Time filter

Source Type

São José dos Campos, Brazil

Cohen A.,University of Arizona | McGlue M.M.,U.S. Geological Survey | McGlue M.M.,University of Kentucky | Ellis G.S.,U.S. Geological Survey | And 4 more authors.
Memoir of the Geological Society of America | Year: 2015

Lake deposystems are commonly associated with retroarc mountain belts in the geological record. These deposystems are poorly characterized in modern retroarcs, placing limits on our ability to interpret environmental signals from ancient deposits. To address this problem, we have synthesized our existing knowledge about the distribution, morphometrics, and sedimentary geochemical characteristics of tectonically formed lakes in the central Andean retroarc. Large, active mountain belts such as the Andes frequently create an excess of sediment, to the point that modeling and observational data both suggest their adjacent retroarc basins will be rapidly overfilled by sediments. Lake formation, requiring topographic closure, demands special conditions such as topographic isolation and arid climatic conditions to reduce sediment generation, and bedrock lithologies that yield little siliciclastic sediment. Lacustrine deposition in the modern Andean retroarc has different characteristics in the six major morphotectonic zones discussed. (1) High-elevation hinterland basins of the arid Puna-Altiplano Plateau frequently contain underfilled and balanced-filled lakes that are potentially long-lived and display relatively rapid sedimentation rates. (2) Lakes are rare in piggyback basins, although a transition zone exists where basins that originally formed as piggybacks are transferred to the hinterland through forward propagation of the thrust belt. Here, lakes are moderately abundant and long-lived and display somewhat lower sedimentation rates than in the hinterland. (3) Wedge-top and (4) foredeep deposystems of the Andean retroarc are generally overfilled, and lakes are small and ephemeral. (5) Semihumid Andean backbulge basins contain abundant small lakes, which are moderately long-lived because of underfilling by sediment and low sedimentation rates. (6) Broken foreland lakes are common, typically underfilled, large, and long-lived playa or shallow systems. © 2014 The Geological Society of America. All rights reserved. Source

Kane R.P.,Instituto Nacional Of Pesquisas Espacias
Planetary and Space Science | Year: 2010

Sunspots have a major 11-year cycle, but the years near the maximum show two or more peaks called Gnevyshev peaks. It was noticed that in cycle 23, the double peaks in sunspot numbers are reflected in the electromagnetic radiations and coronal mass ejections (CMEs) in the solar atmosphere. But, in the interplanetary space, the ICMEs (interplanetary CMEs) show peaks not all coinciding with the peaks of sunspot numbers. Also, there are stream interaction regions (SIR), including co-rotating interaction regions (CIR), which evolve quite differently from sunspot numbers. In the geomagnetic indices, the peaks are related mainly to the peaks in SIRs, indicating that geomagnetic indices have no direct relationship with most of the phenomena at the Sun but are responding only to the interplanetary blobs due to SIRs, which are more predominant in the declining phase of sunspot activity. © 2009 Elsevier Ltd. All rights reserved. Source

Takahashi H.,Instituto Nacional Of Pesquisas Espacias | Lima L.M.,State University of Paraiba | Wrasse C.M.,Institute pesquisa Vale | Batista I.S.,Instituto Nacional Of Pesquisas Espacias | And 4 more authors.
Journal of Atmospheric and Solar-Terrestrial Physics | Year: 2012

Planetary scale 2-day waves in the mesosphere-lower thermosphere winds have been observed mainly from January to February in the southern hemisphere low latitude region. Meteor radar wind measurements at Cariri (7.4°S, 36.5°W) from the year 2005 to 2007 showed a distinct 2-day oscillation in the meridional winds with the amplitude of 50-80 m/s and 20-30 m/s for the zonal winds. During the same period, the ionospheric F-layer maximum critical frequency (foF2) observed at Fortaleza (3.8°S, 38.6°W) also showed distinct 2-day oscillation, indicating influence of planetary 2-day wave in the ionosphere. On the other hand, no clear signature of 2-day oscillation was observed for the F-layer bottom-side virtual height (h ́F). Present results suggest that the 2-day wave induced meridional wind in the thermosphere could generate latitudinal transport of F-region plasma causing day to day variability of equatorial ionization anomaly (EIA). © 2012 Elsevier Ltd. All rights reserved. Source

Vila D.,Instituto Nacional Of Pesquisas Espacias | Vila D.,Cooperative Institute of Climate Studies | Hernandez C.,Cooperative Institute of Climate Studies | Ferraro R.,Instituto Nacional Of Pesquisas Espacias | And 2 more authors.
Journal of Hydrometeorology | Year: 2013

Global monthly rainfall estimates and other hydrological products have been produced from 1987 to the present using measurements from the Defense Meteorological Satellite Program (DMSP) series of the Special Sensor Microwave Imager (SSM/I). The aim of this paper is twofold: to present the recent efforts to improve the quality control (QC) of historical antenna temperature of the SSM/I sensor (1987-2008) and how this improvement impacts the different hydrological products that are generated at NOAA/National Environmental Satellite, Data, and Information Service (NESDIS). Beginning in 2005, the DMSP Special Sensor Microwave Imager/Sounder (SSMI/S) has been successfully operating on the F-16, F-17, and F-18 satellites. The second objective of this paper is focused on the application of SSMI/S channels to evaluate the performance of several hydrological products using the heritage of existing SSM/I algorithms and to develop an improved strategy to extend the SSM/I time series into the SSMI/S era, starting with data in 2009 for F-17. The continuity of hydrological products from SSM/I to SSMI/S has shown to be a valuable contribution for the precipitation and climate monitoring community but several sensor issues must be accounted for to meet this objective. © 2013 American Meteorological Society. Source

Bogossian O.L.,Instituto Nacional Of Pesquisas Espacias | Loureiro G.,Instituto Nacional Of Pesquisas Espacias | Lopes R.V.F.,Instituto Nacional Of Pesquisas Espacias | Roggero E.,Comision Nacional de Actividades Espaciales
Journal of Aerospace Technology and Management | Year: 2014

This paper aims to present the Comprehensiveness Balance for Efficiency (CBfE) method for Platform-Based Satellite Family. The lack of a penalty measurement to assess the performance loss of using a platform could reduce significantly the family performance. The method, taking into account the comprehensiveness of space missions and the platform characteristics defined at the conception phase, assesses the platform inefficiency, in terms of the additional mass required by the platform equipment to cope with the worst environment factors. The method covers the aerodynamic drag and torque, the Earth's magnetic field, the eclipse and Sun energy absorption, the cumulated radiation dose absorbed by the electronic components and the effect on the structure to be prepared for several launchers. Based on this assessment and on an interactive process, the platform designer tunes the comprehensiveness with the suitable level of efficiency. A real case, the Brazilian MultiMission Platform project (PMM), is presented as an example of application. The method covers an existing gap on the platform development process for space applications. Source

Discover hidden collaborations