scholarly journals Behaviour of the quiet-day geomagnetic variation at Livingston Island and variability of the S q focus position in the South American-Antarctic Peninsula region

2010 ◽  
Vol 62 (3) ◽  
pp. 297-307 ◽  
Author(s):  
J. Miquel Torta ◽  
Santiago Marsal ◽  
Juan J. Curto ◽  
Luis R. Gaya-Piqué
Keyword(s):  
Antarctic Peninsula ◽  
Geomagnetic Variation ◽  
South American ◽  
Focus Position ◽  
The South ◽  
Livingston Island ◽  
Quiet Day

scholarly journals Variations in ice rafted detritus on beaches in the South Shetland Islands: a possible climate proxy

2004 ◽  
Vol 16 (3) ◽  
pp. 339-344 ◽  
Author(s):  
BRENDA L. HALL ◽  
ETHAN R. PERRY
Keyword(s):  
Antarctic Peninsula ◽  
Ocean Circulation ◽  
Late Holocene ◽  
Warming Trend ◽  
South Shetland Islands ◽  
The South ◽  
Shetland Islands ◽  
Livingston Island ◽  
The Antarctic ◽  
Glacial Advance

Raised beach ridges on Livingston Island of the South Shetland Islands display variations in both quantity and source of ice rafted detritus (IRD) received over time. Whereas the modern beach exhibits little IRD, all of which is of local origin, the next highest beach (∼250 14C yr BP) has large amounts, some of which comes from as far away as the Antarctic Peninsula. Significant quantities of IRD also were deposited ∼1750 14C yr BP. Both time periods coincide with generally cooler regional conditions and, at least in the case of the ∼250 yr old beach, local glacial advance. We suggest that the increases in ice rafting may reflect periods of greater glacial activity, altered ocean circulation, and/or greater iceberg preservation during the late Holocene. Limited IRD and lack of far-travelled erratics on the modern beach are both consistent with the ongoing warming trend in the Antarctic Peninsula region.

222Rn in the Antarctic Peninsula During 1986

1988 ◽  
Vol 24 (1-4) ◽  
pp. 85-88 ◽  
Author(s):  
E.B. Pereira ◽  
A.W. Setzer ◽  
I.F.A. Cavalcanti
Keyword(s):  
Seasonal Variation ◽  
Antarctic Peninsula ◽  
Radon Concentration ◽  
Positive Association ◽  
Atmospheric Temperature ◽  
South American ◽  
The South ◽  
Short Term ◽  
Strong Positive Association ◽  
The Antarctic

Abstract 222Rn was continuously measured at the Brazilian Antarctic Station (62 oS, 58 oW) during the year of 1986. Baseline radon concentration averaged 0.02 Bq.m-3 with surges peaking at 0.4 Bq.m-3. The data exhibited a characteristic periodicity of about 25 days and a strong positive association with short term fluctuations of atmospheric temperature. No seasonal variation of radon were observed. Interpretation of the radon surges with reference to synoptic charts and weather satellite pictures showed that the continental influence of radon at the Antarctic Peninsula is very small and comes only from the tip of the South American cone.

scholarly journals THE INITIAL STEPS FOR DEVELOPING THE SOUTH AMERICAN K INDEX FROM THE EMBRACE MAGNETOMETER NETWORK

2015 ◽  
Vol 33 (1) ◽  
pp. 79 ◽  
Author(s):  
Clezio Marcos Denardini ◽  
Marlos Rockenbach Da Silva ◽  
Mauricio Alfredo Gende ◽  
Sony Su Chen ◽  
Paulo Roberto Fagundes ◽  
...  
Keyword(s):  
Space Weather ◽  
South American ◽  
The South ◽  
K Index ◽  
Upper Limits ◽  
Quiet Day ◽  
Magnetic Index ◽  
K Scale

ABSTRACT. In this paper we present the first steps given towards the development of the South American K index (Ksa) based on the measurements made by the Embrace Magnetometer Network. We present: (a) a description of the magnetometer and of the network; (b) the procedure used to calibrate the network equipments; (c) the procedure to obtain each station K scale and its corresponding upper limits of ranges for the three-hour-range station K index (thereafter referred as K9 threshold); and (d) some particularities regarding the Quiet Day Curve (QDC) deviation and its long term variation.Keywords: space weather, magnetic index, magnetometer network, aeronomy.RESUMO. No presente artigo, apresentamos os primeiros passos realizados para desenvolvermos o índice K sul-americano (Ksa) baseado nas medidas feitas pela rede Embrace de magnetômetros. Apresentamos (a) uma descrição do equipamento utilizado, bem como da rede de magnetômetros; (b) o procedimento adotado para calibrar todos os equipamentos individuais da rede; (c) o procedimento para se obter a escala K de cada estação magnética e o seu correspondente limite superior para o índice K de três horas (doravante denominado limiar K9); e (d) algumas particularidades com respeito à obtenção da curva do Dia Quieto (QDC) e suas variações de longos períodos.Palavras-chave: clima espacial, índice magn´etico, rede de magnetômetros, aeronomia.

Cnidochloa: A New Genus of Grasses from Brazil (Poaceae: Panicoideae: Paniceae)

2020 ◽  
Vol 105 (2) ◽  
pp. 183-194
Author(s):  
Fernando O. Zuloaga ◽  
Sandra S. Aliscioni ◽  
M. Amalia Scataglini
Keyword(s):  
New Genus ◽  
Phylogenetic Position ◽  
South American ◽  
The South ◽  
South American Species ◽  
Molecular Characters

Generic boundaries of the South American species Panicum longipedicellatum Swallen are explored and compared with allied genera of the tribe Paniceae. On the basis of morphological, anatomical, and molecular characters a new genus, Cnidochloa Zuloaga, is proposed. The phylogenetic position of the new genus within the Paniceae is evaluated.

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