Resolved: Issue with MERRA2 data from June 2021 to September 2021!

Last month, NASA notified about an issue with the MERRA2 data from a 4-month period ranging from June 2021 to September 2021: The issue was caused by an error in the MERRA2 pre-processing of ocean buoys observations of near-surface temperatures and resulting in significant near-surface temperature biases in various regions. At the time of the notification, it was unclear how much the wind-speeds were influenced. As a result, MERRA2 data from the affected period was removed from the online-data services of windPRO and EMD-API: read more at our knowledgebase - here – or our newsletter – here.

This issue has now been resolved and updated data from June to October have been made available. November 2021 data will be available later this week (probably on December 24^th).

We can confirm that the wind fields are also influenced by the issue (see the map below). Thus, if you have downloaded and used MERRA2 data for months June-September 2021 and the data was downloaded before November 30^th, then we recommend replacing the erroneous data and re-do any calculations and analyses.

Image: Showing the difference (in percent) in average wind-speed for erroneous MERRA2 vs corrected MERRA2 data from July 2021.

Best regards,
The windPRO online data team
support@emd.dk