PARAMETRIZATION OF THE HEAT AND MASS EXCHANGE PROCESS IN THE SURFACE ATMOSPHERIC LAYER

When constructing numerical models of the atmosphere and the surface atmospheric layer (PAS) interacting with it, the “parametrization” approach is used, that is, the representation of processes with scales smaller than the scale of the cells of the computational grid intended for modeling processes of larger scales.

Mass Exchange of Water and Soil on the Soil Surface in the Rainfall Splash Erosion

This research aims to unfold the mass exchange mechanism of water and soil on the soil surface in the rainfall splash erosion process. We regard the rainfall splash erosion process as a collision process between the raindrop and the soil particle on the soil interface. This recognition allows us to incorporate research approaches from the spring vibrator model, which has been developed for simulating the impact of liquid drops on solid surface. We further argue that because a same set of factors determine the splash amount and infiltration amount and it is relatively simpler to observe the infiltration amount, an investigation into the relationship between the splash amount and infiltration amount would be able to provide a new channel for quantifying the splash erosion. This recognition leads us to examining the relationship between single raindrop, rainfall kinetic energy and splash erosion from both theoretical and empirical angles, with an emphasis on the relationship between the infiltration amount and the splash erosion. Such an investigation would add value to the collective effort to establish mass exchange law in water-soil interface during rainfall splash erosion. It is found that during the rainfall splash process, the splash erosion is proportional to the rainfall kinetic energy; and has a linear relation to the infiltration amount, with the rainfall intensity as one of important parameters and the slope depending on the unit conversation of the infiltration amount and the splash erosion. If the units of two items are same, the slope is the ratio of the soil and water density, and the splash erosion velocity of the rainfall is half of the rainfall terminal velocity. The single raindrop kinetic energy and the splash erosion have a quadratic parabola relation, and the splash velocity is about 1/3 of single raindrop terminal velocity.

Variation of water mass exchange on tidal scale in Balikpapan Bay

Balikpapan Bay is enclosed water influenced by freshwater from river runoff and saline water from Makassar Strait. The exchange of water mass was examined by 3D numerical model simulation-Hamburg Shelf Ocean Model (HAMSOM) with horizontal resolutions approx. 150 m and 10 vertical layers applied in Balikpapan Bay. The thirteen tidal components, daily river runoff, atmospheric forcing, subsurface temperature, and Salinity in 3D used for model input. The tidal elevation from Geospatial Information Agency (BIG) model fits with this result from 01/03/2020 to 31/03/2020. It has coefficient correlation 0,99 with a significant level of 95% and Root Mean Square Error (RMSE) is 0,1 m. The volume and salt transport in the mouth (Line-A) and middle (Line-B) of bay was examined. The maximum transport in Line-A during spring (neap) high to low tide and low to high tide is −18364.72 m3/s (−1717.57 m3/s) and −17532.27 m3/s (4258.86 m3/s) for volume. Then, 531,947,898.90 kg.psu./s (−45,127,135.38 kg.psu./s) and −536,410,944.50 kg.psu./s (140,700,437.97 kg.psu./s) for salinity. Positive (negative) of water transport is inflow (outflow) to Balikpapan Bay. The net transport in a day during the spring (neap) is −832.45 m3/s (5976.43 m3/s) for volume and −4,463,045.58 kg.psu./s (185,827,573.35 kg.pau./s) for salt. The vertical structure of net volume and salt transport bot in Line-A and Line-B shows the water goes to outer bay in surface and inner bay in subsurface. While in the spring tide the surface deeper than neap tide. It indicated that water mass exchange dominantly influenced by river in surface and tidal in subsurface. It also shows that water mass from inner bay more easy flushing during spring tide than neap tide and vice versa

Melting temperature changes during slip across subglacial cavities drive basal mass exchange

The importance of glacier sliding has motivated a rich literature describing the thermomechanical interactions between ice, liquid water and bed materials. Early recognition of the gradient in melting temperature across small bed obstacles led to focused studies of regelation. An appreciation for the limits on ice deformation rates downstream of larger obstacles highlighted a role for cavitation, which has subsequently gained prominence in descriptions of subglacial drainage. Here, we show that the changes in melting temperature that accompany changes in normal stress along a sliding ice interface near cavities and other macroscopic drainage elements cause appreciable supercooling and basal mass exchange. This provides the basis of a novel formation mechanism for widely observed laminated debris-rich basal ice layers.

Modern approaches to the intensification of heat and mass exchange in multi-temperature condensation filters

The article considers the problems and features of heat and mass exchange on developed surfaces in the conditions of both single-phase and vapour-liquid flow during its condensation. We give a brief analytical review of studies of hydrodynamics and heat exchange in such systems. We analyzed the efficiency of the working channel of the condensation filter and identified problematic points. We offer possible methods for intensifying heat and mass transfer on working surfaces.

A Challenge and Chance for Soil Ecology

The understanding of soil and its response to the global warming is important for the harmony of human and environment. Generally, soil has four majorcomponents as air, water, mineral matter, and organic matter. The relative proportions of these four components greatly influence the behavior and productivity of soils. Through interactions of energy flow and mass exchange,soil plays the role as the crucial interface medium for air, minerals, water and life, and forms a complex integrated body, ecosystem. To a great extent, soil ecology is one new branch of ecology that study the relationship between soil biota and environment, including ecological structure, function, balance and evolution of soil ecosystem. The application of soil ecology will be a benefit for the reasonable and sustainable use of land resources and be important for agriculture, forestry and grazing production.