[HN Gopher] Air quality reporting on iOS
___________________________________________________________________
Air quality reporting on iOS
Author : owl110
Score : 181 points
Date : 2023-06-25 11:20 UTC (11 hours ago)
(HTM) web link (intergalactic.systems)
(TXT) w3m dump (intergalactic.systems)
| hombre_fatal wrote:
| Interesting. This seems like the reasonable way to do it.
|
| What global scale would you pick otherwise? And would it be
| sensitive enough to show gradients in the least/most polluted
| countries and cities or would it just fill them in with one
| color?
| treffer wrote:
| And the image shows that the scale is named differently.
|
| So very likely tied to the most common national air quality
| scale.
|
| So it's explicit in what it shows.
| owl110 wrote:
| I think the problem is that the colors have different meaning.
| The values in the screenshot for Amsterdam using the NL scale
| translates to 'insufficient' and while the DE scale translates
| to 'good' for the same city at the same time.
|
| At the very least, it means that a user cannot use these scales
| for inference without knowing/understanding the technology
| behind them. This is probably not the intention behind showing
| an air quality indicator in the iOS app.
| servercobra wrote:
| The colors having different meanings shouldn't come up in
| typical cases, because who's looking at their air quality map
| from two different countries? There's also a key to the upper
| left.
|
| It's interesting and well designed IMO. I don't think this
| actually causes issues for any users.
| stapled_socks wrote:
| > The colors having different meanings shouldn't come up in
| typical cases, because who's looking at their air quality
| map from two different countries?
|
| Anyone who travels between countries?
| kortilla wrote:
| > because who's looking at their air quality map from two
| different countries
|
| People that travel. Are you serious?
| capitainenemo wrote:
| The difficulty seems to be that depending on what country
| you are in, the colours you are used to will have different
| meanings.
|
| Hopefully the german definition of good air quality isn't
| too overly optimistic, or someone with actual health issues
| might get a surprise if they are used to being ok on days
| with a certain "colour" when traveling.
| hombre_fatal wrote:
| Well, they said the AQ for NL was "insufficient" but the
| same value was "good" according to Germany. So it's not
| just different colors, it's different standards for AQ.
|
| I guess you're proposing that the AQ meter always use the
| scale of your home country. Doesn't seem unreasonable but
| also seems like a quibble so tiny that it could be
| defeated if someone more knowledgeable offered a single
| reason against it.
| capitainenemo wrote:
| Hm. That seemed unnecessarily contentious. We were
| largely in agreement. Yes, the german one is using more
| lax standards, as I was saying, hopefully not too lax,
| but yes, the colours indicate entirely different
| standards.
|
| And yes, I think a simple solution would be to use the
| colour of your home country that you are used to.
| Presumably if you moved, you could just learn the
| standards of your new country. A consistent standard that
| you can rely on in your phone when on a trip to another
| country definitely seems more useful if you are actually
| relying on this iOS app. It could be a simple app pref, a
| little toggle switch..
| [deleted]
| seszett wrote:
| > who's looking at their air quality map from two different
| countries?
|
| I do it a few times per week while I commute from Belgium
| to France and when I'm doing my groceries in whichever
| country is best for what I need. I'm interested in the air
| quality in France when I'm leaving Belgium, and in the
| quality in Belgium when I'm leaving France.
|
| I don't look at them from iOS though so I don't really have
| any problem. But crossing borders is a rather common thing
| around here.
| klausa wrote:
| The colors are usually defined by the same bodies that define
| the scales.
|
| The German LQI has associated colors, I know for sure the
| American does too, and I'll bet the Dutch in the screenshots
| also comes directly from the definition of the scale.
|
| And iOS defaulting to _local_ standards is a good thing! It
| means people get the same information they would from
| watching TV or reading newspaper, which is much more useful
| for most people than comparing their air quality to that of a
| neighboring country.
| amelius wrote:
| Aren't these countries both in the EU? I'd expect an EU-wide
| scale.
| mikerg87 wrote:
| You are correct they should both be using the Common Air
| Quality Index (CAQI). There is a new standard the EAQI and
| perhaps Germany has already switched to that standard.
|
| https://en.wikipedia.org/wiki/Air_quality_index
| yosito wrote:
| I use US AQI, and hadn't really realized that many countries
| have their own measurement. I also usually look at ug/m3 of
| PM2.5, which is a universal standard, but of course doesn't
| tell the whole story of air quality.
