scholarly journals Climate variability since last glacial maximum based on distribution of foraminifera in North Papua Waters, Pacific Ocean

2020 ◽  
Vol 45 (2) ◽  
pp. 59-66
Author(s):  
Adrianus Damanik ◽  
Khoiril Anwar Maryunani ◽  
Septriono Hari Nugroho ◽  
Purna Sulastya Putra
Keyword(s):  
Pacific Ocean ◽  
Climate Variability ◽  
Last Glacial Maximum ◽  
Thermohaline Circulation ◽  
Global Climate ◽  
Abundant Species ◽  
Climatic Conditions ◽  
Glacial Maximum ◽  
Climate Conditions ◽  
Last Glacial

Foraminifera distribution is one of the proxies used to reconstruct climatic conditions and paleoceanography. Specific species or groups of foraminifera can be associated with certain oceanographic parameters. As one of the entrances of Indonesia Through Flow (ITF), North Papua Waters has the role of channeling water masses from the Pacific Ocean to the Indonesian Waters. It is also influenced by global thermohaline circulation and ENSO. In this study, observations were made of changes in the distribution of foraminifera to reconstruct paleoclimate and paleoceanographic conditions in the North Papua Waters and their relation to global climate conditions. The analysis was performed on 246 cm core sediments with eight cm foraminifera observation intervals at sample depths 246-126 cm and four cm at sample depths of 126-0 cm. Pulleniatina spp., Neogloboquadrina spp., and Globorotalia spp., are used for radiocarbon dating. Planktonic abundant species of foraminifera are Pulleniatina obliqueloculata, Neogloboquadrina dutertrei, Globorotalia menardii, Globigerinoides ruber, Globigerinoides trilobus, and the benthonic are Melonis pompilideus, Pullenia bulloides, Oolina sp., Planulina bradyii, Oridorsalis umbonatus, Cibicides subhaidingerii, Eggrela bradyii, Planulina wuelestroffi, and Quinqueloculina spp.,. Division according to cluster analysis can show the difference between Holocene and Pleistocene, which is then more detailed divided into 17 clusters. Based on biozonation there are some events that can be observed: climate variability since Late Pleistocene, record Pleistocene-Holocene boundary based on the significant variability of foraminifera distribution, and records some of the global climate events such as Last Glacial Maximum (~19-17 kyr), Younger Dryas (~11-9 kyr), and 8,2K event.

scholarly journals Antarctic surface temperature and elevation during the Last Glacial Maximum

Science ◽  
2021 ◽  
Vol 372 (6546) ◽  
pp. 1097-1101
Author(s):  
Christo Buizert ◽  
T. J. Fudge ◽  
William H. G. Roberts ◽  
Eric J. Steig ◽  
Sam Sherriff-Tadano ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Last Glacial Maximum ◽  
Climate Models ◽  
Global Climate ◽  
Ice Cores ◽  
Temperature Inversion ◽  
Glacial Maximum ◽  
Global Climate Models ◽  
Surface Cooling ◽  
Last Glacial

Water-stable isotopes in polar ice cores are a widely used temperature proxy in paleoclimate reconstruction, yet calibration remains challenging in East Antarctica. Here, we reconstruct the magnitude and spatial pattern of Last Glacial Maximum surface cooling in Antarctica using borehole thermometry and firn properties in seven ice cores. West Antarctic sites cooled ~10°C relative to the preindustrial period. East Antarctic sites show a range from ~4° to ~7°C cooling, which is consistent with the results of global climate models when the effects of topographic changes indicated with ice core air-content data are included, but less than those indicated with the use of water-stable isotopes calibrated against modern spatial gradients. An altered Antarctic temperature inversion during the glacial reconciles our estimates with water-isotope observations.

scholarly journals Analysis of the global atmospheric methane budget using ECHAM-MOZ simulations for present-day, pre-industrial time and the Last Glacial Maximum

2014 ◽  
Vol 14 (2) ◽  
pp. 3193-3230 ◽  
Author(s):  
A. Basu ◽  
M. G. Schultz ◽  
S. Schröder ◽  
L. Francois ◽  
X. Zhang ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Anthropogenic Sources ◽  
Atmospheric Methane ◽  
Climate Conditions ◽  
Last Glacial ◽  
Methane Budget ◽  
The Last Glacial Maximum ◽  
Methane Concentrations ◽  
The Last Glacial

Abstract. Atmospheric methane concentrations increased considerably from pre-industrial (PI) to present times largely due to anthropogenic emissions. However, firn and ice core records also document a notable rise of methane levels between the Last Glacial Maximum (LGM) and the pre-industrial era, the exact cause of which is not entirely clear. This study investigates these changes by analyzing the methane sources and sinks at each of these climatic periods. Wetlands are the largest natural source of methane and play a key role in determining methane budget changes in particular in the absence of anthropogenic sources. Here, a simple wetland parameterization suitable for coarse-scale climate simulations over long periods is introduced, which is derived from a high-resolution map of surface slopes together with various soil hydrology parameters from the CARAIB vegetation model. This parameterization was implemented in the chemistry general circulation model ECHAM5-MOZ and multi-year time slices were run for LGM, PI and present-day (PD) climate conditions. Global wetland emissions from our parameterization are 72 Tg yr−1 (LGM), 115 Tg yr−1 (PI), and 132 Tg yr−1 (PD). These estimates are lower than most previous studies, and we find a stronger increase of methane emissions between LGM and PI. Taking into account recent findings that suggest more stable OH concentrations than assumed in previous studies, the observed methane distributions are nevertheless well reproduced under the different climates. Hence, this is one of the first studies where a consistent model approach has been successfully applied for simulating methane concentrations over a wide range of climate conditions.

scholarly journals Reconstruction of Pacific Ocean bottom water salinity during the Last Glacial Maximum

2014 ◽  
Vol 41 (8) ◽  
pp. 2914-2920 ◽  
Author(s):  
Tania Lado Insua ◽  
Arthur J. Spivack ◽  
Dennis Graham ◽  
Steven D'Hondt ◽  
Kathryn Moran
Keyword(s):  
Pacific Ocean ◽  
Last Glacial Maximum ◽  
Bottom Water ◽  
Glacial Maximum ◽  
Water Salinity ◽  
Ocean Bottom ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial
Sign in / Sign up

Export Citation Format

Share Document