Identifying External Influences on Global Precipitation

TitleIdentifying External Influences on Global Precipitation
Publication TypeJournal Article
Year of Publication2013
JournalProceedings of the National Academy of Sciences
Volume110
Number48
Pages19301-19306
Abstract / Summary

Changes in global (ocean and land) precipitation are among the most important and least well-understood consequences of climate change. Increasing greenhouse gas concentrations are thought to affect the zonal-mean distribution of precipitation through two basic mechanisms. First, increasing temperatures will lead to an intensification of the hydrological cycle (“thermodynamic” changes). Second, changes in atmospheric circulation patterns will lead to poleward displacement of the storm tracks and subtropical dry zones and to a widening of the tropical belt (“dynamic” changes). We demonstrate that both these changes are occurring simultaneously in global precipitation, that this behavior cannot be explained by internal variability alone, and that external influences are responsible for the observed precipitation changes. Whereas existing model experiments are not of sufficient length to differentiate between natural and anthropogenic forcing terms at the 95% confidence level, we present evidence that the observed trends result from human activities.

URLhttp://www.pnas.org/content/110/48/19301.abstract
DOI10.1073/pnas.1314382110
Journal: Proceedings of the National Academy of Sciences
Year of Publication: 2013
Volume: 110
Number: 48
Pages: 19301-19306

Changes in global (ocean and land) precipitation are among the most important and least well-understood consequences of climate change. Increasing greenhouse gas concentrations are thought to affect the zonal-mean distribution of precipitation through two basic mechanisms. First, increasing temperatures will lead to an intensification of the hydrological cycle (“thermodynamic” changes). Second, changes in atmospheric circulation patterns will lead to poleward displacement of the storm tracks and subtropical dry zones and to a widening of the tropical belt (“dynamic” changes). We demonstrate that both these changes are occurring simultaneously in global precipitation, that this behavior cannot be explained by internal variability alone, and that external influences are responsible for the observed precipitation changes. Whereas existing model experiments are not of sufficient length to differentiate between natural and anthropogenic forcing terms at the 95% confidence level, we present evidence that the observed trends result from human activities.

DOI: 10.1073/pnas.1314382110
Citation:
2013.  "Identifying External Influences on Global Precipitation."  Proceedings of the National Academy of Sciences 110(48): 19301-19306.  https://doi.org/10.1073/pnas.1314382110.