| 404mm wrote:
| Somewhat related, Apple's Air Quality data source (breezometer)
| is now owned by Google.
|
| I wonder what Apple is going to do about it. Will it be just one
| of their data sources or are they going to acquire their own?
| booi wrote:
| Is this really an issue? I bet Apple users use gmail too.
| speedgoose wrote:
| They also use Google Search by default.
| 404mm wrote:
| I don't know. That's not for me to judge :). I am just
| pointing it out because they seemed to have an issue with a
| similar concept in the past (Maps... moving to their own
| product).
|
| Unlike Google as their default search engine, accessing
| weather or air quality API costs money. (While they probably
| get paid for keeping Google as their default search engine)
| zitterbewegung wrote:
| Since its Google, Apple will probably be forced to do something
| once Google kills it off.
| lotsofpulp wrote:
| I am curious how reliable that air quality data is in the first
| place. I cannot find anything about Breezometer having invested
| in installing air quality meters all around the world.
|
| https://www.calcalistech.com/ctechnews/article/sycbrdpbi
|
| This article says they are using "machine learning" and "AI".
| Makes me think it is all fake.
|
| https://www.breezometer.com/pdfs/Ultimate-Guide-to-BreezoMet...
|
| Their own documentation indicates the air quality measures they
| provide are just guesses based on their models. Page 4
| basically says actually measuring particulates in the air is
| very costly, and so their solution is to come up with models to
| predict what it might be.
| pnpnp wrote:
| Yes - it's much like now weather forecasting works.
|
| Data points may come from 2 places 100 mi apart, but what if
| someone lives between them?
|
| Temperature or other weather data is often an extrapolation
| based on official weather data collection points, and AQI
| data is no different.
|
| _How_ that data gets extrapolated varies wildly by
| implementation.
|
| _edit:_ Also a fun fact, I live 2000ft above and 50mi from
| the nearest forecasting center in a valley. "Weather apps"
| are about as accurate as throwing darts at a board up here,
| because the models used to extrapolate known data completely
| fall apart with all the variables.
|
| Our best source of data is the "short term weather
| discussion" by NOAA, which just gives some generalizations
| based on local weather knowledge.
| crazygringo wrote:
| Not just forecasting, but reporting values _right now_.
|
| Spatial interpolation is much more non-obvious than you
| might initially assume, when the data points are coming
| from arbitrary locations and not a regular grid. For anyone
| curious, here [1] is a good place to start, or look up
| "Kriging interpolation".
|
| The basic implementation of any kind of continuous
| temperature estimation is to have a generic equation that
| relates how temperature naturally varies by altitude, use
| that normalize the temperature reported by weather stations
| according to altitude to create a "flat" temperature map,
| interpolate to create a smooth continuous temperature map
| using something like Kriging, and then de-normalize the
| temperature at a desired point according to the altitude of
| that location.
|
| There are always going to be hyper-local variations that
| won't account for (are you on the sunny side or shaded side
| of a mountain? is there an air current? how is
| vegetation/buildings/asphalt affecting it?), but it's the
| basic starting point.
|
| [1] https://geobgu.xyz/r-2020/spatial-interpolation-of-
| point-dat...
| counters wrote:
| Eh, kriging is overkill relative to the skill you end up
| with since fine-grain spatial variability in weather can
| arise from a lot more than the static factors you can
| pull into such a scheme. This is why objective analysis
| techniques are typically preferred.
|
| More importantly, high-resolution priors are universally
| available from weather models, so there is no need to
| just to ever naively interpolate between weather
| observation stations very far apart.
|
| One of the reasons that consumer weather apps perform
| poorly is because in many cases, the companies producing
| them arbitrarily choose some sort of spatial or temporal
| resolution requirements, and then throw the problem to an
| engineer or data scientist who probably doesn't know much
| more than these simple interpolation techniques (and I
| absolutely lump kriging into the 'simple' category these
| days). A modicum of domain knowledge applied here
| produces a much better product with substantially less
| effort.
| crazygringo wrote:
| I'm curious if you could expand -- I researched this a
| while ago but what I'm describing is as deep as I got
| from various online tutorials.
