Occurrence frequencies and regional variations in Visible Infrared Imaging Radiometer Suite (VIIRS) global active...

Area of Science:

• Environmental Science
• Climate Science
• Remote Sensing

Background:

• Active fires are a major driver and consequence of climate change.
• Understanding fire frequency and distribution is vital for carbon cycling, atmospheric chemistry, and ecological impact assessments.
• Previous investigations have not fully explored multiscale variations in fire occurrence frequencies despite data availability.

Purpose of the Study:

• To analyze the occurrence frequencies of Visible Infrared Imaging Radiometer Suite (VIIRS) active fires.
• To investigate these frequencies across national, pan-regional, and global scales.
• To examine temporal variations at hourly, monthly, and annual scales from 2012-2017.

Main Methods:

• Utilized Visible Infrared Imaging Radiometer Suite (VIIRS) active fire data.
• Analyzed fire occurrence frequencies at multiple spatial scales (national to global).
• Examined temporal patterns across hourly, monthly, and annual intervals between 2012 and 2017.

Main Results:

• Total VIIRS global active fires reached 12,193 x 10^4, with minor annual fluctuations and a noticeable increase during the 2014-2016 El Niño event.
• Peak fire occurrences were observed from July to September (35.52%), particularly in August (13.06%), between 10:00-13:00 GMT (42.96%), and at 11:00 GMT (17.65%).
• Fires exhibited a bimodal latitudinal distribution (5°-11°N and 5°-18°S) and a unimodal longitudinal distribution (15°E-30°E), with tropical regions accounting for 75.83% of fires.

Conclusions:

• VIIRS active fire products are valuable for developing advanced fire detection algorithms.
• Data can aid in discriminating fire types and ignition causes through correlation with geographic factors.
• The findings support the assessment of active fires' potential impacts on climate and ecosystems.