HR: 10:50h
AN: PP52A-03    [Abstracts]
TI: Meteorological and Paleoclimatological Studies of Eastern Pacific Tropical Cyclones Using Oxygen and Hydrogen Isotope Ratios
AU: * Lawrence, J R
EM: JLawrence@uh.edu
AF: Department of Geosciences, University of Houston, Houston, TX 77204-5007, United States
AU: Marks, F
EM: frank.marks@noaa.gov
AF: AOML, 4301 Rickenbacker Causeway, Miam, FL 33149, United States
AB: The East Pacific Ocean off the coast of Mexico encompasses the most concentrated region of tropical cyclone activity on the globe. This region offers a multitude of opportunities for scientific discovery concerning the meteorological characteristics of tropical cyclones and a long-term record of tropical cyclone activity. Aircraft flights into Eastern Pacific tropical cyclones by the Hurricane Research Division of NOAA have been conducted and will continue in the future. Understanding rapid changes in dangerous category 3-5 hurricanes has been a priority. A study was conducted in Hurricane Olivia (1994) as it peaked in intensity to a category 4 and then weakened. The combined use of stable analyses and meteorological data provided considerable insight into the dynamics of this transition. Sedimentary deposits in coastal regions may contain records of coastal storm activity, especially from tropical cyclones. A unique characteristic of tropical cyclones is that the oxygen and hydrogen isotopic composition of rain and water vapor from them is far below that from other types of storms. At least two specific opportunities exist. Ostracoda carapaces formed in modern tropical cyclone waters have been shown to record the oxygen isotope signal from floodwaters produced by tropical cyclones. Secondly, the potential exists that tree ring cellulose may record the uniquely low isotope values in the water vapor or rain produced by tropical cyclones. Near Puerto Escondido, Mexico in July 1998 a study was conducted that showed that the oxygen and hydrogen isotopic composition of the water vapor in the atmosphere reflected tropical cyclone activity off the coast. This low isotopic anomaly may control the isotopic composition of leaf water and thereby the isotopic composition of cellulose trees.
DE: 1041 Stable isotope geochemistry (0454, 4870)
DE: 3307 Boundary layer processes
DE: 3344 Paleoclimatology (0473, 4900)
DE: 3354 Precipitation (1854)
DE: 3374 Tropical meteorology
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Joint Assembly