(Image source: NOAA)
Despite an atmospheric train wreck that resulted in stormy weather and below average temperatures for much of Europe and some of the United States, global surface temperatures for March of 2013 were the 10th hottest on record. Large areas south of Australia and over central and northern China experienced their hottest month ever recorded. No monitoring regions experienced their lowest temperature on record.
ENSO neutral conditions remained in force throughout March of 2013. While La Nina conditions tend to cool global surface temperatures and transport atmospheric heat into the deeper ocean, El Nino produces an opposite effect, dumping ocean heat content into the atmosphere and causing surface temperatures to spike. By contrast, ENSO neutral conditions tend to result in more moderate temperatures.
With ENSO neutral conditions extending back to the start of 2013, the period of January through March was the 8th hottest on record. Global land and ocean surface temperatures pushed 1.04 degrees Fahrenheit above the 20th century average for this time of year. As with March, no regions on the surface of Earth experienced record low temperatures. In contrast, a massive region south of Australia experienced their warmest temperatures since record-taking began.
The above image provided by NOAA shows broad swaths of much warmer than average temperatures spreading over most of the world’s tropics, spilling out over Australia and down toward Antarctica. Most of the globe experienced some degree of warmer than average temperatures. In contrast, cooler than average areas were confined to isolated parts of Siberia, Europe, and the western Pacific.
In comparison with January through March of 2012, global temperatures for the same period during 2013 were about .3 degrees Fahrenheit warmer. This temperature increase was likely driven by a slow transition from La Nina to ENSO neutral conditions combined with the long-term upward forcing on temperatures resulting from human greenhouse gas emissions.