Theoretical approach describing the thermal regime of snow-covered sea ice

As the greater part of sea-ice area is covered with snow, the thermal regime of sea ice is characterized by the thermal behavior of snow-covered sea ice. In this paper the thermal regime of snow-covered sea ice is quantitatively investigated with a one-dimensional non-linear boundary model which contains: compaction of snow cover; internal absorption of solar radiation; evaporation–condensation within snow cover; equilibrium phase change of brine within sea ice; and vertical oceanic heat flux from seawater to ice. Penetration of air temperature oscillations into the snow-covered sea ice increases remarkably with increasing snow density. As internal melting within the snow-covered sea ice appears with increasing solar radiation, the rise in air temperature and increase of solar radiation in the springtime produce a corresponding change in the thermal state of sea ice, causing a drastic retreat of sea-ice cover. A case study for warm sea ice is presented describing the thermal state during the melting season.

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New insights into the environmental factors controlling the ground thermal regime across the Northern Hemisphere: a comparison between permafrost and non-permafrost areas

The Cryosphere ◽

10.5194/tc-13-693-2019 ◽

2019 ◽

Vol 13 (2) ◽

pp. 693-707 ◽

Cited By ~ 8

Author(s):

Olli Karjalainen ◽

Miska Luoto ◽

Juha Aalto ◽

Jan Hjort

Keyword(s):

Environmental Factors ◽

Solar Radiation ◽

Soil Properties ◽

Northern Hemisphere ◽

Effect Size ◽

Thermal Regime ◽

Thermal State ◽

Local Scale ◽

The Arctic ◽

Active Layer Thickness

Abstract. The thermal state of permafrost affects Earth surface systems and human activity in the Arctic and has implications for global climate. Improved understanding of the local-scale variability in the global ground thermal regime is required to account for its sensitivity to changing climatic and geoecological conditions. Here, we statistically related observations of mean annual ground temperature (MAGT) and active-layer thickness (ALT) to high-resolution (∼1 km2) geospatial data of climatic and local environmental conditions across the Northern Hemisphere. The aim was to characterize the relative importance of key environmental factors and the magnitude and shape of their effects on MAGT and ALT. The multivariate models fitted well to both response variables with average R2 values being ∼0.94 and 0.78. Corresponding predictive performances in terms of root-mean-square error were ∼1.31 ∘C and 87 cm. Freezing (FDD) and thawing (TDD) degree days were key factors for MAGT inside and outside the permafrost domain with average effect sizes of 6.7 and 13.6 ∘C, respectively. Soil properties had marginal effects on MAGT (effect size =0.4–0.7 ∘C). For ALT, rainfall (effect size =181 cm) and solar radiation (161 cm) were most influential. Analysis of variable importance further underlined the dominance of climate for MAGT and highlighted the role of solar radiation for ALT. Most response shapes for MAGT ≤0 ∘C and ALT were non-linear and indicated thresholds for covariation. Most importantly, permafrost temperatures had a more complex relationship with air temperatures than non-frozen ground. Moreover, the observed warming effect of rainfall on MAGT≤0∘C reverted after reaching an optimum at ∼250 mm, and that of snowfall started to level off at ∼300–400 mm. It is suggested that the factors of large global variation (i.e. climate) suppressed the effects of local-scale factors (i.e. soil properties and vegetation) owing to the extensive study area and limited representation of soil organic matter. Our new insights into the factors affecting the ground thermal regime at a 1 km scale should improve future hemispheric-scale studies.

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The Impact of Milankovitch Solar Radiation Variations on Sea-Ice and Air Temperature in a Coupled Energy-Balance Climate-Sea-Ice Model

Annals of Glaciology ◽

10.3189/s0260305500008454 ◽

1990 ◽

Vol 14 ◽

pp. 144-147 ◽

Cited By ~ 1

Author(s):

Tamara Shapiro Ledley

Keyword(s):

Solar Radiation ◽

Sea Ice ◽

Air Temperature ◽

Energy Transport ◽

Model Simulation ◽

Surface Air Temperature ◽

Ice Thickness ◽

Sea Ice Thickness ◽

The Mean ◽

The Impact

The sensitivity of thermodynamically-varying sea-ice and surface air temperature to variations in solar radiation on the 104 to 105 time scales is examined in this study. Model simulation results show the mean annual sea-ice thickness is very sensitive to the magnitude of midsummer solar radiation. During periods of high midsummer solar radiation between 115 ka B.P. and the present the sea ice is thinner, producing larger summer time leads and longer periods of open ocean. This has an effect on the mean annual sea-ice thickness, but not on the mean annual air temperature. However, the changes in sea ice are accompanied by similar variations in the summer surface air temperature, which are the result of the variations in the solar radiation and meridional energy transport.