|
| What kind of objective analysis techniques? And where
| does someone get high-resolution priors from? Are you
| saying that companies have gone out and done a one-time
| mapping of temperature etc. at a e.g. 1-mile grid across
| the US? (Which would be over 3 million points at that
| scale, compared to the ~10,000 US weather stations?)
| counters wrote:
| Probably the two most common and simplest are Barnes and
| Cressman interpolation (see [1] for a modern
| implementation of Barnes), which use inverse distance
| weighting to combine observations within a neighborhood.
| An improvement to these techniques frequently used to
| grid statistical weather forecasts is the BCDG method
| (see [2]).
|
| The core idea of any objective analysis/interpolation
| scheme is that you model spatial relationships with some
| sort of function. Kriging exemplifies this - you fit a
| spatial covariance model and use that to predict values
| in the far field, using combinations of nearby values. I
| don't really have a good link or textbook reference at
| arms reach, but you can quickly re-frame this entire
| interpolation problem as a data assimilation one where
| you're attempting to approximate a solution to some 2D or
| 3D field using sparsely sampled observations; in the
| weather world, the Real-time Mesoscale Analysis used in
| the USA is a good example of a system which hybridizes a
| weather model and observations to create a high-
| resolution analysis [3].
|
| A problem arises when the field you're analyzing can have
| shocks or variability much smaller than the scale that
| you're able to measure from your network. A front is a
| great example - across a front, temperature and wind
| direction will change over a very small distance, but
| most interpolation schemes will smear this out. The
| problem is that you really do care about that front and
| its location - that's where the interesting weather
| happens!
|
| > And where does someone get high-resolution priors from?
|
| A high-resolution weather forecast model, which uses
| physics to simulate the atmosphere and produce reference
| states. 3-km forecasts are readily and easily available
| in the US.
|
| > Are you saying that companies have gone out and done a
| one-time mapping of temperature etc. at a e.g. 1-mile
| grid across the US?
|
| No, this probably wouldn't be useful. Especially because
| we get a ~1-km mapping of lower troposphere temperatures
| from geostationary weather satellites every 10-15 minutes
| across the entire globe. May not be exactly "surface
| temperature", but it tells you a whole lot about high-
| frequency variability in temperature fields.
|
| [1]: https://gmd.copernicus.org/preprints/gmd-2022-116/gm
| d-2022-1... [2]: https://journals.ametsoc.org/view/journa
| ls/wefo/24/2/2008waf... [3]: https://journals.ametsoc.org
| /view/journals/wefo/26/5/waf-d-1...
| crazygringo wrote:
| Thank you so much, that's all so fascinating! And makes
| perfect sense that priors come from high resolution
| physics solutions.
|
| Much appreciated for all that info.
| aziaziazi wrote:
| Two differences between weather and AQI forecast:
|
| - AQI strongly varies with local human activities, e.g. a
| coal power plant in between the 2 places 100 miles appart.
|
| - temporal and hardly predictable human activities, e.g. a
| chem industry without good attenuation system that boost
| its production to fill a special command. Or an attenuation
| system that breaks.
| dylan604 wrote:
| "I noticed something strange in the iOS weather app"
|
| I've noticed that the weather app on my iOS, iPadOS, and watchOS
| all show differing forecasts with all 3 devices within 18" of
| each other. AQI is just one of the parts of the forecast that I
| just don't pay attention too. Around here in the summer, it is
| always an alert saying don't go outside
| SkyPuncher wrote:
| I'm giving up on Apple Weather (despite recently saying it was
| fine).
|
| I got burned this past weekend when painting my deck. Forecast
| was absolutely clear in the window I needed to paint/dry. Just
| after I started, forecast changed to nearly 100% rain this
| wasn't a case of "oh maybe the chance of rain was wrong". No,
| it went from 0 to having a hundred of mile wide storm pass
| through. The type of storm that doesn't just pop up.
|
| It's insane how they killed dark sky.
| sp332 wrote:
| The past week has been super weird. My local weather station
| kept predicting rain every day and it barely rained at all.
| This week, once again, they say thunderstorms every day.
| We'll see how it goes.
| jeffgreco wrote:
| By killing Dark Sky and their own weather app and pushing me
| to an annual CARROT Weather subscription, they made
| themselves a profit of 30% of the CARROT Weather subscription
| -_-
| can16358p wrote:
| I've never ever seen air quality in iOS. Probably not available
| where I live. You guys at least, well, have it.
