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Smoke, Smog, Dust 2015 Chiang Mai


Tywais

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Just went out to feed my dog and it's just awful awful awful this morning. (I've been enjoying the nice cool mornings with a cup of tea outside, but no more). I feel sick and depressed at the thought of going out now! Mind you none of my doors or windows are particularly well fitting so I guess it's an illusion to think I'm any better off inside.

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My dog won't even go outside today! She seems to know that City Hall just passed 240 micrograms per cubic meter of PM10 particles, or TWICE the dangerous limit. It is rather bad today.

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I am reading a lot of different opinions on the smoke season. Ranging from people who barely noticed to people saying anyone who comes up north around March would be absolutely crazy. So it would be great if anyone else has some information, as we are planning to visit Chiang Mai (doing the Mae Hong Song loop) from the day after tomorrow...

Thanks in advance!

Should be ok. Not really kicked off yet.

visibility this morning March 1st.

Doi Suthep is in the opposite direction, and cannot be seen anyway.

post-111567-0-42735100-1425200472_thumb.

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I, mostly out of curiosity, check the pm2.5 reading of my DC1700 particle counter in the evening. Then I decide whether to switch on the air purifier or not, and at what level; medium or max level. Then, being curious, I check things again in the morning, after the air purifier has run all night. Been doing this since the middle of January.

For reference, the Dylos Corp. has this printed on the DC1700, referring to the number (not the mass) of pm2.5 particles reported.

3000 and above = Very Poor

1050-3000 = Poor

300-1050 = Fair

150-300 = Good

75-150 = Very Good

0-75 = Excellent

There is no good mapping to the standard, mass-based, pm2.5 metric as far as I know, but the above are Dylos Corp's guidelines (not sure what they are based on).

You can read more about Dylos corp's products here: http://www.dylosproducts.com/

Anyway, up until 3-4 weeks ago, the pm2.5 reading had been around 2,000-3,000 most of the time. Sometimes down to around 1,000 also. That's the level it is at much of the year I think, though I have not really attempted to verify that. So I have not bothered running the air purifiers at that time. Then the pm2.5 count started to raise, and most of this month I think it has been around 4-7,000 in the evening, before I switch on the air purifier.

So I've been running the air purifier at medium power most of the nights this month, increasing to the max when the reading was above 6-7,000. There's been some days where it has been close to 10,000. Medium power on my air purifier (Blueair 650E) brings the pm2.5 reading down from 6-7,000 to around 2-3,000. Not great, according to Dylos Corp's guidelines, but in honesty, I am not sure how applicable they are. If I remember, I will try to bring the DC1700 with me next time I leave for work, which it currently looks like will be to one of the supposedly cleanest countries (pollution-wise) in the world, to see what the DC1700 reports there. If the pm2.5 reading is much higher than 6-7,000 the evening before, I need to run the air purifier at max power to bring the pm2.5 reading in the room down to 2-3,000. If run at max power, most of the time, the pm2.5 reading will then be around 1,000 in the morning. But max power generates a lot of noise.

Last night I came home late (Friday night, you know). Mrs. Awk had switched on the air purifier at medium power, and I out of curiosity checked the pm2.5 reading before going to bed. I saw that it was around 6-7000, and since the air purifier was running at medium power, I switched it up to max power, waking up Mrs. Awk in the process.

When I woke up this morning, after running the purifier at max power all night I however saw that the pm2.5 reading was still around 5,000. I thought this was quite strange. I walked around checking if Mrs. Awk had for some reason opened a window or or two, but no. Then I thought maybe I had placed the air purifier at a somewhat stupid location, close to the wall (to reduce the chance of baby-Awk running into it). So I moved it to the middle of the room, and checked the pm2.5 reading again after an hour. Nope, still around 5,000. Then I took my dc1700 outside the room. Outside the room, the pm2.5 reading was almost 20,000, perhaps even above that for some periods.

Indeed, it does appear that it, whatever it is, it has arrived.

Thanks for posting this info, and it confirms my fears that CM air quality is poor year round (PM 2.5 1000 is your estimate).

