Atmospheric Heat Budget Research Articles

The atmospheric heat budget over the western part of the Tibetan plateau during Monex, 1979

The atmospheric heat source strength over western Tibet has been computed for the period beginning with the last ten days in May, 1979 and extending through August, 1979. Our results show a significantly smaller heat source than that obtained by other authors. The discrepancy is mainly due to adjustments in the drag coefficient suggested by observations and numerical modeling experiments. We subdivided western Tibet into northern and southern parts. In the north sensible heating,SH, provides the dominant input into the atmospheric heat source, whereas in the southern part latent heat,LP, offers a significant contribution after the start of the rainy season.

The atmospheric heat budget in summer over Asia monsoon area

For better understanding the mechanism of monsoon formation and designing the numerical simulation of the general atmospheric circulation, a new approach of calculating atmospheric radiation is proposed to investigate the distribution of the atmospheric heat source, and the budget of heat component is recalculated. The results show that there is a tremendous atmospheric heat source region over central India, northeast of the Bay of Bengal, east of the South China Sea and about 10 °N at the west Pacific, among which the heating center with a maximum heating rate of 8 °C/day is located over the Bay of Bengal and the average rate in the Plateau is about 1 °C/day.

On the mechanisms of cooling of the nightside thermosphere of venus

The plausible mechanisms of cooling of the nightside Venus' thermosphere are analysed with the aid of the model of the atmospheric heat budget that incorporates, in addition to thermal conduction and IR radiation in the 15 μ band of CO 2, heating and cooling due to global scale winds, eddy turbulence, and IR radiation in the rotational bands of H 2O and CO, as well as the 63 μ line of atomic oxygen. The H 2O mixing ratio and parameters of turbulence required for cooling of the thermosphere down to the observed low temperatures are evaluated.

Chromosphere-corona transition region models with magnetic field and fluid flow

view Abstract Citations (83) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Chromosphere-corona transition region models with magnetic field and fluid flow Athay, R. G. Abstract Energy balance models of the chromosphere-corona transition region are computed for a segment of average sun network using assumed magnetic field geometry. The energy fluxes considered include radiation, conduction, enthalpy, and gravitational potential energy, but do not include mechanical heating. Two classes of models are considered: conduction driven and flow driven. In the former class, the thermal conductive flux vanishes at the base of the transition region, and in the latter class the thermal conductive flux increases with depth or remains constant. The conduction driven models require primarily outflow, whereas the flow driven models require downflow. Flow-driven models give best overall agreement with observations for T between 300,000 and 1,000,000 K, but neither class of models is satisfactory for T less than 100,000 K. It is concluded however, that the flow-driven models have ample energy supply even in the low transition region, and there is no apparent need for additional energy sources. Publication: The Astrophysical Journal Pub Date: October 1981 DOI: 10.1086/159292 Bibcode: 1981ApJ...249..340A Keywords: Atmospheric Heat Budget; Chromosphere; Magnetohydrodynamic Flow; Solar Atmosphere; Solar Corona; Solar Magnetic Field; Atmospheric Heating; Conductive Heat Transfer; Coronal Holes; Magnetic Field Configurations; Radiative Heat Transfer; Solar Temperature; Transition; Solar Physics full text sources ADS |

Saturn's atmospheric temperature structure and heat budget

The effective temperature of Saturn from 30°S to 10°N is 96.5±2.5 K. This value is 1.9 K higher than our preliminary estimate (Ingersoll et al., 1980). The atmospheric mole fraction of H2 relative to H2 + He is 90±3%. This value is derived by comparing infrared and radio occultation data (Kliore et al., this issue) for the same latitude. The high value of the effective temperature suggests that Saturn has an additional energy source besides cooling and contraction. The high mole fraction of H2 suggests that separation of heavier He toward the core may be supplying the additional energy. Atmospheric temperatures in the 60‐ to 600‐mbar range are 2.5 K lower within 7° of the equator than at higher latitudes. An almost isothermal layer exists between 60 and 160 mbar at all latitudes.

On the simulation of the axisymmetric circulation of the atmosphere

The paper describes a zonally averaged model of the atmospheric state in which the effects of the eddies on the zonal state are parameterized in terms of exchange coefficients which vary with latitude and time in the most general model. In comparison with earlier investigations this model contains a more detailed description of the atmospheric heat budget and a more general description of the exchange mechanisms. However, the basic model is still a quasi-geostrophic, two-level representation of the large-scale flow. Two experiments have been carried out. Both of them simulate the seasonal variation of the zonally averaged state of the atmosphere. The first experiment uses diagnostically determined exchange coefficients which are based on an observational study and which depend upon latitude only. The second experiment employs exchange coefficients which vary with latitude and time. In addition, the magnitude and the functional dependence on latitude are determined by the model parameters at any given time. The results show that a considerably improved simulation of the zonally-averaged state is obtained by a better parameterization of the processes entering the heat budget as compared with earlier studies. Furthermore, the exchange coefficients which vary with latitude and time and which are, at least in part, determined by the model, result in further improvements of most features of the model. The major limitation of the model is its small vertical resolution and its quasi-geostrophic nature. DOI: 10.1111/j.2153-3490.1975.tb01673.x

