Frost Processes Research Articles

Disaster process-based spatiotemporal characteristics of apricot frost in the warm temperate zone (WTZ), China.

Frost stress is a major environmental factor that limits apricot growth in the warm temperate zone (WTZ) of China, and is always triggered by extreme low temperature weather processes. In this study, the characteristics of the apricot frost processes f(D, Tcum), which were identified from historical disaster representation, were analyzed and apricot frost evaluation indicators were developed, thus facilitating the process-based assessment and spatiotemporal analysis of apricot frost processes. Periods of low temperature that persist for 1~2, 3, and ≥4 days (i.e., duration days, D) provide the initial identification indicator for light, moderate, and severe apricot frost. The threshold ranges for Tcum are 0~3.9, 9.2~12.0, and >16.2 for D values of 1~2, 3, and ≥4, respectively. The northwest of the WTZ is dominated by apricot frost, with approximately 80% of apricot frost being light, followed by moderate and severe. Regional apricot frost exhibited a significant decreasing trend over the last four decades. A total of 29.65% of stations, which were mainly located in the northwest and middle parts of the study region, detected an increasing trend in apricot frost. The results provide technical support for targeted apricot frost level detection, and the process-based spatiotemporal characteristics of apricot frost can provide basic information for the prevention and mitigation of apricot frost.

Factors influencing the development of microtextures on cold‐climate aeolian quartz grains revealed by experimental frost action

AbstractAeolian‐originated quartz grains of coarse‐sand size (0.5–1 mm) were subjected to experimental frost weathering. A total of 1,000 freeze–thaw cycles with temperature ranges from −5 to +10°C were simulated under full water availability conditions. Scanning electron microscope microtextural analysis of grain surfaces conducted after 0, 50, 100, 300, 700, and 1,000 freeze–thaw cycles resulted in different‐sized conchoidal fractures and breakage blocks as frost‐induced microtextures. The vast majority of these microtextures were encountered on the most convex parts of aeolian grains and their number increased with ongoing freeze–thaw cycles. However, the number of recorded frost‐originated microtextures remained relatively small up to 700 freeze–thaw cycles and increased after 1,000 freeze–thaw cycles. Transmission electron microscope microstructural analysis of grains after 0, 100, and 1,000 freeze–thaw cycles showed both primary (e.g., inclusions, grain boundaries) and secondary (e.g., cracks) defects in quartz crystals. The frequency of the latter remained unexpectedly low. The susceptibility of aeolian‐originated sand‐sized quartz grains to frost‐induced modifications is interpreted here to depend mainly on their internal characteristics. These include aeolian‐driven development of a subsurface impact zone that determines the depth to which frost‐originated microtextures develop. The outer impact zone consists of a thin layer of surficial crust and a series of more or less parallel ridges arranged into mechanically upturned plates. The inner impact zone consists of intact or cracked quartz crystals. The susceptibility of aeolian‐originated quartz grains to frost‐induced modifications depends therefore on a combination of internal (i.e., original crystallography of quartz grains) and external (i.e., aeolian and frost processes acting upon the grains) factors.

Morphological changes currently occurring in sand-filled gully channels on Mars: Implications for the role of substrates inside channels

Long-term monitoring of dune/non-dune gullies has substantiated extensive and diversified morphological changes whose timing correlates with the time of removal of CO2 frost, thereby implying seasonal control on the active processes. We present evidence for present-day changes in sand-filled gully channels consistent with ripples. These channels are ubiquitous in the mid-latitudes and found in gullies formed over a variety of substrates on crater walls. We investigated 1483 gullied craters having coverage of at least two High Resolution Imaging Science Experiment (HiRISE) images between 30°S and 75°S and identified 98 craters (6.6% of the total) with sand-filled gully channels. Among these 98 craters, sand-filled gully channels in 25 craters (25.5% of the total) exhibit morphological changes indicative of avulsion, narrow channel incision, formation of channels with potential terminal pits, channel widening and extension, downslope flow of mobilized sand inside channels, dark flows and rapid boulder movement inside channels, and local sand rearranging and erasing of channels. Investigation of the sequence of events revealed CO2 frost inside the sand-filled gully channels in the image acquired during winter and prior to the image in which recent changes have been observed. This suggests a connection with the sublimating frost inside the channels and a seasonal control that subsequently produces extensive changes in the sand-filled gully channels during defrosting seasons in approximately a Mars year. Comparison of changes on both sand-filled gully channels and dune gully channels substantiates that the currently active processes have similar effects on the loose, unconsolidated substrate in both the gully types. For example, CO2 frost processes are able to erode both sand-filled gully channels and dune gully channels to form linear channels with terminal pits. In contrast, we have not found similar evidence of linear channels with terminal pits on bedrock and/or LDM substrate on the crater wall suggesting that the bedrock and LDM substrate may not be able to be eroded by CO2 frost processes in a manner similar to the loose, unconsolidated substrate in sand-filled gully channels investigated in this study. Together, the results signify that the sand-filled gully channels represent a significant component of present-day modification of gully channels on Mars.

