HR: 0830h
AN: B11C-0709 [PDF]
TI: Characterization of a high elevation tropical pine forest for isotopic analysis of the North American
Monsoon System: Nevado de Colima, Mexico
AU: * Hartsough, P
EM: peterh@dri.edu
AF: Graduate Program of Hydrology, University of Nevada, Reno
MS 175, Reno, NV 89557 United States
AU: * Hartsough, P
EM: peterh@dri.edu
AF: Divison of Hydrologic Sciences, Desert Research Inst.
2215 Raggio Pkwy, Reno, NV 89512 United States
AU: Biondi, F
EM: fbiondi@unr.edu
AF: Dept. of Geography, University of Nevada, Reno
MS 154, Reno, NV 89557 United States
AU: Biondi, F
EM: fbiondi@unr.edu
AF: Graduate Program of Hydrology, University of Nevada, Reno
MS 175, Reno, NV 89557 United States
AB:
The area watered by the North American Monsoon encompasses a vast geographic region, from tropical Mexico to the deserts of
the Great Basin. The system is ultimately driven by tropical ocean-atmosphere interactions, which in turn orchestrate global
climate variability over a range of timescales. Instrumental observations at the end points of the system span only the past
few decades in the tropical south and are limited to only a few decades more in the desert north. At both locations,
high-resolution proxy records of climate can supplement existing data. The Mexican mountain pine (Pinus hartwegii) has been
shown to hold a paleoclimate record at a high elevation site in tropical Mexico. Warm-season precipitation regime is the
dominant year-to-year signal in a 400-year tree-ring chronology from Nevado de Colima, Mexico, where an automated weather
station and a range of automatic tree growth sensors (phytograms, point and band dendrometers) have been installed at 3770 m
(12,370 ft) elevation. Co-measuring tree growth and climate over a three-year period, has contributed to a better
understanding of the complex response of low latitude, high elevation trees to changing environmental conditions. This
characterization is necessary for interpretation of the stable isotopic record of Monsoon fluctuation as recorded by the
trees. Stable isotopic characterization of the source waters before and after the Monsoon has been completed and analysis of
tree ring cellulose is underway. Preliminary results show a strong seasonal isotopic signal and highlight the importance of
context dependent analysis.
DE: 1615 Biogeochemical processes (4805)
DE: 1620 Climate dynamics (3309)
DE: 1655 Water cycles (1836)
SC: Biogeosciences [B]
MN: 2003 Fall Meeting