A simple, vertically resolved model of tropical disturbances with a humidity closure

Željka Fuchs; David J. Raymond

doi:10.1111/j.1600-0870.2007.00230.x

A simple, vertically resolved model of tropical disturbances with a humidity closure

Tellus

Volume 59 (2007): Issue 3

By: Željka Fuchs and David J. Raymond

Open Access

|Jan 2007

Abstract

A vertically resolved linear model for large-scale motions in an equatorial non-rotating atmosphere is presented. Precipitation is forced by tropospheric precipitable water, cloud—radiation interactions (CRI), and wind-induced surface heat exchange (WISHE). The dynamics of the model are based on the assumption that the vertical heating profile has the shape of the first baroclinic mode. The vertical profiles of vertical velocity, temperature perturbation, etc. are calculated using an upward radiation boundary condition.

The modelled modes are of three types: fast gravity waves that resemble adiabatic modes with the vertical wavelength twice the depth of the troposphere; convectively coupled gravity modes that are damped and move with a phase speed of ≈17 m s⁻¹; and the unstable moisture mode.

The value of the model is that under a single dynamical assumption it yields the observed phase speed for the convectively coupled gravity waves that map to Kelvin waves in the equatorial beta plane case while still producing the unstable moisture mode. However, the model lacks the precipitation physics needed to produce the observed destabilization of the gravity mode.

