Showing papers on "Latent heat published in 1972"
TL;DR: In this article, the large-scale parameterization of the surface fluxes of sensible and latent heat is properly expressed in terms of energetic considerations over land while formulas of the bulk aerodynamic type are most suitahle over the sea.
Abstract: In an introductory review it is reemphasized that the large-scale parameterization of the surface fluxes of sensible and latent heat is properly expressed in terms of energetic considerations over land while formulas of the bulk aerodynamic type are most suitahle over the sea. A general framework is suggested. Data from a number of saturated land sites and open water sites in the absence of advection suggest a widely applicable formula for the relationship between sensible and latent heat fluxes. For drying land surfaces, we assume that the evaporation rate is given by the same formula for evaporation multiplied by a factor. This factor is found to remain at unity while an amount of water, varying from one site to another, is evaporated. Following this a linear decrease sets in, reducing the evaporation rate to zero after a further 5 cm of evaporation, the same at several sites examined.
5,918 citations
TL;DR: In this article, a theoretical analysis is made of the large-scale, stationary, zonally asymmetric motions that result from heating and the orographic effect in the tropical atmosphere.
Abstract: A theoretical analysis is made of the large-scale, stationary, zonally asymmetric motions that result from heating and the orographic effect in the tropical atmosphere. The release of latent heat dominates the sensible and radiational heating and the latter two effects are ignored. The first linear model is a continuous stratified atmosphere in solid westward rotation with no dissipation. Of all the modes, only the rotationally trapped Kelvin wave exhibits a significant response. Because the Kelvin wave response does not compare well with the observed flow, we concluded that the neighboring westerlies in the real atmosphere are important even if the forcing is in low latitudes. The second linear model is a two-layer numerical model including parameterized dissipation and realistic basic currents. Realistic forcing is considered, following an analysis of the response to especially simple forms of heating and orographic forcing. Dissipative effects close to the Equator are very important in this mo...
299 citations
TL;DR: In this paper, the atmospheric structure upwind of the Great takes during arctic air outbreaks is represented by three layers: a lower constant flux layer in contact with the ground, a well-mixed planetary boundary layer surmounted by an inversion, and a deep stratum of overlying stable air.
Abstract: The atmospheric structure upwind of the Great takes during arctic air outbreaks is represented by three layers: a lower constant flux layer in contact with the ground, a well-mixed planetary boundary layer surmounted by an inversion, and a deep stratum of overlying stable air. The set of primitive equations is averaged through the depth of the mixed layer to yield predictive equations for the horizontal components of velocity, potential temperature and specific humidity in the layer, and the height of the inversion. Interactions between the well-mixed convective layer and both the underlying and overlying layers are parameterized so that time-dependent calculations can be limited to a single layer. Precipitation from cumulus clouds within the layer is represented in terms of the mesoscale variables and latent heat is included. The equation set has been solved numerically for a 2000-point grid mesh centered on Lake Erie. Grid separation was 6 km in the cross-lake direction and 12 km along the lake...
134 citations
TL;DR: In this paper, a diagnostic numerical model is used to show that a standing wave oscillation of narrow longitudinal extent in the diabatic heat source in the troposphere can generate the global-scale propagating waves observed in the equatorial stratosphere.
Abstract: Observational evidence suggests that there may be long-period, large-scale variations in the intensity of the latent heat release in the equatorial zone. In this study a diagnostic numerical model is used to show that a standing wave oscillation of narrow longitudinal extent in the diabatic heat source in the troposphere can generate the global-scale propagating waves observed in the equatorial stratosphere. In particular, a heating oscillation which is symmetric about the equator can account for the eastward-moving Kelvin-wave mode, and a source which is antisymmetric can account for the westward-moving, mixed Rossby-gravity wave mode.
117 citations
TL;DR: In this paper, the relationship between the diurnal patterns of the radiant energy exchange in the atmospheric surface layer and the soil heat flux density of a bare irrigated soil in an arid environment was described.
Abstract: This work describes the relationship between the diurnal patterns of the radiant energy exchange in the atmospheric surface layer and the soil heat flux density of a bare irrigated soil in an arid environment. The measurements show that the soil heat flux density is a large fraction of the net radiation. The soil moisture content has little effect on this fraction but modifies the phase relationship between the net radiation and the soil heat flux density waves. Differences between the thermal regimes of the ‘wet’ and ‘dry’ soil appear to be caused by latent heat exchanges rather than changes of the soil thermal properties. The data also show that the variation with depth of the soil thermal properties strongly influences the propagation of the temperature and heat flux density waves in the soil. A heat diffusion theory for non-homogeneous conductors (Lettau, 1962) which enables the thermal properties of the soil to be predicted is tested by comparison with experimental determinations in the field.