Martian gully activity and the gully sediment transport system

The formation process for Martian gullies is a critical unknown for understanding recent climate conditions. Leading hypotheses include formation by snowmelt in a past climate, or formation via currently active CO2 frost processes. This paper presents an expanded catalog of >300 recent flows in gullies. The results indicate that sediment transport in current gully flows moves the full range of materials needed for gully formation. New flows are more likely to transport boulders in gullies that have pre-existing boulder-covered aprons, indicating that current flows are transporting the same materials required for gully formation overall. The distribution of gully activity frequencies can be described by a power law and indicates that the recurrence intervals for flows in individual gullies are commonly tens to hundreds of Mars years. Over the last ~300 kyr, climate variations have been modest but individual gullies have had tens to thousands of flow events. This could be sufficient to account for the entirety of gully formation in some cases, although the same processes are likely to have occurred further in the past. For any gullies that may have initiated under higher-obliquity conditions, this level of recent activity indicates that the observable morphology has been shaped by CO2-driven flows. These observations of sediment transport and the tempo of gully activity are consistent with gully formation entirely by CO2 frost processes, likely with spatial and temporal variability, but with no role required for liquid water.

Process-based indicators for timely identification of apricot frost disaster on the warm temperate zone, China

Frequent occurrences of late spring frost disaster create severe agricultural/forest damage, even given the background of global warming. In the warm temperate zone of China, which is the largest planting area for fresh apricot, late spring frost disaster has become one of the major meteorological hazards during flowering. To prevent cold weather–induced apricot frost disaster and reduce potential losses in related fruit economic value, it is vital to establish a meteorological indicator for timely and accurate identification of cold weather process–based apricot frost disaster, to provide support for timely apricot frost monitoring and warning in late spring. In this study, daily minimax temperature ( $${T}_{\mathrm{min}}$$ ) and apricot frost disaster data during flowering were combined to establish meteorological identification indicators of apricot frost based on cold weather processes. A process-based apricot frost model $$f(D,{T}_{\mathrm{cum}})$$ was firstly constructed, and characteristics of $${T}_{\mathrm{cum}}$$ (accumulated harmful temperature) were explored under different D (duration days) based on the representation of historical apricot frost processes. Thresholds for the $${T}_{\mathrm{cum}}$$ for apricot frost in 1, 2, 3, 4, and more than 5 days of apricot frost process were determined as − 1.5, − 2.9, − 4.4, − 5.8, and − 7.3 °C, respectively. Validation results by reserved independent disaster samples were generally consistent with the historical records of apricot frost disasters, with 89.00% accuracy for indicator-based identification results. Typical process tracking of the proposed identification indicator to an apricot frost event that occurred in North Hebei during April 3–9, 2018, revealed that the indicator-based identification result basically coincides with the historical disaster record and can reflect more detailed information about the apricot frost process.

The Role of Frost Processes in the Retreat of River Banks

The rate of bank retreat was measured using erosion pins on the alluvial banks of the rivers in the Podhale region (the boundary zone between Central and Outer Carpathians) during the hydrological year 2013/2014. During the winter half-year (November–April), the bank retreat was mainly caused by processes related to the freezing and thawing of the ground (swelling, creep, downfall). During the summer half-year (May–October), fluvial processes and mass movements such as lateral erosion, washing out, and sliding predominated. The share of fluvial processes in the total annual amount of bank retreat (71 cm on average) was 4 times greater than that of the frost phenomena. Erosion on bank surfaces by frost phenomena during the cold half-year was greatest (up to 38 cm) on the upper parts of banks composed of fine-grained alluvium, while fluvial erosion during the summer half-year (exceeding 80 cm) mostly affected the lower parts of the banks, composed of gravel. The precise calculation of the relative role of frost phenomena in the annual balance of bank erosion was precluded at some stations by the loss of erosion pins in the summer flood.

