The data processing algorithms have been updated to correct a couple of relatively minor errors related to the data visualizations and post-processed data files.

• The raw dataset was errantly shown with the first charted point having a value of 0.
• If the dataset has any smoothing algorithms applied to it, both the post-processed data visualizations and the post-processed data file available for download likely had incorrect values for the first and last points in the dataset.
• Datasets which had been smoothed using the ONA method had incorrect values for the first window of smoothing and the method of calculating the smoothing windows have been updated which has shifted those windows and therefore most of the post-processed black carbon values.

We have opted not to automatically reprocess your data and give you the option to do so. Data files which have been processed with the old methods will show a notice at the top of the page.