Smoke, Smog, Dust 2014 Chiang Mai

[WinnieTheKhwai]

^ The numbers don't show the same thing. The second link is a China based site that shows numbers as per their AQI index. And then shown as a rolling average.

However the source data is the same, provided by the Thai Pollution Control Department.

I suggest to use the former, as it provides the best base of comparison, as well as the actual PM10 measurement in microgrammes per cubic meter.

The Chinese site may be good to compare roughly between various countries/regions. (If those countries make data available; some of the most interesting areas that I'd really like to know don't have data, such as Burma and places like Luang Prabang which I understand also suffers from bad haze right now. (As reported by people who flew in from there yesterday.)

[T_Dog]

I remember a few years back when everyone was aghast at PM-10 numbers in the 250 uG/m3 in Mae Hong Son. Figures lately are approaching 600! Can't imagine how bad it must be there now.

[sate ayam]

a month ago i could see doi suthep from the north gate

a week ago i couldn't see it anymore from the shell station at huai kaeo road

and today at noon nothing was to be seen while standing at the intersection of huaikaeo road/canal road

[WinnieTheKhwai]

I remember a few years back when everyone was aghast at PM-10 numbers in the 250 uG/m3 in Mae Hong Son. Figures lately are approaching 600! Can't imagine how bad it must be there now.

Again (342nd time and counting) : Be careful using a peak value and comparing it with the daily 24-hour average data, which is the common method of comparing anything anywhere.

But that's bad, yes.

[TheScribe]

Anyone know if Doi Inthanon is smog free at the moment?

I don't have time or funds for a trip to the beaches, but I could drive up there and stay a few days if its worth it.

[SundayAfternoon]

Thanks for the explanation Winnie.

T_DOG, what's the web address for the site you're using there?

Sent from my GT-I9500 using Thaivisa Connect Thailand mobile app

[chiang mai]

Mmmm, rain, in Watkate!

[T_Dog]

Thanks for the explanation Winnie.

T_DOG, what's the web address for the site you're using there?

Sent from my GT-I9500 using Thaivisa Connect Thailand mobile app

http://aqmthai.com/public_report.php

[harrry]

I remember a few years back when everyone was aghast at PM-10 numbers in the 250 uG/m3 in Mae Hong Son. Figures lately are approaching 600! Can't imagine how bad it must be there now.

Again (342nd time and counting) : Be careful using a peak value and comparing it with the daily 24-hour average data, which is the common method of comparing anything anywhere.

But that's bad, yes.

I agree that you cannot compare peak and average values. The average value is the one that reflects the long term damage done to your lungs. The peak value is the one which reflects the triggering of problems in people with asthma alergies and COPD

[puukao]

http://qz.com/136606/here-are-the-worlds-worst-cities-for-air-pollution-and-theyre-not-the-ones-youd-expect/

it's all relative i guess.

wind and rain = allergies better.

[valdor]

I remember a few years back when everyone was aghast at PM-10 numbers in the 250 uG/m3 in Mae Hong Son. Figures lately are approaching 600! Can't imagine how bad it must be there now.

Again (342nd time and counting) : Be careful using a peak value and comparing it with the daily 24-hour average data, which is the common method of comparing anything anywhere.

But that's bad, yes.

I agree that you cannot compare peak and average values. The average value is the one that reflects the long term damage done to your lungs. The peak value is the one which reflects the triggering of problems in people with asthma alergies and COPD

Both the peak and average values are way above the safety limit in Chiang Mai. Where I am from the air is considered unhealthy if the value (peak and average) goes over 25. I have never seen a daily average lower than 25 in Chiang Mai...

[scotinsiam]

Lot of <deleted> being talked here - surely actual news from people in the City about visability and air quality more relevant than some dubious data from whoever - just saying

[jonwilly]

Ah you believe in Joe Craig's system,

If you have to measure it then you haven't got a change.

Yesterday morning after the nights rain visibility from my condo was increased to a kilo from say 500 mtrs.

john

Will check today come daylight, after last nights rain.

[WinnieTheKhwai]

Lot of <deleted> being talked here - surely actual news from people in the City about visability and air quality more relevant than some dubious data from whoever - just saying

It would if actual people would reliably put in their visibility report in every hour for every day of the week and supply it in an digital format so we can analyze it over time, from several known locations and taking reference points at known distances.

Otherwise, well, it would not. (Other than to report on the here and now, assuming that people make sure to state their location, and are able to ignore very local factors such as living right next to a field that is being burned, or a neighbor burning leaves and crap.)

Either way, visual observations match the data very accurately. The provided data just makes for a much more convenient way to compare over time, season to season.

EDIT: Just Saying. I suppose.

