A worker takes a break from extinguishing fire at a burning forest at the Pulo Geronggang village in Ogan Komering Ilir district in Indonesia South Sumatra province on Sept 11, 2015.PHOTO: REUTERShttp://www.straitstimes.com/singapore/environment/indonesia-has-accepted-singapores-offer-to-help-fight-forest-fires-in-sumatra

An aerial view of smoke rising from a burning forest at Ogan Komering Ulu area in Indonesia's south Sumatra province, September 10, 2015. - See more at: http://www.themalaysianinsider.com/world/article/indonesia-sending-thousands-of-troops-to-fight-ires#sthash.4nN0JGSH.dpuf

http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=81431On June 19, 2013, NASAs Terra and Aqua satellites captured striking images of smoke billowing from illegal wildfires on the Indonesian island of Sumatra. The smoke blew east toward southern Malaysia and Singapore, and news media reported that thick clouds of haze had descended on Singapore, pushing pollution to record levels.Singapores primary measure of pollution, the Pollutant Standards Index (PSI)similar to the Air Quality Index(AQI) used by the U.S. Environmental Protection Agencyrose to 371 on June 20, 2013, the highest level ever recorded. The previous record occurred in 1997, when the index hit 226. Health experts consider any level above 300 to be hazardous to human health. Levels above 200 are considered very unhealthy.Both images above were captured by the Moderate Resolution Imaging Spectroradiometer (MODIS), an instrument that observes the entire surface of Earths every 1 to 2 days. The top image shows smoke blowing east at 3:30 Universal Time (11:30 a.m. local time); the lower image shows the same area on the same afternoon at 6:30 UTC (2:30 p.m. local time).Though local laws prohibit it, farmers in Sumatra often burn forests during the dry season to prepare soil for new crops. The BBC reported that Singapores Prime Minister Lee Hsien Loong warned that the haze could easily last for several weeks and quite possibly longer until the dry season ends in Sumatra.ReferencesChannel News Asia (2013, June 20) Palm oil producers deny slash-and-burn practices in Indonesia. Accessed June 20, 2013.New York Times (2013, June 20) Pollution in Singapore Hits Record Level. Accessed June 20, 2013.Singapore National Environment Agency PSI and PM2.5 Readings. Accessed June 20, 2013.Voice of America (2013, June 20) Singapore Haze Soars to Hazardous Levels. Accessed June 20, 2013.Wall Street Journal (June 20, 2013) Singapore Air Pollution Hits Record. Accessed June 20, 2013.Reuters (June 20, 2013) Slideshow: Asia Haze. Accessed June 20, 2013.Further ReadingAtwood, S. (2013, May 3) et al (2013, April 15) Analysis of source regions for smoke events in Singapore for the 2009 El Nino burning season. In press.Earth Observatory (2007, March 30) Tropical Deforestation.

Hyer, E. et al (2012, June 7) Patterns of fire activity over Indonesia and Malaysia from polar and geostationary satellite observations. 122, 504-519.NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Caption by Adam Voiland.

http://www.haze.gov.sg/hotspot-satellite-images

http://cdn6.bq.sg/wp-content/uploads/2015/09/hz.jpg

http://ciresblogs.colorado.edu/mongolia/2012/05/22/ulaanbaatar-air-pollution-under-the-microscope/An example of particulate matter collected in Ulaanbaatar, Mongolia in March 2012. 10x magnification.In Maggie Tolberts lab in CIRES at CU, one of the ways in which we analyzed some Ulaanbaatar particulate matter samples was through Raman spectroscopy on a particle-by-particle basis. What does this mean and why is it so cool? Heres a short explanation:By using a regular microscope, we can look at particulate matter that is on the order of microns or tens of microns in size.A typical image might look like this:

Then we can zoom in even closer on one particle:

https://en.wikipedia.org/wiki/Aerosol#/media/File:Fly_Ash_FHWA_dot_gov.jpgFly ash particles 2,000x magnificationPhotomicrograph made with a Scanning Electron Microscope (SEM): Fly ash particles at 2,000x magnification. Most of the particles in this aerosol are nearly spherical.

http://www.nasa.gov/vision/earth/environment/New_IDEA_Air_Quality_Monitoring_prt.htmImage Left: This image shows a magnified view of aerosol particles collected in the industrial city of Port Talbot, England. Many of the particles measure roughly 2.5 microns across, small enough to easily enter and damage human lungs. (Micrograph courtesy MRC Institute for Environment and Health)

http://sites.keene.edu/biodiesel/files/2010/09/ksc-5b_014.jpgDiesel exhaust particle 71,000 magnificationn winter 2010, samples of diesel & B20 exhaust were photographed at a magnification of 71,000x via TEM. Analysis of particle size & morphology is ongoing. Studying particle morphology is important because many toxicologists believe that particle size, shape, number and surface area may be more valuable metrics of harmful exposure than particle mass. (Smaller particles with higher surface areas may be more harmful to respiratory and cardiovascular health than larger particles with greater mass.)