Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles
A compilation is presented of global sea surface temperature (SST) records that span around one glacial cycle or more, and it is compared with changes in the earth’s radiative balance over the last 520 000 years, as determined from greenhouse gas concentrations, albedo changes related to ice sheet a...
Published in: | Journal of Climate |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2012
|
Subjects: | |
Online Access: | https://eprints.soton.ac.uk/336150/ |
id |
ftsouthampton:oai:eprints.soton.ac.uk:336150 |
---|---|
record_format |
openpolar |
spelling |
ftsouthampton:oai:eprints.soton.ac.uk:336150 2023-08-27T04:03:39+02:00 Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles Rohling, E.J. Medina-Elizalde, M. Shepherd, J.G. Siddall, M. Stanford, J.D. 2012 https://eprints.soton.ac.uk/336150/ unknown Rohling, E.J., Medina-Elizalde, M., Shepherd, J.G., Siddall, M. and Stanford, J.D. (2012) Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles. Journal of Climate, 25 (5), 1635-1656. (doi:10.1175/2011JCLI4078.1 <http://dx.doi.org/10.1175/2011JCLI4078.1>). Article PeerReviewed 2012 ftsouthampton https://doi.org/10.1175/2011JCLI4078.1 2023-08-03T22:19:58Z A compilation is presented of global sea surface temperature (SST) records that span around one glacial cycle or more, and it is compared with changes in the earth’s radiative balance over the last 520 000 years, as determined from greenhouse gas concentrations, albedo changes related to ice sheet area and atmospheric dust fluctuations, and insolation changes. A first scenario uses global mean values for the radiative changes, and a second scenario uses zonal means for 10° latitude bands for a more regionally specific perspective. On the orbital time scales studied here, a smooth increase of SST response from the equator to high latitudes is found when comparison is made to global mean radiative forcing, but a sharply “stepped” increase at 20°–30° latitude when comparing with the more regionally specific forcings. The mean global SST sensitivities to radiative change are within similar limits for both scenarios, around 0.8 ± 0.4°C (W m?2)?1. Combined with previous estimates of 1.3–1.5 times stronger temperature sensitivity over land, this yields an estimate for global climate sensitivity of 0.85 (?0.4/+0.5)°C (W m?2)?1, close to previous estimates. If aerosol (dust) feedback were to be considered as a fast feedback, then the estimated central value for SST sensitivity would change to ~0.95°C (W m?2)?1 and that for global climate sensitivity to ~1.05°C (W m?2)?1. The zonal-mean scenario allows an assessment of (long-term) “normalized amplification” for Greenland and Antarctic temperature sensitivities, which is the ratio of temperature sensitivity for those sites relative to the global mean sensitivity, normalized per watt per meter squared of radiative change. This ratio is found to be 0.9 (?0.2/+0.6) and 1.4 (?0.4/+1.1) for Greenland and Antarctica, respectively. Given its value close to 1 for Greenland, but that larger Arctic amplification on shorter time scales due to fast sea ice albedo processes cannot be excluded, it is suggested that current high Arctic sensitivity is mainly due to sea ice albedo feedback ... Article in Journal/Newspaper albedo Antarc* Antarctic Antarctica Arctic Greenland Ice Sheet Sea ice University of Southampton: e-Prints Soton Antarctic Arctic Greenland Journal of Climate 25 5 1635 1656 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
unknown |
description |
A compilation is presented of global sea surface temperature (SST) records that span around one glacial cycle or more, and it is compared with changes in the earth’s radiative balance over the last 520 000 years, as determined from greenhouse gas concentrations, albedo changes related to ice sheet area and atmospheric dust fluctuations, and insolation changes. A first scenario uses global mean values for the radiative changes, and a second scenario uses zonal means for 10° latitude bands for a more regionally specific perspective. On the orbital time scales studied here, a smooth increase of SST response from the equator to high latitudes is found when comparison is made to global mean radiative forcing, but a sharply “stepped” increase at 20°–30° latitude when comparing with the more regionally specific forcings. The mean global SST sensitivities to radiative change are within similar limits for both scenarios, around 0.8 ± 0.4°C (W m?2)?1. Combined with previous estimates of 1.3–1.5 times stronger temperature sensitivity over land, this yields an estimate for global climate sensitivity of 0.85 (?0.4/+0.5)°C (W m?2)?1, close to previous estimates. If aerosol (dust) feedback were to be considered as a fast feedback, then the estimated central value for SST sensitivity would change to ~0.95°C (W m?2)?1 and that for global climate sensitivity to ~1.05°C (W m?2)?1. The zonal-mean scenario allows an assessment of (long-term) “normalized amplification” for Greenland and Antarctic temperature sensitivities, which is the ratio of temperature sensitivity for those sites relative to the global mean sensitivity, normalized per watt per meter squared of radiative change. This ratio is found to be 0.9 (?0.2/+0.6) and 1.4 (?0.4/+1.1) for Greenland and Antarctica, respectively. Given its value close to 1 for Greenland, but that larger Arctic amplification on shorter time scales due to fast sea ice albedo processes cannot be excluded, it is suggested that current high Arctic sensitivity is mainly due to sea ice albedo feedback ... |
format |
Article in Journal/Newspaper |
author |
Rohling, E.J. Medina-Elizalde, M. Shepherd, J.G. Siddall, M. Stanford, J.D. |
spellingShingle |
Rohling, E.J. Medina-Elizalde, M. Shepherd, J.G. Siddall, M. Stanford, J.D. Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles |
author_facet |
Rohling, E.J. Medina-Elizalde, M. Shepherd, J.G. Siddall, M. Stanford, J.D. |
author_sort |
Rohling, E.J. |
title |
Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles |
title_short |
Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles |
title_full |
Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles |
title_fullStr |
Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles |
title_full_unstemmed |
Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles |
title_sort |
sea surface and high-latitude temperature sensitivity to radiative forcing of climate over several glacial cycles |
publishDate |
2012 |
url |
https://eprints.soton.ac.uk/336150/ |
geographic |
Antarctic Arctic Greenland |
geographic_facet |
Antarctic Arctic Greenland |
genre |
albedo Antarc* Antarctic Antarctica Arctic Greenland Ice Sheet Sea ice |
genre_facet |
albedo Antarc* Antarctic Antarctica Arctic Greenland Ice Sheet Sea ice |
op_relation |
Rohling, E.J., Medina-Elizalde, M., Shepherd, J.G., Siddall, M. and Stanford, J.D. (2012) Sea Surface and High-Latitude Temperature Sensitivity to Radiative Forcing of Climate over Several Glacial Cycles. Journal of Climate, 25 (5), 1635-1656. (doi:10.1175/2011JCLI4078.1 <http://dx.doi.org/10.1175/2011JCLI4078.1>). |
op_doi |
https://doi.org/10.1175/2011JCLI4078.1 |
container_title |
Journal of Climate |
container_volume |
25 |
container_issue |
5 |
container_start_page |
1635 |
op_container_end_page |
1656 |
_version_ |
1775357080571478016 |