Open ivanhanigan opened 12 months ago
Which part is odd? The location of yellow/orange dots or the smoke/PM2.5 readings? (Y axis)
There is also a potential explanation from early Dec 2019 onwards:
@truth-quark the dates in February have high PM2.5 but were not flagged as > smoke_2SD (two standard deviations)
I note these days in ACT have 0 pm25_pred but that is impossible.
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THis is the whole 20 years. I created the green line manually from the data. It shows that some times smoke_2SD is under the true threshold
Here's an ncview
image of smoke 2SD for 2003-01-01:
This looks wrong, given the large angular data block in SE NSW & the ACT. My assumption is the smoke data should look uneven. The shape looks like swaths from a passing satellite. Do we have the source data used to create the smoke_2SD
layer?
Here's an
ncview
image of smoke 2SD for 2003-01-01:This looks wrong, given the large angular data block in SE NSW & the ACT. My assumption is the smoke data should look uneven. The shape looks like swaths from a passing satellite. Do we have the source data used to create the
smoke_2SD
layer?
Most probably the blockiness is from the MERRA-2 satellite resolution (roughly 55-70km). The MERRA-2 satellite variables make up a decent portion of predictors so that distinctive square grid is a visible artefact even in the predicted PM2.5.
But smoke_2sd is binary 1 or zero so it has to have a hard boundary. It is not representing smoke PM
Ok, I assumed the resolution would be much better than 55-70km.
THis is the whole 20 years. I created the green line manually from the data. It shows that some times smoke_2SD is under the true threshold [image removed]
For debugging, is it possible to rejig the R graphing code? Thoughts:
Late 2009 also has a data gap (there's a slight hole showing in the 20 year plot).
this is supposed to be
but when extracting data for SA1s in Canberra to test I found odd result