Title:
The Amazon hydrometeorology: climatology, variability and links to changes in weather patterns

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dc.contributor.advisor Fu, Rong
dc.contributor.author Fernandes, Katia de Avila en_US
dc.contributor.committeeMember Marc Stieglitz
dc.contributor.committeeMember Webster, Peter J.
dc.contributor.committeeMember Dickinson, Robert E.
dc.contributor.committeeMember Black, Robert X.
dc.contributor.department Earth and Atmospheric Sciences en_US
dc.date.accessioned 2010-01-29T20:00:05Z
dc.date.available 2010-01-29T20:00:05Z
dc.date.issued 2009-07-27 en_US
dc.description.abstract Using ERA40 and independent observations, I assess how well Amazon surface water budget is estimated. ERA40 basin wide annual precipitation (P) agrees with observations showing an underestimation of 10%, whereas runoff (R) is underestimated by a larger margin (~25%). Observed residual of precipitation and runoff (P-R) is better estimated by ERA40 P-R than actual ET which includes soil moisture nudging. Nudging is necessary during the dry season to produce realistic ET and compensate for low soil moisture recharge during the wet season. Insufficient recharge may be caused by: underestimation of rainfall amount and intensity; a shallow root layer in the model that does not represent the deep soil water reservoir of the Amazonian forest. The physical links between changes in wet season onset and synoptic scale systems are investigated in the second part of my work. A delayed wet season onset is consistent with a decreasing number of cold air incursion (CAI) days in southern Amazon during 1979-2001. CAI variability in southern Amazon is related to SST in the tropical Pacific and Indian Oceans. The first mode of co-variability shows that during El Nio (La Nia) a strong (weak) subtropical jet stream over South America is related to decreased (increased) CAI days during SON. The second mode shows warm western Indian Ocean also related to strong subtropical jet stream. The absence a well defined subpolar jet stream, favors the northward displacement of transient waves into central South America, but shows little response in southern Amazon. CAI days reconstructed from the first and second modes do not present any significant trend in southern Amazon. CAI days reconstructed from the third mode of co-variability reproduces SON observed trend. This mode describes negative (positive) anomalies in CAI days associated with cold (warm) SST anomalies, anomalous wavetrain in the tropical Pacific and Walker Cell displacement that are unfavorable (favorable) to the incursion of CAI into southern Amazon. This mode's temporal evolution correlates with the Pacific Decadal Oscillation (PDO), suggesting that its recent gradual signal shift reflected on the interannual response of southern Pacific atmospheric patterns, hence on the behavior of transients propagation. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/31846
dc.publisher Georgia Institute of Technology en_US
dc.subject Amazon en_US
dc.subject Climate variability en_US
dc.subject Hydrometeorology en_US
dc.subject Tropics and extratropics interactions en_US
dc.subject.lcsh Hydrologic cycle
dc.subject.lcsh Amazon River
dc.subject.lcsh Climatology
dc.subject.lcsh Climatic changes
dc.title The Amazon hydrometeorology: climatology, variability and links to changes in weather patterns en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.corporatename School of Earth and Atmospheric Sciences
local.contributor.corporatename College of Sciences
relation.isOrgUnitOfPublication b3e45057-a6e8-4c24-aaaa-fb00c911603e
relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
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