is central to the study of the large-scale circulation in the tropics and its interaction with moist convection. Previous studies on the role of heating profiles in the large-scale circulation used either observed heating profiles of mesoscale convective systems (e.g., Mapes and Houze 1995 ; Schumacher et al. 2004 ) or idealized profiles for large-scale diabatic heating (e.g., Geisler 1981 ; Hartmann et al. 1984 ; Wu et al. 2000 ). Our knowledge of large-scale heating structures and
is central to the study of the large-scale circulation in the tropics and its interaction with moist convection. Previous studies on the role of heating profiles in the large-scale circulation used either observed heating profiles of mesoscale convective systems (e.g., Mapes and Houze 1995 ; Schumacher et al. 2004 ) or idealized profiles for large-scale diabatic heating (e.g., Geisler 1981 ; Hartmann et al. 1984 ; Wu et al. 2000 ). Our knowledge of large-scale heating structures and
1. Introduction The convective parameterizations of climate models are typically adjusted to give reasonable climatological distributions of temperature, water vapor, convective mass transport, and rainfall in the tropics. However, these climatological distributions arise from the cumulative impact of individual moist convective events that occur on much shorter time scales. Realistic convective parameterizations should be able to simulate the short-time-scale interactions between moist
1. Introduction The convective parameterizations of climate models are typically adjusted to give reasonable climatological distributions of temperature, water vapor, convective mass transport, and rainfall in the tropics. However, these climatological distributions arise from the cumulative impact of individual moist convective events that occur on much shorter time scales. Realistic convective parameterizations should be able to simulate the short-time-scale interactions between moist
156 JOURNAL OF THE ATMOSPHERIC SCIENCES VoLuta~.31Wave-CISK in the Tropics RICItARD S. [~INDZEN1Center for Earth and Planetary Physics, Harvard University, Cambridge, Mass. 02138(Manuscript received 7 June 1973, in revised form 10 September 1973) ABSTRACTCISK (Conditional Instability of the Second Kind) is examined for internal waves where low-level convergence is
156 JOURNAL OF THE ATMOSPHERIC SCIENCES VoLuta~.31Wave-CISK in the Tropics RICItARD S. [~INDZEN1Center for Earth and Planetary Physics, Harvard University, Cambridge, Mass. 02138(Manuscript received 7 June 1973, in revised form 10 September 1973) ABSTRACTCISK (Conditional Instability of the Second Kind) is examined for internal waves where low-level convergence is
). The TA has no serious problem in the midlatitude. However, some studies have suggested that near the equator where the factor cosine is large, this approximation may not be appropriate. For example, WB95 used a scale analysis to indicate that, since diabatic heating due to cumulus convection involves air mass ascent in the tropics, the NCT associated with vertical motions in the zonal momentum equation may become too large to be neglected. WB95 also implied that in the perturbation form of the
). The TA has no serious problem in the midlatitude. However, some studies have suggested that near the equator where the factor cosine is large, this approximation may not be appropriate. For example, WB95 used a scale analysis to indicate that, since diabatic heating due to cumulus convection involves air mass ascent in the tropics, the NCT associated with vertical motions in the zonal momentum equation may become too large to be neglected. WB95 also implied that in the perturbation form of the
364 JOURNAL OF APPLIED METEOROLOGY VOLUMgI0Optimum Station Network in the Tropics1G. STEINITZ, A. HUss,~ A. Mx~r~s, R. SINAIa AND Z. ALPERSONResearch Division, Israel Meteorological Service, Bet Dagan, Israel(Manuscript received 8 February 1971)ABSTRACT A five-year record of upper air data from 145 stations in the northern tropics was used to determine thestatistical structure of
364 JOURNAL OF APPLIED METEOROLOGY VOLUMgI0Optimum Station Network in the Tropics1G. STEINITZ, A. HUss,~ A. Mx~r~s, R. SINAIa AND Z. ALPERSONResearch Division, Israel Meteorological Service, Bet Dagan, Israel(Manuscript received 8 February 1971)ABSTRACT A five-year record of upper air data from 145 stations in the northern tropics was used to determine thestatistical structure of
