My research interests are in historical meteorology and climatology, extreme events, paleoclimate reconstruction from tree rings, societal impacts of weather and climate extremes, and computer programming applications. These interests stem both from my professional work experience as a severe storms meteorologist and from my graduate-level study and research in meteorology, climatology, dendroclimatology, and climate change. Graduate students having interests along these lines and are interested in the (M.A., M.S., or Ph.D.) programs in the Department of Earth Sciences at the University of Memphis are encouraged to contact me.

Current Funded Projects:

Graduate Student Dana Sjostrom
Proposing Solutions to BLDG Memphis

Community-Based Strategies for Urban Resilience to Extreme Rainfall Events

Funding: University of Memphis, Research Investment Fund, Team Initiation Grant

This project with Claudio Meier (Civil Engineering, University of Memphis) and Laura Saija (City and Regional Planning, University of Memphis) obtained internal seed money from the University of Memphis to initiate a permanent, interdisciplinary research team to study and develop low-tech, highly applicable, community-based strategies for operationalizing concepts of urban resilience to extreme rainfall events and, more generally, issues surrounding the hydrological cycle in the city context.

Two interdisciplinary, graduate-level classes were taught in the Fall 2017 and Spring 2018 semesters (Urban Resilience to Flooding I and II). Graduate students gave presentations to community partners at the end of the Fall 2017 semester, and in the Spring 2018 students proposed low-cost, low-tech solutions to BLDG Memphis (left image). We are currently seeking funding to expand this project nationally and internationally.

Instrumental June-August PDSI
1951-1957 (1950s Drought)
Red = Dry, Blue = Wet

Tree-Ring Reconstructed June-August PDSI
1951-1957 (1950s Drought)
Red = Dry, Blue = Wet

Collaborative Research: P2C2--Cool and Warm Season Moisture Reconstruction and Modeling over North America

Funding: NSF Paleoclimate Program, Paleo Perspectives on Climate Change (Arkansas = AGS-1266014, Columbia = AGS-1301587, Memphis = AGS-1266015)

This collaborative research project involves the University of Arkansas, Lamont-Doherty Earth Observatory of Columbia University, the University of Memphis, and NASA's Goddard Institute for Space Studies. The research will use hundreds of new and existing tree-ring chronologies to reconstruct both cool and warm season moisture levels across much of tropical, subtropical, and temperate North America. The seasonal reconstructions will be developed on a 0.5° grid for every year during two fixed time periods: AD 1500-present and AD 1000-present. The new reconstructions will be used with climate model simulations to test hypotheses concerning the ocean-atmospheric forcing of cool and warm season climate over North America, the climate dynamics responsible for decadal droughts and wet periods in each season, and the influence of anthropogenic trace gas and land surface changes on seasonal droughts and wet periods. The reconstructions and climate simulations will also be used to identify ancient analogues for the extreme decadal droughts and wet periods witnessed during the modern era.

The new reconstructions will have major interdisciplinary applications by providing an objective exactly dated framework for evaluating the impacts of seasonal climate extremes on social and ecological change during the prehistoric, colonial, and modern eras. The reconstructions will be served on a web-based interface with interactive analytical capabilities to leverage the widest possible use of the seasonal reconstructions [the North American Seasonal Drought Atlas (NASDA)]. Students will be provided with authentic field and laboratory experience in scientific research and publication. This project will support an early career scientist, will initiate a new collaboration with NASA scientists, and will strengthen a long-term collaboration with the Mexican Forest Research Service (INIFAP, Torreon, Mexico).

This research has produced five publications so far (Cook et al. 2016, WIREs Climate Change; Stahle et al . 2016, Quaternary Science Reviews; Stahle et al. 2015, Tree-Ring Research; and Torbenson et al. 2016, Tree-Ring Research, Torbenson and Stahle 2018, Journal of Climate). Additional papers on the drought portal (see below) and a new seasonal precipitation atlas for North America are forthcoming.

A portal of webtools for all tree-ring reconstructed drought atlases,, was launched at the American Meteorological Society Annual Meeting in January 2018.

University of Arkansas Tree-Ring Laboratory
Lamont-Doherty Earth Observatory Tree-Ring Lab
NASA Goddard Institute for Space Studies

Past Funded Projects:

Ancient Baldcypress
Black River, North Carolina, USA

Millennium-Long Reconstructions of Cool and Warm Season Precipitation Over the Southeastern and Southwestern United States

Funding: NOAA Climate Change and Detection, Paleoclimatology (NA08OAR4310727)

Part of my postdoctoral funding with Dave Stahle at the University of Arkansas came from this project. This research project reanalyzed existing tree-ring collections from the Southeast and Southwest to build new earlywood, latewood, total ring width, and adjusted latewood width chronologies. These new chronologies were then used to derive separate millennium-long reconstructions of cool and warm season precipitation. A review of the paleoclimate applications of long tree-ring chronologies derived from living and subfossil baldcypress trees in the U.S., Mexico, and Guatemala has been published using these new chronologies (Stahle et al. 2012, Quaternary Science Reviews). A second manuscript improved on the chronological "gap" from AD 1250 to 1400 at Mesa Verde, Colorado (Stahle et al. 2015, Tree-Ring Research).

University of Arkansas Tree-Ring Laboratory

Montezuma Baldcypress
Barranca de Amealco, Queretaro, Mexico

Mesoamerican Dendroclimatology: Climate Dynamics and Socioeconomic Applications

Funding: NSF Paleoclimate Program (ATM-0753399)

Part of my postdoctoral funding with Dave Stahle at the University of Arkansas came from this project. The project developed the first exactly dated millennium-long chronology of tree growth and climate history in central Mexico (Stahle et al. 2011, Geophysical Research Letters), and investigated the ocean-atmospheric dynamics responsible for drought and wetness over the region (Stahle et al. 2012, Climate Dynamics). A review of the paleoclimate applications of long tree-ring chronologies derived from living and subfossil baldcypress trees in the U.S., Mexico, and Guatemala has also been published (Stahle et al. 2012, Quaternary Science Reviews).

University of Arkansas Tree-Ring Laboratory

Fort Scott, Kansas, USA

Historical Climate of Kansas

Funding: NSF Doctoral Dissertation Research Improvement Grant (BCS-0622894)

This was my Ph.D. project that recovered daily temperature and precipitation data from selected 19th century stations in Kansas, Missouri, and Oklahoma to extend the temperature and precipitation history of northeastern Kansas backward into the 19th century (Burnette et al. 2010, Journal of Climate; Burnette and Stahle 2013a, Climatic Change). Helpful methods and computer code were also developed to facilitate additional development of historical climate data across the United States (Burnette and Stahle 2013b, Computers and Geosciences).

Project Website