References

Aralcawa , A. and Schubert , W. H. 1974 . Interaction of a cumulus cloud ensemble with the large-scale environment. Part I. J. Atmos. Sc i . 31 , 674 – 701 .
Search in Google Scholar Back to article
Battisti , D. S. , Sarachilc , E.S. and Hirst , A. C. 1999 . A consistent model for the large-scale steady surface atmospheric circulation in the tropics . J. Climate 12 , 2956 – 2964 .
Search in Google Scholar Back to article
Betts , A.K. and Miller , M. J. 1986 . A new convective adjustment scheme. Part II: single column tests using GATE wave, BOMEX, ATEX and arctic air-mass data sets . Quart. J. Roy. Meteor Soc . 112 , 693 – 709 .
Search in Google Scholar Back to article
Bretherton , C. S. , Peters , M.E. and Back , L. E. 2004 . Relationships between water vapor path and precipitation over the tropical oceans . J. Climate 17 , 1517 – 1528 .
Search in Google Scholar Back to article
Brown , R. G. and Bretherton , C. S. 1997 . A test of the strict quasi-equilibrium theory on long time and space scales. J. Atmos. Sc i . 54 , 624 – 638 .
Search in Google Scholar Back to article
Charney , J. 1971 . Tropical cyclogenesis and the formation of the intertropical convergence zone . Lectures Appl. Math. American Mathe-matical Society 13 , 355 – 368 .
Search in Google Scholar Back to article
Charney , J. G. and Eliassen , A. 1964 . On the growth of the hurricane depression. J. Atmos. Sc i . 21 , 68 – 75 .
Search in Google Scholar Back to article
Cho , H. -R. and Jenkins , M. A. 1987 . The thermal structure of tropical easterly waves. J. Atmos. Sci . 44 , 2531 - 2539 .
Search in Google Scholar Back to article
Davies , H. C. 1979 . Phase-lagged wave-CISK . Quart. J. Roy. Meteor. Soc . 105 , 325 – 353 .
Search in Google Scholar Back to article
Derbyshire , S. H. , Beau , I. , Bechtold , P. , Grandpeix , J. -Y. , Piriou and co-authors . 2004. Sensitivity of moist convection to environmental humidity. Quart. J. Roy. Meteor Soc . 130 , 3055 - 3079 .
Search in Google Scholar Back to article
Emanuel , K. A. 1987 . An air-sea interaction model of intraseasonal oscillations in the tropics. J. Atmos. Sc i . 44 , 2324 – 2340 .
Search in Google Scholar Back to article
Emanuel , K. 1993 . The effect of convective response time on WISHE modes. J. Atmos. Sc i . 50 , 1763 – 1775 .
Search in Google Scholar Back to article
Emanuel , K. A. , Neelin , J. D. and Bretherton , C. S. 1994 . On large-scale circulations in convecting atmospheres . Quart. J. Roy. Meteor Soc . 120 , 1111 – 1143 .
Search in Google Scholar Back to article
Fuchs , Z. and Raymond , D. J. 2002 . Large-scale modes of a nonrotating atmosphere with water vapor and cloud-radiation feedbacks . J. Atmos. Sci . 59 , 1669– 1679 .
Search in Google Scholar Back to article
Fuchs , Z. . and Raymond , D. J. 2005 . Large-scale modes in a rotating atmosphere with radiative-convective instability and WISHE. J. Atmos. Sci . 62 , 4084 - 4094 .
Search in Google Scholar Back to article
Fulton , S. R. and Schubert , W. H. 1985 . Vertical normal mode transforms: Theory and application. Mon. Wea. Re v . 113 , 647 – 658 .
Search in Google Scholar Back to article
Grabowski , W. W. 2003 . MJO-Like coherent structures: Sensitivity simulations using the cloud-resolving convection parameterization (CRCP). J. Atmos. Sc i . 60 , 847 – 864 .
Search in Google Scholar Back to article
Hayashi , Y. 1970 . A theory of large-scale equatorial waves generated by condensation heat and accelerating the zonal wind . J. Meteor Soc. Japan 48 , 140 – 160 .
Search in Google Scholar Back to article
Kiladis , G. N. , Straub , K. H. and Haertel , P. T. 2005 . Zonal and vertical structure of the Madden-Julian oscillation. J. Atmos. Sc i . 62 , 2790 – 2809 .
Search in Google Scholar Back to article
Kuo , H. L. 1965 . On the formation and intensification of tropical cyclones through latent heat release by cumulus convection. J. Atmos. Sc i . 22 , 40 – 63 .
Search in Google Scholar Back to article
Kuo , H. L. 1974 . Further studies of the parameterization of the influence of cumulus convection on large-scale flow. J. Atmos. Sc i . 31 , 1232 – 1240 .
Search in Google Scholar Back to article
Lindzen , R. S. 1974 . Wave-CISK in the tropics. J. Atmos. Sc i . 31 , 156 – 179 .
Search in Google Scholar Back to article
Lindzen , R. S. and Nigam , S. 1987 . On the role of sea surface temperature gradients in forcing low-level winds and convergence in the tropics. J. Atmos. Sc i . 44 , 2418 – 2436 .
Search in Google Scholar Back to article
López Carrillo , C. and Raymond , D. J. 2005 . Moisture tendency equations in a tropical atmosphere. J. Atmos. Sc i ., 62 , 1601 – 1613 .
Search in Google Scholar Back to article
Lucas , C. , Zipser , E. J. and Ferrier , B. S. 2000 . Sensitivity of tropical west Pacific oceanic squall lines to tropospheric wind and moisture profiles. J. Atmos. Sc i . 57 , 2351 – 2373 .
Search in Google Scholar Back to article
Madden , R. A. and Julian , P. R. 1994 . Observations of the 40-50 day tropical oscillation-a review. Mon. Wea. Re v . 122 , 814 – 837 .
Search in Google Scholar Back to article
Majda , A. J. , Khouider , B. , Kiladis , G. N. , Straub , K. H. and Shefter , M. G. 2004 . A model for convectively coupled tropical waves: Nonlin-earity, rotation, and comparison with observations. J. Atmos. Sc i . 61 , 2188 – 2205 .
Search in Google Scholar Back to article
Majda , A. J. and Shefter , M. G. 2001 . Models for stratiform instability and convectively coupled waves. J. Atmos. Sc i ., 58 , 1567 – 1584 .
Search in Google Scholar Back to article
