Francisco Eliseu Aquino

An improved topographic database for King George Island: compilation, application and outlook

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.

Perfuração, processamento e primeiros resultados de um testemunho do manto de gelo da Antártica Ocidental

Manuscript ID: 20150035. Received in: 09/29/2015. Approved in: 01/13/2016. ABSTRACT: An ice core, 92.26 m in length, was collected near the ice divide of the West Antarctica ice sheet during the 2008/2009 austral summer. This paper described the fieldwork at the Mount Johns site (79o55’S; 94o23’W) and presented the first results of the upper 45.00 m record covering approximately 125 years (1883 – 2008), dated by annual layer counting and volcanic reference horizons. Trace element concentrations in 2,137 samples were determined using inductively coupled plasma mass spectrometry. The concentrations obtained for Al, Ba, Ca, Fe, K, Mg, Mn, Na, Sr and Ti are controlled by climate variations, the transport distance, and the natural sources of these aerosols. Natural dust contributions, mainly derived from the arid areas of Patagonia and Australia, are important sources for aluminum, barium, iron, manganese and titanium. Marine aerosols from sea ice and transported by air masses are important sources of sodium and magnesium. Calcium, potassium and strontium showed considerable inputs of both continental dust and marine aerosols.

Avaliação de desastres no Rio Grande do Sul associados a complexos convectivos de mesoescala

Mesoscale Convective Complexes (CCM) are organized clusters of convective clouds, which often arrive at Southern Region of Brazil and produce a variety of hazards. This study evaluated hazards

Mesoscale convective complexes in Rio Grande do Sul between October and December of 2003 and associated precipitation.

This study investigates the occurrences of Mesoscale Convective Complexes (MCC) and the associated precipitation in the southernmost Brazilian state, Rio Grande do Sul (RS), from October to December of 2003. The identification of MCC events was done using ForTraCC. The MCC precipitation was based on the daily data of 31 local weather stations. Twenty-two MCC events were identified over RS during the three month study period, and this total, seven events occurred in October, seven in November and eight in December. Results point to an MCC associated precipitation average of 119 mm in October, 90 mm in November and 152 mm in December. The percentages for MCC precipitation averages, for the period, were 64% in October, 65% in November and 61% in December. The average accumulated volume of MCC precipitation for the three months was 361 mm (63%). This confirms that MCC events contributed significantly to the precipitation totals in RS, and were responsible for almost two thirds of the precipitation in RS, for the period.

A GIS FOR THE ANTARCTIC SPECIALLY MANAGED AREA OF ADMIRALTY BAY, KING GEORGE ISLAND, ANTARCTICA

A GIS is proposed as a tool for the managing plan for the Antarctic specially managed area (ASMA) in Admiralty Bay. The ASMA comprises the area considered to be within the glacial drainage basin of the bay. Furthermore, it includes part of SSSI No. 8 adjacent to the area but outside of the glacial drainage basin. Three stations and six refuges are located in the area. Using a SPOT satellite image map, the limits of the ASMA are marked and its area is re-calculated. It consists of 362 km2, including 186 km2 island ice field and small cirque glaciers and 32 km2 ice-free field. The rest comprises water of the bay and a small adjacent area (8 km2) of the Bransfield Strait.The ASMA-GIS will consists of 12 data layers ranging from the physiographic settings to the biological and administrative features. All data will be implemented into Arc/Info GIS according to the cartographic guidelines of the SCAR WG-GGI. First, five plans of information will be realised using a topographic database compiled from various sources and data from the revised bathymetric chart published by the Brazilian Navy Hydrographic Survey and also including: 1) Limits of the ASMA and protected areas; 2) Glaciological features (e.g. drainage basin limits) and 3) Human presence (e.g. stations and historical sites). These basic GIS layers will be operational in early 2001. Then, additional data on the remaining layers (e.g. hydrology, geology and geomorphology) will be included from published sources.The ASMA-GIS will form an important database for environmental monitoring and studies surveying temporal changes of features such as glacier front positions or bird breading sites.

Precipitation anomalies in the Brazilian southern coast related to the SAM and ENSO climate variability modes

The precipitation pattern of the State of Rio Grande do Sul (RS) is changing, indicating an increase, although there are long periods of drought. Several studies indicate the influence of climate variability modes on RS precipitation. This work analyzes the influence of the Southern Annular Mode (SAM) and the El Niño Southern Oscillation (ENSO) on precipitation anomalies (PP) of the Rio Grande do Sul Coastal Plain (RGSCP), dividing it into three regions: south, central and north. Contingency tables were used to correlate the indices, classifying them as neutral, below ou above the mean. To statistical significance we used percentage correctly classified with which the Student’s t was aplied for each region. The PP of the RGSCP and the south coast have correlation with the ENSO and SAM; the central only with SAM. The PP of the north is not correlated to either index. Periods with more than 5 months of PP, SAM and ENSO anomalies were identified. Below average events were majority. The results indicate greater influence of SAM + and La Niña. The trend towards SAM+ and intensification of ENSO, could increase the frequency of droughts in RGSCP. In addition, it was possible to interpret that the geographical differences of the RGSCP can influence the results of precipitation totals. This work contributes to the understanding of the effects of the new trends of climatic variability under regional and geographical aspects.