Every time I leave, I notice the cleaner air, no matter where I go.

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Just a gentle reminder what is to expect for the coming weeks and month for the once who are still uncertain but able to leave. You won't see this kind of readings and news this year due to the "happy Thailand promotion" but be sure it is same same as every year. Oh I have a flight to catch for all others .. Good luck back in May.

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I am reading a lot of different opinions on the smoke season. Ranging from people who barely noticed to people saying anyone who comes up north around March would be absolutely crazy. So it would be great if anyone else has some information, as we are planning to visit Chiang Mai (doing the Mae Hong Song loop) from the day after tomorrow...

Thanks in advance!

Should be ok. Not really kicked off yet.

visibility this morning March 1st.

Doi Suthep is in the opposite direction, and cannot be seen anyway.

Read post 78 whistling.gif

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I, mostly out of curiosity, check the pm2.5 reading of my DC1700 particle counter in the evening. Then I decide whether to switch on the air purifier or not, and at what level; medium or max level. Then, being curious, I check things again in the morning, after the air purifier has run all night. Been doing this since the middle of January.

For reference, the Dylos Corp. has this printed on the DC1700, referring to the number (not the mass) of pm2.5 particles reported.

3000 and above = Very Poor

1050-3000 = Poor

300-1050 = Fair

150-300 = Good

75-150 = Very Good

0-75 = Excellent

There is no good mapping to the standard, mass-based, pm2.5 metric as far as I know, but the above are Dylos Corp's guidelines (not sure what they are based on).

You can read more about Dylos corp's products here: http://www.dylosproducts.com/

Anyway, up until 3-4 weeks ago, the pm2.5 reading had been around 2,000-3,000 most of the time. Sometimes down to around 1,000 also. That's the level it is at much of the year I think, though I have not really attempted to verify that. So I have not bothered running the air purifiers at that time. Then the pm2.5 count started to raise, and most of this month I think it has been around 4-7,000 in the evening, before I switch on the air purifier.

So I've been running the air purifier at medium power most of the nights this month, increasing to the max when the reading was above 6-7,000. There's been some days where it has been close to 10,000. Medium power on my air purifier (Blueair 650E) brings the pm2.5 reading down from 6-7,000 to around 2-3,000. Not great, according to Dylos Corp's guidelines, but in honesty, I am not sure how applicable they are. If I remember, I will try to bring the DC1700 with me next time I leave for work, which it currently looks like will be to one of the supposedly cleanest countries (pollution-wise) in the world, to see what the DC1700 reports there. If the pm2.5 reading is much higher than 6-7,000 the evening before, I need to run the air purifier at max power to bring the pm2.5 reading in the room down to 2-3,000. If run at max power, most of the time, the pm2.5 reading will then be around 1,000 in the morning. But max power generates a lot of noise.

Last night I came home late (Friday night, you know). Mrs. Awk had switched on the air purifier at medium power, and I out of curiosity checked the pm2.5 reading before going to bed. I saw that it was around 6-7000, and since the air purifier was running at medium power, I switched it up to max power, waking up Mrs. Awk in the process.

When I woke up this morning, after running the purifier at max power all night I however saw that the pm2.5 reading was still around 5,000. I thought this was quite strange. I walked around checking if Mrs. Awk had for some reason opened a window or or two, but no. Then I thought maybe I had placed the air purifier at a somewhat stupid location, close to the wall (to reduce the chance of baby-Awk running into it). So I moved it to the middle of the room, and checked the pm2.5 reading again after an hour. Nope, still around 5,000. Then I took my dc1700 outside the room. Outside the room, the pm2.5 reading was almost 20,000, perhaps even above that for some periods.

Indeed, it does appear that it, whatever it is, it has arrived.

Thanks for posting this info, and it confirms my fears that CM air quality is poor year round (PM 2.5 1000 is your estimate).

Every time I leave, I notice the cleaner air, no matter where I go.

