Open AccessStable water isotopes in HadCM3: Isotopic signature of El Niño–Southern Oscillation and the tropical amount effect
Author(s) -
Tindall J. C.,
Valdes P. J.,
Sime L. C.
Publication year - 2009
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2008jd010825
Subject(s) - hadcm3 , precipitation , anomaly (physics) , climatology , environmental science , sea surface temperature , water cycle , geology , atmosphere (unit) , atmospheric sciences , climate change , oceanography , meteorology , geography , general circulation model , gcm transcription factors , physics , ecology , condensed matter physics , biology
Stable water isotopes have been added to the full hydrological cycle of the Hadley Centre Climate model (HadCM3) coupled atmosphere‐ocean GCM. Simulations of δ 18 O in precipitation and at the ocean surface compare well with observations for the present‐day climate. The model has been used to investigate the isotopic anomalies associated with ENSO; it is found that the anomalous δ 18 O in precipitation is correlated with the anomalous precipitation amount in accordance with the “amount effect.” The El Niño δ 18 O anomaly at the ocean surface is largest in coastal regions because of the mixing of ocean water and the more depleted runoff from the land surface. Coral δ 18 O anomalies were estimated, using an established empirical relationship, and generally reflect ocean surface δ 18 O anomalies in coastal regions and sea surface temperatures away from the coast. The spatial relationship between tropical precipitation and δ 18 O was investigated for the El Niño anomaly simulated by HadCM3. Weighting the El Niño precipitation anomaly by the precipitation amount at each grid box gave a large increase in the spatial correlation between tropical precipitation and δ 18 O. This improvement was most apparent over land points and between 10 and 20° of latitude.