An Automated Plot Heater for Field Frost Research in Cereals

Frost research to improve genetics or management solutions requires a robust experimental design that minimizes the effects of all other variables that can cause plant damage except for the treatment (frost). Controlled environment facilities cannot faithfully replicate field radiative frost processes, but field studies are limited by the reliability of field methods to exclude frost. An effective field frost exclusion method needs to prevent frost damage while not impacting growing microclimate or yield, and be automatic, modular, mobile, and affordable. In this study, we designed an effective prototype treatment with these features for field frost research that uses diesel heating. The effectiveness of the plot heater to provide an unfrosted control is evaluated by monitoring canopy temperature (CT) and air temperature during frost events, showing that these remain above zero in the heated plots when ambient temperature drops below zero. We find that the plot heater method can prevent potential frost damage at the plot-scale, while not appearing to have an impact on either plant development or yield components. This offers a potential new tool for frost field crop researchers to incorporate a plot-scale control into their experimental design.

Landforms and morphogenetic processes in the locality of Geodetic Observatory Pecný, Ondřejovská vrchovina Highland

The presented paper deals with physical-geographical environment and landform patterns in the locality of Geodetic Observatory Pecný (GOPE) in the Ondřejovska vrchovina Highland. Landforms transience of the Ondřejovska vrchovina Highland by erosion and denudation processes is proportional to a high potential energy of the relief due to progressive tectonic uplift of the central part of the Bohemian Massif in the late Cenozoic. The Seradovský potok Brook valley between the Pecný Ridge (545 m a.s.l.) and the Sazava valley bottom (284 m a.s.l.) intersects several levels of planation surfaces and its source area erodes the etchplain exhumed during the Palaeogene. In the lower part of the valley, the stream deepened during the late Quaternary by approximately 50 m, whereas the relatively steep erosional slopes of the canyon-like part of the antecedent Sazava valley have a relative height of 60–75 m. In the rugged terrain of the GOPE locality, there are visible marks of regelation and frost processes, gully and fluvial erosion, slow slope movements and anthropogenic activities. Intensity of recent morphogenetic processes with its maximum in spring corresponds to combination of seasonal changes of air and soil temperature and at the same time to increased water content in the rock massif and in the weathered mantle. The suitable geodynamic location of scientific observatories on the Pecný ridge, stable from engineering-geological and geomorphological point of view, and in its near neighbourhood is menaced by increasing intensity of anthropogenic activities in the landscape.

Periglacijalni reljef na području Velebita

Although the Velebit is a low mountain situated in the moderate climate zone, there exist periglacial processes in relief modelling in its highest part. The reason for this is interdependance of geological, geomorphological, climatic, vegetational and pedological influences, but also long antropogenic and zoogenic influences. Among periglacial forms the features which originated from the activity of nival and frost processes can be singled out.

Poszukiwanie wieloletniej zmarzliny i budowa geologiczna Babiej Góry w świetle wyników obrazowania elektrooporowego

The article reports the results of fieldwork carried out on the peak of Babia Gora to verify a hypothesis regarding the existence of permafrost at this location. The climate and geomorphological evolution of this area suggest that both past and current frost processes play an important role here. Furthermore, not far from this massif – in the Tatra Mts – permafrost was detected at an altitude of ca. 2000 m a.s.l., in an area where mean annual air temperature (MAAT) drops to minus 0.8°C. The MAAT at the summit of Babia Gora is likewise below 0°C. Given that long-term freezing of the massif in the glacial period reached down to considerable depths, the climatic evolution of the massif indicates that permafrost could have lasted through to the present time. In the study area three resistivity profiles were made using the resistivity imaging method. Two of these were 300 m long and one 400 m. The depth of interpretation extends to approx. 90 m below the ground surface in the last case. While the results of the geophysical surveys do not confirm the presence of permafrost in the study area unambiguously, its presence may not be precluded in certain places in the shallow subsurface layer. The permafrost originating in older geological periods and located at greater depth was probably exposed to relatively rapid degradation, given the geological structure of Babia Gora allowing for deep water drainage. Resistivity models shows the geological structure of the research area close to the summit of Babia Gora, but do not resolve the issue of the existence of modern or fossil permafrost. The temperature of the water in springs located close to the summit is almost constant, though, and does not exceed 1°C. This shows that water circulation is a relatively deep one, and the temperature within the massif cannot therefore be higher than this. The existence of permafrost is not therefore precluded, and this might be possible in the form of the cryotic state. The measurements made present only the first approach to the hypothesis regarding the possible existence of permafrost on Babia Gora, and further research applying other, complementary methods may still change views on this subject.