I don't believe anything is confirmed! I think it is inadvisable to take one persons home grown attempt at air quality measurement as conclusive fact in this matter. certainly it may serve as an input but it is far far away from confirmed fact. Whilst it is appropriate to be concerned about air quality, it is easy to become compulsive/obsessive about the subject which is somewhat at odds with a continued presence here, especially for those with young families. Simply, if a person is so convinced of the extreme levels of pollution here, they must move, especially those with young children.

For my part I have watched and participated in debates on this subject, as have many other posters, for the past ten years. Is it really that bad, is it not, is the pollution imported from neighboring countries or is it home grown, by farmers or by drivers, what is the role of the inversion layer and so on. My take on it all is that the NASA firemaps are the second best indicator of whether or not there is a problem, the first being my nose and eyes. Certainly during March and April there is a pollution problem caused primarily by burning, but to suggest it is a year round problem is a step too far in my book.

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I noticed the ug/m3 readings have a daily cycle, except today unusually high most of the day.

AQI is much smoother because it averages over 24 hours, so this detail is missed.

Here's a graph of the past few days, so it seems the best time to get stuff done outside is around 12pm-7pm. The readings come in an hour or two delayed so this info isn't available real time.

I'm assuming unscientifically that inside the house is safer, just seems much fresher air inside.

The bottom axis is time.

post-13135-0-68410800-1425211133_thumb.p

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for all the poor visibility, which i noticed today also... i am missing the smell of smoke.

Not missing as in "i want it", but i just don't smell smoke... i went to a couple of neighbors homes tonight

and while we all agreed that visibility was crap, no one had smelled any smoke at all...

a previous poster mentioned that on the NASA maps, it showed few fires and that is what my nose tells me too.

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for all the poor visibility, which i noticed today also... i am missing the smell of smoke.

Not missing as in "i want it", but i just don't smell smoke... i went to a couple of neighbors homes tonight

and while we all agreed that visibility was crap, no one had smelled any smoke at all...

a previous poster mentioned that on the NASA maps, it showed few fires and that is what my nose tells me too.

Just a few seconds outside the house left my eyes stinging. Doesn't smell of smoke, but smells of something. Not the air I would want to spend any time outside in. As for exercising or working in the garden, forget it.

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I, mostly out of curiosity, check the pm2.5 reading of my DC1700 particle counter in the evening. Then I decide whether to switch on the air purifier or not, and at what level; medium or max level. Then, being curious, I check things again in the morning, after the air purifier has run all night. Been doing this since the middle of January.

For reference, the Dylos Corp. has this printed on the DC1700, referring to the number (not the mass) of pm2.5 particles reported.

3000 and above = Very Poor

1050-3000 = Poor

300-1050 = Fair

150-300 = Good

75-150 = Very Good

0-75 = Excellent

There is no good mapping to the standard, mass-based, pm2.5 metric as far as I know, but the above are Dylos Corp's guidelines (not sure what they are based on).

You can read more about Dylos corp's products here: http://www.dylosproducts.com/

Anyway, up until 3-4 weeks ago, the pm2.5 reading had been around 2,000-3,000 most of the time. Sometimes down to around 1,000 also. That's the level it is at much of the year I think, though I have not really attempted to verify that. So I have not bothered running the air purifiers at that time. Then the pm2.5 count started to raise, and most of this month I think it has been around 4-7,000 in the evening, before I switch on the air purifier.

So I've been running the air purifier at medium power most of the nights this month, increasing to the max when the reading was above 6-7,000. There's been some days where it has been close to 10,000. Medium power on my air purifier (Blueair 650E) brings the pm2.5 reading down from 6-7,000 to around 2-3,000. Not great, according to Dylos Corp's guidelines, but in honesty, I am not sure how applicable they are. If I remember, I will try to bring the DC1700 with me next time I leave for work, which it currently looks like will be to one of the supposedly cleanest countries (pollution-wise) in the world, to see what the DC1700 reports there. If the pm2.5 reading is much higher than 6-7,000 the evening before, I need to run the air purifier at max power to bring the pm2.5 reading in the room down to 2-3,000. If run at max power, most of the time, the pm2.5 reading will then be around 1,000 in the morning. But max power generates a lot of noise.