| pridkett wrote:
| You might have to dig for it - I didn't know this feature was
| available before this post. You need to click on the map button
| then toggle the air quality layer.
|
| Seems to cover most of the US, Canada, Mexico. Western Europe
| is largely present but is missing a handful of countries
| (Belgium, Luxembourg, Ireland, Switzerland, Austria,
| Liechtenstein, Portugal, and Iceland). Also covers most of
| Japan and South Korea and small localized portions of India and
| China.
| smileybarry wrote:
| Apple don't have it enabled for all regions, even if
| Breezometer have data there. (E.g.: looks like they have
| [fairly good] data here [in Israel], but AQI is disabled in
| Apple Maps)
| almokhtar wrote:
| you mean palestine ?
| [deleted]
| Havoc wrote:
| I mean tech is full of conflicting standards. (see relevant
| xkcd...)
|
| In this particular case the actual values just happen to land on
| the edge of two colours in the scales with very different
| connotations - orange vs green.
| [deleted]
| [deleted]
| sandworm101 wrote:
| >> I noticed something strange in the iOS weather app: The air
| quality index seems to be defined relative to the country from
| which one accesses the air quality map.
|
| Yup. And if you look closely the underlying map also sometimes
| changes based on which country one is standing in
| (Crimea/Taiwan). Services like iOS are not scientific but
| consumer and government-focused services. They exist to appease a
| host of interested parties, not to render dispassionate
| information.
| brookst wrote:
| Many products have multiple stakeholders. I can't think of a
| single product that exists "to render dispassionate
| information" and nothing else.
| crazygringo wrote:
| Really not sure what your point is? The temperature and
| humidity values that iOS Weather reports are objective and
| "dispassionate", no? Likewise wind speed and so forth?
|
| AQI is unique in this case, in that it is a color-coded
| _interpretation_ of combining multiple underlying objective
| values (PM2.5, etc.). And different governments have chosen
| different official national schemes for this, according to
| what they want the population to consider "normal"/green.
|
| Which means that air-polluting industry in one country might
| lobby for a wider "green" band. Nothing like that is
| happening around temperature or humidity as far as I'm aware
| on iOS.
|
| (Though I do believe Beijing had a history of under-reporting
| official maximum daytime summer temperatures, since people
| couldn't work outdoors above a certain threshold.)
| rodgerd wrote:
| > The temperature and humidity values that iOS Weather
| reports are objective and "dispassionate", no?
|
| You sound like someone who has never lived anywhere that
| people bitch and moan about the temperature on the weather
| reports being wrong because people think it's warmer than
| weather stations report, and get into arguments that the
| weather stations aren't placed correctly.
| benatkin wrote:
| > air-polluting industry
|
| Like producing food? A wider green band than what, the
| Netherlands map?
|
| I think it's nice to be able to aspire to live in a green
| area. That one leaves little options, and paints a bleak
| picture.
| thebruce87m wrote:
| The way things are going I'm sure there will be some
| questioning the temperature and humidity values and how we
| really know if they are true or not.
| crazygringo wrote:
| As long as we can buy thermometers and hygrometers to
| verify with our own eyes, I don't think too many people
| will be questioning them.
|
| And as long as ice continues to freeze at 32degF and
| water continues to boil at 212degF, I don't think anybody
| will be questioning the accuracy of the thermometers they
| buy.
| mistercheph wrote:
| No, they are neither objective nor dispassionate, despite
| being grounded in empirical data and methods.
|
| Factors like building shade, vehicle density, wind cover,
| terrain, cloud coverage, and variations in humidity, mean
| that thermometers placed at different points in any
| selected area will report massive variations in
| temperature, and the naive (and impossible) approach of
| even distributions of identical sensors taking measurements
| at the same clock times placed across some given weather
| area will yield numbers that are not helpful for most
| people.
|
| For example, about 1/3 of the area of Burbank, CA is
| recreation and park spaces that are in the verdugo
| mountains, at their highest point within Burbank limits
| 1800 ft. above sea level, and with almost zero residents.
| The other 2/3 of Burbank are about 600 ft. above sea level.
| How would you offer a number that summarized the weather in
| Burbank?