84 citations
TL;DR: The net loss of heat by the Mediterranean Sea was determined for February 1969 while oceanographers observed the cooling and sinking of the water south of France as mentioned in this paper, and the heat loss during the four preceding months was found to be sufficient to produce the unstable stratification necessary for the sinking of water.
Abstract: The net loss of heat by the Mediterranean Sea was determined for February 1969 while oceanographers observed the cooling and sinking of the water south of France. The heat loss during the four preceding months was found to be sufficient to produce the unstable stratification necessary for the sinking of the water. The mistral wind removed most of the heat through evaporation and sensible heat flux. On days when the mistral was blowing 1200 cal cm−2 day−1 of heat and 1.5 cm day−1 of water were removed from the sea. Throughout the winter season an average of 400 cal cm−2 day−1 was lost by the sea through sensible and latent heat fluxes. About half of the solar radiation absorbed by the water in the winter was lost through infrared radiation. Monthly heat exchanges are computed for an area south of France which show the dominant roles of latent heat exchange and solar radiation absorption in determining the temperature cycle and circulation of Mediterranean water. The flow patterns, turbulence and e...
57 citations
TL;DR: One hundred fortyone simultaneous wind speed, temperature and humidity profiles measured during the Barbados Oceanographic and Meteorological Experiment (BOMEX) are analyzed in this paper, where the observations were from heights 2-11 m above MSL and were made from the R/V Flip, a research vessel specially designed to be stable at sea.
Abstract: One hundred forty-one simultaneous wind speed, temperature and humidity profiles measured during the Barbados Oceanographic and Meteorological Experiment (BOMEX) are analyzed. The observations were from heights 2–11 m above MSL and were made from the R/V Flip, a research vessel specially designed to be stable at sea. The wind measurements are corrected for the interference of Flip's hull with the air flow. Evaporation estimates from the profiles are in fair agreement with simultaneous estimates by the eddy-correlation method. However, the heat fluxes estimated by the two methods are in poor agreement. There appear to be diurnal variations in air temperature, sea surface temperature and stress. The flux of latent heat is large, averaging 17 mW cm−2, while the flux of sensible heat is always upward and ∼1 mW cm−2.
52 citations
TL;DR: In this article, eddy fluxes of momentum, sensible heat and water vapour were measured over Lake Mendota, Wisconsin, U.S.A., which was covered by an extensive snowfall.
Abstract: On March 26, 1971, eddy fluxes of momentum, sensible heat and water vapour were measured over Lake Mendota, Wisconsin, U.S.A., which was covered by an extensive snowfall. An evaporation rate of about 0.7mm day−1 (2.2 mW cm−2) was detected. Wind speeds were light and the atmosphere near the surface was highly stable. In these conditions, the average sensible heat transfer and Reynolds stress were -0.9 mW cm−2 and 0.10 dyn cm−2, respectively. Comparison with measured gradients of wind speed, temperature and humidity yield a drag coefficient of about 0.54 × 10−3, and bulk transfer coefficients for sensible and latent heat of 0.41 × 10−3 and 0.78 × 10−3, respectively, applied to 10-m data. When corrected for the effect of atmospheric stability, these three coefficients become (in the same order) 1.2 × 10−3, 0.9 × 10−3 and 2.5 × 10−3. The errors in these estimates are such that the drag coefficient is not significantly different from that corresponding to an aerodynamically smooth surface, while the heat coefficients are similar to those normally applied over liquid water surfaces.
40 citations
TL;DR: In this paper, the microclimate of the tundra during spring of 1971 (29 May to 17 June) at Barrow, is described and analyzed in terms of the heat balance at the terrestrial surface and the effects of terrain parameters on heat balance components.
Abstract: The microclimate of the tundra during spring of 1971 (29 May to 17 June) at Barrow, is described and analysed in terms of the heat balance at the terrestrial surface and the effects of terrain parameters on the heat balance components. Changes through the snow-melting period are large. Within 2 weeks, 35 cm of snow are removed, soil interface temperatures increase by 15°C and the dry snow environment is replaced by a saturated water-soaked tundra surface. As a result, evaporation rates are high: up to 6 mm/day occurs immediately after the snow melt. The latent heat required for this is 40 times higher than during the pre-melting period.
