Corrigendum to &quot;High-resolution interpolar difference of atmospheric methane around the Last Glacial Maximum&quot; published in Biogeosciences, 9, 3961–3977, 2012

Abstract. Reconstructions of past atmospheric methane concentrations are available from ice cores from both, Greenland and Antarctica. The difference observed between the two polar methane concentration levels is a valuable additional parameter which allows to constrain the geographical location of the responsible methane sources. Here we present new high-resolution methane records from the North Greenland Ice Core Project (NGRIP) and the European Project for Ice Coring in Antarctica (EPICA) Dronning Maud Land (EDML) ice cores covering Termination 1, the Last Glacial Maximum, and parts of the last glacial back to 32 000 years before present. Due to the high-resolution records the synchronisation between the ice cores from NGRIP and EDML is considerably improved and the interpolar concentration difference of methane is determined with unprecedented precision and temporal resolution. Relative to the mean methane concentration, we find a rather stable positive interpolar difference throughout the record with its minimum value of 3.7 ± 0.7 % between 21 900–21 200 years before present, which is higher than previously estimated in this interval close to the Last Glacial Maximum. This implies that Northern Hemisphere boreal wetland sources were never completely shut off during the peak glacial. Starting at 21 000 years before present, i.e. severval millenia prior to the transition into the Holocene, the relative interpolar difference becomes even more positive and stays at a fairly stable level of 6.5 ± 0.8 % during Termination 1. We hypothesise that the anti-correlation observed in the monsoon records from the Northern and Southern Hemispheres induces a methane source redistribution within lower latitudes, which could explain parts of the variations in the interpolar difference.

Download Full-text

Seismostratigraphy of a submerged coastal transition zone: Precise determination of paleocoastal environments during the last glacial maximum from high-resolution 3D multichannel seismic

10.1190/segam2018-2998308.1 ◽

2018 ◽

Author(s):

Chris M. Castillo ◽

Simon Klemperer

Keyword(s):

High Resolution ◽

Transition Zone ◽

Last Glacial Maximum ◽

Precise Determination ◽

Glacial Maximum ◽

Last Glacial ◽

The Last Glacial Maximum ◽

The Last Glacial

Download Full-text

High-resolution climate simulation of the last glacial maximum

Climate Dynamics ◽

10.1007/s00382-007-0332-z ◽

2007 ◽

Vol 31 (1) ◽

pp. 1-16 ◽

Cited By ~ 68

Author(s):

Seong-Joong Kim ◽

Thomas J. Crowley ◽

David J. Erickson ◽

Bala Govindasamy ◽

Phillip B. Duffy ◽

...

Keyword(s):

High Resolution ◽

Last Glacial Maximum ◽

Glacial Maximum ◽

Climate Simulation ◽

Last Glacial ◽

The Last Glacial Maximum ◽

The Last Glacial

Download Full-text

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

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-3193-2014 ◽

2014 ◽

Vol 14 (2) ◽

pp. 3193-3230 ◽

Cited By ~ 1

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.

Download Full-text

Terrestrial methane emissions from the Last Glacial Maximum to the preindustrial period

Climate of the Past ◽

10.5194/cp-16-575-2020 ◽

2020 ◽

Vol 16 (2) ◽

pp. 575-595 ◽

Cited By ~ 1

Author(s):

Thomas Kleinen ◽

Uwe Mikolajewicz ◽

Victor Brovkin

Keyword(s):

Last Glacial Maximum ◽

Methane Emissions ◽

Glacial Maximum ◽

Minor Importance ◽

Atmospheric Methane ◽

Max Planck ◽

Natural Sources ◽

Last Glacial ◽

The Last Glacial Maximum ◽

The Last Glacial

Abstract. We investigate the changes in terrestrial natural methane emissions between the Last Glacial Maximum (LGM) and preindustrial (PI) periods by performing time-slice experiments with a methane-enabled version of MPI-ESM, the Max Planck Institute Earth System Model. We consider all natural sources of methane except for emissions from wild animals and geological sources, i.e. emissions from wetlands, fires, and termites. Changes are dominated by changes in tropical wetland emissions, with mid-to-high-latitude wetlands playing a secondary role, and all other natural sources being of minor importance. The emissions are determined by the interplay of vegetation productivity, a function of CO2 and temperature; source area size, affected by sea level and ice sheet extent; and the state of the West African monsoon, with increased emissions from northern Africa during strong monsoon phases. We show that it is possible to explain the difference in atmospheric methane between LGM and PI purely by changes in emissions. As emissions more than double between LGM and PI, changes in the atmospheric lifetime of CH4, as proposed in other studies, are not required.

Download Full-text