Manabe , S. , Smagorinsky , J. and Strickler , R. F. 1965 . Simulated climatology of a general circulation model with a hydrologic cycle. Mon. Wea. Re v . 93 , 769 – 798 .
Search in Google Scholar Back to article
Mapes , B. E. 2000 . Convective inhibition, subgrid-scale triggering energy, and stratiform instability in a toy tropical wave model. J. Atmos. Sc i . 57 , 1515 – 1535 .
Search in Google Scholar Back to article
McBride , J. L. and Frank , W. M. 1999 . Relationships between stability and monsoon convection. J. Atmos. Sc i . 56 , 24 – 36 .
Search in Google Scholar Back to article
McGauley , M. , Zhang , C. and Bond , N. A. 2004 . Large-scale characteristics of the atmospheric boundary layer in the eastern Pacific cold tongue-ITCZ region . J. Climate 17 , 3907 – 3920 .
Search in Google Scholar Back to article
Moskowitz , B. M. and Bretherton , C. S. 2000 . An analysis of frictional feedback on a moist equatorial Kelvin mode. J. Atmos. Sc i . 57 , 2188 – 2206 .
Search in Google Scholar Back to article
Neelin , J. D. and Held , I. M. 1987 . Modeling tropical convergence based on the moist static energy budget. Mon. Wea. Re v . 115 , 3 – 12 .
Search in Google Scholar Back to article
Neelin , J. D. and Yu , J.-Y. 1994 . Modes of tropical variability under convective adjustment and the Madden-Julian oscillation. Part I: Analytical theory. J. Atmos. Sc i . 51 , 1876 – 1894 .
Search in Google Scholar Back to article
Ooyama , K. 1982 . Conceptual evolution of the theory and modeling of the tropical cyclone . J. Meteor. Soc. Japan 60 , 369 – 379 .
Search in Google Scholar Back to article
Raymond , D. J. 1975 . A model for predicting the movement of continuously propagating convective storms. J. Atmos. Sc i . 32 , 1308 – 1317 .
Search in Google Scholar Back to article
Raymond , D. J. , Bretherton , C. S. and Molinari , J. 2006 . Dynamics of the intertropical convergence zone of the east Pacific. J. Atmos. Sc i . 63 , 582 – 597 .
Search in Google Scholar Back to article
Raymond , D. J. and Zeng , X. 2005 . Modelling tropical atmospheric convection in the context of the weak temperature gradient approximation . Quart. J. Roy. Meteor Soc . 131 , 1301 – 1320 .
Search in Google Scholar Back to article
Reed , R. J. and Recker , E. E. 1971 . Structure and properties of synoptic-scale wave disturbances in the equatorial western Pacific. J. Atmos. Sc i . 28 , 1117 – 1133 .
Search in Google Scholar Back to article
Sherwood , S. C. 1999 . Convective precursors and predictability in the tropical western Pacific. Mon. Wea. Re v . 127 , 2977 – 2991 .
Search in Google Scholar Back to article
Sobel , A. H. , Nilsson , J. and Polvani , L. M. 2001 . The weak temperature gradient approximation and balanced tropical moisture waves. J. Atmos. Sc i . 58 , 3650 – 3665 .
Search in Google Scholar Back to article
Sobel , A. H. , Yuter , S. E. , Bretherton , C. Sand Kiladis , G. N . 2004 . Large-scale meteorology and deep convection during TRMM KWAJEX. Mon. Wea. Re v . 132 , 422 – 444 .
Search in Google Scholar Back to article
Sobel , A. H. and Bretherton , C. S. 2003 . Large-scale waves interacting with deep convection. Tellus 55a , 45 - 60 .
Search in Google Scholar Back to article
Sobel , A. H. and Horinouchi , T. 2000 . On the dynamics of easterly waves, monsoon depressions, and tropical depression type disturbances . J. Meteor Soc. Jpn . 78 , 167 – 173 .
Search in Google Scholar Back to article
Stark , T. E. 1976 . Wave-CISK and cumulus parameterization. J. Atmos. Sc i . 33 , 2383 – 2391 .
Search in Google Scholar Back to article
Straub , K. H. and Kiladis , G. N. 2002 . Observations of a convectively coupled Kelvin wave in the eastern Pacific ITCZ. J. Atmos. Sc i . 59 , 30 – 53 .
Search in Google Scholar Back to article
Thompson , R. M. , Payne , S. W. , Recker , E. E. and Reed , R. J. 1979 . Structure and properties of synoptic-scale wave disturbances in the intertropical convergence zone of the eastern Atlantic. J. Atmos. Sc i . 36 , 53 – 72 .
Search in Google Scholar Back to article
Tomas , R. A. , Holton , J. R. and Webster , P. J. 1999 . The influence of cross-equatorial pressure gradients on the location of near-equatorial convection . Quart. J. Roy. Meteor Soc . 125 , 1107 – 1127 .
Search in Google Scholar Back to article
Wang , B. and Rui , H. 1990 . Dynamics of the coupled moist Kelvin-Rossby wave on an equatorial beta plane. J. Atmos. Sc i . 47 , 397 – 413 .
Search in Google Scholar Back to article
Wheeler , M. , Kiladis , G. N. and Webster , P. J. 2000 . Large-scale dynamical fields associated with convectively coupled equatorial waves. J. Atmos. Sc i . 57 , 613 – 640 .
Search in Google Scholar Back to article
Wheeler , M. and Kiladis , G. N. 1999 . Convectively coupled equatorial waves: Analysis of clouds and temperature in the wavenumber-frequency domain. J. Atmos. Sc i . 56 , 374 – 399 .
Search in Google Scholar Back to article
Yano , J.-I. and Emanuel , K. 1991 . An improved model of the equatorial troposphere and its coupling with the stratosphere. J. Atmos. Sc i . 48 , 377 – 389 .
Search in Google Scholar Back to article

Articles in this issue

DOI: https://doi.org/10.1111/j.1600-0870.2007.00230.x | Journal eISSN: 3035-9554

Journal RSS Feed

Language: English

Page range: 344 - 354

Submitted on: Jul 28, 2006

Accepted on: Jan 12, 2007

Published on: Jan 1, 2007

Published by: Stockholm University Press

In partnership with: Paradigm Publishing Services

© 2007 Željka Fuchs, David J. Raymond, published by Stockholm University Press
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 59 (2007): Issue 3