U.S. Air Quality

Special Feature: California fires of October 2003

Introduction

At the end of October 2003, intense fires started in California and lasted several days. The Old Fire/Grand Prix fires, which were included in these destructive wildfires, were located in the San Bernardino Mountains and destroyed more than 80,000 acres and 450 buildings (NASA Earth Observatory). The California fires generated large quantities of smoke particles that traveled to the east coast. This special post is about the advection of the smoke plumes generated by the California wildfires from October 24th to November 3rd.

NASA Earth Observing image from San Bernardino Oct. 26 2003

The above thermal image is from the NASA Earth Observing site. It shows the city of San Bernardino next to the San Bernardino Mountains. The brownish color represents the scorched land and the reddish color indicates the intensity of the fire. The picture was taken by ASTER on October 26, 2003.

Smoky West

The fires were first mentioned on the Smog blog on October the 24th. The main fires, known as the Old Fire/Grand Prix fires, were located in the San Bernadino Mountains. The Cedar and Paradise fires were in close proximity to San Diego. The San Diego Union Tribune website has a map showing the location of the Cedar and Paradise fires. As shown on the MODIS Direct image below, a large smoke plume generated by the intense flames covered Los Angeles. The Santa Ana winds were directing the smoke toward the Pacific. The progression of the fires was rapid due to the strong dry winds. The state of California official website has several pictures related to this event. One of them shows the smoke generated by the Old Fire.

MODIS Direct image from Oct. 24 2003

On October 26th, the smoke plume was well visible in satellite images. According to the MODIS IDEA image below, its Aerosol Optical Depth (AOD) was about 1.3. This agrees with the NAAPS model from the Naval Research Laboratory (NRL) website. The AOD in southern parts of California was above 0.8 (first quadrant). The NRL NAAPS model also indicated elevated smoke concentrations for the same location, which ranged from 64 ug/m3 to 128 ug/m3 or greater (last quadrant). For a more detailed description of this product, please refer to the NRL website. Ground based measurements from EPA AirNow also showed “unhealthy” (65.5 ug/m3 to 150.4 ug/m3) air quality in the same region (red dots). See map.

MODIS IDEA and NAAPS model images

The smoke plume in the IDEA image is represented in warm colors. See help files to understand how to interpret this image and to know more about MODIS IDEA products.

On the 28th, the smoke plume was very thick over the Pacific Ocean with the AOD being around 1.0. Note that there was some lingering haze in the Four Corners region. An AVHRR NOAA 15 image taken at 7:46 am, shows the wildland fires in southern California. The fires are represented in red and large smoke plumes may be seen advecting over the Ocean (red arrow). This image is an "enhanced natural color" image created using bands 1, 2 and 3 (US Dept. of Agriculture Forest Service).

AVHRR NOAA 15 image from Oct. 28 2005

The image below was created by the UMBC Atmospheric Lidar Group using MODIS Terra data. The map shows the AOD above the US. Please see Help Files for more information regarding this type of images.

MODIS Terra AOD above US Oct. 28 2003

The MODIS true color image below from the 29th shows a thick smoke plume reaching Arizona, Nevada, and Utah. EPA AirNow showed "unhealthy" (65.5 ug/m3 to 150.4 ug/m3) air quality in southern California (shown in red), and "moderate" AQ (15.5 ug/m3 to 40.4 ug/m3) in Las Vegas. Note that the poor conditions in Nevada were also due to the dust transported into the atmosphere by strong winds blowing over the State. The ADEQ reported the PM10 AQI to be 64 (81 ug/m3) in southern Arizona. On the 30th, the PM2.5 AQI was 75 (27.7 ug/m3) (ADEQ) and the plume extended from California to the Midwest passing through northern Arizona, New Mexico, Texas, Kansas, Iowa and Illinois. See EPA AirNow site for map legend.

MODIS Direct image and EPA AirNow from Oct. 29 2003

The smoke is visible on this MODIS Direct true color image below taken on November 2nd, from 3:21 pm to 3:30 pm. The plume is seen exiting the continent thru Delaware, New Jersey, and New York. Around that same time, the total particle concentration in Baltimore was about 21 ug/m3 at 3:00pm.

MODIS Direct image from Nov. 02 2003

The following day, the air quality in Baltimore was good with Aerosol Optical Depth being 0.2 or less. The UMBC Polar ELF lidar profile shows a very clear sky above Baltimore.

Movies

The Department of Geography at San Diego State University has some movies illustrating the advancement of the Cedar and Paradise wildfires from October 25th to 31st. San Diego is shown in the foreground.

Movie illustrating transport of smoke plume from California to Maryland Oct. 2003

This movie made by UMBC ALG illustrates the advancement of the smoke plume across the US. The true color images were created using MODIS Terra data and HDFLook. Note that on the 28th, there was significant haze in Utah, Colorado, Arizona and New Mexico, which could have been due to the California smoke, local fires and dust. On the 29th, the haze had advected southward and lingered south of Texas and Louisiana. Please, see the Help Files for help in interpreting the color images.

Data sources

The data came from the MODIS instrument aboard the Terra and Aqua satellites. NASA DAAC provides several products. In this post, we used MYD04 level 2 to create Aerosol Optical Depth (AOD) images. Data was also sourced from GOES, UW MODIS Quick look , IDEA and NRL. Some of the images were generated using HDFLook.

Posted by Kamonayi Mubenga at June 30, 2005 1:40 PM