Snow and frost: implications for spatiotemporal infiltration patterns – a review

AbstractVast regions of the northern hemisphere are exposed to snowfall and seasonal frost. This has large effects on spatiotemporal distribution of infiltration and groundwater recharge processes as well as on the fate of pollutants. Therefore, snow and frost need to be central inherent elements of risk assessment and management schemes. However, snow and frost are often neglected or treated summarily or in a simplistic way by groundwater modellers. Snow deposition is uneven, and the snow is likely to sublimate, be redistributed and partly melt during the winter influencing the mass and spatial distribution of snow storage available for infiltration, the presence of ice layers within and under the snowpack and, therefore, also the spatial distribution of depths and permeability of the soil frost. In steep terrain, snowmelt may travel downhill tens of metres in hours along snow layers. The permeability of frozen soil is mainly influenced by soil type, its water and organic matter content, and the timing of the first snow in relation to the timing of sub‐zero temperatures. The aim with this paper is to review the literature on snow and frost processes, modelling approaches with the purpose to visualize and emphasize the need to include these processes when modelling, managing and predicting groundwater recharge for areas exposed to seasonal snow and frost. Copyright © 2015 John Wiley & Sons, Ltd.

Frost for the trees: Did climate increase erosion in unglaciated landscapes during the late Pleistocene?

Understanding climatic influences on the rates and mechanisms of landscape erosion is an unresolved problem in Earth science that is important for quantifying soil formation rates, sediment and solute fluxes to oceans, and atmospheric CO2 regulation by silicate weathering. Glaciated landscapes record the erosional legacy of glacial intervals through moraine deposits and U-shaped valleys, whereas more widespread unglaciated hillslopes and rivers lack obvious climate signatures, hampering mechanistic theory for how climate sets fluxes and form. Today, periglacial processes in high-elevation settings promote vigorous bedrock-to-regolith conversion and regolith transport, but the extent to which frost processes shaped vast swaths of low- to moderate-elevation terrain during past climate regimes is not well established. By combining a mechanistic frost weathering model with a regional Last Glacial Maximum (LGM) climate reconstruction derived from a paleo-Earth System Model, paleovegetation data, and a paleoerosion archive, we propose that frost-driven sediment production was pervasive during the LGM in our unglaciated Pacific Northwest study site, coincident with a 2.5 times increase in erosion relative to modern rates. Our findings provide a novel framework to quantify how climate modulates sediment production over glacial-interglacial cycles in mid-latitude unglaciated terrain.

Przekształcenia powierzchni brzegów rzecznych przez procesy mrozowe

The effects of frost processes on undercut riverbanks in the period November-April, at the turn of 2011/2012 were examined Erosion of the riverbanks in the Czarny Dunajec basin (Orava Basin, Gubalowka Hills) and in the Ropa basin (Low Beskid) was studied by erosion pins and catchers of bank sediments There were 4-5 multigelation periods It has been shown that the frost processes caused the largest erosion in area of rocky banks; erosion was smaller on banks built with medium and coarse gravels, and the smallest on banks built with sands and clays The size of this erosion was influenced not only by lithology and the degree of cohesion, but also the presence and density of cracks

Stratigraphic position and natural environment of the oldest Middle Palaeolithic in central Podolia, Ukraine: New data from the Velykyi Glybochok site

Velykyi Glybochok is an important multi-cultural Palaeolithic site, known since 1979. Besides the Late Palaeolithic (I) and Upper Palaeolithic (II) cultural layers, in this site the following Middle Palaeolithic layers are found: III-B in the soil from the last interglacial, III-A in the Ternopil soil horizon from the penultimate glaciation, and III (the oldest Palaeolithic settlement in Podolia) in the soil from the penultimate interglacial. The ages of these cultural layers are determined from their situation in a complex sequence of loesses and paleosols. In this paper we report the results of excavations carried out in the years 2007–2012, which were supplemented with geophysical recognition. The excavations were conducted in a karst depression formed in Neogene limestones. It is filled and covered by loess containing partially redeposited paleosols. These deposits were sampled for lithological, palaeopedological, palaeomagnetic and palynological analyses, the results of which were used for palaeoenvironmental interpretation. Chronostratigraphy was determined based on TL and IRSL dating as well as palaeomagnetic studies. In comparison with the older investigations, the new discovery is quite well-preserved, with a bipartite complex of paleosols (S2-II and S2-I) from the penultimate interglacial (MIS 7), which occurs between the Odranian (Dnieper) loess L3 and the Wartanian (Tyasmin) loess L2. The paleosols are of interglacial nature. Forest and then steppe vegetation grew during two stages of their formation, which were separated by a cool period when a small accumulation of loess and frost processes occurred. The oldest Middle Palaeolithic cultural layer occurs in the older soil (S2-II), indicating that it is the trace of the oldest Palaeolithic settlement in the western Ukraine. Flint artefacts were made using the Levallois method, rarely found in the sites with the Middle Palaeolithic oldest assemblages, rare in Eastern Europe.

