scholarly journals Permafrost model in coarse-blocky deposits for the Dry Andes, Argentina (28°-33° S)

2020 ◽  
Vol 46 (1) ◽  
pp. 33-58
Author(s):  
C. Tapia-Baldis ◽  
D. Trombotto-Liaudat
Keyword(s):  
Air Temperature ◽  
Mathematical Formulation ◽  
Climatic Conditions ◽  
Distribution Model ◽  
Permafrost Degradation ◽  
Probability Models ◽  
Rock Glaciers ◽  
Solar Radiation Model ◽  
Mean Annual Air Temperature

In this work, a statistical permafrost distribution model for coarse-blocky deposits in the Dry Andes of Argentina (28-33°S) is presented. The empiric mathematical formulation was based on a logistic regression. The final model is a combination of two independent occurrence probability models: a) a mean annual air temperature-terrain ruggedness model and, b) a mean annual air temperature-potential incoming solar radiation model. For all cases, calibration was made according the complete geomorphological characterization of a periglacial basin with 250 km2. Lately, the results of probabilistic model were extrapolated to the whole study area in the Dry Andes and compared with the Argentine rock glacier inventory data base. High permafrost likelihood, in coarse debris, is expected above 4200 and 5700 m a.s.l., from south to north in the study area and covers a surface of approximately 1200 km2. Medium permafrost likelihood is expected above 3400 and 4200 m a.s.l. with a surface of 6178 km2 while low permafrost likelihood, occurs between 3000 and 3400 m a.s.l. with an area of 11.060 km2. These findings indicate that permafrost may occur in several types of coarse-blocky deposits in the Dry Andes, not only restricted to rock glaciers. Thermal properties of the ground in coarse-blocky deposits allow permafrost permanence, even under unfavourable climatic conditions.The performance of the permafrost model was also tested, considering the transition from cold paleoclimate Tardiglacial to present climatic conditions. During the warming, likely permafrost surface reduced from 56 to 13%. In the same way, rock glaciers with high and medium permafrost likelihood decrease from 62 to 30%, respectively while, rock glaciers with low likelihood and no permafrost category, increased 75% and 474%, respectively. Moreover, we identified some sites in which permafrost degradation is arguably expected. About that, 0.9% of the rock glaciers in the study area display possible permafrost degradation and 33% of them, likely permafrost degradation.

scholarly journals Dynamics of the ice cap on King George Island, Antarctica: field measurements and numerical simulations

2010 ◽  
Vol 51 (55) ◽  
pp. 80-90 ◽  
Author(s):  
Martin Rückamp ◽  
Norbert Blindow ◽  
Sonja Suckro ◽  
Matthias Braun ◽  
Angelika Humbert
Keyword(s):  
Air Temperature ◽  
Water Layer ◽  
Climatic Conditions ◽  
King George Island ◽  
Differential Gps ◽  
Ice Flow ◽  
Climate Conditions ◽  
Ice Cap ◽  
Ice Surface ◽  
Mean Annual Air Temperature

AbstractKing George Island is located at the northern tip of the Antarctic Peninsula, which is influenced by maritime climate conditions. The observed mean annual air temperature at sea level is –2.4˚C. Thus, the ice cap is regarded as sensitive to changing climatic conditions. Ground-penetrating radar surveys indicate a partly temperate ice cap with an extended water layer at the firn/ice transition of the up to 700 m high ice cap. Measured firn temperatures are close to 0˚C at the higher elevations, and they differ considerably from the measured mean annual air temperature. The aim of this paper is to present ice-flow dynamics by means of observations and simulations of the flow velocities. During several field campaigns from 1997/98 to 2008/09, ice surface velocities were derived with repeated differential GPS measurements. Ice velocities vary from 0.7 m a−1 at the dome to 112.1 m a−1 along steep slopes. For the western part of the ice cap a three-dimensional diagnostic full-Stokes model was applied to calculate ice flow. Parameters of the numerical model were identified with respect to measured ice surface velocities. The simulations indicate cold ice at higher elevations, while temperate ice at lower elevations is consistent with the observations.

scholarly journals Towards accurate quantification of ice content in permafrost of the Central Andes – Part II: an upscaling strategy of geophysical measurements to the catchment scale at two study sites

2021 ◽  
Author(s):  
Tamara Mathys ◽  
Christin Hilbich ◽  
Lukas U. Arenson ◽  
Pablo A. Wainstein ◽  
Christian Hauck
Keyword(s):  
Geophysical Data ◽  
Distribution Model ◽  
Permafrost Degradation ◽  
Rock Glacier ◽  
Ground Ice ◽  
Data Set ◽  
Refraction Seismic ◽  
Geophysical Surveys ◽  
Rock Glaciers ◽  
Ice Content