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The Impact of Milankovitch Solar Radiation Variations on Sea-Ice and Air Temperature in a Coupled Energy-Balance Climate-Sea-Ice Model

Annals of Glaciology ◽

10.1017/s0260305500008454 ◽

1990 ◽

Vol 14 ◽

pp. 144-147 ◽

Cited By ~ 5

Author(s):

Tamara Shapiro Ledley

Keyword(s):

Solar Radiation ◽

Sea Ice ◽

Air Temperature ◽

Energy Transport ◽

Model Simulation ◽

Surface Air Temperature ◽

Ice Thickness ◽

Sea Ice Thickness ◽

The Mean ◽

The Impact

The sensitivity of thermodynamically-varying sea-ice and surface air temperature to variations in solar radiation on the 104 to 105 time scales is examined in this study. Model simulation results show the mean annual sea-ice thickness is very sensitive to the magnitude of midsummer solar radiation. During periods of high midsummer solar radiation between 115 ka B.P. and the present the sea ice is thinner, producing larger summer time leads and longer periods of open ocean. This has an effect on the mean annual sea-ice thickness, but not on the mean annual air temperature. However, the changes in sea ice are accompanied by similar variations in the summer surface air temperature, which are the result of the variations in the solar radiation and meridional energy transport.

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The influence of snow cover, air temperature, and groundwater flow on the active-layer thermal regime of Arctic hillslopes drained by water tracks

Hydrogeology Journal ◽

10.1007/s10040-020-02166-2 ◽

2020 ◽

Vol 28 (6) ◽

pp. 2057-2069 ◽

Cited By ~ 1

Author(s):

Caitlin R. Rushlow ◽

Audrey H. Sawyer ◽

Clifford I. Voss ◽

Sarah E. Godsey

Keyword(s):

Groundwater Flow ◽

Snow Cover ◽

Active Layer ◽

Air Temperature ◽

Thermal Regime

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Vertical distribution of brine and volume structure thin one year ice Amur bay on base NMR and MRT dates

Океанология ◽

10.31857/s0030-1574595859-869 ◽

2019 ◽

Vol 59 (5) ◽

pp. 859-869

Author(s):

N. A. Mel’nichenko ◽

A. V. Tyuveev ◽

A. Yu. Lazaryuk ◽

V. E. Savchenko ◽

E. V. Kustova

Keyword(s):

Sea Ice ◽

Snow Cover ◽

Air Temperature ◽

Phase Distribution ◽

Solid Phase ◽

Empirical Relation ◽

Amur Bay ◽

Spatial Phase ◽

Arctic Ice ◽

One Year

It was studying distribution of liquid and solid phases in pores one year sea ice on Amur Bay with using NMR and MRT methods in period 20132016. According to findings predominant factor in ice structure formation is snow cover. The patterns of brine content and solid phase distribution are considered in interdependence with air temperature and corresponding ice layer temperatures in compliance with preceding weather conditions. Differences in vertical profiles for temperature and salinity for winter and spring periods was marked. The main features of spatial phase dictribution in thin ice in comparision Arctic ice are presented. Just snow cover effects on ice parameters was demonstrated using data 20132016. The relationship of interlayings number in ice with its thickness, air temperature, and snow cover thickness is discussed. The main features of spatial phase dictribution in thin ice in comparision Arctic ice are presented. The empirical relation for calculations thin sea ice thickness was suggested.

