scholarly journals Late Quaternary vegetation and climate dynamics in central‐eastern Brazil: insights from a ~35k cal a bp peat record in the Cerrado biome

2020 ◽  
Vol 35 (5) ◽  
pp. 664-676 ◽  
Author(s):  
Ingrid Horák‐Terra ◽  
Antonio Martínez Cortizas ◽  
Cynthia Fernandes Pinto Da Luz ◽  
Alexandre Christófaro Silva ◽  
Tim Mighall ◽  
...  
2007 ◽  
Vol 161 (1) ◽  
pp. 22-31 ◽  
Author(s):  
Hermann Behling ◽  
Lydie Dupont ◽  
Hugh DeForest Safford ◽  
Gerold Wefer

Terra Nova ◽  
2009 ◽  
Vol 21 (5) ◽  
pp. 375-385 ◽  
Author(s):  
Felipe Torres Figueiredo ◽  
Renato Paes de Almeida ◽  
Eric Tohver ◽  
Marly Babinski ◽  
Dunyi Liu ◽  
...  

The Holocene ◽  
2018 ◽  
Vol 28 (6) ◽  
pp. 1011-1022 ◽  
Author(s):  
Bing Song ◽  
Sangheon Yi ◽  
Wook-Hyun Nahm ◽  
Jin-Young Lee ◽  
Limi Mao ◽  
...  

To understand the early- to mid-Holocene vegetation and climate dynamics on the eastern coast of the Yellow Sea, we obtained a sedimentary core with high-resolution accelerator mass spectrometry (AMS) carbon 14 (14C) data from the Gunsan coast in South Korea. The palynological analysis demonstrated that the riverine wetland meadow from 12.1 to 9.8 cal. kyr BP changed to temperate deciduous broad-leaved forest in 9.8–2.8 cal. kyr BP. In addition, the cold climate from 12.1 to 9.8 cal. kyr BP became warmer from 8.5 to 7.3 cal. kyr BP. This was followed by another relatively cold period from 7.3 to 2.8 cal. kyr BP. The temperature change was mainly in response to solar factors. However, there are two relatively humid periods from 12.1 to 9.8 and 8.5 to 7.3 cal. kyr BP, which arose for different reasons. The earlier humid period resulted from strong westerlies and a rapidly rising sea level. The later humid period was produced mainly by the strong East Asian summer monsoon (EASM) and may also be linked to La Niña–like activity. The cold ‘Younger Dryas’ event from 12.0 to 11.4 cal. kyr BP recorded in this study may have been produced by a North Atlantic meltwater pulse. This would have reduced temperatures that were already low because of weak insolation, and the strong winter monsoons would have increased the precipitation.


2015 ◽  
Vol 50 (1) ◽  
pp. 1-12
Author(s):  
Deepak Banjade ◽  
Kabir Sharma ◽  
Khum N. Paudayal

The Thimi Formation is fluvio-deltaic deposit that constitutes the uppermost part of the sedimentary sequence in the Kathmandu Basin, and is featured by carbonaceous and diatomaceous clay, silty clay, silt, fine to medium grained sand beds, and thin to medium lignite beds. The Phaidhoka Section is located on the way to Nala from Chyamasingh, and is one of the major exposures of the Thimi Formation. Forty four samples were collected from 25 m thick surface exposure for palynological study. The study revealed the dominance of gymnosperm over the angiosperm and herbaceous members. The pollen diagram suggested Pinus, Picea and Quercus as the most dominant trees whereas Poaceae is other dominant among the grasses. Three major pollen assemblage zones were marked in the Thimi Formation. Zone P-I indicated warm temperate climate, whereas zone P-II and P-III indicated cold temperate climate. Molluscan operculum in the upper part indicated shallow water condition. The Bovid molars, limb and pelvic bones from the middle part of the section confirm the early findings of molar bones in this area.


2016 ◽  
Vol 29 (18) ◽  
pp. 6751-6763 ◽  
Author(s):  
Verónica Martín-Gómez ◽  
Emilio Hernández-Garcia ◽  
Marcelo Barreiro ◽  
Cristóbal López

Abstract Sea surface temperature (SST) anomalies over the tropical oceans are able to generate extratropical atmospheric circulation anomalies that can induce rainfall variability and changes in the sources of moisture. The work reported here evaluates the interdecadal changes in the moisture sources for southeastern South America (SESA) during austral summer, and it is divided into two complementary parts. In the first part the authors construct a climate network to detect synchronization periods among the tropical oceans and the precipitation over SESA. Afterward, taking into account these results, the authors select two periods with different degrees of synchronization to compare the spatial distribution of the SESA moisture sources. Results show that during the last century there were three synchronization periods among the tropical oceans and the precipitation over SESA (during the 1930s, 1970s, and 1990s) and suggest that the main moisture sources of SESA are the recycling over the region, the central-eastern shore of Brazil together with the surrounding Atlantic Ocean, and the southwestern South Atlantic surrounding the SESA domain. Comparison of SESA moisture sources for the 1980s (a period of nonsignificant synchronization) and the 1990s (a synchronized period) shows that the principal differences are in the intensity of the recycling and in the strength of the central-eastern shore of Brazil. Moreover, the authors find that a region centered at (20°S, 300°E) is a moisture source for SESA only during the 1990s. These differences can be associated with the development of a low-level anticyclonic (cyclonic) anomaly circulation over central-eastern Brazil that favors the transport of moisture from central Brazil (central-eastern shore of Brazil) toward SESA in the 1990s (1980s).


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