32 citations
Journal Article•
TL;DR: Leaf and berry temperatures, cluster water loss, and stomatal resistances of Vitis vinifera L. grape-vines 9Carignane9, 9Muscat of Alexandria9, and 9Torontel9 were determined.
Abstract: Leaf and berry temperatures, cluster water loss, and stomatal resistances of Vitis vinifera L. grape-vines 9Carignane9, 9Muscat of Alexandria9, and 9Torontel9 were determined. The temperature of exposed fruits were 1.4 to 7.3°C higher than air temperatures and shaded berries were 0.5 to 4.4°C lower than air temperatures between 8:00 a.m. and 6:00 p.m. The maximum temperature differential across the berry at a given time was 10.7°C. The increase in berry temperature above air temperature was the result of low transpirational cooling. The latent heat flux density and the change in heat storage terms were only a small fraction of the total energy balance of the grape berry, and most of the absorbed energy went into sensible heat. Leaf temperatures were very close to air temperatures. Transpirational cooling in leaves is very efficient as a result of low stomatal resistances at times of high energy load. The abaxial stomatal resistances decreased with increasing leaf temperature.
31 citations
TL;DR: In this article, the authors derived formulas for the variation with height of the buoyancy, volume, and water vapor fluxes from large wet cooling towers for estimating plume rise, if the possibility of the release of latent heat is accounted for in the definition of the initial buoyancy flux.
Abstract: Formulas for the variation with height of the buoyancy, volume, and water vapor fluxes from large wet cooling towers are derived. The simple formulas developed by Briggs are suggested for estimating plume rise, if the possibility of the release of latent heat is accounted for in the definition of the initial buoyancy flux. The probability of whether condensation will occur is sensitive to small variations in moisture content and temperature of the environment. Verification of the theory is hampered by the scarcity of adequate measurements of cooling tower plumes.
TL;DR: The transfer of latent heat from an animal to its environment is often estimated by multiplying the loss in weight attributable to evaporation by the latent heat of vaporization of water, λ, which decreases from 2,501 J/g at 0° C to 2,406 J/G at 40° C.
Abstract: THE evaporation of water from the skin and the respiratory tract is an important mechanism of heat loss in homeotherms, and man's ability to sweat is essential for his survival when the temperature of the environment approaches or exceeds body temperature. The transfer of latent heat from an animal to its environment is often estimated by multiplying the loss in weight attributable to evaporation by the latent heat of vaporization of water, λ, which decreases from 2,501 J/g at 0° C to 2,406 J/g at 40° C.
TL;DR: In this paper, the total vertical velocity and the heating field were evaluated for a portion of the Indian region for a typical monsoon day in July 1966 using a two-level geostrophic model.
Abstract: The total vertical velocity and the heating field were evaluated for a portion of the Indian region for a typical monsoon day in July 1966 using a two-level geostrophic model. The generation of zonal and eddy available potential energy was computed with these values of heating and cooling. Both forms of available potential energy seem to be generated by diabatic processes. The generation of eddy available potential energy may be due to the released latent heat of condensation.
TL;DR: In this paper, a review of the complete solution of the problem of freezing and thawing soils is presented, in which LATENT HEAT is considered as a heat source.
Abstract: A REVIEW OF THE COMPLEXITIES IN THE SOLUTION OF THERMAL PROBLEMS ON FREEZING AND THAWING SOILS IS PRESENTED. THE DIFFERENTIAL EQUATIONS GOVERNING THE CONDUCTION OF HEAT, IN WHICH LATENT HEAT IS CONSIDERED AS A HEAT SOURCE, ARE STATED. AN EQUIVALENT CONVOLUTION VARIATIONAL THEOREM IS USED TO CONSTRUCT A TWO-DIMENSIONAL FINITE ELEMENT MODEL WITH LINEAR VARIATION OF TEMPERATURE WITHIN THE ELEMENT. TWO TIME STEP IDEALIZATIONS OF THE EQUATIONS ARE DESCRIBED, AND ALTERNATIVE FORMS OF THE LATENT HEAT MATRIX ARE DERIVED. SOME RESULTS OBTAINED WITH THE SIMPLEST LATENT HEAT MATRIX ARE PRESENTED TO ILLUSTRATE THE VERSATILITY OF THE TECHNIQUE. /RATAOC/
TL;DR: In this paper, an eight-level primitive-equation model was used to study a vigorous winter storm over North America by means of an 8-level grid with orography, surface and internal friction, long-wave radiation from clouds and water vapor, large-scale release of latent heat, and fluxes of sensible heat and water from water surfaces.
