Tom Quirk, an AEF Director, has published an interesting paper on Jo Nova's website [link here] looking at the relationship between rainfall and atmospheric temperature in Australia. In it Tom seeks to answer the question as to whether temperature determines rainfall or vice versa. This is an important issue in climate modelling and long-term temperature projections made with climate models.
Tom has found a clear interaction between temperature and rainfall. This was based on his analysis of standardised temperature and rainfall anomalies—the difference between the value in any given period and the long term average for the variable in question. For this purpose he used the near-surface temperature and rainfall datasets published by the Australian Bureau of Meteorology (BOM) and the lower troposphere temperature dataset of the University of Alabama in Huntsville (UAH) in the US.
The sensitivity of the UAH-BOM temperature anomaly and the rainfall anomaly varied with both the rainfall and the period of time the moisture remained on the ground. This reflects the fact that evaporation cools near- surface temperatures but not those in the lower troposphere. With above-average rainfall, the BOM temperature anomaly may be less than the UAH temperature anomaly, while with below-average rainfall the reverse occurs and the BOM temperature anomaly exceeds the UAH temperature anomaly.
A copy of Tom's paper may be downloaded from here.