Last night I came home late (Friday night, you know). Mrs. Awk had switched on the air purifier at medium power, and I out of curiosity checked the pm2.5 reading before going to bed. I saw that it was around 6-7000, and since the air purifier was running at medium power, I switched it up to max power, waking up Mrs. Awk in the process.

When I woke up this morning, after running the purifier at max power all night I however saw that the pm2.5 reading was still around 5,000. I thought this was quite strange. I walked around checking if Mrs. Awk had for some reason opened a window or or two, but no. Then I thought maybe I had placed the air purifier at a somewhat stupid location, close to the wall (to reduce the chance of baby-Awk running into it). So I moved it to the middle of the room, and checked the pm2.5 reading again after an hour. Nope, still around 5,000. Then I took my dc1700 outside the room. Outside the room, the pm2.5 reading was almost 20,000, perhaps even above that for some periods.

Indeed, it does appear that it, whatever it is, it has arrived.

Thanks for posting this info, and it confirms my fears that CM air quality is poor year round (PM 2.5 1000 is your estimate).

Every time I leave, I notice the cleaner air, no matter where I go.

Oh, no no no. Please read again what I said carefully. The pm2.5 number I mention of 1000 is not the microgram/m^3 that is used in most other places, but the number of particles the Dylos reported. It has no direct relation to the health standards for pm2.5 and represents something very different. 1000, if reported by the Dylos device, is "good air".

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I noticed the ug/m3 readings have a daily cycle, except today unusually high most of the day.

AQI is much smoother because it averages over 24 hours, so this detail is missed.

Here's a graph of the past few days, so it seems the best time to get stuff done outside is around 12pm-7pm. The readings come in an hour or two delayed so this info isn't available real time.

I'm assuming unscientifically that inside the house is safer, just seems much fresher air inside.

The bottom axis is time.

Using the Dylos DC1700 I did some amateur measurements last year, including evaluating the effect of being inside, versus being outside. I posted the PDF resulting from my amateur analysis here on thaivisa for anyone interested, but just to recap that part:

- There are about 30% fewer particles with the a size above pm2.5 inside, compared to outside. I.e., as far as pm10 is concerned, it is quite a bit better to be inside.

- There is no significant differences between inside and outside for particles smaller than pm2.5. Unfortunately, pm2.5 is, most now seem to think, the main hazard, and being inside does not help. What does help is running an AC, with or without 3M Filtrete, or better, an air purifier. Best: AC and air purifier.

Btw, the Dylos unit was amongst other places evaluated in a paper "Prepared for the California Air Resources Board and the California Environmental Protection Agency", by a

Professor Kirk R. Smith
School of Public Health
University of California Berkeley
His conclusion was that "the [Dylos] monitor meets the majority of the stated criteria and is useful as an ambient particle monitor.":
One can note that they modified the unit a little for their purpose, partly to better evaluate the accuracy I think, but as far as I can tell, the modifications are not relevant to this discussion.
Anyway, anyone with half a brain can easily google for the Dylos monitor himself and see that it is by most accounts a quality device that has been used many places by people who, unlike me, are in the business.
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I, mostly out of curiosity, check the pm2.5 reading of my DC1700 particle counter in the evening. Then I decide whether to switch on the air purifier or not, and at what level; medium or max level. Then, being curious, I check things again in the morning, after the air purifier has run all night. Been doing this since the middle of January.

For reference, the Dylos Corp. has this printed on the DC1700, referring to the number (not the mass) of pm2.5 particles reported.

3000 and above = Very Poor

1050-3000 = Poor

300-1050 = Fair

150-300 = Good

75-150 = Very Good

0-75 = Excellent

There is no good mapping to the standard, mass-based, pm2.5 metric as far as I know, but the above are Dylos Corp's guidelines (not sure what they are based on).

