The role of the Amazon Basin moisture in the atmospheric branch of the hydrological cycle: a Lagrangian analysis
We used a Lagrangian model (FLEXPART) together with the 1979–2012 ERA-Interim reanalysis data to investigate the role of the moisture in the Amazon Basin in the regional hydrological budget over the course of the year. FLEXPART computes budgets of evaporation minus precipitation by calculating chang...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-07-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | http://www.hydrol-earth-syst-sci.net/18/2577/2014/hess-18-2577-2014.pdf |
| Summary: | We used a Lagrangian model (FLEXPART) together with the 1979–2012
ERA-Interim reanalysis data to investigate the role of the moisture in the
Amazon Basin in the regional hydrological budget over the course of the year.
FLEXPART computes budgets of evaporation minus precipitation by calculating
changes in the specific humidity along forward and backward trajectories. The
tropical Atlantic is the most important remote moisture source for the Amazon
Basin. The tropical North Atlantic (NA) mainly contributed during the austral
summer, while the contribution of the tropical South Atlantic (SA) prevailed
for the remainder of the year. At the same time, the moisture contribution
from the Amazon Basin itself is mainly for moisture supplying the
southeastern South America. The 33-year temporal domain allowed the
investigation of some aspects of the interannual variability of the moisture
transport over the basin, such as the role of the El Niño Southern
Oscillation (ENSO) and the Atlantic Meridional Mode (AMM) on the hydrological
budget. During the peak of the Amazonian rainy season (from February to May,
FMAM) the AMM is associated more with the interannual variations in the
contribution from the tropical Atlantic sources, while the transport from the
basin towards the subtropics responds more to the ENSO variability. The
moisture contribution prevailed from the SA (NA) region in the years
dominated by El Niño/positive AMM (La Niña/negative AMM) conditions. The
transport from the Amazon towards the subtropics increased (reduced) during
El Niño (La Niña) years. |
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| ISSN: | 1027-5606 1607-7938 |