Haze Review

Review of Regional Haze Situation for February 2020

1.1 In February 2020, Northeast Monsoon conditions prevailed over the ASEAN region. During this period, which is also traditional dry season in the northern ASEAN region, dry weather persisted over the Mekong sub-region. In the southern ASEAN region, there were scattered showers on most days. However, brief periods of dry weather were experienced in Malaysia, and northern and central Sumatra (Figure 1).

Figure 1: Average Daily Rainfall for Feb 2020. (Source: JAXA GsMaP)

1.2 In the northern ASEAN region, dry weather gave rise to scattered hotspot activities in the Mekong sub-region. Based on surveillance by the NOAA-20 satellite, the highest number of hotspots was detected in Cambodia and Myanmar. In Lao PDR, Thailand and Viet Nam, the hotspot count in February 2020 was comparable to the same period in 2019 (Figure 2).

Figure 2: Hotspot count for the northern ASEAN region for Feb 2013 – 2020. [Note: Hotspot count from year 2019 onward is based on the NOAA-20 satellite, and for the period from year 2013-2018 is based on the Suomi-NPP satellite.]

1.3 In the southern ASEAN region, hotspot activities were generally subdued in February 2020. The number of hotspots detected was slightly lower than the same period in 2019 (Figure 3).

Figure 3: Hotspot count for the southern ASEAN region for Feb 2013 – 2020. [Note: Hotspot count from year 2019 onward is based on the NOAA-20 satellite, and for the period from year 2013-2018 is based on the Suomi-NPP satellite.]

1.4 During February 2020, there were persistent hotspot activities in parts of the Mekong sub-region. In particular, significant clusters of hotspots were detected in Cambodia. In Thailand, clusters of hotspots were occasionally detected in its northern, northeastern and central regions. Hotspots were detected frequently in central and eastern Myanmar, and northern and southern Lao PDR during the month. In the southern ASEAN region, occasional isolated hotspots were detected mostly in Sumatra, Malaysia and Kalimantan.

Figure 4: Distribution of hotspots detected based on NOAA-20 satellite surveillance for Feb 2020.

1.5 Based on NOAA-20 satellite surveillance, hotspots with moderate to high fire intensity were detected mainly in Cambodia, southern Lao PDR and parts of Thailand and Myanmar.

Figure 5: Maximum fire intensity based on NOAA-20 satellite surveillance in Feb 2020.

1.6 In February 2020, hazy conditions were observed on many days in northern, northeastern and central Thailand, northern Cambodia and eastern Myanmar. Slight haziness was detected in northern Myanmar and southern Lao PDR on some days. There were also occasions of transboundary smoke haze when the prevailing winds transported the smoke haze from northern Thailand to northern Lao PDR, and from Cambodia to eastern Thailand.

Figure 6: Number of days with moderate to dense smoke haze observed over an area based on satellite imageries, ground observations and air quality reports in Feb 2020.