Review of Regional Haze Situation for August 2022 |

Review of Regional Haze Situation for August 2022

1.1 The monsoon rainband remained north of the Equator in August 2022, as Southwest Monsoon conditions persisted over the ASEAN region. The prevailing low-level winds blew mainly from the east or southeast for areas south of the Equator and from the southeast or southwest over areas north of the Equator.

1.2 For the southern ASEAN region, shower activities were observed across many areas despite the ongoing traditional dry season. Rainfall was most intense in Luzon, Philippines contributed by Severe Tropical Storm Ma-on which made landfall on August 23, 2022. Persistent dry weather conditions developed in Java and the Lesser Sunda Islands during the month. In addition, intermittent periods of drier weather were observed in Sumatra, Borneo, Peninsular Malaysia and Singapore in early to mid-August. The traditional wet season for the northern ASEAN region persisted in August 2022 and shower activities were observed over the region on most days of the month (Figure 1).

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

1.3 There was an increase in hotspot activity in the southern ASEAN region during brief periods of drier weather in the first half of August 2022. For the northern ASEAN region, continued showers helped to keep the hotspot counts low. The hotspot count for most parts of the ASEAN region were comparable or lower to previous years, except for Kalimantan where hotspot counts were higher compared to 2020 and 2021 (Figure 2 and 3).

Figure 2: Hotspot counts for the southern ASEAN region for the month of August (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 northern ASEAN region for the month of August (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 4. Dry periods in early to mid-August 2022, contributed to an escalation in hotspot activity in the southern ASEAN region (Figure 4). In particular, clusters of hotspots with high intensity were detected in West Kalimantan on several days during this period. Increased hotspot activity was also detected in parts of Viet Nam and Sumatra. (Figure 5). Moderate smoke haze was observed in the vicinity of the hotspot clusters in West Kalimantan on several days in the first half of August 2022, but the haze was generally localized. (Figures 6 and 7).

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

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

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

Figure 7: Himawari-8 satellite imagery showing moderate smoke haze in the vicinity of clusters of hotspots located in West Kalimantan on 9 August 2022 (left) and 18 August 2022 (right).