An Analysis for the Applicability of Monin-Obukhov Similarity Theory in Stable Conditions

作者：Kumar Pramod; Sharan Maithili^*

来源：Journal of the Atmospheric Sciences, 2012, 69(6): 1910-1915.

DOI：10.1175/JAS-D-11-0250.1

An analysis in a plane of the stability parameters zeta = z/L (where z is a height above the ground surface and L is the Obukhov length) and bulk Richardson number Ri(B) is proposed to examine the applicability of Monin-Obukhov similarity (MOS) theory in stable conditions. In this analysis, the data available from two different experimental datasets [(i) Cooperative Atmosphere Surface Exchange Study-1999 (CASES-99) and (ii) Cardington] are divided into four quadrants. An unexpected behavior of decreasing zeta with increasing Ri(B) was observed with both datasets in quadrant II characterized by zeta %26lt; 1 and Ri(B) %26gt; 0.2 and in quadrant IV with zeta %26gt; 1 and Ri(B) %26lt; 0.2. This is in contrast to a commonly expected monotonically increasing behavior between zeta and Ri(B). It is shown that the MOS theory is consistent for computing the surface fluxes corresponding to the data points lying in quadrants I (with zeta %26gt; 1 and Ri(B) %26gt; 0.2) and III (with zeta %26lt; 1 and Ri(B) %26lt; 0.2), whereas it may not be applicable for the points in quadrants II and IV. Thus, a breakdown of the relationship between observed zeta and Ri(B) with growing stability in these quadrants may limit the applicability of MOS theory in stable conditions. Since quadrant IV has very few data points, the applicability of MOS theory needs to be substantiated further with the availability of sufficient data points in this regime.

• 出版日期2012-6