Premium
Cisk: A theory for the response of tropical convective complexes to variations in sea surface temperature
Author(s) -
McBride John L.,
Fraedrich Klaus
Publication year - 1995
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49712152404
Subject(s) - instability , convection , mode (computer interface) , mechanics , stability (learning theory) , physics , mathematics , machine learning , computer science , operating system
A set of balanced and unbalanced slab‐symmetric linear 2‐layer models is analysed. the stability properties depend on a parametrized moisture budget dominated by the value of the underlying sea surface temperature. Convective heating occurs within an inner region characterizing the size of the convective disturbance. the heating is equal to the sum of two terms, representing the mid‐level and lower‐level upward mass‐fluxes. A fast and a slow mode of instability can be distinguished. the slow mode shows finite maximum growth for infinitesimally small disturbances and is the instability traditionally associated with Conditional Instability of the Second Kind (CISK). the fast mode reveals infinitely large positive growth‐rates for finite‐size disturbances. The transition of the model solution from slow to fast mode occurs at a threshold value of sea surface temperature. For the parameters chosen in this study, the threshold occurs at approximately 25.5°C.