Description

Wildland fire is a natural phenomenon and influential force of the Earth’s climate system. During the past decades, increased large wildland fire activities, longer wildland fire durations, and longer wildfire seasons in the United States have received more and more attention because of increasing extreme weather and climate events. While there is no significant trend of fire numbers, the burned area apparently increased during the recent decade, which implies increase of large fires. Early studies have demonstrated dramatic changes of surface dynamic, radiative, vegetative, thermal and hydrological properties caused by large wildland fires and significant impacts of wildland fires on ecosystem and regional climate. Wildland fires may lead to either warming or cooling at regional scale. The net impacts of wildland fires depend on the integrated effects of many factors, such as fire emissions, changes in surface albedo, and carbon deposition. Previous studies about the climatic impacts of large wildland fires mainly focused on western region, especially in Alaska and found both positive and negative implications for climatic feedbacks. It’s also important to investigate and compare the impacts of large fires over other regions.

To further understand wildland fire trends, forest recovery patterns, and fire-climate interactions, it is essential to quantitatively characterize various changes caused by wildland fires, such as atmospheric composition, cloud cover, surface albedo, soil composition and moisture etc. Providing global coverage and repetitive observations, satellite remote sensing has emerged as an advanced technique for land and climate study. The satellites of Landsat series (Landsat 1-8) have been providing continuous and consistent measurements of the earth from early 1970s to now. Landsat data have been playing important role in wildland fire study, including fuel and burned area mapping. Landsat imagery is the foundation of the LANDFIRE's vegetation and disturbance data layers. From 2000, the launch of NASA’s EOS platform with a series of polar-orbiting satellites provided the opportunity for systematic observation and study of the Earth’s surface and atmosphere. Especially, the Moderate-resolution Imaging Spectroradiometer (MODIS) data products are available since 2000. With plenty of products and consistent records over 15 years, MODIS has improved our understanding of global dynamics and processes occurring on the Earth’s surface, and provides the potential for further investigation of fire-climate interactions.

This presentation will focus on results from our investigating land property changes in Alaska by combining using satellite remote sensing and in-situ measurements. The preliminary results include: an integrated spatiotemporal database in Alaska since 1982, including fire information, time series of land surface properties, as well as climate/weather data; post-fire land surface properties changes of burned areas spatially and temporally; and the impacts of large post-fires on regional climate in Alaska.