Abstract: A vigorous winter storm over North America is studied by means of an eight-level primitive-equation model. Included are orography, surface and internal friction, long-wave radiation from clouds and water vapor, large-scale release of latent heat, and fluxes of sensible heat and water vapor from water surfaces. Sigma coordinates are employed. The grid size is 190 km at 60°N. Two 36-hr numerical integrations are performed, one with and one without the effects of the Great Lakes and other water surfaces. When these influences are included, lower tropospheric temperatures are raised by more than 7°C and 1000-mb heights are reduced as much as 70 m. Ekman layer wind speeds are modified by up to 6 m/s. The maximum increase in large-scale precipitation over the Great Lakes is 0.5 cm with decreases to the southeast. Below 800 mb, isobaric surfaces are lowered; they are raised at higher levels. Effects on vorticity and divergence also change sign between lower and upper troposphere. Near the earth's surfac...
TL;DR: In this paper, it was shown that even when allowance is made for ablation, not enough heat is conducted into the ice to bring it all to the melting point, even when all the ice will reach a temperature of 0°C by the end of summer, how much of the layer of ice, cooled during the previous winter, is removed by ablation.
Abstract: Ten-meter temperature measurements show that Athabasca Glacier is temperate in the accumulation area but not in the ablation area. An important factor in determining whether all the ice will reach a temperature of 0° C by the end of summer is how much of the layer of ice, cooled during the previous winter, is removed by ablation. However, calculations show that, even when allowance is made for ablation, not enough heat is conducted into the ice to bring it all to the melting point. As recent work suggests that ice at 0° C is permeable to water, latent heat released by refreezing of percolating melt water is considered; it appears likely that this process is an insignificant heat source in the ablation area. Available data show that the penetration of solar radiation can probably also be neglected. The question of how widespread temperate glaciers are is discussed; it is predicted that in most, if not all, glaciers there is a region below the equilibrium line where, because ablation is low, the glacier is not strictly temperate.
Patent•
07 Feb 1972
TL;DR: In this paper, a heat transfer medium in the form of a lower boiling immiscible liquid is employed in a manner to give up its latent heat of condensation directly to the solution and the resulting condensate is re-evaporated by heat from the resulting fresh water.
Abstract: Apparatus and method for distilling aqueous solutions, especially saline water, for the purpose of producing fresh water, wherein a heat transfer medium in the form of a lower boiling immiscible liquid is employed in a manner to give up its latent heat of condensation directly to the solution and the resulting condensate is re-evaporated by heat from the resulting fresh water; such apparatus and method providing certain advantages such as ability to work with a small heat differential between the temperature of the source of external heat and the temperature of the heat sink.
01 Jan 1972
TL;DR: In this article, the authors derived expressions for the optimal pore radius and maximum throughput length for a given pipe ID and a given acceleration field, and used the expressions in selecting the best working fluid and in designing the wick structure.
Abstract: Candidate working fluids for cryogenic heat pipes [1] exhibit very low values of surface tension and latent heat of vaporization, resulting in low-capacity heat pipes which are very sensitive to acceleration fields. It is important in the design of cryogenic heat pipes to optimize the wick geometry characterized by the pore radius R c,and wick thickness ratio R v/R, w , in order to achieve the maximum throughput Q and length Z for a given pipe ID and a given acceleration field. It is the purpose of this paper to derive expressions for optimum capillary pore radius R co and maximum throughput length product Q(Z + Z a ), to use the expressions in selecting the best cryogenic working fluid and in designing the wick structure, and to show the dramatic effect of acceleration fields on heat pipe performance. To complete the optimum heat pipe design, a heat transfer model based on conduction is presented for both the homogeneous wick structure and the channel wick. Total heat pipe temperature drop comparisons are made between optimized cryogenic heat pipes and the best solid thermal conductor.
TL;DR: In this article, the momentum theorem of classical hydrodynamics is applied to a scheme for controlled atmospheric convention within a vertical tube of large height and diameter, open at both ends, for which the name aerological accelerator was previously suggested.
