The frequency of extreme maximum (minimum) temperatures of hot days (cool nights) was analyzed over the Maritime Continent with data from observations, a dynamic downscaling of a hindcast experiment forced by the European Centre for Medium-Range Weather Forecasts Reanalysis-Interim dataset, a historical experiment forced by the Hadley Centre Global Environmental Model Version 2-Atmosphere-Ocean (HadGEM2-AO) global coupled model, near-future projections from a Representative Concentration Pathway (RCP) 4.5 experiment, and a far-future projection from an RCP 8.5 experiment forced by the future projections of the

HadGEM2-AO output.

Correlations between observed extreme temperature frequency and the El Nino Southern Oscillation (ENSO) during hot or cool seasons were quantified over the local lands. We found that the impact of ENSO on extremes was dependent on the Madden-Julian Oscillation (MJO) phases. The overlapped downdraft anomaly of ENSO and MJO increased solar radiation during the daytime and outgoing longwave radiation during the nighttime, thus increasing the extreme events.

The hindcast experiment reasonably simulated the climate annual cycle of maximum and minimum temperature. Qualitatively, the impacts of ENSO and MJO on the frequency of hot days were reasonably reproduced in the hindcast experiment but not on the frequency of cool nights. The main features of extreme variation as a function of ENSO and MJO were generally comparable with observation. Generally, the model produced realistic probability distributions of the extreme exceedance over all lands.

The historical experiment was capable of representing the phases of the annual cycle of maximum and minimum temperature, but the links between extreme temperature and ENSO or MJO were not very clear. The probability distributions of extreme exceedances were reasonably reproduced in the historical experiment.

There was a decreasing trend for slightly extreme hot day events in the future. However, the severely extreme hot days are often likely in the future. The extreme exceedance is likely to have a larger mean and spread in the future. The return period for all levels of extreme hot days is likely to become shorter in the future.

1. INTRODUCTION

2. DATA

3. MODEL

4. EXPERIMENTAL DESIGN

5. RESULTS

5.1 Observational analysis

5.2 Hindcast experiment

5.3 Historical experiment

5.4 Future projections

6. CONCLUSION AND DISCUSSION

Acknowledgements

REFERENCE

TABLES

FIGURES