Multiple fires have started and spread in California over the past week. Kincade fire in northern California’s Sonoma County was almost twice the size of San Francisco as of October 28th. Within the region, there are more than 200,000 people under mandatory evacuation (including members of my family) and many more without power due to shut downs by local utility Pacific Gas and Electric.
Government agencies, disaster preparedness groups and individuals need real-time data to respond to emergencies and take preventative action. Three datasets on Resource Watch can help us track the location of fires and smoke from space and provide information on if these fires might spread.
Satellites monitor the locations of fires, based on the light that radiates out to space. NASA tracks fire locations and intensity using the Visible Infrared Imaging Radiometer Suite (VIIRS) satellite instrument. The Resource Watch map below shows large fires that measure more than 100 megawatts in intensity. This dataset has two layers, so you can also track smaller fires (<100 megawatts) happening in the region. The color of the dots represents how many days ago the fire was detected, with yellow showing more recent detections and red being up to seven days ago.
The map below shows the VIIRS fires data and imagery available as of Tuesday, October 29th .
Another way to track fires is by the smoke they produce. The U.S. National Oceanic and Atmospheric Administration (NOAA) tracks smoke plumes in North America by using a combination of satellite imagery and analyst confirmation. NOAA analysts outline the area of the smoke plume from satellite imagery and include an estimate of the smoke concentration.
As of Monday, October 28th, smoke plumes have engulfed much of western California. Winds have been keeping much of the smoke offshore, taking with it particulate matter, a hazardous air pollutant.
If the wind direction changes, smoke and air pollutants may drift into communities throughout the region. You can monitor fine particulate matter concentration with data from OpenAQ.
NASA also provides data on where fires might start and spread, with the agency’s Fire Weather Index (FWI). The FWI combines meteorological data on temperature, wind speed, relative humidity and recent precipitation with data on the moisture content of leaf litter and other organic matter that fuels fires. Developed by the Canadian Forest Service, the FWI is the most widely used fire weather dataset in the world, according to NASA Goddard’s Earth Sciences division. These indicators can’t tell us if fires will start, but they tell us where they could start and spread, given temperature and dryness.
The map below shows the FWI data for the past day on Resource Watch.
FWI values above 50 are considered extreme. The average value for Sonoma County when the Kincade fire started on Friday, October 25th was 54; by Sunday, the average index had increased to 81.
The recent fires in California, on top of last year’s deadly Camp fire, the largest wildfire on record, may reveal what’s to come in a hotter, drier future. The extent of wildfires in the western United States has increased five-fold since 1972. Using FWI data, researchers also found that the fire season in western U.S. states has increased by 17 days in recent decades, which they estimate is twice the rate of increase that would have occurred absent warming from anthropogenic climate change.
You can overlay fire weather and fire locations on Resource Watch to monitor fire behavior in your area.