[harrry]

Lot of <deleted> being talked here - surely actual news from people in the City about visability and air quality more relevant than some dubious data from whoever - just saying

It would if actual people would reliably put in their visibility report in every hour for every day of the week and supply it in an digital format so we can analyze it over time, from several known locations and taking reference points at known distances.

Otherwise, well, it would not. (Other than to report on the here and now, assuming that people make sure to state their location, and are able to ignore very local factors such as living right next to a field that is being burned, or a neighbor burning leaves and crap.)

Either way, visual observations match the data very accurately. The provided data just makes for a much more convenient way to compare over time, season to season.

EDIT: Just Saying. I suppose.

Not to mention the fact that many members have very poor vision anyway and especially after a night in the local see double.

Seriously unless they are trained observers who know how to estimate distance and visibility under varying conditions it is vary hard to comare results. All we know is that person considers it is bad...and I fully accept for him it is. Reports are valueable. They provide the description of what is happening and its effects. Figures can never do that. The figures reported by the test stations do so. Their accuracy may be argued,although I think in general they are pretty good, but they do give some valid method of comparing the situation.

Because of my lung condition I am very very sensitive to any form of polution so often I say there is when others can barely detect it. The figures give the reality.

[jonwilly]

Well I estimate I can see 3 Kilos this morning from my balcony.

I can make out buildings the other side of Cm uni and Doi Suthep was clear today from the swimming pool I use.

The owner uses Doi Suthep as his standard reference and today is very clear.

john

One who suffers with poor air quality.

More rain please.

[chiang mai]

Lot of <deleted> being talked here - surely actual news from people in the City about visability and air quality more relevant than some dubious data from whoever - just saying

Visibility and pollution levels are not quite the same thing. I live near downtown on the twelth floor with a good 360 degree view and this morning I can see about one kilometre and Doi Suthep is hidden. But following the rains last night there's very little pollution in the air I would guess, certainly there's no trace of the smell of burning.

[CNXBKKMAN]

10 km visibility at the airport at 11:31. 10 km is the limit the airport reports so it may be better than 10km.

[chiang mai]

10 km visibility at the airport at 11:31. 10 km is the limit the airport reports so it may be better than 10km.

At what altitude, that's clearly not at ground level.

[Tywais]

10 km visibility at the airport at 11:31. 10 km is the limit the airport reports so it may be better than 10km.

At what altitude, that's clearly not at ground level.

Airport readings are always at the same level as the runways. This is what is shown now. Temperature seems spot on with other weather reports, but those often use an airport as the reporting site. http://www.chiangmaiairportonline.com/node/10

• Few clouds
• Temperature: 27 °C
• Wind: South, 7.4 km/h
• Pressure: 1015 hPa
• Rel. Humidity: 51 %
• Visibility: 10 km

This is the information that the pilots will get for preflight briefing. http://aviationweather.gov/adds/tafs/?station_ids=vtcc&std_trans=translated&submit_both=Get+TAFs+and+METARs

VTCC (CHIANG MAI(CIV/A, TH) observed 0500 UTC 05 April 2014 Temperature: 28.0°C (82°F) Dewpoint: 15.0°C (59°F) [RH = 45%] Pressure (altimeter): 29.97 inches Hg (1015.0 mb) Winds: from the SSW (210 degrees) at 5 MPH (4 knots; 2.1 m/s) Visibility: 6 or more miles (10+ km) Ceiling: ceiling and visibility are OK Clouds: unknown Weather: no significant weather observed at this time

[chiang mai]

So presumably that's vertical visibility and if so, I wonder how they measure that, horizontal visibility at zero feet is always near to zero, curvature etc!

EDIT: and the answer is:

Visibility

To determine visibility, automated airport weather stations use one of two sensor types:

• forward scatter sensors
• transmissometers

The forward scatter sensor uses a beam of infrared light which is sent from one end of the sensor toward the receiver, but offset from a direct line to the receiver by a certain angle. The amount of light scattered by particles in the air and received by the receiver determines the extinction coefficient. This is then converted to visibility using either Allard's or Koschmieder's law.

In a transmissometer, a beam of visible light is transmitted from its transmitter to receiver head. The extinction coefficient is derived from the amount of light lost in the air.

There also are sensors that, to a certain degree combine a transmissometer with a forward scatter sensor.

Forward scatter sensors are more popular due to their lower price, smaller size and lower maintenance requirements. However, transmissometers are still used at some airports as they are more accurate at low visibilities and are fail-safe, i.e. in case of failure report visibility lower than actual.