Abstract: The momentum theorem of classical hydrodynamics is applied to a scheme for controlled atmospheric convention within a vertical tube of large height and diameter, open at both ends, for which the name aerological accelerator was previously suggested by the writers. The interior thermodynamic process is conceived as being moist adiabatic, although departures from this ideal case must be considered. The condensation and consequent latent heat release renders unnecessary any external drive, save for a proper supply of moist air. As discussed previously by the writers, the most important practical application of the device is the production of fresh water for ordinary uses from atmospheric water vapor. A year of daily soundings from the aerological station at Brownsville, Texas, is analyzed to examine the probable success of the procedure. The theoretical results are encouraging, but a host of questions and problems remain. Various of these are commented upon, and suggestions are made for further investigation of them.
01 Jun 1972
TL;DR: In this paper, a genetic climatic classification is presented which uses the fluxes of energy and moisture at the interface as its basis, where long and short wave inputs are abstracted into net radiation, whereas latent heat flux, vertical sensible heat flux and horizontal sensible heat flow are used as output components in this global classification.
Abstract: A genetic climatic classification is presented which uses the fluxes of energy and moisture at the interface as its basis. Long and short wave inputs are abstracted into net radiation, whereas latent heat flux, vertical sensible heat flux and horizontal sensible heat flux (at interface level) are used as output components in this global classification. Six climatic groups and sixty-two climates result. For purposes of demonstration of the system, Budyko's model was used to derive the necessary data. It is believed, until future models generate more accurate data, that the main global features portrayed by the scheme are consistent and show reasonable trends.
TL;DR: In this paper, the authors studied the collapse of a vapour bubble in subcooled liquid, in view of the fact that the predicted duration is delayed in comparison with the recorded graphs of size reduction.
01 Jan 1972
TL;DR: In this article, a conflict of experimental literature values for the heat of vaporization of n-propanol between 111" and 200°C was resolved with the resolution of literature vapor volumes, enthalpy changes in the vapor at 300°F (149.1"C) were reduced to better agree with those calculated from PVT data.
Abstract: Selected values of the critical constants, vapor pressure, saturated liqu.4 vc ume, saturated vapor volume, normal boiling point, latent heat of vaporization, and calculated thermodynamic properties for n-propanol are presented. Major emphasis is on literature data since 1962, with the resolution of a previous conflict of literature vapor volumes, heats of vaporization, and vapor enthalpies from 140-225°C. This work was undertaken for the primary purpose of resolving a conflict of experimental literature values for the heat of vaporization of n-propanol between 111" and 200°C. The pressure-enthalpy diagram of Eubank and Smith (8) is also corrected to reflect recent values of C," with the result that isothermal enthalpy changes in the vapor at 300°F (149.1"C) are reduced to better agree with those calculated from PVT data
01 Feb 1972
TL;DR: In this paper, the simulation of certain thermal processes such as the solidification of castings, freezing of biological fzuids, and the heating of metals requires the solution of a heat conduction problem involving temperature-dependent properties.
Abstract: The simulation of certain thermal processes such as the solidification of castings, freezing of biological fzuids, and the heating of metals requires the solution of a heat conduction problem involving temperature-dependent properties. Because of this, numerical techniques are frequently employed, In such techniques, the addition of temperature-dependent thermal conductivity presents no great problem. How-
TL;DR: In this article, a seven-layer physical-numerical model for the lower tropospheric region (surface - 1600m) is described, which is an integral part of the complete Air Force Global Weather Central (AFGWC) meso-scale (sub-synoptic) numerical analysis and prediction system.
Abstract: A limited-area seven-layer physical-numerical model for the lower tropospheric region (surface - 1600m) is described. The grid interval, approximately 190km, is half that of the standard numerical weather-prediction grid used in the hemispheric free atmospheric operational model at the Air Force Global Weather Central (AFGWC). This model is an integral part of the complete AFGWC meso-scale (sub-synoptic) numerical analysis and prediction system and is used to provide greater horizontal and vertical resolution in both numerical analyses and forecasts. Important features of this boundary-layer model include: a completely automated objective analysis of input data; the transport of heat and moisture by three-dimensional wind flow; latent heat exchange in water substance phase changes; and eddy fluxes of heat and water vapor. Input data are conventional synoptic surface and upper air reports. Other operational AFGWC prediction models provide input in the form of horizontal wind components at the upper boundary and an estimate of cloudiness above the boundary layer. Forecasts for the lower boundary and surface layer are empirically derived. Despite some approximations which broadly simplify the real planetary boundary-layer processes, operational use for highly weather-sensitive Air Weather Service support indicates that the model is capable of producing accurate detailed forecasts for periods of up to 24h.
