Review of Regional Haze Situation for March 2022 |

Review of Regional Haze Situation for March 2022

1.1 In March 2022, Northeast Monsoon conditions prevailed over the ASEAN region. While the prevailing winds over the areas north of the Equator blew mostly from the northeast or east, the winds over the Mekong sub-region were light and variable in direction. The prevailing winds over the areas south of the Equator blew mostly from the west or northwest. As the Northeast Monsoon conditions gradually weakened in the second half of the month, the prevailing winds over most of the ASEAN region were light and variable in direction on several days during the review period (Figure 1).

1.2 The dry conditions over the Mekong sub-region continued in March 2022, even though isolated showers were observed over the sub-region on some days. In the rest of the ASEAN region, generally wet conditions were observed but brief periods of drier weather were experienced in Sumatra and West Kalimantan (Figure 1).

Figure 1: Average Daily Rainfall and Mean Winds for March 2022. (Source: JAXA GsMaP and GFS, respectively)

1.3 For March 2022, the total number of hotspots were lower or comparable compared to previous years for the same period (Figure 2 & 3).

Figure 2: Hotspot counts for the northern ASEAN region for the month of March (2018 – 2022). [Note: The hotspot counts from 2019 onwards are based on the NOAA-20 satellite, while those from 2018 are based on the Suomi-NPP satellite.]

Figure 3: Hotspot counts for the southern ASEAN region for the month of March (2018 – 2022). [Note: The hotspot counts from 2019 onwards are based on the NOAA-20 satellite, while those from 2018 are based on the Suomi-NPP satellite.]

1.4 Scattered to widespread hotspots were detected during the continued dry weather conditions over the Mekong sub-region. Clusters of hotspots were more intense and persistent in Myanmar, Lao PDR and northeastern Cambodia, with smoke haze observed to emanate from these hotspots on several days. In particular, smoke haze was observed to be denser over parts of Myanmar and northern Lao PDR.

1.5 Elsewhere in the ASEAN region, isolated to scattered hotspots were observed mostly in the Philippines, central Sumatra, West Kalimantan and Sulawesi. Localised smoke plumes were observed to emanate from the hotspots detected in West Kalimantan and the western coastal areas of central Sumatra on some days in the second half of the month.

Figure 4: Distribution of hotspots detected in March 2022 based on NOAA-20 satellite surveillance.

Figure 5: Maximum fire intensity in March 2022 based on NOAA-20 satellite surveillance.

Figure 6: Number of days with moderate to dense smoke haze observed in March 2022 based on satellite imagery, ground observations, and air quality reports.

Figure 7: Moderate to dense smoke haze observed over western Myanmar, as well as the northern parts of Thailand and Lao PDR on 14 March 2022, based on NOAA-20 satellite imagery.

Figure 8: Localised smoke plumes observed to emanate from hotspots detected in the western coastal areas of central Sumatra (Left) and in West Kalimantan (Right) on 27 March 2022, based on NOAA-20 satellite imagery.