|
| Imagine factoring time into this. There is no temperature
| of the hour, there are individual measurements taken at
| specific moments in time in specific places, using
| differing methodologies, different equipment, variations in
| MoE, and at varying frequencies. Put all this together, and
| the work of the observational meteorologist to produce
| daily or hourly temperature averages becomes extremely
| complicated, and the first question they would ask is,
| "What will the averages be used for?"
|
| Here are some examples from the _large_ literature on these
| problems:
|
| https://www.tandfonline.com/doi/full/10.1080/07055900.2015.
| 1...
|
| https://www.sciencedirect.com/science/article/abs/pii/S0022
| 1...
|
| https://link.springer.com/chapter/10.1007/978-1-935704-35-5
| _...
| crazygringo wrote:
| You make a good point that the phone isn't (usually)
| reporting a direct measurement, but is rather
| interpolating weather station temperatures for a single
| coordinate. (And cities generally have a single lat/lon
| "center" for weather reporting, although your iPhone will
| attempt to report the weather for _your_ location rather
| than the nearest city 's center.)
|
| But nevertheless, a correct, objective, dispassionate
| temperature reading for that coordinate does exist in
| reality. And the phone's weather service is trying to
| approximate that as closely as possible. And you can
| objectively measure the error to improve future models.
|
| My point is still that this is qualitatively different
| from composite air quality indexes, which are politically
| designed, and therefore designed differently for
| different countries.
| wahnfrieden wrote:
| To recognize stakeholders says nothing of their power
| dynamics. You're obfuscating by generalizing
| verelo wrote:
| I guess you don't own a TV /s
| mfer wrote:
| Who defines what is "good" air quality in a dispassionate way?
| Or any of the other levels.
|
| If they just showed numbers without colors, how would the UX
| work for the general public who isn't all that knowledgeable?
|
| Building a useful [1] experience while dealing with groups who
| read things differently isn't easy and it's not going to lead
| to global consistency because people are diverse and
| inconsistent
|
| [1]
| https://www.nngroup.com/articles/usability-101-introduction-...
| mattnewton wrote:
| I think the poster is referring to governments that want to
| control this information too. There are often allegations
| that China is censoring AQI information for political
| purposes on iOS https://9to5mac.com/2018/01/30/weather-app-
| air-quality/
|
| I believe one of the controversial aspects of Google's
| "project dragonfly", (the now scrapped reintroducing-google-
| search-for-China initiative) were modules that check with
| Chinese government servers for displaying knowledge cards
| deemed sensitive, and air quality reports were one of those.
| https://amp.theguardian.com/technology/2018/nov/27/google-
| em...
| moritzwarhier wrote:
| Maybe the WHO?
|
| If the air makes people sick is a pretty objectively
| quantifiable question.
|
| The differences go beyond unit conversion and a main issue is
| how much we are used to tolerate people dying early or having
| seriously reduced quality of their lives because of
| pollution.
|
| Especially in urban and industrial areas.
|
| What adds to the complexity is that air quality can vary
| significantly within a city. Compare having a flat between
| two busy roads and a nice house in the suburbs.
|
| And compare that flat between two busy roads to a room next
| to a factory in the global south, or the US, or in Europe.
|
| It's a question of how many suicides, cancers, strokes etc we
| want to tolerate.
|
| There are studies quantifying the effects of these "local
| differences". And they are easy to find.
|
| To me, pretending this was a question of culture or genetics
| is malicious obfuscation of the actual issues - not accusing
| you personally, but this is the essence of the combination of
| many of the comments here.
|
| Air quality is measurable using several objective categories
| of pollutants.
|
| Standardizing the units is one issue, facing the reality of
| millions of casualties per year is another one.
| teekert wrote:
| I live in the Netherlands, I've tried to get this air quality
| report out of the iOS app, so have others. It just tells me every
| day the air is shit. I mean when you tap on it, it tells you not
| to exercise outside for example. It's rarely "good", mostly it is
| "insufficient", sometimes it's "very bad".
|
| Is it really so bad? You don't hear anything about it from other
| sources... Tapping on, one finds the main pollutant to be ozone,
| "usually caused by traffic and it can be transported over large
| distances."
|
| Idk what to think of this. Many people seem confused. Are we
| really in such poor air all the time?
|
| Sometimes I bike through the fields in the morning, sniff the
| fresh humid air that has a coldness in it, I smell grass and
| flowers... Apple tells me: Insufficient (don't bike to fast!) :(.