01 Jan 1972
TL;DR: One-dimensional two-phase flow transpiration cooling through porous metal is studied experimentally in this paper, where good agreement with calculated temperature distribution is obtained as long as the basic assumptions of the analytical model are satisfied.
Abstract: One-dimensional two-phase flow transpiration cooling through porous metal is studied experimentally. The experimental data is compared with a previous one-dimensional analysis. Good agreement with calculated temperature distribution is obtained as long as the basic assumptions of the analytical model are satisfied. Deviations from the basic assumptions are caused by nonhomogeneous and oscillating flow conditions. Preliminary derivation of nondimensional parameters which characterize the stable and unstable flow conditions is given. Superheated liquid droplets observed sputtering from the heated surface indicated incomplete evaporation at heat fluxes well in access of the latent energy transport. A parameter is developed to account for the nonequilibrium thermodynamic effects. Measured and calculated pressure drops show contradicting trends which are attributed to capillary forces.
TL;DR: In this article, day-time records of the microstructure of humidity and temperature at 2 and 4 m are analyzed. But the two variables are remarkably similar and share the following properties: the characteristic scale of turbulence increases with height and decreases with increasing instability beyond near-neutral conditions.
Abstract: Day-time records of the microstructure of humidity and temperature at 2 and 4 m are analysed. Supporting data include the temperature and wind gradients, the net radiation, the sensible heat flux, and a derived value for the latent heat flux.
The two variables are remarkably similar and share the following properties: The characteristic scale of turbulence increases with height and decreases with increasing instability beyond near-neutral conditions. The logarithmic spectra follow a −5/3 slope for wave numbers greater than 0.15 m−1. In this range, the spectral estimates increase with increases in the appropriate flux (sensible or latent heat flux for temperature or humidity spectra), and decrease with height.
The humidity variance contains large-scale components which are of lesser importance in the temperature variance. This difference in the two variables has tentatively been attributed to properties of the site.
01 Mar 1972
TL;DR: In this article, a detailed comparison of the diurnal variation of the fluxes shows that the ship creates an island of turbulence quite different from open sea conditions, and measurements from the buoy indicate that the constant flux layer may be less than 6 m thick.
Abstract: Computations of sensible and latent heat fluxes from measurements taken aboard a ship and from a spar buoy east of Barbados in July and August, 1968 are reported. A detailed comparison of the diurnal variation of the fluxes shows that the ship creates an island of turbulence quite different from open sea conditions. Measurements from the buoy, which are believed to be more typical of open ocean conditions indicate that the constant flux layer may be less than 6 m thick.
TL;DR: Rodgers and Sotto as mentioned in this paper calculated the daily heat flux for the open water of Lake Ontario for the period beginning January 1, 1965, and ending June 30, 1969, based on the 'principal factors associated with the gain and loss of heat by large lakes' incident and reflected solar radiation, absorbed and emitted long-wave radi ation, sensible heat transfer across the air/water interface, and the latent heat associated with water vapor exchange at the interface.
Abstract: Readability is not necessarily a common characteristic of scientific reports, but G.K. Rodgers and G.K. Sotto of the Great Lakes Institute of the University of Toronto have achieved it in this preliminary report on the calculation of the heat budget of Lake Ontario.
The two investigators essentially calculated a daily heat flux for the open water of Lake Ontario for the period beginning January 1, 1965, and ending June 30, 1969. They based their calculations on the 'principal factors associated with the gain and loss of heat by large lakes' incident and reflected solar radiation, absorbed and emitted long-wave radi ation, sensible heat transfer across the air/water interface, and the latent heat associated with water vapor exchange at the interface.
TL;DR: In this paper, a 2-year study of snowmelt in the Upper Peninsula of Michigan is summarized, showing that although it was frozen in early winter, the ground thawed and remained unfrozen as snow accumulated from mid-February on, which gave rise to a winter base flow twice that of summer.
Abstract: A 2-year study of snowmelt in the Upper Peninsula of Michigan is summarized. The major results are (1) that although it was frozen in early winter, the ground thawed and remained unfrozen as snow accumulated from mid-February on; (2) that the unfrozen ground allowed the production and infiltration of ground melt, which gave rise to a winter base flow twice that of summer; and (3) that a standard equation for predicting air-snowpack moisture exchange was inadequate, especially when condensation occurred. It is proposed that this latter discrepancy is due to the occurrence of condensation just above, rather than at, the snow surface, so that the latent heat is released largely to the air rather than to the snowpack.