horizontal temperature gradients in the equatorial middle troposphere are weak in various flow regimes formally yields simplified equatorial balanced dynamics ( Charney 1963 ; Held and Hoskins 1985 ; Browning et al. 2000 ). There has been a recent surge of activity in developing and utilizing such balanced weak temperature gradient (WTG) approximations in the Tropics and subtropics with horizontal advection of moisture included in order to model the regions of surface precipitation and their
horizontal temperature gradients in the equatorial middle troposphere are weak in various flow regimes formally yields simplified equatorial balanced dynamics ( Charney 1963 ; Held and Hoskins 1985 ; Browning et al. 2000 ). There has been a recent surge of activity in developing and utilizing such balanced weak temperature gradient (WTG) approximations in the Tropics and subtropics with horizontal advection of moisture included in order to model the regions of surface precipitation and their
December 1964Harold A. Bedient and Joseph Vederman565COMPUTER ANALYSIS AND FORECASTING IN THE TROPICS* HAROLD A. BEDIENT Lt. Col., U.S. Air Force and JOSEPH VEDERMANUS. Weather Bureau, Honolulu, HawaiiABSTRACT Comput,rr-prcpared analyses of the upper-air wind field are being made for several levels for the tropical PacificOcean arra of both t8he Northern and Southern Hemispheres. Computer analyses compare favorably with convcn-tional analyscs. The availability and accuracy of
December 1964Harold A. Bedient and Joseph Vederman565COMPUTER ANALYSIS AND FORECASTING IN THE TROPICS* HAROLD A. BEDIENT Lt. Col., U.S. Air Force and JOSEPH VEDERMANUS. Weather Bureau, Honolulu, HawaiiABSTRACT Comput,rr-prcpared analyses of the upper-air wind field are being made for several levels for the tropical PacificOcean arra of both t8he Northern and Southern Hemispheres. Computer analyses compare favorably with convcn-tional analyscs. The availability and accuracy of
, we show how some of the changes in the observing system appear to have adversely affected the ECMWF reanalyses of the temperature and moisture fields in the Tropics. Those influences are seen in other fields as well, thereby potentially limiting the usefulness of the reanalyses in addressing climate variability. Comprehensive evaluation of the moisture budget from NCEP–NCAR reanalysis was given by Trenberth and Guillemot (1998) who concluded that there is a negative bias in tropical
, we show how some of the changes in the observing system appear to have adversely affected the ECMWF reanalyses of the temperature and moisture fields in the Tropics. Those influences are seen in other fields as well, thereby potentially limiting the usefulness of the reanalyses in addressing climate variability. Comprehensive evaluation of the moisture budget from NCEP–NCAR reanalysis was given by Trenberth and Guillemot (1998) who concluded that there is a negative bias in tropical
JUNE 1958 MONTHLY WEATHER REVIEW 201ANALYSIS AIDS FOR THE AMERICAN TROPICSL. F. HUBERTU. S. Weather Bureau, Washington, D. C.[Manuscript received February 12, 1958; revised April 14, 19581ABSTRACTAnalysis of upper-level charts for the American Tropics, which is a largely ocearic area, is difficult becausedata are inadequate and are likely to remain so in the foreseeable future. Despite tbis handicap and the unsatis-factory character of the map, the 500-mb. analyses are routinely used for many
JUNE 1958 MONTHLY WEATHER REVIEW 201ANALYSIS AIDS FOR THE AMERICAN TROPICSL. F. HUBERTU. S. Weather Bureau, Washington, D. C.[Manuscript received February 12, 1958; revised April 14, 19581ABSTRACTAnalysis of upper-level charts for the American Tropics, which is a largely ocearic area, is difficult becausedata are inadequate and are likely to remain so in the foreseeable future. Despite tbis handicap and the unsatis-factory character of the map, the 500-mb. analyses are routinely used for many
for diagnostic analysis and forinvestigating the slow evolution of the large-scale flow in the tropics.1. Introduction Quasi-geostrophic theory provides a dynamicalframework for understanding the slowly evolving, meteorologically significant large-scale phenomena inmiddle latitudes. Within this approximation the fastergravity waves are filtered out by neglect of the divergentcomponent of the horizontal flow, which is typicallysmaller than the rotational component by a factor ofthe Rossby number
for diagnostic analysis and forinvestigating the slow evolution of the large-scale flow in the tropics.1. Introduction Quasi-geostrophic theory provides a dynamicalframework for understanding the slowly evolving, meteorologically significant large-scale phenomena inmiddle latitudes. Within this approximation the fastergravity waves are filtered out by neglect of the divergentcomponent of the horizontal flow, which is typicallysmaller than the rotational component by a factor ofthe Rossby number