You can read more about Dylos corp's products here: http://www.dylosproducts.com/

Anyway, up until 3-4 weeks ago, the pm2.5 reading had been around 2,000-3,000 most of the time. Sometimes down to around 1,000 also. That's the level it is at much of the year I think, though I have not really attempted to verify that. So I have not bothered running the air purifiers at that time. Then the pm2.5 count started to raise, and most of this month I think it has been around 4-7,000 in the evening, before I switch on the air purifier.

So I've been running the air purifier at medium power most of the nights this month, increasing to the max when the reading was above 6-7,000. There's been some days where it has been close to 10,000. Medium power on my air purifier (Blueair 650E) brings the pm2.5 reading down from 6-7,000 to around 2-3,000. Not great, according to Dylos Corp's guidelines, but in honesty, I am not sure how applicable they are. If I remember, I will try to bring the DC1700 with me next time I leave for work, which it currently looks like will be to one of the supposedly cleanest countries (pollution-wise) in the world, to see what the DC1700 reports there. If the pm2.5 reading is much higher than 6-7,000 the evening before, I need to run the air purifier at max power to bring the pm2.5 reading in the room down to 2-3,000. If run at max power, most of the time, the pm2.5 reading will then be around 1,000 in the morning. But max power generates a lot of noise.

Last night I came home late (Friday night, you know). Mrs. Awk had switched on the air purifier at medium power, and I out of curiosity checked the pm2.5 reading before going to bed. I saw that it was around 6-7000, and since the air purifier was running at medium power, I switched it up to max power, waking up Mrs. Awk in the process.

When I woke up this morning, after running the purifier at max power all night I however saw that the pm2.5 reading was still around 5,000. I thought this was quite strange. I walked around checking if Mrs. Awk had for some reason opened a window or or two, but no. Then I thought maybe I had placed the air purifier at a somewhat stupid location, close to the wall (to reduce the chance of baby-Awk running into it). So I moved it to the middle of the room, and checked the pm2.5 reading again after an hour. Nope, still around 5,000. Then I took my dc1700 outside the room. Outside the room, the pm2.5 reading was almost 20,000, perhaps even above that for some periods.

Indeed, it does appear that it, whatever it is, it has arrived.

Thanks for posting this info, and it confirms my fears that CM air quality is poor year round (PM 2.5 1000 is your estimate).

Every time I leave, I notice the cleaner air, no matter where I go.

Oh, no no no. Please read again what I said carefully. The pm2.5 number I mention of 1000 is not the microgram/m^3 that is used in most other places, but the number of particles the Dylos reported. It has no direct relation to the health standards for pm2.5 and represents something very different. 1000, if reported by the Dylos device, is "good air".

But in the table you provide 1050-3000 is considered poor. And this refers to the number of particles report by Dylos, does it not?

I figured 1000 is close to 1050.

I did not think it referred to micrograms/m^3.

From your table, good air is 150-300, again the number of particles reported by Dylos. 1000 would be at the high end of the fair reading

What am I missing?

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I, mostly out of curiosity, check the pm2.5 reading of my DC1700 particle counter in the evening. Then I decide whether to switch on the air purifier or not, and at what level; medium or max level. Then, being curious, I check things again in the morning, after the air purifier has run all night. Been doing this since the middle of January.

For reference, the Dylos Corp. has this printed on the DC1700, referring to the number (not the mass) of pm2.5 particles reported.

3000 and above = Very Poor

1050-3000 = Poor

300-1050 = Fair

150-300 = Good

75-150 = Very Good

0-75 = Excellent

There is no good mapping to the standard, mass-based, pm2.5 metric as far as I know, but the above are Dylos Corp's guidelines (not sure what they are based on).

You can read more about Dylos corp's products here: http://www.dylosproducts.com/

Anyway, up until 3-4 weeks ago, the pm2.5 reading had been around 2,000-3,000 most of the time. Sometimes down to around 1,000 also. That's the level it is at much of the year I think, though I have not really attempted to verify that. So I have not bothered running the air purifiers at that time. Then the pm2.5 count started to raise, and most of this month I think it has been around 4-7,000 in the evening, before I switch on the air purifier.

