Ulisses Franz Bremer

Prof. Ulisses Franz Bremer

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Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 1999 in Annals of Glaciology
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JSJefferson Cardia Simões
Jefferson Cardia Simões
Ulisses Franz BremerUlisses Franz Bremer
Ulisses Franz Bremer
FAFrancisco E. Aquino
Francisco E. Aquino
FFFrancisco A. Ferron
Francisco A. Ferron
A Système probatoire pour l’observation de la terre (SPOT) mosaic of King George Island, the largest (1250 Km2) of the South Shetland Islands, West Antarctica, shows its major morphological features. Three main ice domes and 70 glacier drainage basins, covering 92.7% of the King George Island area, strongly controlled by the subglacial morphology and drained by relatively fast-moving tidewater outlet glaciers, were delineated. A general retreat of ice fronts through four decades, more intensely on the eastern side of the island (to the Bransfield Strait), resulted in the loss of about 7% of the glacial cover area. Superficial snow fades were derived from SPOT multispectral imagery and, together with field observations, allowed the transient-snowline elevation to be obtained The latter is estimated to have risen from about 200-250 m in the mid-1950s to 300-350 m by 1988. Spot radio-echo sounding surveys give an overview of the bedrock morphology.

1 August 2017 in Journal of South American Earth Sciences
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Journal Article
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BVBijeesh Veettil
Bijeesh Veettil
SWShanshan Wang
Shanshan Wang
SSSergio Florêncio de Souza
Sergio Florêncio de Souza
Ulisses Franz BremerUlisses Franz Bremer
Ulisses Franz Bremer
JSJefferson Cardia Simões
Jefferson Cardia Simões

22 March 2014 in Climate Dynamics
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BVBijeesh Veettil
Bijeesh Veettil
ÉMÉder Leandro Bayer Maier
Éder Leandro Bayer Maier
Ulisses Franz BremerUlisses Franz Bremer
Ulisses Franz Bremer
SSSergio Florencio de Souza
Sergio Florencio de Souza

1 March 2001 in Antarctic Science
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MBMatthias Braun
Matthias Braun
JSJefferson Cardia Simões
Jefferson Cardia Simões
SVSteffen Vogt
Steffen Vogt
Ulisses Franz BremerUlisses Franz Bremer
Ulisses Franz Bremer
NBNorbert Blindow
Norbert Blindow
FFFrancisco A. Ferron
Francisco A. Ferron
A new topographic database for King George Island, one of the most visited areas in Antarctica, is presented. Data from differential GPS surveys, gained during the summers 1997/98 and 1999/2000, were combined with up to date coastlines from a SPOT satellite image mosaic, and topographic information from maps as well as from the Antarctic Digital Database. A digital terrain model (DTM) was generated using ARC/INFO GIS. From contour lines derived from the DTM and the satellite image mosaic a satellite image map was assembled. Extensive information on data accuracy, the database as well as on the criteria applied to select place names is given in the multilingual map. A lack of accurate topographic information in the eastern part of the island was identified. It was concluded that additional topographic surveying or radar interferometry should be conducted to improve the data quality in this area. In three case studies, the potential applications of the improved topographic database are demonstrated. The first two examples comprise the verification of glacier velocities and the study of glacier retreat from the various input data-sets as well as the use of the DTM for climatological modelling. The last case study focuses on the use of the new digital database as a basic GIS (Geographic Information System) layer for environmental monitoring and management on King George Island.

9 January 2018 in International Journal of Remote Sensing
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AAAndré Medeiros Andrade
André Medeiros Andrade
RMRoberto Ferreira Machado Michel
Roberto Ferreira Machado Michel
Ulisses Franz BremerUlisses Franz Bremer
Ulisses Franz Bremer
CSCarlos Ernesto Gonçalves Reynaud Schaefer
Carlos Ernesto Gonçalves Reynaud Schaefer
JSJefferson Cardia Simões
Jefferson Cardia Simões
The aim of this work is to produce a simplified vegetation map of ice-free areas of the Fildes Peninsula (FP) and Ardley Island (AI) thought object-oriented classification using a QuickBird satellite image and to evaluate the influence of the global solar radiation (GSR) over the vegetation distribution. The vegetation data were generated from multiresolution segmentation using the panchromatic and infrared layers, and for the classification we calculated the normalized vegetative difference index (NVDI) and the green NVDI. Two classes were created – Lichen and Moss Cushion SubFormation and Moss Subformation – with 48 vegetation samples collected on surveys during the austral summers of 2008 and 2009. We used a kappa index to evaluate the classification efficiency using 100 sampled points obtained in austral summer of 2013. The GSR was estimated, and in order to evaluate the effect of meteorological phenomena and cloudless, we measured the GSR using a net radiometer model CNR4 installed in FP between 2014 and 2016. The estimate of GSR was done for seasons of 2015, in order to estimate the light compensation point and the saturation point for the plant communities in FP and AI. The kappa index was 0.73 and the global accuracy was 0.78, showing consistency between the classification and ground truth. The area was covered by vegetation in FP was 16.7% and in AI is 59.1%. The vegetation cover is distributed differently at FP and AI, and our results suggest GSR plays an important role in vegetation distribution and these tendencies could be related to greater GSR demand by mosses when compared to lichens.

9 August 2022 in Ecological Informatics
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MSMaria E. Sotille
Maria E. Sotille
Ulisses Franz BremerUlisses Franz Bremer
Ulisses Franz Bremer
GVGonçalo Vieira
Gonçalo Vieira
LVLuiz F. Velho
Luiz F. Velho
CPCarina Petsch
Carina Petsch
JSJefferson C. Simões
Jefferson C. Simões