The University of Southampton
University of Southampton Institutional Repository

Twentieth century temperature trends in CMIP3, CMIP5, and CESM-LE climate simulations – spatial-temporal uncertainties, differences and their potential sources

Twentieth century temperature trends in CMIP3, CMIP5, and CESM-LE climate simulations – spatial-temporal uncertainties, differences and their potential sources
Twentieth century temperature trends in CMIP3, CMIP5, and CESM-LE climate simulations – spatial-temporal uncertainties, differences and their potential sources
The twentieth century climate simulations from the Coupled Model Intercomparison Project Phase 3 (CMIP3) and Phase 5 (CMIP5) are compared to assess the models' ability to capture observed near-surface air temperature trends at global, continental, and regional scales. We computed trends by using a nonparametric method and considering long-term persistence in the time series. The role of internal variability is examined by using large ensemble climate simulations from the National Center for Atmospheric Research model Community Earth System Model (CESM). We computed temperature trends for three periods: (1) the twentieth century, (2) the second half of the twentieth century, and (3) the recent hiatus period to contrast the roles of external forcing and internal variability at various spatial and temporal scales. Both CMIP ensembles show statistically significant warming at global and continental scales during the twentieth century. We found a small but statistically significant difference between CMIP3 (0.57?±?0.07?°C/century) and CMIP5 (0.47?±?0.06?°C/century) twentieth century temperature trends, with the CMIP3 estimate being closer to the observations. The spatial structure of long-term temperature trends, and top-of-the atmosphere net radiation trends, suggests that differences in model parameterizations and feedback processes that lead to a smaller net radiative forcing are likely contributing to the differences between CMIP3 and CMIP5. The estimate of internal variability based on the CESM large ensemble spans 24% of the uncertainty in CMIP5 for the twentieth century temperature trends, and 76% for the recent hiatus period, both at global scales, and 43% and almost 100% during the corresponding time periods at regional scales.
0148-0227
9561-9575
Kumar, Sanjiv
4488e829-d6dc-45e3-b6ef-a746e94bcb96
Kinter, James
1ebfe50a-6cc4-4a2a-90fb-8b0e1db04bc8
Pan, Zaitao
100dc13f-6ee7-4d88-b326-4dfc600a99fa
Sheffield, Justin
dd66575b-a4dc-4190-ad95-df2d6aaaaa6b
Kumar, Sanjiv
4488e829-d6dc-45e3-b6ef-a746e94bcb96
Kinter, James
1ebfe50a-6cc4-4a2a-90fb-8b0e1db04bc8
Pan, Zaitao
100dc13f-6ee7-4d88-b326-4dfc600a99fa
Sheffield, Justin
dd66575b-a4dc-4190-ad95-df2d6aaaaa6b

Kumar, Sanjiv, Kinter, James, Pan, Zaitao and Sheffield, Justin (2016) Twentieth century temperature trends in CMIP3, CMIP5, and CESM-LE climate simulations – spatial-temporal uncertainties, differences and their potential sources. Journal of Geophysical Research, 121 (16), 9561-9575. (doi:10.1002/2015JD024382).

Record type: Article

Abstract

The twentieth century climate simulations from the Coupled Model Intercomparison Project Phase 3 (CMIP3) and Phase 5 (CMIP5) are compared to assess the models' ability to capture observed near-surface air temperature trends at global, continental, and regional scales. We computed trends by using a nonparametric method and considering long-term persistence in the time series. The role of internal variability is examined by using large ensemble climate simulations from the National Center for Atmospheric Research model Community Earth System Model (CESM). We computed temperature trends for three periods: (1) the twentieth century, (2) the second half of the twentieth century, and (3) the recent hiatus period to contrast the roles of external forcing and internal variability at various spatial and temporal scales. Both CMIP ensembles show statistically significant warming at global and continental scales during the twentieth century. We found a small but statistically significant difference between CMIP3 (0.57?±?0.07?°C/century) and CMIP5 (0.47?±?0.06?°C/century) twentieth century temperature trends, with the CMIP3 estimate being closer to the observations. The spatial structure of long-term temperature trends, and top-of-the atmosphere net radiation trends, suggests that differences in model parameterizations and feedback processes that lead to a smaller net radiative forcing are likely contributing to the differences between CMIP3 and CMIP5. The estimate of internal variability based on the CESM large ensemble spans 24% of the uncertainty in CMIP5 for the twentieth century temperature trends, and 76% for the recent hiatus period, both at global scales, and 43% and almost 100% during the corresponding time periods at regional scales.

Text
Manuscript_rev5_final_rev5_07_22_track_change_JK_ZP_final.docx - Accepted Manuscript
Download (8MB)

More information

Accepted/In Press date: 30 July 2016
e-pub ahead of print date: 4 August 2016
Published date: 27 August 2016
Organisations: Global Env Change & Earth Observation

Identifiers

Local EPrints ID: 402176
URI: http://eprints.soton.ac.uk/id/eprint/402176
ISSN: 0148-0227
PURE UUID: 2469e8e8-e9d5-4cad-8d0e-ca0f37bbc3f0
ORCID for Justin Sheffield: ORCID iD orcid.org/0000-0003-2400-0630

Catalogue record

Date deposited: 02 Nov 2016 16:40
Last modified: 07 Oct 2020 05:44

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×