The effect of a warm mid‐latitude sea surface temperature anomaly on a numerical simulation of the general circulation of the southern hemisphere

• Published in: Quarterly Journal of the Royal Meteorological Society
• Main Authors: Simpson, R. W., Downey, W. K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1975
• Subjects: Antarctic; The Antarctic; Indian; Antarc*
• Online Access: http://dx.doi.org/10.1002/qj.49710143010; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fqj.49710143010; https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.49710143010

Abstract A mid‐latitude Sea Surface Temperature Anomaly (SSTA) is introduced into a 9‐level polar stereographic southern hemisphere model. Two 50‐day anomaly integrations (SSTAR1 and SSTAR2) are compared with their respective control integrations. In SSTAR2 the anomaly is introduced 10 days later than in SSTAR1. Comparison of the two integrations reveals systematic effects in some regions of the Antarctic trough and the mid‐Atlantic and Indian Oceans, but no systematic effect in the immediate area of the SSTA. The latter region shows a weak variation in SSTAR2 while SSTAR 1 is characterized by a strong variation and a blocking sequence some 20 days into the integration. The region of enhanced cyclogenesis in SSTAR1 occurs on the equatorial side of the anomaly and not the region of enhanced surface baroclinicity. One such large cyclone is a major feature of the blocking sequence. Enhanced latent heat release appears to be an important factor in these developments.