HR: 09:15h
AN: PP21A-04    [Abstracts]
TI: New Stable Isotope Tropical Paleoclimate Proxies
AU: * Lawrence, J R
EM: JLawrence@uh.edu
AF: Department of Geosciences University of Houston, 4800 Calhoun Rd, Houston, TX 77204-5007 United States
AB: Organized tropical rain systems such as tropical cyclones (TC) and mesoscale convective systems (MCS) produce both water vapor and rainfall with distinctly low isotope ratios. This lowering is caused by recyling of water in organized systems. Therefore, fresh water carbonate organisms have considerable potential to act as proxy recorders of these systems. Ostracoda are ephemeral making them especially attractive candidates. Tropical trees offer another opportunity because the low isotopic spikes produced in both soil waters when heavy rains result and ambient water vapor surronding the trees may be recorded in the tree cellulose. Ostracoda living in the surface waters derived from Tropical Storm Allison (2001) document the passage of the storm in their oxygen isotope ratios. The stable isotopic composition of water vapor along the southwest coast of Mexico shows considerable variation in response to TC and MCS activity offshore even when no rain falls in the region. Potentially a long-term record of this activity may be found in the stable isotopic composition of trees providing low elevation trees of sufficient longevity can be found.
DE: 1040 Isotopic composition/chemistry
DE: 1829 Groundwater hydrology
DE: 3344 Paleoclimatology
DE: 3374 Tropical meteorology
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2005 Joint Assembly