Vegetation fire activity and the Potential Fire Index (PFIv2) performance in the last two decades (2001–2016)

Abstract

Fire incidence has been linked to multiple factors such as climate conditions, population density, agriculture, and lightning. Recently, fire frequency and severity have induced health problems and contributed to increase atmospheric greenhouse gases. Based on atmospheric susceptibility to fire, this study evaluates the use of a Potential Fire Index (PFIv2) to identify regions prone to fire development, as demonstrated by the satellite detected-fire in the 2001-2016 interval. It is demonstrated that PFIv2 delivers an efficiency by up to 80% in matching the observed fires from Terra/MODIS satellite. The PFIv2 is also able to reproduce more accurately areas with fire activity with respect to its previous version, the PFI. This better performance is linked to the implementation of parameterization of water pressure deficit and atmospheric stability in the lower troposphere, and a new term to represent the effect of surface temperatures, particularly in mid-latitudes and extra-Tropics. To evaluate the performance of the PFIv2 in more details, its comparison to MODIS burned areas demonstrated correlations values higher than 0.6 over the most susceptible regions such as Africa and South America, slightly lower correlation is found where fire does not primary follows the climate annual cycle, and is dominated by high frequency events. These findings indicate that the PFIv2 can be an important tool for decision makers in predicting the potential for vegetation fires development and fire danger.

Arctic Oscillation and Pacific-North American pattern dominated-modulation of fire danger and wildfire occurrence

“…Figure 1g-j shows changes of PFIv2 and FWI associated with positive AO and PNA. These two fire danger rating indices have been used to estimate the environmental vulnerability to wildfires, over the tropics and extratropical regions 10 . The pattern in PFIv2 is mainly dictated by changes in DD, but an important contribution to fire danger rating is due to temperatures, in particular over northern Eurasia, east Asia and NA (Fig.…”

“…Although, consensus exists that weather characteristics are the main driving forcing for the environmental susceptibility to fire occurrences. Vegetation plays a determinant role for burned area extent and fire severity 10,47 , and exerts important role because fuel loading and flammability are dependent on vegetation types. Limitation arises in the sense that parameterization of fuel amount related to each plant type in response to drought, is extremely difficult because it also depends upon soil characteristics that are not available worldwide.…”

“…According to the US National Interagency Fire Center the years 2015-2020 have experienced severe fires and unprecedent area burned (https://www.nifc.gov/fire-information/statistics/wildfires). Fire activity is enhanced globally as well 2,10 and in many countries such as Brazil, Russia, Australia and Canada ecosystem processes and vegetation have been seriously affected. Since 2015, the NASA fire product has improved the probability of detection of fires showing regionally an increase of ≈3% in North America and Asia compared to Collection 5.…”

“…The PFIv2 has been described in other studies and for brevity only a summary is provided below 10,35 . The method relies on precipitation, temperature, atmospheric water vapor deficit and atmospheric stability at low levels, as a function of surface elevation according to a logistic function.…”

“…Summer climatic conditions across the Pan-Arctic region and extra-tropics, exhibit features which are conducive to fire activity due to dry and warm conditions 9 . This is not a particular characteristic of Boreal latitudes, as the tropics in summer are also prone to wildfire occurrences 2,10 due to warm and dry conditions. In both regions, precipitation distribution is not uniform throughout spring-summer, and high temperature and low precipitation lead to reduced soil moisture affecting local vegetation properties such as productivity and greenness [11][12][13] .…”