Current sensors are capable of reporting visibility in a wide range. For aviation purposes, the reported values are rounded down to the nearest step in one of the following scales:

• M1/4 (less than 1/4 mile), 1/4, 1/2, 3/4, 1, 1-1/4, 1-1/2, 2, 2-1/2, 3, 4, 5, 7, 10 and 10+ (greater than 10 miles)
• In steps of 50 m when the visibility is less than 800 m; in steps of 100 m when it is 800 m or more, but less than 5 km; in kilometer steps when the visibility is 5 km or more but less than 10 km; and 10 km when visibility is 10 km or more.

http://en.wikipedia.org/wiki/Automated_airport_weather_station

[CNXBKKMAN]

The airports weather report is continually updated 24h a day so its quite handy for checking stuff. I have noticed when there is thunderstorm during the day say in the rainy season temp drops from 36 to 26 c. Seems to be a 10 c drop every time .

[connda]

With all the rain and wind last night I was hoping that this smog and haze would be cleaned out of the vaiieys. No such luck. Bummer. Well, it should get better around Songkhan when the local have better things to do than burn their country down.

[nikster]

With all the rain and wind last night I was hoping that this smog and haze would be cleaned out of the vaiieys. No such luck. Bummer. Well, it should get better around Songkhan when the local have better things to do than burn their country down.

Where are you located? It's certainly washed the sensors as the measured PM10 is around 50. Which would be fine.

[connda]

With all the rain and wind last night I was hoping that this smog and haze would be cleaned out of the vaiieys. No such luck. Bummer. Well, it should get better around Songkhan when the local have better things to do than burn their country down.

Where are you located? It's certainly washed the sensors as the measured PM10 is around 50. Which would be fine.

Screen Shot 2014-04-05 at 16.54.30 .png

I'm in downtown CM. Just looking out the window of my 4th floor apartment, looking at the visibility or lack thereof. I could barely make out Doi Suthep this morning, but it's nice to see that a lot of the larger particulate has been washed out according to the chart.. Maybe this is fog as opposed to smog? But my alleragies tells me we have a ways to go. Now where did I put my Actifed and eye drops?

[kimbathewhitelion]

With all the rain and wind last night I was hoping that this smog and haze would be cleaned out of the vaiieys. No such luck. Bummer. Well, it should get better around Songkhan when the local have better things to do than burn their country down.

Where are you located? It's certainly washed the sensors as the measured PM10 is around 50. Which would be fine.

Screen Shot 2014-04-05 at 16.54.30 .png

I'm jin downtown CM. Just looking out the window of my 4th floor apartment, looking at the visibility of lack thereof. I could barely make out Doi Suthep this morning, but it's nice to see that a lot of the larger particulate has been washed out according to the chart.. Maybe this is fog as opposed to smog? But my alleragies tells me we have a ways to go. Now where did I put my Actifed and eye drops?

Finally, thanks for confirming, Songkran in CM is OUT.

Sent from my iPad using Thaivisa Connect Thailand

[chiang mai]

Lack of visibility is not always down to pollution, in the case of today it's seriously doubtful that it is, fog, mist et al.

But don't get me wrong, it's OK that fewer people come here for Songkran, we're already way overcrowded so good choice.

[chiang mai]

With all the rain and wind last night I was hoping that this smog and haze would be cleaned out of the vaiieys. No such luck. Bummer. Well, it should get better around Songkhan when the local have better things to do than burn their country down.

Where are you located? It's certainly washed the sensors as the measured PM10 is around 50. Which would be fine.

Screen Shot 2014-04-05 at 16.54.30 .png

I'm in downtown CM. Just looking out the window of my 4th floor apartment, looking at the visibility or lack thereof. I could barely make out Doi Suthep this morning, but it's nice to see that a lot of the larger particulate has been washed out according to the chart.. Maybe this is fog as opposed to smog? But my alleragies tells me we have a ways to go. Now where did I put my Actifed and eye drops?

I have a very clear view of Suthep, for what that's worth.

[connda]

With all the rain and wind last night I was hoping that this smog and haze would be cleaned out of the vaiieys. No such luck. Bummer. Well, it should get better around Songkhan when the local have better things to do than burn their country down.

Where are you located? It's certainly washed the sensors as the measured PM10 is around 50. Which would be fine.

Screen Shot 2014-04-05 at 16.54.30 .png

I'm in downtown CM. Just looking out the window of my 4th floor apartment, looking at the visibility or lack thereof. I could barely make out Doi Suthep this morning, but it's nice to see that a lot of the larger particulate has been washed out according to the chart.. Maybe this is fog as opposed to smog? But my alleragies tells me we have a ways to go. Now where did I put my Actifed and eye drops?

I have a very clear view of Suthep, for what that's worth.

Yeah, it's not bad right now. Nice sunset over Doi Suthep. A bit misty, but much clearer than it has been.

[Choonpon]

High temperature, with thunderstorms and some hail expected in north and northeast.