Dendrochronology: A tool to explore past climate of San Antonio

• In Event: Geosciences: Oral session 1

Abstract

The climatic records during the instrumentation period of data collection date back to 1946 at the San Antonio International Airport and farther back to 1846 from other sites in San Antonio (Grice, 2007). Specific area climates have been estimated through the use of data proxies and data interpolation. There are at least 18 different data proxy types that are generally used to study paleoclimatology. Dendrochronology, study of tree rings, is one method that has been used to extract climatological proxy data since the early 18th century. An unusually old specimen of an Arizona Ash became available at the University of the Incarnate Word in the Fall of 2017, from Terrill Hills, Texas. The specimen measured between 69 and 75 centimeters in diameter. The ring count tree age estimate was between 85 and 89 years.
A meteorology student team under took a climatological analysis using the tree ring numbers and widths. A digital microscope, calibration rulers, calipers, and stage micrometers were used to extract the tree ring data. The historical meteorological records were used to develop a response function. This airport site is approximately eight kilometers away from the tree location. The response function was developed by a regression of the ring width against the annual growing season temperature and rainfall amounts using the statistical package “R”. This correlation will then be used to estimate the climate during the period before the airport records. The results will be compared against the San Antonio climate records from other locations within the city.

Authors

• Janice Davila, University of the Incarnate Word

• Jillian Guse, Univer of the Incarnate Word

• Darcy McCutchen, Univer of the Incarnate Word

• Mireles Brittany, Univer of the Incarnate Word

• Kyle Sanchez, Univer of the Incarnate Word

• Gerald Mulvey, University of the Incarnate Word