Tree Rings (IMAGE) University of Arizona Caption By analyzing growth rings in trees such as this Douglas fir cross-section from the Santa Catalina Mountains near Tucson, scientists can garner information about the monsoon rains in centuries past. Credit Copyright: Daniel Griffin, UA LTRR Usage Restrictions Usage only permitted in conjunction with reporting/posting of this news release. Credit must be stated as follows: Copyright: Daniel Griffin, UA LTRR License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.