El Niño years are characterized by a high sea surface temperature anomaly in the Equatorial Pacific Ocean, which leads to unusually warm and dry conditions over many fire-prone regions globally. This can lead to an increase in burned area and emissions from fire activity, and socio-economic, and environmental losses. Previous studies using satellite observations to assess the impacts of the recent 2015/16 El Niño found an increase in burned area in some regions compared to La Niña years. Here, we use the dynamic land surface model JULES to assess how conditions differed as a result of the El Niño by comparing simulations driven by observations from the year 2015/16 with mean climatological drivers of temperature, precipitation, humidity, wind, air pressure, and short and long-wave radiation. We use JULES with the interactive fire module INFERNO to assess the effects on precipitation, temperature, burned area, and the associated impacts on the carbon sink globally and for three regions: South America, Africa, and Asia. We find that the model projects a variable response in precipitation, with some areas including northern South America, southern Africa and East Asia getting drier, and most areas globally seeing an increase in temperature. As a result, higher burned area is simulated with El Niño conditions in most regions, although there are areas of both increased and decreased burned area over Africa. South America shows the largest fire response with El Niño, with a 13% increase in burned area and emitted carbon, corresponding with the largest decrease in carbon uptake. Within South America, peak fire occurs from August to October across central-southern Brazil, and temperature is shown to be the main driver of the El Niño-induced increase in burned area during this period. Combined, our results indicate that although 2015/16 was not a peak year for global total burned area or fire emissions, the El Niño led to an overall increase of 4% in burned area and 5% in emissions compared to a “No El Niño” scenario for 2015/16, and contributed to a 4% reduction in the terrestrial carbon sink.

厄尔尼诺现象的特点是赤道太平洋海平面温度异常高，导致全球许多火灾多发地区异常干燥和温暖。这可能导致燃烧面积的增加和火灾的排放，以及社会经济和环境损失。之前使用卫星观测评估2015/16年度厄尔尼诺现象影响的研究发现，与拉尼娜年份相比，某些地区的烧伤面积有所增加。在这里，我们使用动态地表模型JULES来评估厄尔尼诺现象所导致的条件差异，方法是将2015/16年的观测结果与温度，降水，湿度，风，气压，以及短波和长波辐射。我们将JULES与交互式火灾模块INFERNO结合使用，以评估对降水，温度，燃烧面积以及对全球以及三个地区（南美，非洲和亚洲）碳汇的相关影响。我们发现该模型预测了降水的变化响应，包括南美北部，南部非洲和东亚在内的某些地区变得更干燥，全球大多数地区的温度都在升高。结果，在非洲大多数地区，在厄尔尼诺条件下，模拟了更高的烧毁面积，尽管非洲的烧毁面积有所增加和减少。南美对厄尔尼诺现象的火灾响应最大，燃烧面积和碳排放量增加了13％，对应的碳吸收量下降幅度最大。在南美，巴西中南部南部地区在8月至10月发生了最高火势，在这一时期，温度是导致厄尔尼诺现象导致燃烧面积增加的主要因素。总的来说，我们的结果表明，尽管2015/16年不是全球总燃烧面积或火灾排放的高峰年，但与“没有厄尔尼诺现象”相比，厄尔尼诺现象导致燃烧面积和排放量总体增加了4％ 2015/16年的情况”，使陆地碳汇减少了4％。