New M6 data now available – Local climate projections using advanced downscaling techniques

November 7, 2024 – Today ClimateData.ca released a new dataset called M6, which is short for “Canadian Downscaled Climate Scenarios-Multivariate dataset for CMIP6 (CanDCS-M6).” M6 offers several improvements and enhanced capabilities over the previous generation of downscaled data, referred to as CanDSC-U6 or just U6.

M6 was made possible through collaboration amongst the Canada’s leading climate organizations. The new M6 data covers all of Canada’s land area and is the new default dataset on all ClimateData.ca pages, including the interactive map, the Analyze page, and the Download page.

What makes M6 better?

  1. More accurate precipitation data for Canada’s west coast – A limitation of the previous U6 dataset was that it underrepresented total precipitation along the west coast. M6 addresses this by using a new target dataset that more accurately represents historical rainfall patterns in this region.
  2. Multivariate analyses – ca provides a range of temperature- and precipitation-based indices, such as the number of freezing days or days with precipitation per year. However, prior to M6, combining variables for more complex analyses was not advised. For example, a user may have wanted to estimate whether precipitation falls as rain or snow by combining precipitation information with air temperature. The U6 data were not as amenable to this type of analysis because precipitation and temperature were downscaled separately, thus, potentially misrepresenting the physical relationship between these variables at short timescales.  At its core, M6 was designed to enable these types of “multivariate” analyses. Users who download daily data today from the Download page will now be able to calculate things like “number of hot and wet days” or “number of cold and dry” days, just to name a few additional examples.
  3. New climate indices – Building off the previous point, M6 will allow the partners behind ClimateData.ca to calculate and host several new climate change indices. These include snowfall projections, which are being finalized, and upcoming new return period calculations. To stay up to date with the new tools and products that M6 makes possible, subscribe to our newsletter or follow us on social media so that you can be amongst the first to know when these new products are launched.

Before using M6 data, it is important to note that this new dataset is based on the same set of Global Climate Models (GCMs) used in the previous generation of downscaled climate model data shared via ClimateData.ca. Both M6 and U6 are driven by CMIP6-era GCMs. Aside from addressing some known issues related to precipitation along Canada’s west coast, these new data do not change the story for how climate change will impact communities in Canada. Instead, these new data unlock new capabilities and functionalities and set the stage for future innovation.

Our team has also published a new Learning Zone resource to go alongside the M6 launch. If you would like to learn more about the data and what makes it different from U6, please take a moment to read through this article: Understanding the Canadian Downscaled Climate Scenarios-Multivariate dataset for CMIP6 (CanDCS-M6).

What’s coming next?

If you’ve read our previous article on M6, then you will know that several other important updates will follow soon. In particular, the ClimateData.ca team is putting the final touches on adding a new scenario to the site: SSP3-7.0. Here, SSP stands for Shared Socioeconomic Pathway. You can learn all about SSPs by reading this Learning Zone article. The SSP3-7.0 scenario sits between SSP5-8.5 – the scenario that results in the most climate warming by the end of the century on ClimateData.ca – and SSP2-4.5, sometimes referred to as the ‘middle of the road’ scenario.