Abstract. With ongoing climate change, there is a pressing need to better understand how much water is stored as ground ice in areas with extensive permafrost occurrence and how the regional water balance may alter in response to the potential generation of melt water from permafrost degradation. However, field-based data on permafrost in remote and mountainous areas such as the South-American Andes is scarce and most current ground ice estimates are based on broadly generalised assumptions such as volume-area scaling and mean ground ice content estimates of rock glaciers. In addition, ground ice contents in permafrost areas outside of rock glaciers are usually not considered, resulting in a significant uncertainty regarding the volume of ground ice in the Andes, and its hydrological role. In part I of this contribution, Hilbich et al. (submitted) present an extensive geophysical data set based on Electrical Resistivity Tomography (ERT) and Refraction Seismic Tomography (RST) surveys to detect and quantify ground ice of different landforms and surface types in several study regions in the semi-arid Andes of Chile and Argentina with the aim to contribute to the reduction of this data scarcity. In part II we focus on the development of a methodology for the upscaling of geophysical-based ground ice quantification to an entire catchment to estimate the total ground ice volume (and its estimated water equivalent) in the study areas. In addition to the geophysical data, the upscaling approach is based on a permafrost distribution model and classifications of surface and landform types. Where available, ERT and RST measurements were quantitatively combined to estimate the volumetric ground ice content using petrophysical relationships within the Four Phase Model (Hauck et al., 2011). In addition to introducing our upscaling methodology, we demonstrate that the estimation of large-scale ground ice volumes can be improved by including (i) non-rock glacier permafrost occurrences, and (ii) field evidence through a large number of geophysical surveys and ground truthing information. The results of our study indicate, that (i) conventional ground ice estimates for rock-glacier dominated catchments without in-situ data may significantly overestimate ground ice contents, and (ii) substantial volumes of ground ice may also be present in catchments where rock glaciers are lacking.

scholarly journals Regional Climate Change (Karelia, Russia)

2015 ◽  
Vol 2 ◽  
pp. 356
Author(s):  
Larisa Nazarova
Keyword(s):  
Air Temperature ◽  
Global Climate ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Climatic Conditions ◽  
Temperature And Precipitation ◽  
The Mean ◽  
Weather Stations ◽  
Meteorological Observations ◽  
Mean Annual Air Temperature

The overview of climatic conditions in Karelia is based on the data from meteorological observations carried out in 1951-2009 at Roskomgidromet weather stations situated in the study area. Taking the period in question into account, the mean annual air temperature norm has increased by 0.2-0.3°C. The greatest deviation from multiyear averages of mean monthly air temperature is observed in January and March. The investigation of the changes the basic regional climate characteristics is very important in present time because the global climate is changed. The analysis the data about air temperature and precipitation, that were obtained for the different meteorological stations in the investigated region, shows that the regional climate is changed and the main tendencies are directly proportional to the change of the global characteristics.

Effect of Potential Warming on Evapotranspiration from Forest Catchments in Karelia

2003 ◽  
Vol 34 (3) ◽  
pp. 147-160
Author(s):  
Yury V. Karpechko ◽  
Natalia L. Bondarik
Keyword(s):  
Air Temperature ◽  
Catchment Area ◽  
Forest Type ◽  
Climatic Conditions ◽  
Average Productivity ◽  
Stand Productivity ◽  
Mean Annual Air Temperature ◽  
Large Catchment

The amount of evapotranspiration from a woodland largely depends on the site and stand productivity. The factor largely responsible for the stand productivity (productivity class) of an individual forest type under the climatic conditions of northwest Russia is temperature. If mean annual air temperature rises by 1°C and 2°C the average productivity of a coniferous stand in Karelia will increase by 0.3-0.4 and 0.6-0.8 of the productivity class, respectively. The average estimated increment of annual evapotranspiration from a forest in a sufficiently large catchment area will not exceed 15-20 mm even if the warming up is 2°C.

Permafrost

2021 ◽  
Keyword(s):  
Active Layer ◽  
Air Temperature ◽  
Ground Surface ◽  
Rooting Depth ◽  
Permafrost Degradation ◽  
Frozen Ground ◽  
Air Temperatures ◽  
Discontinuous Permafrost ◽  
Deep Infiltration ◽  
Mean Annual Air Temperature

