Haze Review for Year 2021 Archives - Page 2 of 2

Review of Regional Haze Situation for February 2021

1.1 Northeast Monsoon conditions continued to prevail over the ASEAN region in February 2021. In the northern ASEAN region, the prevailing winds blew mainly from the east or the northeast although the strength of the winds was weaker over the Mekong sub-region. For parts of the southern ASEAN region north of the Equator, the winds blew mainly from the north, while south of the Equator, they blow from the northwest or west.

1.2 Dry conditions persisted over the Mekong sub-region in February 2021. Additionally, Sumatra, Peninsular Malaysia, and the northern and western parts of Borneo Island experienced periods of drier weather. Isolated to scattered showers fell elsewhere over the ASEAN region.

Figure 1: Average Daily Rainfall and Mean Wind for February 2021. (Source: JAXA GsMaP and GFS respectively)

1.3 In Myanmar and Kalimantan, the hotspot counts were slightly higher for the month of February this year as compared to prior years for the same review period. In other parts of the ASEAN region, the hotspot counts this year were comparable to previous years (Figures 2 and 3).

Figure 2: Hotspot counts for the northern ASEAN region for the month of February (2017 – 2021). [Note: The hotspot counts from 2019 onwards are based on the NOAA-20 satellite, while those from 2017 – 2018 are based on the Suomi-NPP satellite.]

Figure 3: Hotspot counts for the southern ASEAN region for the month of February (2017 – 2021). [Note: The hotspot counts from 2019 onwards are based on the NOAA-20 satellite, while those from 2017 – 2018 are based on the Suomi-NPP satellite.]

1.4 In the northern ASEAN region, hotspot activities were detected in most parts of the Mekong sub-region. Persistent clusters of hotspots were also detected in Cambodia, southern Lao PDR, and northern Myanmar (Figures 4 and 5).

1.5 Throughout the month, intermittent cloudy conditions were observed over various parts of the Mekong sub-region which were associated with isolated to scattered showers. In areas that received rainfall, the hotspot and smoke haze situation was temporarily subdued. However, by the end of the month, dry and fair conditions had returned to the sub-region. This led to an escalation of the fire and smoke haze situation, particularly over northern Myanmar, northwestern Thailand, and northern Cambodia where moderate to dense smoke haze was observed (Figure 6).

1.6 In the southern ASEAN region, periods of drier weather over northern Sumatra, Peninsular Malaysia and the western parts of Borneo Island led to a progressive escalation of hotspot activities in these areas during the month. Localised smoke plumes were observed to emanate from some of these hotspots on several days. By the end of the month, moderate to dense smoke haze were observed to emanate from persistent hotspot clusters in West Kalimantan and Central Kalimantan.

Figure 4: Distribution of hotspots detected in February 2021 based on NOAA-20 satellite surveillance.

Figure 5: Maximum fire intensity in February 2021 based on NOAA-20 satellite surveillance.

Figure 6: Number of days with moderate to dense smoke haze observed in February 2021 over an area based on satellite imagery, ground observations and air quality reports.

Review of Regional Haze Situation for January 2021

1.1 Northeast Monsoon conditions prevailed over the ASEAN region in January 2021. In the northern ASEAN region, the prevailing winds blew mainly from the northeast or east, strengthening at times under the influence of high-pressure systems moving eastwards over continental Asia. Dry conditions persisted over the Mekong sub-region while wet weather conditions were observed mostly over the eastern parts of the Philippines. In the southern ASEAN region, the prevailing winds blew mainly from the northwest or northeast over areas near the Equator, and mainly from the west or northwest over areas south of the Equator. There were isolated to scattered shower activities over the region, with rainfall observed to be higher over parts of Malaysia, Singapore, North Kalimantan, central Sumatra, and Java Island.

Figure 1: Average Daily Rainfall and Mean Wind for January 2021. (Source: JAXA GsMaP and GFS respectively)

1.2 The hotspot counts in the ASEAN region for January 2021 were comparatively lower than those from the same review period in previous years, with the exception of Myanmar (Figure 2 and Figure 3).

Figure 2: Hotspot counts for the northern ASEAN region for the month of January (2017 – 2021). [Note: The hotspot counts from 2019 onwards are based on the NOAA-20 satellite, while those from 2017 – 2018 are based on the Suomi-NPP satellite.]

Figure 3: Hotspot counts for the southern ASEAN region for the month of January (2017 – 2021). [Note: The hotspot counts from 2019 onwards are based on the NOAA-20 satellite, while those from 2017 – 2018 are based on the Suomi-NPP satellite.]

1.3 In the northern ASEAN region, hotspot activities were detected in many parts of the Mekong sub-region. In particular, persistent clusters of hotspots were detected in the northeastern parts of Myanmar, and the northern and eastern parts of Cambodia (Figure 4 and Figure 5). During the first fortnight of the month, moderate smoke haze was first observed to emanate from the hotspot clusters in the northern and eastern parts of Cambodia (Figure 6).

1.4 In view of the prolonged dry conditions, increased hotspot activities and persistent hotspot clusters in the Mekong sub-region, the Alert Level was raised to Level 2 for the sub-region on 14 January 2021. The hotspot and haze situation in the Mekong sub-region further deteriorated during the second fortnight of the month when moderate smoke haze was observed over larger areas of Cambodia, as well as over parts of Thailand and Myanmar (Figure 6). In particular, dense smoke haze was detected over the northern and eastern parts of Cambodia towards the end of the month. In the southern ASEAN region, hotspot activities were subdued due to the wet weather conditions.

Figure 4: Distribution of hotspots detected based on NOAA-20 satellite surveillance for January 2021.

Figure 5: Maximum fire intensity based on NOAA-20 satellite surveillance for January 2021.

Figure 6: Number of days with moderate to dense smoke haze observed over an area based on satellite imagery, ground observations and air quality reports in January 2021.