Dinámica de Fluidos Geofísicos Computacional
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Browsing Dinámica de Fluidos Geofísicos Computacional by Subject "ITCZ"
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Item Restricted Impacts of different ENSO flavors and tropical Pacific convection variability (ITCZ, SPCZ) on austral summer rainfall in South America, with a focus on Peru(Royal Meteorological Society, 2018-01) Sulca Jota, Juan Carlos; Takahashi, Ken; Espinoza, Jhan Carlo; Vuille, Mathias; Lavado-Casimiro, WaldoEl Niño in the eastern and central Pacific has different impacts on the rainfall of South America, and the atmospheric pathways through the South Pacific Convergence Zone (SPCZ) and Inter‐Tropical Convergence Zone (ITCZ) are poorly understood. To address this, we performed linear regression analysis of E (eastern Pacific) and C (central Pacific) indices of sea surface temperature (SST), as well as precipitation indices for the SPCZ and ITCZ, with gridded precipitation and reanalysis data sets during the austral summer (December–February) for the 1980–2016 period. Positive C induces dry anomalies along the tropical Andes and northern South America (NSA), while wet anomalies prevail over southeastern South America (SESA). Moreover, it produces wet conditions in the northwestern Peruvian Amazon. In contrast, positive E enhances wet conditions along the coasts of Ecuador and northern Peru associated with the southward displacement of the eastern Pacific ITCZ and induces dry conditions in Altiplano, Amazon basin, and northeastern Brazil (NEB). Both El Niño Southern Oscillation (ENSO) indices are associated with weakened upper‐level easterly flow over Peru, but it is more restricted to the central and southern Peruvian Andes with positive E. Both SPCZ indices, the zonal position of the SPCZ and its latitudinal displacement, suppress rainfall along western Peruvian Andes when are positive, but the latter also inhibits rainfall over the Bolivian Altiplano. They are also linked to upper‐level westerly wind anomalies overall of Peru, but these anomalies do not extend as far south in the first. The southward displacement of the eastern Pacific ITCZ also induces wet anomalies in SESA while dry anomalies prevail over NEB, the western Amazon basin, and Bolivia. Oppositely, the southward displacement of the central Pacific ITCZ induces dry anomalies in NEB and along the northern coast of Peru; while wet anomalies occur mainly in eastern Brazil, Paraguay, and Bolivia through an enhancement of the low level jet.Item Open Access The vertical structure of the eastern Pacific ITCZs and associated circulation using the TRMM Precipitation Radar and in situ data(American Geophysical Union (AGU), 2016-08-16) Huaman, L.; Takahashi, KenThe atmospheric circulation associated with the eastern Pacific single and double ITCZs, particularly its vertical structure, is little known due to the sparce observations. Using precipitation profiles from the Tropical Rainfall Measure Mission (TRMM) Precipitation Radar, with approximations to the liquid water and energy budget equations, we estimated vertical profiles of latent heating and vertical velocity in the far eastern Pacific (95°W–85°W) ITCZs in the 800–730 hPa layer. We combined this with Eastern Pacific Investigation of Climate campaign (EPIC2001) and other in situ data to produce a preliminary characterization of the meridional‐vertical circulation. We found evidence of a double‐cell structure in boreal fall between the ITCZ and the equator, with both shallow and upper level peaks in vertical velocity. In spring, the flow poleward of the two ITCZs has a single‐cell structure, although around the equator it shows some hints of the double cells. Reanalysis and satellite‐based data are shown to be unreliable for describing the vertical structure of the circulation.