Tracking the moisture transport from the Pacific towards Central and northern South America since the late 19th century
Por:
Gallego D., García-Herrera R., De Paula Gómez-Delgado F., Ordonez-Perez, Paulina, Ribera P.
Publicada:
2 may 2019
Categoría:
Earth and planetary sciences (miscellaneous)
Resumen:
In this paper, we develop an instrumental index based on historical wind
direction observations aimed to quantify the moisture transport from the
tropical Pacific to Central and northern South America at a monthly
scale. This transport is mainly driven by the so-called ``Choco jet'',
a low-level westerly jet whose core is located at 5 degrees N and 80
degrees W. The Choco jet is profoundly related to the dynamics of the
Intertropical Convergence Zone in the eastern equatorial Pacific and it
is responsible for up to 30% of the total precipitation in these areas.
We have been able to produce an index for this transport starting in the
19th century, adding almost a century of data to previous comparable
indices. Our results indicate that the seasonal distribution of the
precipitation in Central America has changed throughout the 20th century
as a response to the changes in the Choco jet, decreasing (increasing)
its strength in July (September). Additionally, we have found that in
general, the relationship between the Choco jet and the El Nino-Southern
Oscillation has been remarkably stable throughout the entire 20th
century, a finding particularly significant because the stability of
this relation is usually the basis of the hydrologic reconstructions in
northern South America.
Filiaciones:
Gallego D.:
Univ Pablo Olavide, Dept Sistemas Fis Quim & Nat, Seville 41013, Spain
Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Seville, 41013, Spain
García-Herrera R.:
Univ Complutense, Dept Fis Tierra & Astrofis, E-28040 Madrid, Spain
UCM, CSIC, IGEO, Inst Geociencias, Madrid 28040, Spain
Departamento de Física de la Tierra y Astrofísica, Universidad Complutense, Madrid, 28040, Spain
IGEO, Instituto de Geociencias (CSIC, UCM), Madrid, 28040, Spain
De Paula Gómez-Delgado F.:
Univ Pablo Olavide, Dept Sistemas Fis Quim & Nat, Seville 41013, Spain
Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Seville, 41013, Spain
Ordonez-Perez, Paulina:
Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City 04510, DF, Mexico
Ribera P.:
Univ Pablo Olavide, Dept Sistemas Fis Quim & Nat, Seville 41013, Spain
Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Seville, 41013, Spain
Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
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