A strong control of the South American SeeSaw on the intra-seasonal variability of the isotopic composition of precipitation in the Bolivian Andes

Details A strong control of the South American SeeSaw on the intra-seasonal variability of the isotopic composition of precipitation in the Bolivian Andes A strong control of the South American SeeSaw on the intra-seasonal variability of the isotopic composition of precipitation in the Bolivian Andes

Jul 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011e%26psl.307...47v&link_type=abstract

Earth and Planetary Science Letters, Volume 307, Issue 1, p. 47-58.

Computer Science

1

Water Stable Isotopes, Precipitation, Bolivia, Convective Activity, South American Seesaw

Scientific paper

Water stable isotopes (δ) in tropical regions are a valuable tool to study both convective processes and climate variability provided that local and remote controls on δ are well known. Here, we examine the intra-seasonal variability of the event-based isotopic composition of precipitation (δDZongo) in the Bolivian Andes (Zongo valley, 16°20′S-67°47′W) from September 1st, 1999 to August 31st, 2000. We show that the local amount effect is a very poor parameter to explain δDZongo. We thus explore the property of water isotopes to integrate both temporal and spatial convective activities. We first show that the local convective activity averaged over the 7-8 days preceding the rainy event is an important control on δDZongo during the rainy season (~ 40% of the δDZongo variability is captured). This could be explained by the progressive depletion of local water vapor by unsaturated downdrafts of convective systems. The exploration of remote convective controls on δDZongo shows a strong influence of the South American SeeSaw (SASS) which is the first climate mode controlling the precipitation variability in tropical South America during austral summer. Our study clearly evidences that temporal and spatial controls are not fully independent as the 7-day averaged convection in the Zongo valley responds to the SASS. Our results are finally used to evaluate a water isotope enabled atmospheric general circulation model (LMDZ-iso), using the stretched grid functionality to run zoomed simulations over the entire South American continent (15°N-55°S; 30°-85°W). We find that zoomed simulations capture the intra-seasonal isotopic variation and its controls, though with an overestimated local sensitivity, and confirm the role of a remote control on δ according to a SASS-like dipolar structure.

Affiliated with

Also associated with

No associations

Rating

A strong control of the South American SeeSaw on the intra-seasonal variability of the isotopic composition of precipitation in the Bolivian Andes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A strong control of the South American SeeSaw on the intra-seasonal variability of the isotopic composition of precipitation in the Bolivian Andes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A strong control of the South American SeeSaw on the intra-seasonal variability of the isotopic composition of precipitation in the Bolivian Andes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-990231