|
| Maybe they are right, maybe they are forcing us to come to terms
| with the things we do to our air.
| esafak wrote:
| Sounds like a bug. I don't recall the Netherlands having bad
| air; it's pretty green. I wonder how this can be reported?
| zerealshadowban wrote:
| I've been using the PurpleAir website (map.purpleair.com) for
| many years now, mostly out of concern for heavy wildfire
| pollution and winter inversions vs personal outdoor+athletic
| activities; one interesting aspect is that you can buy your own
| sensor and thus join the community of local sensors for increased
| accuracy of measurements. They let you pick between various
| international standards and types of pollutants. They seem to
| have a dense network of sensors in North America, not sure about
| the rest of the world.
| davidkuennen wrote:
| I'm also curious why there's no data for countries like Belgium,
| Switzerland and Austria.
| counters wrote:
| The problem here is twofold.
|
| First, many countries have their own laws and policies regarding
| air quality exposure. Often times these regulations use metrics
| about time-average exposure (e.g. the annual average 8-hr maximum
| ozone concentration) and can't trivially be converted between
| agencies. It causes very negative user experiences when your air
| quality summary disagrees with what a regulatory agency is
| putting out to the public due to a measurement technicality -
| much easier just to localize the data in the same way you'd
| localize the rest of the UI.
|
| Second, we're stuck with AQI and similar indices because air
| quality is a multi-faceted problem with different components
| measured wildly differently. For instance, PM2.5 and PM10 are
| typically reported in ug/m^3 - but who actually knows what these
| measurements mean? What's the difference between 15 and 30
| ug/m^3? It's very far outside of the experiences that many
| individuals have, so end users really struggle to interpret these
| values, even when you translate them into simple
| "low"/"medium"/"high" categories. Then of course gas-phase
| pollutants are typically reported in volume concentrations like
| parts-per-billion or parts-per-million. Aside from the fact that
| these values are very commonly misinterpreted as much smaller
| than they actually are, the difference in units adds another bit
| of complexity into users interpreting what they're seeing.
|
| A well-designed air quality index could factor our all these
| challenges. I definitely h/t Breezometer for their attempts
| there, even if it is generally poorly received. But it's a very
| challenging problem no matter how you slice it.
| owl110 wrote:
| These are very good points but at least Apple could give the
| user a choice to report air quality consistently when
| traveling. At the core, this is not a measurement problem (the
| underlying data is likely the same) but it is a user experience
| issue since a user cannot use the color coding as a way to
| compare different scales across locations.
| counters wrote:
| Well, the underlying data might not actually be the same.
|
| One country may lump in PM10 into their AQI, so if there is a
| dust storm or similar event, the AQI could spike. Other
| countries may only include PM2.5 or not include PM at all,
| which wouldn't capture the dust storm.
| 908B64B197 wrote:
| > many countries have their own laws and policies regarding air
| quality exposure. Often times these regulations use metrics
| about time-average exposure (e.g. the annual average 8-hr
| maximum ozone concentration) and can't trivially be converted
| between agencies. It causes very negative user experiences when
| your air quality summary disagrees with what a regulatory
| agency is putting out to the public due to a measurement
| technicality
|
| Ultimately, why not simply compute it and give the user a
| warning that the local measurement isn't compatible with proper
| AQI measurement?
|
| Also, does my body magically changes the way it reacts to air
| pollution as soon as I take my first step abroad?
| counters wrote:
| > Ultimately, why not simply compute it and give the user a
| warning that the local measurement isn't compatible with
| proper AQI measurement?
|
| You totally could, but in practice it doesn't always or
| obviously lead to a positive user experience our outcome.
| andix wrote:
| I didn't know that there is actually any data for this view. With
| an Austrian iPhone the air quality map is always empty "no data".
| Also for Germany and the Netherlands.
| Nocturium wrote:
| [flagged]
| bilekas wrote:
| In Italy I have noticed that the air quality is usually
| considered bad only in places that actually have data. For a lot
| of the places that are considered good, checking the sources for
| them usually result in only 1 device.
|
| It's a nice to have certainly but I wish it was more consistent.
| studmuffin650 wrote:
| As someone who just visited Italy for the first time in 10
| years, I was surprised how polluted the air was (especially
| around the coast). While the air quality was marked as "OK", it
| was quite hazy and you could actually see the smog in the air.
