Regarding the color of the sky in Muaro Jambi, red and with the sun veiled by thick smoke, the Meteorology, Climatology and Geophysics Agency (BMKG) confirmed that the event can be explained scientifically.
According to BMKG, the Himawari-8 satellite image analysis on September 21, 2019 around Muaro Jambi, seems to have many critical points and a very thick smoke distribution.
The smoke from these forest and land fires is different from other areas that have also experienced fires, other areas on the satellite appear brown but in Muaro Jambi they show a white color that indicates that the smoke layer is very thick. This is possible because the fires of lands and forests that occur in the region, occur mainly in peat bogs.
Smoke thickness is also supported by high concentrations of <10 microns (PM10) of dust polluting particles. The measurement of the concentration of PM10 = 373.9 μg / m3 in Jambi shows unhealthy conditions.
While in Pekanbaru, the air quality was even worse, since the PM10 polluting dust concentration was in the dangerous category with 406.4 ug / m3.
Why is the sky flushed? According to the BMKG, if viewed from the theory of atmospheric physics at visible wavelengths, the red sky is caused by the dispersion of sunlight by particles floating in small air (aerosols), known as scattered noodles (noodles) scattered) Scattered noodles are produced if the diameter of the pollutants in the atmosphere is equal to the wavelength of the sun's visible rays.
The wavelength of the red light has a size of 0.7 micrometers. From the BMKG data, it is known that the concentration of polluting dust particles (<10 micrometers) is very high around Jambi, Palembang and Pekanbaru. But the sky that turned red happened in Muaro Jambi. This means that the polluting dust in the predominant area measures about 0.7 micrometers or more with very high concentrations.
In addition to the high concentrations, of course, the distribution of polluting particles is also wide, in order to redden the sky. Why do you say the particle size can be more than 0.7 micrometers? This is because the human eye can only see in visible spectra (0.4-0.7 micrometers).
In 2015, Palangkaraya was also reported to have experienced an orange sky several times due to karhutla, which means that the size of the polluting dust particles slightly smaller than the dust from the event of the reddened sky in Muaro Jambi.