Document Type
Article
Publication Date
11-1-2006
Publication Title
Water Resources Research
Abstract
Climate and land use change may diminish orographic clouds over tropical montane forests, stressing biota and water resources during dry seasons. From 2003 to 2005 we measured the stable isotopic composition of precipitation and throughfall in Monteverde, Costa Rica, to distinguish convective, wet season rainfall associated with the Intertropical Convergence Zone (ITCZ) from dry season, orographic rain produced by northeasterly trade winds. While event-to-event fluctuations of δ18O and δ2H are high, monthly samples reveal a seasonal signal that may be used to trace water through the hydrologic cycle. Deuterium excess indicates that water evaporated from land is an important flux to the region during the transitional and dry seasons when winds from the Caribbean slope dominate. Following the shift to convective rainfall at the start of the wet season, when the western equatorial winds influence the Pacific slope of Costa Rica, d excess values become depressed. Yet as the wet season progresses, d excess begins to climb. These data suggest that several months of rain are needed following an acute dry season on the northern Pacific slope before a terrestrial evaporative signal is detected in wet season precipitation. The evaporative flux may result from a wet season expansion of surface water bodies and flooding of seasonal wetlands.
Volume
42
Issue
11
DOI
10.1029/2005WR004535
ISSN
00431397
Rights
Copyright 2006 by the American Geophysical Union
Recommended Citation
Rhodes, Amy L.; Guswa, Andrew J.; and Newell, Silvia E., "Seasonal Variation in the Stable Isotopic Composition of Precipitation in the Tropical Montane Forests of Monteverde, Costa Rica" (2006). Engineering: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/egr_facpubs/36
Comments
Archived as published.