Modeling water balance and effects of different subsurface drainage methods on water outflow components in a clayey agricultural field in boreal conditions

Proper drainage practices to remove excess water are crucial for crop cultivation in the humid climatic conditions of the boreal areas. The objectives of this study were to close the water balance, to quantify the amount of groundwater outflow, to identify the effects of topography on drain discharge, and to determine the effects of different subsurface drain installation methods and spacing of drainage lines on water outflow components in a clayey agricultural field. Hydro-meteorological, soil and topographic data were available from paired field sections in southern Finland including two control sections and two sections where different subsurface drainage methods were applied. A 3D hydrological model (FLUSH) was applied to the whole field area for snow- and frost-free periods in three measurement years to decipher the hydrological effects of the drainage improvements. The simulated field area was 14ha. Simulation results revealed that a steep slope outside of the field decreased drain discharge with 40% and increased groundwater outflow, which was quantified to be a major component of the water balance, approximately 9–15% of the precipitation. The model simulations demonstrated and quantified how drainage improvements in a treatment section affected the hydrology of an adjacent control section. This revealed that the sections shared a hydrological connection through subsurface flow processes. Such connection is typically neglected in the experimental comparison of measurement results from paired field sections. According to the simulations trenchless drain installation changed soil hydraulic properties by decreasing the volumetric fraction of connected soil macropores and by increasing the rate of water exchange between soil matrix and macropores. This affected more the dynamics than the absolute amount of drain discharge. The 3D model was useful in closing the water balance although the limitations were lack of data outside monitored sections and exclusion of snow and frost processes.

Assessing geochemical indicators of weathering and sorting in last interglacial palaeosols in the Chinese Loess Plateau and its implications for palaeoclimatic reconstruction

Based on a W–E transect through the northern loess regions of Austria, palaeoenvironmental studies were carried out in three loess–palaeosol sequences (Gunderding, Krems-Wachtberg and Stillfried B locus typicus) to complement available results in the context of a multi-methodological approach. On the base of previously published datings, our study concentrates on the MIS 3/2 transition. The results of detailed micromorphological investigations prove that palaeopedogenesis, frost processes, and sedimentation rates differ in their spatial occurrence in the loess belt of Austria. All three sequences are in line with the general trend of a reduced intensity of pedogenic and cryogenic features from western to (south-)eastern Europe, which can be explained by lower Atlantic moisture influence towards the east. Interstadial cambic horizons are well developed in the MIS 3 sequence of western Austria, whereas the eastern loess profiles only show weak pedogenesis. In all studied sequences frost processes were active during the upper MIS 3 and MIS 2. The studied MIS 2 records are characterised by tundra soils with reductaquic horizons, which is a clear sign for prolonged phases of permafrost. On the spatial scale, the sedimentation rate increases in the eastern loess regions and particularly the Krems-Wachtberg sequence in the centre of the transect experienced an exceptionally high sedimentation rate and can thus be seen as one of the most important high resolution records for the MIS 3/2 transition in European loess regions.

The effect of synoptic scale weather systems on sub‐surface soil temperatures in a diurnal frost environment: preliminary observations from sub‐antarctic marion island

.Marion Island in the South Indian Ocean has a maritime climate dominated by diurnal frost processes in the landscape. We test the hypothesis that synoptic time‐scale measurements are essential in understanding the drivers of diurnal frost processes. Preliminary results from automated microclimate measurements in a polar desert habitat show that diurnal soil surface temperatures on Marion Island are influenced by a complex interaction of radiation balance, air mass circulation, cloud cover and snow. The passage of synoptic scale weather systems influences soil thermal characteristics through changes in dominance of the radiation budget. Soil frost on Marion appears to be dependent on clear skies, while synoptic weather systems affect the duration and intensity of soil frost processes and non‐radiative heat fluxes. Air circulation patterns at Marion Island influence diurnal scale temperature fluctuations and its direct and indirect interactions with ecosystem processes. The data suggest that in a maritime sub‐Antarctic environment the climatic drivers of soil frost occur at a finertemporal resolution than for seasonal and permafrost environments and needs to be measured at a diurnal time‐scale to be meaningful.

