Climate and Dynamics
Recent widening of the tropical belt from global tropopause statistics: Sensitivities
Article first published online: 3 DEC 2010
Copyright 2010 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 115, Issue D23, 16 December 2010
How to Cite
2010), Recent widening of the tropical belt from global tropopause statistics: Sensitivities, J. Geophys. Res., 115, D23109, doi:10.1029/2010JD014664.(
- Issue published online: 3 DEC 2010
- Article first published online: 3 DEC 2010
- Manuscript Accepted: 24 SEP 2010
- Manuscript Revised: 25 AUG 2010
- Manuscript Received: 22 JUN 2010
- climate change;
- general circulation
 Several recent studies have shown evidence for a widening of the tropical belt over the past few decades. One line of evidence uses statistics of the tropopause height to distinguish between tropics and extratropics and defines tropical edge latitudes as those latitudes at which the number of days per year with tropopause heights greater than 15 km exceeds a certain threshold (typically 200 days/yr). This definition involves two somewhat arbitrary thresholds. Here the sensitivity of the resulting widening trend of the tropical belt to these thresholds is investigated using four different reanalysis data sets. Widening trends are found to be particularly sensitive to changes in the tropopause height threshold. Ways to objectively determine appropriate thresholds to define tropical edge latitudes based on tropopause statistics are presented. Trend estimates for the width of the tropical belt from different reanalysis data sets are found to be mostly inconsistent with each other despite consistent seasonal and interannual variations.