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    PM2.5 Noticeable Discrepancy with Live Data?

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    • Colter CederlofC Offline
      Colter Cederlof
      last edited by

      Hi Windy Folks,
      I'm looking to better understand the PM2.5 model and whether it's accurate.
      Today is a typical day in Southern California and has been for a while. No wildfires nor other anomalies to drastically skew the predictions.
      I overlaid the current PM2.5 prediction with the PM2.5 live data using the PM2.5 layer and the "Air Quality" toggle as shown below.

      test1.jpg

      Here is the data overlaid and both layers are synced to the current time:

      photo_2023-06-14_15-01-55.jpg

      I compared the values of the live readings with the faded colors and scale of the prediction. Based on the color scale at the very bottom of the image, the prediction appears to suggest the max PM2.5 is about 15-20 microg/m3. The live data, however, suggests a good portion of the map should be light to dark orange instead.

      Will someone help me understand this discrepancy?
      Thank you!

      idefix37I 1 Reply Last reply Reply Quote 0
      • idefix37I Offline
        idefix37 Sailor Moderator @Colter Cederlof
        last edited by idefix37

        @Colter-Cederlof
        Hi,

        Here is what you read about the data used for the PM2.5 layer based on satellite measurements.

        9696FF82-9725-45C6-8D73-D53BC09DBA2B.jpeg

        In the area you mention there is not a huge discrepancy.

        00F1515E-D220-4664-A299-861693C69A99.jpeg

        But locally in some valleys the Air quality stations show higher PM2.5 concentration for the reasons explained above.

        Note the Quality Index and the color shown at Air quality stations are not only in relation with PM2.5 but with the pollutant showing the worse concentration.

        Colter CederlofC 1 Reply Last reply Reply Quote 1
        • Colter CederlofC Offline
          Colter Cederlof @idefix37
          last edited by

          @idefix37 Thank you for your response. Durr, I missed that the number shown for the AQI was not the same as the particulate matter value.

          1 Reply Last reply Reply Quote 0
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