So I've been running the air purifier at medium power most of the nights this month, increasing to the max when the reading was above 6-7,000. There's been some days where it has been close to 10,000. Medium power on my air purifier (Blueair 650E) brings the pm2.5 reading down from 6-7,000 to around 2-3,000. Not great, according to Dylos Corp's guidelines, but in honesty, I am not sure how applicable they are. If I remember, I will try to bring the DC1700 with me next time I leave for work, which it currently looks like will be to one of the supposedly cleanest countries (pollution-wise) in the world, to see what the DC1700 reports there. If the pm2.5 reading is much higher than 6-7,000 the evening before, I need to run the air purifier at max power to bring the pm2.5 reading in the room down to 2-3,000. If run at max power, most of the time, the pm2.5 reading will then be around 1,000 in the morning. But max power generates a lot of noise.

Last night I came home late (Friday night, you know). Mrs. Awk had switched on the air purifier at medium power, and I out of curiosity checked the pm2.5 reading before going to bed. I saw that it was around 6-7000, and since the air purifier was running at medium power, I switched it up to max power, waking up Mrs. Awk in the process.

When I woke up this morning, after running the purifier at max power all night I however saw that the pm2.5 reading was still around 5,000. I thought this was quite strange. I walked around checking if Mrs. Awk had for some reason opened a window or or two, but no. Then I thought maybe I had placed the air purifier at a somewhat stupid location, close to the wall (to reduce the chance of baby-Awk running into it). So I moved it to the middle of the room, and checked the pm2.5 reading again after an hour. Nope, still around 5,000. Then I took my dc1700 outside the room. Outside the room, the pm2.5 reading was almost 20,000, perhaps even above that for some periods.

Indeed, it does appear that it, whatever it is, it has arrived.

Thanks for posting this info, and it confirms my fears that CM air quality is poor year round (PM 2.5 1000 is your estimate).

Every time I leave, I notice the cleaner air, no matter where I go.

Oh, no no no. Please read again what I said carefully. The pm2.5 number I mention of 1000 is not the microgram/m^3 that is used in most other places, but the number of particles the Dylos reported. It has no direct relation to the health standards for pm2.5 and represents something very different. 1000, if reported by the Dylos device, is "good air".

But in the table you provide 1050-3000 is considered poor. And this refers to the number of particles report by Dylos, does it not?

I did not think it referred to micrograms/m^3.

From your table, good air is 150-300, again the number of particles reported by Dylos.

Sorry, I misunderstood you then. Yes, what you say is correct, and yes, that is according to Dylos Corp's guidelines.

However:

In honesty I am as said not sure how applicable those guidelines are. I suspect they are quite a bit to strict for normal home use. If one googles,. one sees that even in California people report a pm2.5 count inside above 1000. I've gotten very used to thinking that anything close to 1,000 inside is good, though I should not have said that above since I do not know, and realize now it was a bit stupid. So again, sorry. My mistake.

I would put more faith in the government monitoring stations and the (WHO-based?) pm2.5 and pm10 standards for this.

Most of the year, the pm10 reported for Chiang Mai is afaik pretty good (there was another fellow here, Priceless, that seemed to keep good track of that, though I have not seen anything from him for a while now).

It will be interesting to see if the pm2.5 values will be similarly good, now that they seem to be available from at least one monitoring station here in CM.

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I noticed the ug/m3 readings have a daily cycle, except today unusually high most of the day.

AQI is much smoother because it averages over 24 hours, so this detail is missed.

Here's a graph of the past few days, so it seems the best time to get stuff done outside is around 12pm-7pm. The readings come in an hour or two delayed so this info isn't available real time.

I'm assuming unscientifically that inside the house is safer, just seems much fresher air inside.

The bottom axis is time.

Thanks for that graph. I have also noticed that there seems to be semi-regular pattern, so it was to nice to see several days graphed together like that. I can only wonder what causes it, as looking at your graphs, it seems strangely regular.

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I noticed the ug/m3 readings have a daily cycle, except today unusually high most of the day.

AQI is much smoother because it averages over 24 hours, so this detail is missed.

