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Title: Final Technical Report [for Collaborative Research on Ecophysiological Controls on Amazonian Precipitation Seasonality and Variability]

Abstract

The principal objective of our project is to address how vegetation influences climate variability and precipitation over Amazonian rainforests, with an emphasis on plant physiological controls on deep convection triggering along a geographical water stress gradient. Using a new tool of sun-induced chlorophyll fluorescence (SIF), our study integrates plant physiological observations and climate modeling and aims to decrease the gap between field ecology and climate modeling. We have installed sensors at Manaus site (K34) and at Rebio Jaru (Ji-Paraná, Rondonia). From field observations, we found a diversity of hydraulic functioning, indicating that within the same forest we will find different responses to the predicted climatic changes. The hydraulic strategies varied through a continuum of hydraulic security and water transport efficiency, which can be related to a long process of taxa evolution. The fact that taller trees are more hydraulically vulnerable indicates that if these forests go through higher drought conditions and temperature increase, they could experience a massive tree mortality that will promote changes on forest structure, changing the ecosystem functions, such as water fluxes and carbon storage. To investigate the role of water stress on the onset of the rainy season, we have developed high-resolution cloud resolving model (CRM)more » simulations using a new strategy coupling convective and large-scales. The first results show that the presence of early morning fog reduces the wet season transpiration and carbon uptake over the everwet regions of Amazonia. We have incorporated SIF into CLM to constrain energy, carbon and water flux of tropical forests. By using CloudSat-observed cloud vertical structure, we show an empirical relationship between atmospheric energetics and convective clouds in Amazonia, in comparison with the savanna/shrubland and tropical West Pacific, emphasizing predominant deep convection during the early wet season when Bowen ratio and convective available potential energy (CAPE) increase. Although on average the deep convections are prominent only during the short dry-to-wet transition while shallow/congestus clouds dominate the rest of the year in Amazonia, there is a clear cloud regime shift when CAPE grows beyond a threshold value. Our project helped initiate and maintain collaboration between US and Brazilian scientists. We have been collaborating through yearly field campaigns, weekly international research meetings, and ongoing other collaborative projects. Through these activities, we helped our students and postdocs fill their knowledge gaps and learn new research techniques.« less

Authors:
Publication Date:
Research Org.:
Rutgers, The State University of New Jersey
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Contributing Org.:
Brown University Columbia University Carnegie Institution for Science
OSTI Identifier:
1499992
Report Number(s):
DE-SC0011069
DOE Contract Number:  
SC0011069
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; Amazon Tropical Convection Land Surface Vegetation Observations Modeling

Citation Formats

Lintner, Benjamin Richard. Final Technical Report [for Collaborative Research on Ecophysiological Controls on Amazonian Precipitation Seasonality and Variability]. United States: N. p., 2018. Web. doi:10.2172/1499992.
Lintner, Benjamin Richard. Final Technical Report [for Collaborative Research on Ecophysiological Controls on Amazonian Precipitation Seasonality and Variability]. United States. doi:10.2172/1499992.
Lintner, Benjamin Richard. Sat . "Final Technical Report [for Collaborative Research on Ecophysiological Controls on Amazonian Precipitation Seasonality and Variability]". United States. doi:10.2172/1499992. https://www.osti.gov/servlets/purl/1499992.
@article{osti_1499992,
title = {Final Technical Report [for Collaborative Research on Ecophysiological Controls on Amazonian Precipitation Seasonality and Variability]},
author = {Lintner, Benjamin Richard},
abstractNote = {The principal objective of our project is to address how vegetation influences climate variability and precipitation over Amazonian rainforests, with an emphasis on plant physiological controls on deep convection triggering along a geographical water stress gradient. Using a new tool of sun-induced chlorophyll fluorescence (SIF), our study integrates plant physiological observations and climate modeling and aims to decrease the gap between field ecology and climate modeling. We have installed sensors at Manaus site (K34) and at Rebio Jaru (Ji-Paraná, Rondonia). From field observations, we found a diversity of hydraulic functioning, indicating that within the same forest we will find different responses to the predicted climatic changes. The hydraulic strategies varied through a continuum of hydraulic security and water transport efficiency, which can be related to a long process of taxa evolution. The fact that taller trees are more hydraulically vulnerable indicates that if these forests go through higher drought conditions and temperature increase, they could experience a massive tree mortality that will promote changes on forest structure, changing the ecosystem functions, such as water fluxes and carbon storage. To investigate the role of water stress on the onset of the rainy season, we have developed high-resolution cloud resolving model (CRM) simulations using a new strategy coupling convective and large-scales. The first results show that the presence of early morning fog reduces the wet season transpiration and carbon uptake over the everwet regions of Amazonia. We have incorporated SIF into CLM to constrain energy, carbon and water flux of tropical forests. By using CloudSat-observed cloud vertical structure, we show an empirical relationship between atmospheric energetics and convective clouds in Amazonia, in comparison with the savanna/shrubland and tropical West Pacific, emphasizing predominant deep convection during the early wet season when Bowen ratio and convective available potential energy (CAPE) increase. Although on average the deep convections are prominent only during the short dry-to-wet transition while shallow/congestus clouds dominate the rest of the year in Amazonia, there is a clear cloud regime shift when CAPE grows beyond a threshold value. Our project helped initiate and maintain collaboration between US and Brazilian scientists. We have been collaborating through yearly field campaigns, weekly international research meetings, and ongoing other collaborative projects. Through these activities, we helped our students and postdocs fill their knowledge gaps and learn new research techniques.},
doi = {10.2172/1499992},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2018},
month = {3}
}