Kc)' words - Energetics. Lower tropOSphert. w ave number domain. Fourier technique.

M AUSAM , 51. 2 (Apri l 2(00). 119· 126

S.M.BAWISKAR. M.D. CHIPADE and S.S.SINGH

wind direction. humidity and circulation features overland and ocean show a marked contrast. Lands arewarmer than the oceans causing lows over land and highsover ocean. Zonal wind is westerly over land and easterlyover ocean while meridional wind is southerly over landand northerly over ocean. Lands are humid and oceans are

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55 1.5 11.62 : 55 1.553.21

lndian lnstitute ofTropical Meteorology, Prine - 411008, lndia

(Received 17 November 1998, Modified 21 April 1999)

AUSTRA CT . lower troposp heric energetics and energy processes of zona! W3\'CS for three consecutivenonhero summer monsooo seasons of 1994. 1995 and 1996 arc presented. Fourier technique is used. The features of thetropical and extra -tropical region s are "'CT)' well reflec ted by the data set used for this study. The results do not showmarked )'C'3r to year variations in the pattern of energy processes. The character of energy processes differs significantlyfrom one latitudinal region to other. w ave to zonal mean flow interacticos and wavc to wa ve interactions are almostopposi te in charac ter over RI (10" S - lOON) and R2 (10" N - 3<r N). l. (n) interaction indicates that RI acts as source ofLinetic energy to the wavesover R2. Particularly. sund ing waves I and 2 over RI arc the majorsourceof kinetic energyto thc waves over R2. Extra-tropical region R3 (30" N - 500 N) is dominated by transient waves while tropica l regionsRI and R2 are dominated by sta nding waves , Medium and short waves have sign ificant contribut ions over extra-tropica lregion wbcreas tropical regions are dominated by long waves . The pattern of energy processes over R3 is somewhatsimilar to the energy processes over RI. Th is is because both the regions have anti-cyclonic lateral shear.

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Energetics of the lower tropospheric eddies in wave number domainduring northern summer monsoon

I. Int roduclion

Zonal asymmetry between land and ocean in thetrop ics plays a dominant role in the dynamics of thetropical atmosphere, During northern summer (June ­August). the lower tropospheric temperature. pressure.