Here's a graph of the past few days, so it seems the best time to get stuff done outside is around 12pm-7pm. The readings come in an hour or two delayed so this info isn't available real time.

I'm assuming unscientifically that inside the house is safer, just seems much fresher air inside.

The bottom axis is time.

Thanks for that graph. I have also noticed that there seems to be semi-regular pattern, so it was to nice to see several days graphed together like that. I can only wonder what causes it, as looking at your graphs, it seems strangely regular.

It's even clearer with this PM2.5 one below.

From http://aqicn.org/city/thailand/chiangmai/yupparaj-wittayalai-school/m/ this week as the temperature rises the pressure falls and the wind rises, perhaps taking some of the smoke high enough in the air streams to get carried away. The wind fits the 10am-2pm period where the levels are decreasing. Today was the least windy and the highest PM levels, but if burning increases there's unlikely to be enough wind to compensate for that. I also guess from this graph the local farmers are getting up at 6am for a session of burning, and so this makes me feel most of the problem is local rather than far away.

post-13135-0-92627100-1425234284_thumb.p

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JJ...Lived in the middle of the burning for several years and have watched them lighting the fires. Generally the fires are set in late afternoon or into the evening, but I have run into people setting fires on my early morning bike rides as well. (I've posted photos taken at night showing the fire lines in the mountains as the locals set them. You can see them well at night in the early season but later on, smoke obscures those views.) The fires smoulder all night and the cooling night air slowly brings the smoke into the valleys. That could match up with the trends you have plotted. After the sun comes up, I think there is enough thermal energy for the winds to kick up to start dispersing the particulates in the afternoon.

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I agree, burning is not typically an early morning sport, most often it takes place in the afternoon or evening hence the uptick in the graph (post 109) at 6 am is more likely to be caused by the effect of sunrise and thermals - it is inappropriate to conclude the source of burning (local or distant) from that graph.

My interpretation of probable events depicted in that graph are as follows:

Late afternoon/early evening, local burning takes place and this continues into late evening - pollution levels increase as a result but cooler night air at all altitudes allows the smoke to disperse.

At 6 am the sun rises and the air begins to heat up but the inversion layer traps the polluted cooler air which accumulates closer to the ground. This continues until around midday when the heat from the sun becomes so intense as to warm the cooler air and the inversion effect is negated and the polluted air disperses more naturally and so the cycle repeats. Evidence in part to support the above is the early morning fog in the mountains close to where I live.

"Given enough pressure, the normal vertical temperature gradient is inverted such that the air is colder near the surface of the Earth. This can occur when, for example, a warmer, less-dense air mass moves over a cooler, denser air mass. This type of inversion occurs in the vicinity of warm fronts, and also in areas of oceanic upwelling such as along the California coast in the United States. With sufficient humidity in the cooler layer, fog is typically present below the inversion cap. An inversion is also produced whenever radiation from the surface of the earth exceeds the amount of radiation received from the sun, which commonly occurs at night, or during the winter when the angle of the sun is very low in the sky. This effect is virtually confined to land regions as the ocean retains heat far longer. In the polar regions during winter, inversions are nearly always present over land.

A warmer air mass moving over a cooler one can "shut off" any convection which may be present in the cooler air mass. This is known as a capping inversion"

http://en.wikipedia.org/wiki/Inversion_%28meteorology%29

As for the source of pollution, imported or home grown, one would need to look at a combination of wind and fire maps to conclude more accurately. From memory, winds at this time of year are from the south west bringing with them the polluted residue from burning in Myanmar.

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It's officially started now - smoke smell in the air since March 1st and Air4Thai app read 170 for PM10 this morning. That's an averaged value so the peaks are way higher.

Up in Pai burning of mountain sides has been going on for 2-3 weeks now.

Planning my escape now, just have to wait for schools to close.

