Wow, this is a pretty big deal because NOx is notoriously difficult and expensive to detect at the levels where it starts to affect humans (double-digit ppb).
There are no cheap and reliable health-threshhold sensors for NOx like there are for particulates and VOCs. The really accurate detectors with enough sensitivity are consumables -- the NOx reacts with them and eventually you have to throw them away. The cheapest non-disposable low-ppb-rated sensors (~$500) require frequent professional recalibration.
This is the main reason why we don't have a "purpleair for NOx" and aren't likely to have one anytime soon. At best you might get one or two EPA-run sensors for a given city.
I don't know why you contrast "incentives and legislation" with "taxes"?
What kind of legislation are you thinking of, which would produce incentives to reduce the pollution, if not to make it so that one profits more by polluting less?
Or are you thinking of some other way to make it so that one profits more by polluting less, which somehow doesn't qualify as a "tax"?
I suppose you could give all the companies that might be hit under this (the amount of money that they would be taxed if addressing it with a tax, if they didn't change their behavior from their current behavior) - (the amount of money they would be taxed if addressing it with a tax, given their actual behavior),
and then say that "you aren't taxing them, you are just paying them more to stop polluting", and, ok, sure, in a sense, but that also just seems like...
why?
That's just the "tax" them solution, but adding on some arbitrary gift. Why give them that gift?
I am by no means an expert, but as far as I understand NO2 pollution is mainly generated by internal compustion engines (especially diesel?), so I don't understand why there would be a causal link to A/C use. I can imagine various reasons for there to be a correlation without direct causation, in particular because the atmospheric chemistry of NOx [1], though to be honest I don't really see the correlation you mention just from the visualizations.
The data are (or will be) available in the sources mentioned here [2], if anyone wants to analyze them (I think, I haven't actually tried to access them). I don't know where you would get geospatial data on A/C use to compare with though.
It looks like power plants are also a significant source of nitrogen oxides in the atmosphere, though I don't know what the major/top sources are. From the US EPA [1]:
NO2 primarily gets in the air from the burning of fuel. NO2 forms from emissions from cars, trucks and buses, power plants, and off-road equipment.
As I say, I'm no expert, bu my understanding is that NOx compounds can be formed whenever nitrogen and oxygen are mixed at sufficiently high temperatures, e.g. when burning stuff in air.
Maybe it is because that isn't an entirely true take. You don't need the AC as much in Chicago? Having lived near that region for a long time that isn't what I find to be the case. Yes it gets hotter in Texas but there are several reasons that AC gets ran nonstop for many people here. Inefficient building design is probably a big one. Also the heat is no joke even this far north. Add in heat waves and you have all the justification you need for running it if you can. I for one have had my AC running since May and I'm still too hot at home.
If you're ever in the position to provide a comparison of two images in a Web page like this, please consider providing a button to toggle back and forth between the two. (The toggling can also show the label for which is currently being shown.)
Neither mechanism this Web page provides is as useful as that, IMHO.
Agreed. You want to be able to do a blink comparison. The animation is just a distraction.
That said, a bigger problem is that, without having read your comment here, I doubt I would have noticed there was an option to see changes in the image, and I certainly wouldn't have poked at it hard enough to discover their were multiple affordances available.
Double clicking in the slider moves it to that double clicked point. Double clicking on the same spot to undo or return to the before position seems like intuitive missing functionality.
You only have to click/tap once, right? At least on mobile. Or was this changed?
Honestly that "undo" thing sounds like the least intuitive feature in the world to me. Would just seem like glitchy behavior to me.
Regarding OP:
> If you're ever in the position to provide a comparison of two images in a Web page like this, please consider providing a button to toggle back and forth between the two. (The toggling can also show the label for which is currently being shown.)
> Neither mechanism this Web page provides is as useful as that, IMHO.
But the "show only left/right" buttons below the slider do exactly that, no? The 0.5s animation would not be needed ok.
And the labels are not clear. A single toggle button with changing label would be great, I agree
> TBH I've always like the little 'wiper' widget that I can control and swipe back and forth at my own volition.
The part that's missing here is the drag function right.
Also, the sliding thing can be selected like text.
Good example for something where using polished components is better than one/off code, IMO.
Agree with OP about the button thing, that's really the clearest and simplest thing and should be added to such a component for better discoverability and to make the slider thing optional
Literally zooming out to see India and China wouldn't work, as TEMPO is on the Intelsat 40e geostationary satellite and the field of view doesn't include India or China. [1]
That said, TEMPO is part of the same polution monitoring project as GEMS [2], which was launched a few years ago and covers China.
And of course, TEMPO/GEMS/Sentinel-4 is not the only satellite-based pollution monitoring project. If you actually want to look at global pollution data from satellite-based instruments, NASA's EOSDIS Worldview site is a pretty interesting place to start, e.g. this may be of interest: [3]
It would be interesting to compare the India sub-continent to Asia (China, Vietnam, Laos, Cambodia, Hong Kong, etc...) along with Europe and South and Central America. I think folks would be enlightened as to where the issues are.
"Because TEMPO uses visible sunlight to make measurements, it cannot see pollution below clouds. Cloudy areas appear as missing data in the visualization." No wonder SF is missing. Could have been sea fog that day, huh?
There are no cheap and reliable health-threshhold sensors for NOx like there are for particulates and VOCs. The really accurate detectors with enough sensitivity are consumables -- the NOx reacts with them and eventually you have to throw them away. The cheapest non-disposable low-ppb-rated sensors (~$500) require frequent professional recalibration.
This is the main reason why we don't have a "purpleair for NOx" and aren't likely to have one anytime soon. At best you might get one or two EPA-run sensors for a given city.