Modeling the sensitivity of precipitation oxygen isotopes to the Last Glacial Maximum boundary conditions: A study using Community Atmosphere Model (CAM3.0)


Autoria(s): Tharammal, Thejna; Paul, André; Merkel, Ute; Noone, D
Data(s)

29/07/2013

Resumo

To understand the validity of d18O proxy records as indicators of past temperature change, a series of experiments was conducted using an atmospheric general circulation model fitted with water isotope tracers (Community Atmosphere Model version 3.0, IsoCAM). A pre-industrial simulation was performed as the control experiment, as well as a simulation with all the boundary conditions set to Last Glacial Maximum (LGM) values. Results from the pre-industrial and LGM simulations were compared to experiments in which the influence of individual boundary conditions (greenhouse gases, ice sheet albedo and topography, sea surface temperature (SST), and orbital parameters) were changed each at a time to assess their individual impact. The experiments were designed in order to analyze the spatial variations of the oxygen isotopic composition of precipitation (d18Oprecip) in response to individual climate factors. The change in topography (due to the change in land ice cover) played a significant role in reducing the surface temperature and d18Oprecip over North America. Exposed shelf areas and the ice sheet albedo reduced the Northern Hemisphere surface temperature and d18Oprecip further. A global mean cooling of 4.1 °C was simulated with combined LGM boundary conditions compared to the control simulation, which was in agreement with previous experiments using the fully coupled Community Climate System Model (CCSM3). Large reductions in d18Oprecip over the LGM ice sheets were strongly linked to the temperature decrease over them. The SST and ice sheet topography changes were responsible for most of the changes in the climate and hence the d18Oprecip distribution among the simulations.

Formato

text/tab-separated-values, 28 data points

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.834468

doi:10.1594/PANGAEA.834468

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Tharammal, Thejna; Paul, André; Merkel, Ute; Noone, D (2013): Influence of Last Glacial Maximum boundary conditions on the global water isotope distribution in an atmospheric general circulation model. Climate of the Past, 9(2), 789-809, doi:10.5194/cp-9-789-2013

Palavras-Chave #Center for Marine Environmental Sciences; File name; File size; File type; GeoB; Geosciences, University of Bremen; MARUM; Uniform resource locator/link to model result file
Tipo

Dataset