The potential use of land-atmosphere coupling metrics as a global drought-monitoring tool

Recent summers in the United States have been plagued by intense droughts that have caused significant economic impact to society that could be reduced through preparations made possible by monitoring and prediction. In particular, the recent drought in 2012 was termed by many as a “Flash drought”, due to its quick development and intensification. One possible mechanism for the sudden development of such a drought is through land-atmosphere interactions. In particular, during the convective season, when the potential of extreme drought is the highest, the soil moisture can provide a feedback mechanism that can cause or intensify drought. Recent work has developed a new classification of land-atmosphere interactions that was the basis for a Coupling Drought Index (CDI) that assesses the impact of coupling on drought and the development of the Coupling Statistical Model (CSM), which uses a Markov Chain framework to make statistical predictions. One thing that makes the CDI unique is that it can be calculated based on estimates from satellite remote sensing, which makes it particularly useful as a global drought monitor. In this work the extent to which the CDI can be used as a global drought monitor is explored along with other metrics of local land-atmosphere coupling (LoCo) for reanalysis and satellite remote sensing along with observations at the ARM test facility in the Southern Great Plains of the US. The analysis focuses on 2003 through 2013 with a particular emphasis on drought years, including the 2012 drought. Furthermore, the use of the CSM to provide a short-term global prediction of drought is also explored in order to determine its potential as a global monitoring and prediction tool.