As for theories there is a shockingly simple conclusion: People are burning shit. Lots and lots of people are burning lots and lots of things. From the neighbors setting a small pile of moist leaves on fire - just for the heck of it, it seems - to the villagers burning up mountainsides, everyone in this country is doing their part. The NASA fire maps are very useful but they only capture massive fires. Anything on the NASA map is an unusually large fire and I guess those in Thailand must be in remote areas or the locals would take care of it.

BTW as bad as this is, I am not sure it can change. Let's say locals suddenly stopped burning the forests. That seems like a remote possibility right now. But even if they did, there would then be huge forest fires every couple of years instead. See California, Australia. The controlled burns the locals are doing never get out of control. I've actually seen locals dousing the flames, and I was amazed. I was at a friend's house in Pai, next to the forest. We noticed flames coming closer, and didn't know what to do. The entire forest front was on fire at some point with flames maybe 2 - 3 meters high. As we stood there wondering whether the flames would engulf the house, two little old ladies appeared. Each carried a small bucket. They dipped their hands into the bucket, and were sort of flinging a spray of water from their hands into the flames. The flames went down right away... not exactly the fire trucks and power hoses I had imagined... Pai didn't use to have a fire station until a few years ago. Not saying the burning is good but I think it's important to take a holistic view of it.

As for what you can do there's groups organizing every year. There is talk of a silent protest at Ta Pae gate of groups with air filter masks on. I think that could go a long way. It doesn't take much to make this kind of thing go viral.

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Out of interest, where are those planning an escape going to, and how long do you plan to be away?

I only ask, because year after year I've sort of planned to go south... perhaps to one of the islands, but have never quite made it. Just too many commiments to be able to leave for that amount of time. I realise the answer could be just about ANYWHERE other than here, LOL but I'm interested in what others do to 'escape' and when you envisage on coming back.

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Out of interest, where are those planning an escape going to, and how long do you plan to be away?

We've done Hua Hin (within driving distance, 10 hours later you're there), Samui (direct flights even if they're really expensive), Phuket (flights), Ko Chang.

Important criteria: Needs to be on the ocean. All inland places are just as polluted as up here.

We usually come back at or around Songkran, April 15th. The last 2 years that's when the first rains fell, and air improves quickly after that. Not immediately, but in a week or two.

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Code Red

Again today in Chaingmai a huge warning for pollution code Yellow which stand for unhealthy and it slowely goes to code red very unhealthy .

Its adviced to stay in the house and not to do any heavy activity .. my god its 2015 ...

Why is the government not in power to tackle this problem ....

how dificult is it to work together with the land office and the poojabaan .

the land office now excaly who is the owner of the land wich can be fined with lets say 10.000 bht per rai they burn , the poojabaan is the end responsible and have to eductated the people not to burn there riced field He can be cut with the money from bangkok if he fail .

In my opinion this whole problem can be solved on a saterday afternoon , so why take this so long and why so many people have to suffer with health problems , not to mention the tourist industrie

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Out of interest, where are those planning an escape going to, and how long do you plan to be away?

I only ask, because year after year I've sort of planned to go south... perhaps to one of the islands, but have never quite made it. Just too many commiments to be able to leave for that amount of time. I realise the answer could be just about ANYWHERE other than here, LOL but I'm interested in what others do to 'escape' and when you envisage on coming back.

Anywhere along the Andaman Sea coastal region, except Phuket other than when absolutely necessary, until Songkran is well over. Have had sun and clean air every day since arriving mid January.

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Gas Attack?

It's getting bad here, waking up through the night coughing and sneezing.

I'm told there's a guy wandering the streets of Chiang Mai with a full mask, as used in gas attacks.

must be a sight to see. any photos?

post-111567-0-20398800-1425274887_thumb.

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Since PM<2.5 reports are now made at Site 36T, out of curiosity, I compared them with PM<10 reports since 1 February. The smaller particules were roughly 75 - 80% of the larger ones. That is bad news.

If I recall previous research (posted on this topic last year) correctly, a relatively higher proportion of the PM<2.5 is present in rice straw smoke than in general pollution which is "commonly acknowledged" as 40-60%. The smaller particles, of course, are the really insidious ones damaging to health, as people have come to realize.

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