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Surface Contribution to Planetary Albedo Variability in Cryosphere Regions

Journal of Climate ◽

10.1175/jcli3555.1 ◽

2005 ◽

Vol 18 (24) ◽

pp. 5239-5252 ◽

Cited By ~ 36

Author(s):

Xin Qu ◽

Alex Hall

Keyword(s):

Solar Radiation ◽

Sea Ice ◽

Snow Cover ◽

Climate Sensitivity ◽

High Latitude ◽

Surface Albedo ◽

Sea Ice Extent ◽

Damping Effect ◽

Planetary Albedo ◽

Snow And Ice

Abstract Climatological planetary albedo obtained from the International Satellite Cloud Climatology Project (ISCCP) D-series flux dataset is broken down into contributions from the surface and atmosphere in cryosphere regions. The atmosphere accounts for much more of climatological planetary albedo (≥75%) than the surface at all times of the year. The insignificance of the surface contribution over highly reflective cryosphere regions is attributed mostly to the damping effect of the atmosphere. The overlying atmosphere attenuates the surface’s contribution to climatological planetary albedo by reducing the number of solar photons initially reaching the surface and the number of photons initially reflected by the surface that actually reach the top of the atmosphere. The ISCCP datasets were also used to determine the relative contributions of the surface and atmosphere to seasonal and interannual planetary albedo variability in cryosphere regions. Even damped by the atmosphere to the same degree as in the climatological case, the surface contribution dominates the variability in planetary albedo on seasonal and interannual time scales. The surface accounts for about 75% of the change in climatological planetary albedo from one season to another with similar zenith angle and more than 50% of its interannual variability at nearly all times of the year, especially during seasons with extensive snow and sea ice extent. The dominance of the surface in planetary albedo variability is because surface albedo variability associated with snow and ice fluctuations is significantly larger than atmospheric albedo variability due to cloud fluctuations. The large effect of snow and ice variations on planetary albedo variability suggests that if cloud fields do not change much in a future warmer climate, a retreat of snow cover or sea ice would lead to a significant increase in net incoming solar radiation, resulting in an enhancement of high-latitude climate sensitivity.

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Snow Depth and Air Temperature Seasonality on Sea Ice Derived From Snow Buoy Measurements

Frontiers in Marine Science ◽

10.3389/fmars.2021.655446 ◽

2021 ◽

Vol 8 ◽

Author(s):

Marcel Nicolaus ◽

Mario Hoppmann ◽

Stefanie Arndt ◽

Stefan Hendricks ◽

Christian Katlein ◽

...

Keyword(s):

Sea Ice ◽

Snow Cover ◽

Air Temperature ◽

Snow Depth ◽

Snow Accumulation ◽

Arctic Sea Ice ◽

Weddell Sea ◽

The Arctic ◽

Validation Data ◽

Antarctic Sea Ice

Snow depth on sea ice is an essential state variable of the polar climate system and yet one of the least known and most difficult to characterize parameters of the Arctic and Antarctic sea ice systems. Here, we present a new type of autonomous platform to measure snow depth, air temperature, and barometric pressure on drifting Arctic and Antarctic sea ice. “Snow Buoys” are designed to withstand the harshest environmental conditions and to deliver high and consistent data quality with minimal impact on the surface. Our current dataset consists of 79 time series (47 Arctic, 32 Antarctic) since 2013, many of which cover entire seasonal cycles and with individual observation periods of up to 3 years. In addition to a detailed introduction of the platform itself, we describe the processing of the publicly available (near real time) data and discuss limitations. First scientific results reveal characteristic regional differences in the annual cycle of snow depth: in the Weddell Sea, annual net snow accumulation ranged from 0.2 to 0.9 m (mean 0.34 m) with some regions accumulating snow in all months. On Arctic sea ice, the seasonal cycle was more pronounced, showing accumulation from synoptic events mostly between August and April and maxima in autumn. Strongest ablation was observed in June and July, and consistently the entire snow cover melted during summer. Arctic air temperature measurements revealed several above-freezing temperature events in winter that likely impacted snow stratigraphy and thus preconditioned the subsequent spring snow cover. The ongoing Snow Buoy program will be the basis of many future studies and is expected to significantly advance our understanding of snow on sea ice, also providing invaluable in situ validation data for numerical simulations and remote sensing techniques.

