associated thermodynamic and dynamic characteristics. This demonstration of subseasonal variability of the convective diurnal cycle motivates this analysis of variability in the monthly TOA flux diurnal cycle in the tropics. The spatial domain is restricted to the tropics, defined as 30°N–30°S, to focus on regions with large, and persistent diurnal cycle signals. The monthly-mean diurnal cycle is defined as the composite of hourly or 3-hourly TOA fluxes over a single month using the Clouds and the Earth
associated thermodynamic and dynamic characteristics. This demonstration of subseasonal variability of the convective diurnal cycle motivates this analysis of variability in the monthly TOA flux diurnal cycle in the tropics. The spatial domain is restricted to the tropics, defined as 30°N–30°S, to focus on regions with large, and persistent diurnal cycle signals. The monthly-mean diurnal cycle is defined as the composite of hourly or 3-hourly TOA fluxes over a single month using the Clouds and the Earth
of in situ observations: it makes both the initialization and the validation processes less reliable. While convection-permitting models that run operationally in the tropics become more and more common, their validation is not frequent in scientific literature, except for models dedicated for tropical cyclone forecasting, like HWRF ( Bernardet et al. 2015 ). One of the most comprehensive studies to date is Woodhams et al. (2018) , who characterized the added value of a convection
of in situ observations: it makes both the initialization and the validation processes less reliable. While convection-permitting models that run operationally in the tropics become more and more common, their validation is not frequent in scientific literature, except for models dedicated for tropical cyclone forecasting, like HWRF ( Bernardet et al. 2015 ). One of the most comprehensive studies to date is Woodhams et al. (2018) , who characterized the added value of a convection
FEBRU^RV 1993 ISLAM ET AL. 297Predictability of Mesoscale Rainfall in the Tropics SHAFIQUL ISLAM *Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio RAFAEL L. BRASRalph M. Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts KERRY A. EMANUELDepartment of Earth, Atmosphere, and Planetary
FEBRU^RV 1993 ISLAM ET AL. 297Predictability of Mesoscale Rainfall in the Tropics SHAFIQUL ISLAM *Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio RAFAEL L. BRASRalph M. Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts KERRY A. EMANUELDepartment of Earth, Atmosphere, and Planetary
such as the degree to which the locations of the emissions coincide with strong convection can also have a strong influence on the overall flux ( Russo et al. 2015 ). To address these issues, the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 atmospheric research aircraft was deployed in Guam in January and February 2014 as part of the Coordinated Airborne Studies in the Tropics (CAST) campaign, a large multi-institutional project funded by the U.K. Natural Environment Research
such as the degree to which the locations of the emissions coincide with strong convection can also have a strong influence on the overall flux ( Russo et al. 2015 ). To address these issues, the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 atmospheric research aircraft was deployed in Guam in January and February 2014 as part of the Coordinated Airborne Studies in the Tropics (CAST) campaign, a large multi-institutional project funded by the U.K. Natural Environment Research
land-cover changes inducing teleconnection behavior nor discussion of climate model representation of these teleconnection processes. Tropical landmasses are a large source of energy for the atmosphere and the general circulation is responsible for transporting this energy poleward to maintain the global radiation balance. Consequently, the tropics have a direct influence on the extratropical climate, and any changes to the tropical energy balance and the poleward atmospheric transport
land-cover changes inducing teleconnection behavior nor discussion of climate model representation of these teleconnection processes. Tropical landmasses are a large source of energy for the atmosphere and the general circulation is responsible for transporting this energy poleward to maintain the global radiation balance. Consequently, the tropics have a direct influence on the extratropical climate, and any changes to the tropical energy balance and the poleward atmospheric transport
