Eye in the Sky: Satellites That Show Us the Western Wildfires

Raji Sahota posted 2020-09-16
The Swan Lake fire has burned 167,164 acres and is 90 percent contained. (Image courtesy of Southern Area Blue Incident Management Team.)

Over the past couple of months, firefighters across California have been fighting against one of the largest and hottest wildfire seasons in American history. Currently, 17,000 firefighters are working to contain 28 major wildfires as well as many smaller, subsidiary fires. Since the beginning of 2020, wildfires have burned over 3.2 million acres, killed more than 20 people and destroyed more than 4,100 structures. 

(Image courtesy of State of California.)

While many of the fires were initially caused by more than 13,845 lightning strikes during multiple storms over three and a half days, over the following month the number and intensity of the wildfires have increased dramatically as weather conditions continue to elevate the risk factors. Due to the combination of record-high air temperatures, drought conditions, gusting winds and low humidity, the south of Northeastern California is in danger of critical fires. 

The majority of the fire is burning in Siskiyou County, Yuba County, Mendocino County, North Bay, Hennessey, San Bernardino, Monterey County, Los Angeles County, Tehama County, San Diego, Wallbridge, Fresno County, Plumas County, East Bay, San Mateo and Santa Cruz. 

NASA has photographed the thick smoke and aerosol particles throughout the region, using the NOAA-NASA Suomi NPP satellite, Terra satellite, ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station, and NOAA’s GOES-S. 

Satellites capture rare number of aerosol particles blowing throughout the U.S. (Image courtesy of NASA.)

The unprecedented number of wildfires have created an extremely thick blanket of smoke along the West Coast, while the smoke from one explosive pyrocumulus cloud expanded 10 miles into the atmosphere to reach the stratosphere, a record for any North American fire.

On August 20, NASA captured the approximately 1,214 mile-long smoke cloud caused by the California wildfires. The smoke cloud was composed of carbon monoxide, carbon dioxide, and particulate matter as well as aldehydes, acid gases, sulfur dioxide, nitrogen oxides, polycyclic aromatic hydrocarbons (PAHs), benzene, toluene, styrene, metals and dioxins. 

The California wildfire smoke trail is 1,214 miles long. (Image courtesy of NASA Worldview.)

The smoke trail led from the northeast of Pocatello, Idaho heading southwest to the Pacific Ocean near mid-Baja California and Mexico, affecting all individuals in the way.  

The Aerosol Optical Thickness, a measure of how much of the solar light is blocked due to dust and haze, shows that the smoke is affecting the sky across the state of California. The light yellow areas in the satellite image point to clear blue skies, while the dark red spots indicate areas where the sun is obstructed. In Los Angeles, Las Vegas, parts of San Francisco and even into Idaho, the sky is an orangey tan or cement gray-brown under the effects of the smoke. 

Optical depth of the smoke coming off the California wildfires. (Image courtesy of NASA Worldview.)

Since 1999, the Terra satellite has been observing the atmosphere and environment using five instruments: Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Clouds and Earth's Radiant Energy System (CERES), Multi-angle Imaging Spectroradiometer (MISR), Moderate Resolution Imaging Spectroradiometer (MODIS) and Measurements of Pollution in the Troposphere (MOPITT).

Sketch of Terra spacecraft. (Image courtesy of NASA.)

ASTER takes high-resolution, stereoscopic images of Earth in 14 different wavelengths of the electromagnetic spectrum to help create detailed maps of land surface temperatures, emissivity, reflectance and elevation. 

One of the two identical CERES instruments acts in cross-track scan mode, taking measurements for the Earth Radiation Budget Experiment (ERBE) and the Tropical Rainfall Measuring Mission (TRMM). The other CERES instrument acts in a biaxial scan mode, providing data into the angular models used to determine the Earth's radiation balance.

MISR measures the amount of sunlight, clouds and aerosols under natural conditions with cameras pointed at nine different angles in each blue, green, red and near-infrared wavelengths. 

