Summer Zonal mean temperature (colours) and zonal wind (contours) anomalies with respect to 1950-2000 climatology

The anomalies, relative to respective 1950-2000 climatologies of the zonal mean temperature and zonal wind for (top) the modeled Dust Bowl drought (Seager et al. 2005, J. Climate), (middle) the NCEP Reanalysis during the 1998-2002 period of the most recent drought, and (bottom) for the 2021-2040 period in the GFDL CM2.1 model, a period in which subtropical drying is already well establshed. The Dust Bowl drought is a naturally occuring drought while 2021-2040 is a model rendition of an anthropogenic subtropical drying. The observations during the 1998-2002 drought suggest a possible mix of a natural, La Nina-induced, drought amidst the impacts of global warming. Units are deg C and m/s.