Mechoso Carlos R. author Robertson Andrew W. author Columbia University. International Research Institute for Climate and Society Ropelewski Chester F. author Columbia University. Earth Institute Grimm Alice M. author Columbia University. International Research Institute for Climate and Society originator text Articles 2005 manuscript version English This paper examines similarities and differences among major features of the North and South American monsoon systems. Over both North and South America the summertime circulation shows upper-level anticyclone/low-level heat low structures. These develop at different distances from the equator. It is argued that ascent to the east where convective and subtropical convergence zones develop, and subsidence over the cool waters of the eastern Pacific where stratocumulus decks provide a radiative heat sink to the tropical atmosphere are integral and unifying aspects of both monsoon systems. The intraseasonal and interannual variability of the systems are contrasted. The reported links between anomalies in soil conditions and sea surface temperatures are marginal, and consistently long-range predictability is low. Ropelewski et al. (2004) and Grimm et al. (2004) focus on each of the American monsoon systems in companion papers. Atmospheric sciences Meteorology Chang Chih-Pei editor Wang Bin editor Lau Ngar-Cheung editor Geneva World Meteorological Organization 2005 197 206 1266 http://hdl.handle.net/10022/AC:P:14471 NNC NNC 2012-08-21 13:44:28 -0400 2012-08-21 14:11:49 -0400 8491 eng