Modelling of macroscopical transient frost processes and microscopical driving forces

AbstractThe artificial saturation phenomenon due to freeze–thaw cycles is described by a multi–phase and multiscale model [1,2,3] formulated within the Theory of Porous Media, [4]. It represents partially saturated concrete as a mixture of 5 interacting constituents φα, namely the solid skeleton φs, the bulk water φl, the pore volume occupied by vapour φv, the ice φi and the gel water phase φp. Most relevant for the model is the distinction between two length scales and their characteristic time scales. The boundary is marked where macroscopic bulk conditions change to surface physics and chemistry. Surface physics and chemistry acting on the nano–scale affect fundamental properties of concrete and consequently the durability of concrete against freeze–thaw.At the macroscopic scale the model describes transient conditions (i.e. water–uptake, heat transport, volume dilatation of 9%, phase change of first order considering hysteresis) which are characterized by a relatively long time period to reach equilibrium in contrast to the processes modelled on the microstructure. At the microscopic scale the model represents the nanoscopic CSH–gel system consisting of solid CSH and water as a linked system of both components basing on the concept of the “Solid–Liquid Gel System” [5]. In the constribution the numerical results of the model are presented with focus on the evaluation of the process zone during the penetration of the melting front into the matrix. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

SPATIAL INVENTORY OF LANDFORMS IN THE RECENTLY EXPOSED CENTRAL HIGHLAND OF SUB-ANTARCTIC MARION ISLAND

ABSTRACT Until recently, the Central Highland of sub-Antarctic Marion Island (above 750m a.s.l.) was covered by snow. Climatic amelioration is deemed responsible for the disappearance of the former permanent snowline which had a lower altitudinal limit of approximately 650m a.s.l. during the early-1950s. The recent sub-aerial exposure of this area now enables the geology and geomorphology to be documented. Mapping incorporated air-photo interpretation and field surveys using a hand-held Global Positioning System (GPS) to ensure spatial accuracy. Most grey lava outcrops above 750m a.s.l. exhibit some evidence of previous glaciations whereas black lava flows show no evidence of the effects of glaciers and must, therefore, post-date the Last Glacial Maximum (LGM). Frost processes currently predominate in the Central Highland, but there is a conspicuous lack of periglacial landforms (i.e. patterned ground) in scoria and grey lava areas. With the exception of thermal contraction cracking at one location, no other evidence for the development of geomorphological landforms in black lava areas exists. Other geomorphological landforms include meltout features, a manifestation of landscape process responses to climatic amelioration, mass movement landforms and the emergence of rudimentary aeolian landforms. Receding snow cover may enhance frost and aeolian processes, which could result in an interesting myriad of geomorphological landforms.

Modelling of macroscopical transient frost processes and microscopical driving forces

AbstractThe artificial saturation phenomenon due to freeze‐thaw cycles is described by a multi‐phase and multiscale model (1; 2; 3) formulated within the Theory of Porous Media, (4). It represents partially saturated concrete as a mixture of 5 interacting constituents φa, namely the solid skeleton φs, the bulk water φl, the pore volume occupied by vapour φv, the ice φi and the gel water phase φp. Most relevant for the model is the distinction between two length scales and their characteristic time scales. The boundary is marked where macroscopic bulk conditions change to surface physics and chemistry. Surface physics and chemistry acting on the nano‐scale affect fundamental properties of concrete and consequently the durability of concrete against freeze‐thaw.At the macroscopic scale the model describes transient conditions (i.e. water‐uptake, heat transport, volume dilatation of 9 %, phase change of first order considering hysteresis) which are characterized by a relatively long time period to reach equilibrium in contrast to the processes modelled on the microstructure. At the microscopic scale the model represents the nanoscopic CSH‐gel system consisting of solid CSH and water as a linked system of both components basing on the concept of the “Solid‐Liquid Gel System” (5). In the constribution the numerical results of the model are presented with focus on the evaluation of the process zone during the penetration of the melting front into the matrix. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)