Red skies over Indonesia's Jambi province due to haze: Meteorological agency

Red skies over Indonesia's Jambi province due to haze: Meteorological agency

Jambi red sky
Red sky blanketing Jambi, Indonesia. (Photo: Twitter/@xakakuyyy)

JAKARTA: Red skies seen over Indonesia's Jambi province at the weekend amid worsening haze was due to a phenomenon called Mie scattering, said the Meteorology, Climatology and Geophysics Agency (BMKG). 

The agency explained on Sunday (Sep 22) that the coloured sky was caused by scattering of sunlight by micro particles called aerosols that float in the air.

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Beberapa hari terakhir, beredar viral di masyarakat langit di Muaro Jambi berwarna merah, sinar matahari tertutup asap tebal. . . BMKG mencatat hal tersebut peristiwa yang dapat dijelaskan secara ilmiah. . . Hasil analisis citra satelit Himawari-8 tanggal 21 September di sekitar Muaro Jambi, tampak terdapat *banyak titik panas* dan sebaran *asap yang sangat tebal*. . . Asap dari kebakaran hutan dan lahan ini berbeda dari daerah lain yang juga mengalami kebakaran, wilayah lain pada satelit tampak berwarna cokelat namun di Muaro Jambi menunjukkan warna putih yang mengindikasikan bahwa lapisan asap yang sangat TEBAL. Hal ini dimungkinkan karena kebakaran lahan / hutan yang terjadi di wilayah tersebut, terutama pada lahan-lahan gambut. . . Tebalnya asap juga didukung oleh tingginya konsentrasi debu partikulat polutan berukuran <10 mikron (PM10). Hari ini, tengah malam di Jambi, pengukuran konsentrasi PM10 = 373,9 ug/m3, menunjukkan kondisi TIDAK SEHAT. . . Di Pekanbaru lebih parah lagi, yaitu konsentrasi debu polutan PM10 kategori BERBAHAYA 406,4 ug/m3 . . Informasi Konsentrasi Partikulat (PM10) BMKG tiap jamnya dapat dipantau pada laman . . *Mengapa Langit Memerah?* Jika ditinjau dari teori fisika atmosfer pada panjang gelombang sinar tampak, langit berwarna merah ini disebabkan oleh adanya hamburan sinar matahari oleh partikel mengapung di udara yang berukuran kecil (aerosol), dikenal dengan istilah hamburan mie ( Mie Scattering ) . Mie scattering terjadi jika diameter aerosol dari polutan di atmosfer sama dengan panjang gelombang dari sinar tampak ( visible) matahari. . . Panjang gelombang sinar merah berada pada ukuran 0,7 mikrometer. Dari data BMKG kita mengetahui bahwa konsentrasi debu partikulat polutan berukuran <10 mikrometer sangat tinggi di sekitar Jambi, Palembang, dan Pekanbaru. Tetapi langit yang berubah merah terjadi di Muaro Jambi. Ini berarti debu polutan di daerah tersebut DOMINAN berukuran sekitar 0,7 mikrometer atau lebih dengan konsentrasi sangat tinggi. Selain konsentrasi tinggi, tentunya sebaran partikel polutan ini juga LUAS untuk dapat membuat langit berwarna merah.

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BMKG said the phenomenon occurred when diameter of the aerosols is about the same as the wavelength of visible sunlight.

“Red light has a wavelength of 0.7 micrometres. Based on BMKG data, the concentration of pollutant particles measuring less than 10 micrometres was very high in Jambi, Palembang and Pekanbaru but only the sky in Muaro Jambi turned red," it said.

“This means air pollutants there have a high concentration of 0.7 micrometre particles.”  

red sky Jambi
The Muaro Jambi district was cast in an alarming hue of orange-red. (Photo: Twitter/@filsuflogic) 

The Muaro Jambi district was cast in an alarming hue of orange-red, as worried residents posted videos and photos of the rare phenomenon on social media.

Twitter user Zuni Shofi Yatun Nisa said: “This is afternoon, not night. This is Earth not Mars. This is Jambi, not outer space. We are breathing with lungs, not gills. We humans need clean air, not smoke.”

Sharing a video from his friend, another Twitter user Rizal Wahid wrote: “This is noon. Come on, let’s stop arguing for a moment. There are hundreds of thousands of human lives at stake.”

Forest and peat fires in Indonesia have been sending haze to neighbouring countries in Southeast Asia in recent weeks.

Schools in Malaysia were closed when air quality entered unhealthy range while flights were cancelled due to poor visibility.   

Health Minister Dzulkefly Ahmad said last week that number of outpatients at government hospitals has increased between 20 and 30 per cent since the haze hit.

In a visit to Riau province last week, Indonesian President Joko Widodo ordered stern actions against individuals and companies responsible for forest fires. 

READ: At ground zero, Indonesians cry foul over inadequate response to fight forest fires

Meanwhile, seven helicopters have been deployed to water bomb hotspots in South Sumatra province since Sunday as hotspots rose to more than 700, according to news site Tempo.

The two districts with the highest hotspots were Ogan Komering Ilir and Musi Banyuasin, with 251 and 159 hotspots respectively.

Tempo also reported that haze in Palembang – capital of South Sumatra – might worsen due to wind from the east-southeast direction, said Palembang Airport BMKG.

Source: CNA/tx(aw)