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A Decade of Ground–Air Temperature Tracking at Emigrant Pass Observatory, Utah

Journal of Climate ◽

10.1175/jcli3808.1 ◽

2006 ◽

Vol 19 (15) ◽

pp. 3722-3731 ◽

Cited By ~ 47

Author(s):

Marshall G. Bartlett ◽

David S. Chapman ◽

Robert N. Harris

Keyword(s):

Solar Radiation ◽

Snow Cover ◽

Air Temperature ◽

Surface Air Temperature ◽

Incident Solar Radiation ◽

Ground Temperatures ◽

Temperature Tracking ◽

Air Temperatures ◽

Winter Snow ◽

A Minor

Abstract Observations of air and ground temperatures collected between 1993 and 2004 from Emigrant Pass Geothermal Climate Observatory in northwestern Utah are analyzed to understand the relationship between these two quantities. The influence of surface air temperature (SAT), incident solar radiation, and snow cover on surface ground temperature (SGT) variations are explored. SAT variations explain 94% of the variance in SGT. Incident solar radiation is the primary variable governing the remaining variance misfit and is significantly more important during summer months than winter months. A linear relationship between the ground–air temperature difference (ΔTsgt-sat) and solar radiation exists with a trend of 1.21 K/(100 W m−2); solar radiation accounts for 1.3% of the variance in SGT. The effects of incident solar radiation also account for the 2.47-K average offset in ΔTsgt-sat. During the winter, snow cover plays a role in governing SGT variability, but exerts only a minor influence on the annual tracking of ground and air temperatures at the site, accounting for 0.5% of the variance in SGT. These observations of the tracking of SGT and SAT confirm that borehole temperature changes mimic changes in SAT at frequencies appropriate for climatic reconstructions.

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Winter arctic sea-ice cover variability and the prediction of spring vegetation growth over Eurasia

10.5194/egusphere-egu2020-22339 ◽

2020 ◽

Author(s):

Liuqing Ji ◽

Ke Fan

Keyword(s):

Sea Ice ◽

Snow Cover ◽

Air Temperature ◽

Prediction Models ◽

Surface Air Temperature ◽

Ice Cover ◽

Arctic Sea Ice ◽

Hybrid Scheme ◽

Coupled Modes ◽

Previous Season

The changes in Eurasian vegetation not only have important effects on regional climate, but also have effects on global temperatures and the carbon cycle. In this study, the interannual linkage between spring vegetation growth over Eurasia and winter sea-ice cover over the Barents Sea (SICBS), as well as the prediction of spring Euraisan vegetation are investigated. The Normalized Difference Vegetation Index (NDVI) derived from the advanced very high resolution radiometer is used as the proxy of vegetation growth. During 1982&#8211;2015, the winter SICBS is significantly correlated with the spring NDVI over Eurasia (NDVIEA). The positive (negative) winter SICBS anomalies tend to increase (decrease) the spring NDVIEA. The increased winter SICBS corresponds to higher winter surface air temperature and soil temperature over most parts of Eurasia, and in turn, corresponds to less winter snow cover and less snow water equivalent. The persistent less and thinner snow cover from winter to spring over Eurasia, especially over Western and Central Siberia, tends to induce increased surface air temperature through decreased surface albedo and less snowmelt latent heat. Subsequently, the increased surface air temperature corresponding to increased SICBS contributes to higher vegetation growth over Eurasia in spring and vice versa. Based on this linkage, seasonal predictions of spring NDVI over Eurasia are explored by applying the year-to-year increment approach. The prediction models were developed based on the coupled modes of singular value decomposition analyses between Eurasian NDVI and climate factors. One synchronous predictor, the spring surface air temperature from the NCEP&#8217;s Climate Forecast System (SAT-CFS), and three previous-season predictors (winter SICBS, winter sea surface temperature over the equatorial Pacific (SSTP), and winter North Atlantic Oscillation (NAO) were chosen to develop four single-predictor schemes: the SAT-CFS scheme, SICBS scheme, SSTP scheme, and NAO scheme. Meanwhile, a statistical scheme that involves the three previous-season predictors (i.e., SICBS, SSTP, and NAO) and a hybrid scheme that includes all four predictors are also proposed. To evaluate the prediction skills of the schemes, one-year-out cross-validation and independent hindcast results are analyzed, revealing the hybrid scheme as having the best prediction skill in terms of both the spatial pattern and the temporal variability of spring Eurasian NDVI.

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