On the recent warming in the Murray-Darling Basin: land surface interactions misunderstood

Abstract

Previous studies of the recent drought in the Murray-Darling Basin (MDB) have noted that low rainfall totals have been accompanied by anomalously high air temperatures. Subsequent studies have interpreted an identified trend in the residual timeseries of non-rainfall related temperature variability as a signal of anthropogenic change, further speculating that increased air temperature has exacerbated the drought through increasing evapotranspiration rates. In this study, we explore an alternative explanation of the recent increases in air temperature. This study demonstrates that significant misunderstanding of known processes of land surface – atmosphere interactions has led to the incorrect attribution of the causes of the anomalous temperatures, as well as significant misunderstanding of their impact on evaporation within the Murray-Darling Basin.