HR: 11:05h
AN: GC32A-04 INVITED     [Abstracts]
TI: ``And What is There to be Gained, if we Never Question our Hydrologic Paradigms?" Extreme Events and Mountain Hydroclimatology
AU: * Barros, A P
EM: barros@duke.edu
AF: Ana P. Barros, Duke University, 2457 Fitzpatrick Bldg., Box 90287, Durham, NC 27708 United States
AB: The title of this abstract is the last sentence from the first Chester C. Kiesel Memorial Lecture given by Nick Matalas at the University of Arizona in 1982. It seems fitting for this session on Extreme Events and Mountain Climate. Indeed, over the last three decades, the working paradigms in Mountain Hydrology were vigorously questioned, and much was gained in interdisciplinary scientific understanding. Here, the focus is on precipitation processes and the trajectory that lead us from asking questions such as -What is the best (statistically defensible) spatial distribution of precipitation in mountainous regions at seasonal and annual time-scales that can be derived from incomplete and sparse raingauge networks? to asking -What are the fundamental processes that control the spatial organization of distinct orographic precipitation regimes at multiple scales, and how do these processes affect the diurnal cycle of precipitation and extreme events? Advances in observational systems and modeling capability have provided the means to study mountain environments from the level of specific physical processes to the level of entire mountain ranges. The view of mountains as bulk obstacles, elevated heat sources, and rough boundaries for large-scale atmospheric flows was extended and refined to integrate the role of landform as the organizing canvas for weather and precipitation at sub-seasonal and diurnal timescales. Likewise, the view of orographic precipitation phenomena evolved from the textbook description of stationary 2D humps in isohyetal maps to complex 4D features that result from the multi-scale interactions between synoptic flows with regional topography and modulation via land-atmosphere interactions on hydro-ecological gradients. Scaling studies show that there are strong and stable relationships between the spatial and temporal variability of rainfall and snow, landform and land-cover, and hydrometeorological regime. These findings provide a basis for localized (high spatial resolution), physically constrained estimation of extreme precipitation in mountainous regions. Results from recent work with regard to Probable Maximum Precipitation (PMP) estimation will be presented.
DE: 1640 Remote sensing (1855)
DE: 1833 Hydroclimatology
DE: 1839 Hydrologic scaling
DE: 1854 Precipitation (3354)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
SC: Global Climate Change [GC]
MN: Fall Meeting 2005