On meridional circulation and heat budget of the troposphere over the Equatorial Central Pacific

The existence of an equatorial dry zone in the Central Pacific enclosed between moister belts in both hemispheres is borne out by rainfall measurements and daily ESSA III and ESSA V cloud mosaics. The tropospheric wind regime is studied mainly on the basis of aerological soundings during the Line Islands Experiment (LIE) in spring 1967 and observations of earlier periods. During LIE, upper-tropospheric Westerlies extend continuously across the equator. In the lower layers, Easterlies dominate in the equatorial belt. The meridional wind component in the region of the Line Islands is from the South in the lower layers, and from the North in the upper troposphere. From the vertical profiles of heat content and the distribution of diabatic heat sources and sinks during LIE, vertical profiles of divergence are derived, with the constraint that both the atmospheric heat and moisture budgets are satisfied. Lower-layer convergence and upper-tropospheric divergence result for the rain belt (Palmyra), with the opposite pattern prevailing in the equatorial dry zone (Christmas). Circulation in a mean meridional-vertical plane, derived from these profiles under certain assumptions is characterized by poleward flow in the lower layers, ascending motion in the rain belt, equatorward flow in the upper troposphere, and subsidence in the equatorial dry zone. The ocean-troposphere system gains heat by radiation in both the rain belt and the equatorial dry zone. In the rain belt, export of potential energy and sensible heat exceeds the lower-layer import of latent heat; both troposphere and ocean in this region act as exporters of heat to other parts of the globe. In the equatorial dry zone, import of potential energy and sensible heat exceeds the export of latent heat, resulting in a net import of heat for the tropospheric column as a whole. Heat surplus from this region is disposed of only by the ocean. DOI: 10.1111/j.2153-3490.1971.tb00546.x

TROPOSPHERIC HEAT SOURCES AND SINKS AT WASHINGTON, D.C., SUMMER 1961, RELATED TO THE PHYSICAL FEATURES AND ENERGY BUDGET OF THE CIRCULATION

Estimates of atmospheric heating in the troposphere at Washington, D.C., for each successive 12 hr. during June and July 1961, were used to study the relation between local heating and the large-scale features of the circulation, to determine the local production of available potential energy, and to assist in interpreting cloud and radiation data from meteorological satellites. Some interesting inter-connections are found between heating and the circulation: e.g., it is shown that there is a very critical phase relation between heating and the temperature field which is important in determining the generation or destruction of the atmosphere's potential energy. This suggests that special care is needed in designing numerical computations of diabatic heating. A major effort should be directed to interpreting satellite data in terms of the atmospheric heat budget, because such global estimates may be useful (using a procedure suggested in this paper) in determining the world-wide distribution of regions of maintenance or destruction of potential energy.

An Analysis of the Atmospheric Heat Budget

With the aid of recent climatological data and laboratory radiation data, a meridional heat budget has been formed for the atmosphere below the 25-mb level and between 2ON and 7ON latitude. The significant components and balance requirements of the budget are presented as a function of height, latitude and season. Components of the budget include infrared radiative cooling, solar heating, net latent beating, the heat flux across the lower boundary, and the rate of heat storage. Balance requirements are those demanded solely of the atmospheric motions. Each item of the budget is discussed and some comparisons with related studies are included. Although the heat sources produced an extensive lower layer of excessive heating, except in the arctic winter region, the total atmospheric columns revealed thermal deficits almost everywhere within the model. The convergences of the large-scale eddy heat transports determined by other investigators are sufficient to balance the deficits north of 50N latitude. Heat transports by mean meridional motions must become important balancing agents in the sub-tropical latitudes of the model, especially in winter.

PRELIMINARY STUDY OF PLANETARY-SCALE OUTGOING LONG-WAVE RADIATION AS DERIVED FROM TIROS II MEASUREMENTS

Daily composite Northern Hemisphere charts of outgoing long-wave radiation were derived from TIROS II measurements for about 25 days in late November and December 1960. Although data coverage was incomplete and variable each day, both latitudinal and overall daily averages of long-wave radiation were obtained. Large-scale temporal variations in the long-wave radiation are observed and are found to be generally related to temporal variations in kinetic and available potential energy over the Northern Hemisphere. Examination of the radiation latitudinally for various stages of an energy cycle that occurred at this time shows that the outgoing radiation, particularly at lower latitudes, decreased as westerly flow increased at lower latitudes. An average latitudinal profile of the TIROS long-wave data for all days studied shows rather good agreement with previous estimates made by investigators of the atmospheric heat budget.