Tropical atmospheric and oceanic temperature variations (1979)

Since 1979, temperatures of the atmosphere and ocean surface in the tropical third of the globe have revealed variations and trends that are somewhat different. This presentation examines deep layer atmospheric temperatures from three sources (MSU, Radiosonde and NCEP Reanalyses), night marine (near-surface) air temperatures (NMATs), and sea water temperatures (SSTs) to document the differences observed. For this particular period, all atmospheric measures, including near-surface NMATs, show less warming than observed in SSTs. High-quality measurements of PMEL buoy SSTs and MATs are examined and verify this pattern of change, indicating the NMAT observations from the Hadley Centre are a useful observational dataset for studying global change. Using near-surface air temperatures over land and NMATs over the ocean allows for a systematic database of air-temperatures only, and indicates that since 1979, the global surface air temperature has experienced less warming than indicated by mixed datasets which use near-surface air temperatures over land and SSTs over oceans (globally, +0.13 K/decade vs. +0.18 K/decade since 1979).