MODIS is a spectroradiometer that can view over 2,330-km-wide and measure the number of clouds, gas fires as well aerosols in 36 discrete spectral bands. 

Using gas correlation spectroscopy, MOPITT compares the absorption of carbon monoxide to a known gas to identify the distribution, transport, sources and sinks of carbon monoxide. It also measures the radiance from Earth in three spectral bands using sensors. 

Overall, the TERRA spacecraft provides key information about the human impact on the environment and provides data about natural hazards. It also helps scientists determine the impact of clouds and aerosols on Earth's energy budget.

The National Oceanic and Atmospheric Administration (NOAA) photographed a smoke cloud growing hundreds of miles over the east of the Pacific Ocean heading south into Mexico from 22,300 miles in the air. Using a GeoColor band, they saw the smoke covered the globe from western Australia to eastern North America from a wider angle. 

The GOES-S spacecraft, which captured the incident, is three-axis stabilized with satellites that allow for up to 100 Mbps of near-continuous data. The spacecraft combines three technologies: nadir-pointing, which is pointed towards the earth, solar-pointing, which is pointed towards the sun, and in-situ, which is in the geosynchronous orbit. 

The 20 feet by 18 feet device has a life of 15 years and features systems such as Search and Rescue, Data System Collection and Emergency Manager’s Weather Information Network (EMWIN).

The NOAA-NASA Suomi NPP satellite recorded vast amounts of smoke emanating from the LNU and the SCU Lightning Complexes using the Visible Infrared Imaging Radiometer Suite (VIIRS).

Nighttime image of the California fires with city lights scattered by smoke. (Image courtesy of NOAA/NASA/William Straka U of W-Madison/CIMSS/SSEC.)

The LNU Complex fire is currently raging across 215,000 acres in the Napa Valley Area. It now ranks as the ninth largest fire in California history. While the SCU complex fire is spread across 157,475 acres, it is mostly contained near Santa Clara.

The powerful fires are creating their own localized weather systems since the hot air is producing an updraft and moisture in the upper atmosphere. A fire cloud is formed as the air cools and condenses into water droplets on the ash. Larger clouds can also produce winds and lightning, leading to more fires. Stronger and quicker updrafts can generate fire tornadoes. 

The highly autonomous Suomi NPP spacecraft uses a three-axis stabilized Attitude Determination and Control Subsystem, which provides real-time attitude, spacecraft position, and attitude control data. The craft uses four reaction wheels, three torquer bars, thrusters, trackers and sensors to collect and provide information. 

Heat from the fire measures above 400K (260 degrees F). (Image courtesy of NOAA/NASA/William Straka U of W-Madison/CIMSS/SSEC.)

The Suimi NPP’s Electrical Power Subsystem generates an average power of about 2 kW (EOL) using GaAs solar cells and provides thermal input using a solar array. Powered by a NiH (nickel hydrogen) battery system, the Command and Data Handling Subsystem collects instrument data and communicates it using a FireWire chipset. 

NASA’s ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) showed 28 major active wildfires across California that had a surface temperature higher than 375 degrees Fahrenheit. The surrounding areas were also abnormally warm due to the ongoing heatwave caused by the fires.

Active fires across California, including the El Dorado fire near Yucaipa and the Valley fire in Japatul Valley in the southern part of the state. (Image courtesy of NASA.)

NASA’S ECOSTRESS measures the temperature of plants using its Evaporative Stress Index (ESI). It can also create heat vulnerability index (HVI) maps using its thermal infrared sensor and images collected by satellite-based remote sensing. 

This spacecraft provides data with high spatial resolution and accurate temperature sensitivity. It can also provide a wide view of a point at a steady rate using its double-sided scan mirror and internal blackbody calibration. The system also features geolocation and cloud detection. 

As smoke continues to cover a huge portion of the Western U.S., Americans are being greatly impacted by 2020's rampant fires—and it isn't over yet. In fact, a new Stanford-led study states that the rise of hotter weather will increase the risk of longer, more dangerous wildfire seasons in the future.