Impacts of the Western Pacific and Indian Ocean Warm Pools on Wildfires in Yunnan, Southwest China: Spatial Patterns With Interannual and Intraannual Variations

Abstract

The Indo‐Pacific warm pool affects the regional climatic conditions in Southeast Asia mediated by the Western Pacific (WP) and Indian Ocean (IO) monsoons, which are recognized as critical regulators of wildfires in this region. Our study explored the spatiotemporal effects of the warm pools on wildfire records in Yunnan, Southwest China. We showed the interannual records had a negative relationship with the simultaneous WP warm pool area index. The Ailao Mountains in the central Yunnan could be a geographical barrier that blocked the influences of the WP warm pool from the east side. For the intraannual changes, the wildfire number variations had a stronger connection to the IO warm pool dynamics than the WP. Our study provided the novel evidence on the teleconnection between the Indo‐Pacific warm pool dynamics and regional environmental processes in Yunnan, also indicating this area as a part of the transitional zone between the two warm pools.

Extreme winter-spring drought in Southwest China in 2023: response to the phase transition from La Niña to El Niño

“…As a result, the extreme drought in Yunnan is a footprint over Southeast Asia. It has been suggested that anthropogenic warming has increased the extreme hot and dry conditions and drought risks over Southwest China (Ma et al 2017, 2021, Luo et al 2022 and even over mainland southeast Asia (Thirumalai et al 2017, Zhang et al 2021). Thus, the extreme winter-spring 2023 drought in Yunnan would have been 'virtually impossible' without human-caused climate change, as suggested by the World Weather Attribution (WWA) to the April heat wave in Southeast Asia (Zachariah et al 2023).…”

“…Yunnan Province in Southwest China is a droughtprone and mountain region, locates in the southeastern margin of the Tibetan Plateau and border with Thailand, Myanmar, Laos and Vietnam. Under recent global warming, Yunnan has witnessed more frequent, severe and longer persistent droughts (Lü et al 2012, Ma et al 2017, 2021, Luo et al 2022, Wang et al 2022. The frequent droughts largely affected the local energy and water supplies, reduced grain production and caused wildfires as well.…”

“…In addition, the negative-phase North Atlantic Oscillation (NAO) (Song et al 2011, Huang et al 2012, Yang et al 2012, Feng et al 2014, the warm SST anomalies over the tropical western Indian Ocean (Wang et al 2022), and the warm SST anomalies in Indian-Pacific warm pool (Huang et al 2012, Ma et al 2017, Ying et al 2022 also contributed to the extraordinarily severe drought in Yunnan. It is found the linkage between the NAO (or SST over tropical Indian and western Pacific) and drought in Yunnan is strongly modulated by the ENSO (Song et al 2011, Ma et al 2021, Wang et al 2022).…”

Fire in the Earth System: Introduction to the Special Collection

“…Finally, Ying et al. (2022) identified connections between wildfire occurrence in Yunnan, southwest China, and dynamics of the Western Pacific and Indian Ocean warm pools mediated by the regional monsoon climate.…”

“…From peatland cores in Borneo, Yamamoto et al (2021) inferred at least 12 major fires in the last 6,000 years and tied them to intervals of high solar activity thought to have been associated with drier climate. Finally, Ying et al (2022) identified connections between wildfire occurrence in Yunnan, southwest China, and dynamics of the Western Pacific and Indian Ocean warm pools mediated by the regional monsoon climate.…”