| Just something that really took me by surprise as when I think
| of polluted areas, the Amalfi coast is not an area that comes
| to mind
| DangerousPie wrote:
| I have never understood how to interpret AQI in iOS. Confusingly,
| the UI will (edit: or at least used to?) say "Air Quality: Low"
| when what it means is that the pollution level is low (ie. air
| quality is high). Somewhat disappointing coming from Apple.
| hombre_fatal wrote:
| Did the green color on the green to yellow to orange to red
| scale bar never tip you off?
| evanriley wrote:
| Hmm, what country does this happen in? I've never seen it use
| Low/High, only from Good to Hazardous.
| DangerousPie wrote:
| In the UK for example.
| cjrp wrote:
| Right now mine says "Air pollution: low. Air quality index
| is 3". Apparently using the DAQI for classification
| DangerousPie wrote:
| Huh, looks like you're right. Maybe they fixed it at some
| point?
| jsjohnst wrote:
| Same for me in US English. For example, right now it's "18 -
| Good". It was "469 - Hazardous" just three weeks ago though.
| Arn_Thor wrote:
| That's why I like Air Matters. You can choose your scale
| nullindividual wrote:
| I should be able to translate what my local government/news says
| about air quality, just like any other portion of the weather
| forecast (C, F, etc).
|
| Information based on user locality seems like an excellent
| design.
| 908B64B197 wrote:
| > what my local government/news says about air quality
|
| That's assuming the local government is giving the truth
| regarding air quality and that their "official scale" is made
| to reflect reality and not obscure some measurements.
| nullindividual wrote:
| Let's not go there. Unsubstantiated conspiracy theories do
| not add to this discussion.
| 908B64B197 wrote:
| > Unsubstantiated
|
| [0] https://www.sciencedaily.com/releases/2021/04/210421151
| 224.h...
|
| [1] https://www.globaltimes.cn/page/202106/1225792.shtml
| calsy wrote:
| Unlike basic weather metrics like temperature, humidity
| etc. Air quality measurements are directly impacted by
| human activity and are extremely contentious.
|
| In my hometown, there is a fight between locals and waste
| operators over excessive burn offs. The validity of air
| quality readings from the area are being tested in court.
|
| In the past, the Vietnamese government removed IQAir from
| the App Store and Google Play as citizens became
| increasingly concerned about the air quality in the capital
| cities.
|
| You wont learn much if you label everything you don't
| understand a 'conspiracy theory'. Air quality is not just
| another weather measurement.
| bluecalm wrote:
| A Government massaging the data to make the situation look
| better than it is doesn't qualify as a conspiracy theory.
| Rather as expected outcome if anything.
|
| The point is that the raw data is always the most valuable.
| Translating it is an easy task that can be done if the user
| wishes so.
| rkapsoro wrote:
| Yeah, I've noticed this too.
|
| It looks like the air quality models that iOS Weather is using
| are integrated into a single system, and then that system is
| asked to render maps in any of the different regions' AQI
| systems.
|
| Which means, as OP has observed, if you open the map from one
| region, and then navigate the map viewer to another region, you
| can see how the AQI scoring system from the first region would
| evaluate the second. Which is rather interesting.
|
| Also fwiw I've reckoned that these AQI models are clearly highly
| algorithmic, extrapolating and synthesizing data where sensors
| are not available.
| mensetmanusman wrote:
| 'This air quality level is known to cause cancer in California'
| dylan604 wrote:
| California air quality used to cause acid rain, so cancer was
| the least of the problems. So at least they've gotten to the
| point where you can now worry about the cancer
| 404mm wrote:
| Wildfires will do that :(
| apwheele wrote:
| Of interest to folks looking at this post -- Chris Said has a
| deeper dive on US air quality metrics and their provenance,
| https://chris-said.io/2023/06/19/the-air-quality-index-doesn....
|
| The attempt to make things easy to interpret using a nice
| relative scale ends up in the end make them very opaque to
| interpret the number itself in any meaningful way.
| mrob wrote:
| The "inexplicable" addition of 0.4 to the round multiples of 50
| looks like it's there to stop people claiming that limits apply
| after rounding to the nearest fifty.
|
| If the threshold is 50, people might claim 74 is acceptable
| because it rounds to 50. If the threshold is 50.4 this is
| obviously false.
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