (use Shift+drag to draw the region), or enter the North, South, West and East coordinates of the region.

Plot Options

  1. If you are doing a comparison between datasets, you can either plot the result as a difference between the two fields, or as 2 separate plots.
  2. You can select to plot the data as an image (Map) or load it into Google Earth.
  3. For some fields, you can select the output units for the plot.
  4. You can select a mask for the data to block out either ocean or land areas.
  5. You can plot the output as color-filled contours and optionally overlay contour lines and labels.
  6. You can override the default contour intervals for the plots by specifying a contour interval, minimum and maximum values.

Make Plot

  1. After you have made your selections, click the Make Plot button to generate the image or load the data into Google Earth.
  2. If you selected Map for the plot type, an image will be displayed to the right of the data selection region. You can click on the image to get a full sized version of it. There is link below the image which allows you to download the image to your computer.
  3. If you selected Google Earth for the plot type, then the result will be loaded into the Google Earth Plugin. You may have to download the plugin for this to work. If you do not have the plugin, or you want to load the image into Google Earth outside the browser, then you can use the Download Google Earth (KMZ) file link to download the file to your computer.
  4. There are links for downloading the files that were used to create the images and to download all files (images, kmz, etc)