/early evening over land. However, some studies also showed an afternoon maximum in precipitation and cloudiness over the oceans (e.g., McGarry and Reed 1978 ; Augustine 1984 ; Shin et al. 1990 ). Janowiak et al. (1994) provided an extensive analysis of the diurnal cycle of cold clouds in the global tropics based on 3-hourly geostationary satellite data that had been averaged on to a 2.5° latitude–longitude grid. Their results confirmed the existence of an early morning maximum in the extent of the
/early evening over land. However, some studies also showed an afternoon maximum in precipitation and cloudiness over the oceans (e.g., McGarry and Reed 1978 ; Augustine 1984 ; Shin et al. 1990 ). Janowiak et al. (1994) provided an extensive analysis of the diurnal cycle of cold clouds in the global tropics based on 3-hourly geostationary satellite data that had been averaged on to a 2.5° latitude–longitude grid. Their results confirmed the existence of an early morning maximum in the extent of the
( Mapes et al. 2003 ). At higher latitudes, Carbone et al. (2002) documented diurnal eastward-moving envelopes of precipitation over the United States in summer, although the role of advection versus wave processes is not as clear in that setting. Fourier spectral methods have proven useful for identifying and classifying zonally propagating cloud disturbances in the tropics. For example, it is now clear on the basis of spectral filtering that many eastward-moving “superclusters” of convection (e
( Mapes et al. 2003 ). At higher latitudes, Carbone et al. (2002) documented diurnal eastward-moving envelopes of precipitation over the United States in summer, although the role of advection versus wave processes is not as clear in that setting. Fourier spectral methods have proven useful for identifying and classifying zonally propagating cloud disturbances in the tropics. For example, it is now clear on the basis of spectral filtering that many eastward-moving “superclusters” of convection (e
summarized and discussed. 2. Data a. IMERG The IMERG product 3IMERGHH is used to estimate gridded surface precipitation. The horizontal and temporal resolutions of this latest IMERG product, 3IMERGHH, have been improved from 0.25° to 0.1° latitude/longitude spatial resolution (~10 km in the tropics), and from a 3-hourly to a 30-min temporal resolution. This offers global precipitation monitoring based on a merged retrieval using algorithms developed by several groups: TRMM Multisatellite Precipitation
summarized and discussed. 2. Data a. IMERG The IMERG product 3IMERGHH is used to estimate gridded surface precipitation. The horizontal and temporal resolutions of this latest IMERG product, 3IMERGHH, have been improved from 0.25° to 0.1° latitude/longitude spatial resolution (~10 km in the tropics), and from a 3-hourly to a 30-min temporal resolution. This offers global precipitation monitoring based on a merged retrieval using algorithms developed by several groups: TRMM Multisatellite Precipitation
1. Introduction To the first order, the atmospheric general circulation redistributes energy and balances the horizontal and vertical gradients of diabatic heating. Since the earth’s atmosphere is primarily heated from the surface, convective processes are required to maintain the troposphere close to neutral stratification. On the large scale, the heating gradient between the tropics and extratropics is balanced by the poleward transport of the heat of the general circulation. However, the
1. Introduction To the first order, the atmospheric general circulation redistributes energy and balances the horizontal and vertical gradients of diabatic heating. Since the earth’s atmosphere is primarily heated from the surface, convective processes are required to maintain the troposphere close to neutral stratification. On the large scale, the heating gradient between the tropics and extratropics is balanced by the poleward transport of the heat of the general circulation. However, the
1064 JOURNAL OF THE ATMOSPHERIC SCIENCES VoLmm29Simulation Experiments for Determining Wind Data Requirements in the Tropics C. T. GORDON, L. U~rscm~m, Jm., Am) K. MIYAKODAGeophysical Fluid Dynamics Laboratory, NOAA, Princeton University, Princeton, N. Y. 08540(Manuscript received 2 February 1972, in revised form 28 April 1972)ABSTRACT Numerical simulation experiments are performed with a 9-1evel global
1064 JOURNAL OF THE ATMOSPHERIC SCIENCES VoLmm29Simulation Experiments for Determining Wind Data Requirements in the Tropics C. T. GORDON, L. U~rscm~m, Jm., Am) K. MIYAKODAGeophysical Fluid Dynamics Laboratory, NOAA, Princeton University, Princeton, N. Y. 08540(Manuscript received 2 February 1972, in revised form 28 April 1972)ABSTRACT Numerical simulation experiments are performed with a 9-1evel global
