ENSO-Driven Energy Budget Perturbations in Observations and CMIP Models

Autor(en)

Michael Mayer, John T. Fasullo, Leopold Haimberger, Kevin E Trenberth

Abstrakt

Various observation-based datasets are employed to robustly quantify changes in ocean heat content (OHC), anomalous ocean–atmosphere energy exchanges and atmospheric energy transports during El Niño-Southern Oscillation (ENSO). These results are used as a benchmark to evaluate the energy pathways during ENSO as simulated by coupled climate model runs from the CMIP3 and CMIP5 archives. The models are able to qualitatively reproduce observed patterns of ENSO-related energy budget variability to some degree, but key aspects are seriously biased. Area-averaged tropical Pacific OHC variability associated with ENSO is greatly underestimated by all models because of strongly biased responses of net radiation at top-of-the-atmosphere to ENSO. The latter are related to biases of mean convective activity in the models and project on surface energy fluxes in the eastern Pacific Intertropical Convergence Zone region. Moreover, models underestimate horizontal and vertical OHC redistribution in association with the generally too weak Bjerknes feedback, leading to a modeled ENSO affecting a too shallow layer of the Pacific. Vertical links between SST and OHC variability are too weak even in models driven with observed winds, indicating shortcomings of the ocean models. Furthermore, modeled teleconnections as measured by tropical Atlantic OHC variability are too weak and the tropical zonal mean ENSO signal is strongly underestimated or even completely missing in most of the considered models. Results suggest that attempts to infer insight about climate sensitivity from ENSO-related variability are likely to be hampered by biases in ENSO in CMIP simulations that do not bear a clear link to future changes.

Organisation(en)

Institut für Meteorologie und Geophysik

Externe Organisation(en)

National Center for Atmospheric Research (NCAR)

Journal

Climate Dynamics

Band

47

Seiten

4009-4029

Anzahl der Seiten

21

DOI

https://doi.org/10.1007/s00382-016-3057-z

Publikationsdatum

12-2016

Peer-reviewed

Ja

ÖFOS 2012

105204 Klimatologie

Schlagwörter

ASJC Scopus Sachgebiete

Atmospheric Science

Sustainable Development Goals

SDG 13 – Maßnahmen zum Klimaschutz

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/14892aee-8bd6-4fc8-99d0-2fcf7109376e