Changes in zonal surface temperature gradients and Walker circulations in a wide range of climates

Details Changes in zonal surface temperature gradients and Walker circulations in a wide range of climates Changes in zonal surface temperature gradients and Walker circulations in a wide range of climates

2010-09-01

arxiv.org/abs/1009.0301v2

Physics

Atmospheric and Oceanic Physics

Scientific paper

Variations in zonal surface temperature gradients and zonally asymmetric tropical overturning circulations (Walker circulations) are examined over a wide range of climates simulated with an idealized atmospheric general circulation model (GCM). The asymmetry in the tropical climate is generated by an imposed ocean energy flux, which does not vary with climate. The range of climates is simulated by modifying the optical thickness of an idealized longwave absorber (representing greenhouse gases). The zonal surface temperature gradient in low latitudes generally decreases as the climate warms in the idealized GCM simulations. A scaling relationship based on a two-term balance in the surface energy budget accounts for the changes in the zonally asymmetric component of the GCM-simulated surface temperature gradients. The Walker circulation weakens as the climate warms in the idealized simulations, as it does in comprehensive simulations of climate change. The wide range of climates allows a systematic test of energetic arguments that have been proposed to account for these changes in the tropical circulation. The analysis shows that a scaling estimate based on changes in the hydrological cycle (precipitation rate and saturation specific humidity) accounts for the simulated changes in the Walker circulation. However, it must be evaluated locally, with local precipitation rates. If global-mean quantities are used, the scaling estimate does not generally account for changes in the Walker circulation, and the extent to which it does is the result of compensating errors in changes in precipitation and saturation specific humidity that enter the scaling estimate.

Affiliated with

Also associated with

No associations

Rating

Changes in zonal surface temperature gradients and Walker circulations in a wide range of climates does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Changes in zonal surface temperature gradients and Walker circulations in a wide range of climates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Changes in zonal surface temperature gradients and Walker circulations in a wide range of climates will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-375041