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GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L12709, doi:10.1029/2007GL029505, 2007

Positive surface temperature feedback in the stable nocturnal boundary layer

Justin T. Walters

Research and Environmental Affairs, Southern Company Services, Birmingham, Alabama, USA


Richard T. McNider

Department of Atmospheric Sciences, University of Alabama in Huntsville, Huntsville, Alabama, USA


Xingzhong Shi

Computer Science Department, Alabama A. & M. University, Normal, Alabama, USA


William B. Norris

Earth System Science Center, University of Alabama in Huntsville, Huntsville, Alabana, USA


John R. Christy

Earth System Science Center, University of Alabama in Huntsville, Huntsville, Alabana, USA


Abstract

The techniques of nonlinear analysis are used to examine the behavior of the stable nocturnal boundary layer (SNBL) when it is subjected to changes in incoming radiation or in surface characteristics. A single-column model and nonlinear bifurcation techniques are used to demonstrate that any atmospheric forcing, such as weak radiative forcing from greenhouse gases or cloud cover, can trigger a potentially significant positive feedback. Multiple solutions occur in some parameter spaces. This analysis shows that any forcing that decreases the stability, whether by increasing greenhouse gases or surface heat capacity, can cause large increases in surface temperature as the SNBL shifts from a weak turbulent regime, which allows the surface to cool, to a turbulent regime, which mixes warm air from aloft. Positive feedback may be a key factor in interpreting the long-term observed nocturnal warming trend in the SNBL.

Received 29 January 2007; accepted 14 May 2007; published 22 June 2007.

Keywords: diurnal temperature range; stable boundary layer; climate.

Index Terms: 1620 Global Change: Climate dynamics (0429, 3309); 1631 Global Change: Land/atmosphere interactions (1218, 1843, 3322); 1622 Global Change: Earth system modeling (1225); 1626 Global Change: Global climate models (3337, 4928); 1694 Global Change: Instruments and techniques.

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Citation: Walters, J. T., R. T. McNider, X. Shi, W. B. Norris, and J. R. Christy (2007), Positive surface temperature feedback in the stable nocturnal boundary layer, Geophys. Res. Lett., 34, L12709, doi:10.1029/2007GL029505.