Permafrost is permanently frozen ground that remains continuously below 0 °C for two or more years. The upper level of permafrost, the permafrost table, can occur within a centimeter of the ground surface or at a depth of several meters. The active layer, which thaws each summer, overlies permafrost. Permafrost underlies about a quarter of the northern hemisphere and can form in sediment or bedrock and on land or under the ocean. Permafrost forms incrementally and, in the regions where it is up to 1 km thick, permafrost can represent thousands of years of formation. Permafrost is present at high latitudes and high altitudes. In these regions, permafrost can be described as continuous, discontinuous, sporadic, or isolated. Continuous permafrost forms at mean annual air temperatures below -5 °C and is laterally continuous, regardless of surface aspect or material. Discontinuous permafrost forms where the mean annual air temperature is between -2 and -4 °C, allowing permafrost to persist in 50 to 90 percent of the landscape. Permafrost is sporadic where 10 to <50 percent of the landscape is underlain by permafrost and mean annual air temperature is between 0 and -2 °C. Permafrost is considered isolated where less than 10 percent of the landscape is underlain by permafrost. When it is present, permafrost creates unique conditions. Permafrost forms an impermeable layer beneath the active layer, for example, which limits the rooting depth of plants and prevents infiltration by water during the summer. The lack of deep infiltration can facilitate formation of extensive wetlands in high-latitude areas that receive relatively little precipitation. Permafrost degradation (thaw) creates diverse environmental hazards, including instability of the ground surface that affects infrastructure and fluxes of water, sediment, and organic matter entering rivers, lakes and oceans. Permafrost degradation releases frozen microbes, some of which are pathogens, and organic carbon. Permafrost degradation also influences the geographic range of plants and animals and thus ecosystem processes and biotic communities. The greatest concern with permafrost degradation at present, however, is the potential for releasing significant carbon into the atmosphere. Globally, soils are the largest terrestrial reservoir of carbon and permafrost soils are the single largest component of the carbon reservoir. Carbon released by degrading permafrost can enter the atmosphere as the greenhouse gases carbon dioxide and methane, or the carbon can be taken up by plants or transported by rivers to the ocean and buried in marine sediments. The balance among these different pathways is largely unknown, but carbon release to the atmosphere presents a serious threat as a mechanism to enhance global warming.

scholarly journals Long-term air temperature changes in Ljubljana (Slovenia) in comparison to Trieste (Italy) and Zagreb (Croatia)

2015 ◽  
Vol 23 (3) ◽  
pp. 17-26 ◽  
Author(s):  
Darko Ogrin
Keyword(s):  
Air Temperature ◽  
Urban Climate ◽  
Warming Trend ◽  
Climatic Conditions ◽  
City Growth ◽  
Temperature Changes ◽  
Air Temperatures ◽  
Urban Heat ◽  
The Impact ◽  
Mean Annual Air Temperature

Abstract The cities of Ljubljana, Trieste and Zagreb are proximate in terms of distance but differ in terms of geographical and climatic conditions. Continuous meteorological measurements in these cities began in the mid-19th century. The 100-year trends of changes in mean annual and seasonal air temperatures for these cities are presented here, evaluating the differences between them which result from their different geographical and climatic positions. Differences in trends between Ljubljana and Zagreb that result from different measurement histories and the impact of urban climate are also presented: the impact of city growth on air temperatures in Ljubljana after 1950 was not completely eliminated in the process of data homogenization. The lowest air warming trends occur in the maritime climate of Trieste (mean annual air temperature: + 0.8 °C × 100 yr−1), where measurements were continuously performed in the densely built-up section of the city. The strongest trends occur in Ljubljana, mainly due to city growth (mean annual air temperature: + 1.1 °C × 100 yr−1). Comparing the linear trends in Zagreb-Grič and in Ljubljana, the impact of Ljubljana's urban heat island on the 100-year warming trend was assessed at about 0.2 °C, at 0.3–0.4 °C for the trend after 1950, and if non-homogenized data are used, at about 0.5 °C.

scholarly journals Climate dynamics of the Beloe Sea catchment area

2015 ◽  
Vol 2 ◽  
pp. 232
Author(s):  
Larisa Nazarova
Keyword(s):  
Air Temperature ◽  
Catchment Area ◽  
Climatic Conditions ◽  
Climate Dynamics ◽  
Total Size ◽  
Instrumental Observations ◽  
Climatic Regime ◽  
Weather Stations ◽  
Using Data ◽  
Mean Annual Air Temperature

The climate of the Beloe Sea  catchment area (total size 717.7 km<sup>2</sup>, 714 of which belongs to Russia) is described. The territory is characterized by several geographic zones, thus substantial diversity of climatic conditions is observed. Climate variability in the region was studied using data from the longest available instrumental observations at weather stations (WS) and gauge sites of the Russian Federal Hydrometeorology and Environmental Monitoring Agency located in the study area, covering the period from the beginning of observations at the stations until 2012-2013. The data obtained were statistically processed with due regard to the research tasks. Modern observational data are analyzed to distinguish the changes in the climatic regime of the main parameters, i.e. air temperature, precipitation, sunshine length, etc. Since 1989, the stable increase of mean annual air temperature (1-2<sup>о</sup>C) over a climatic norm is observed. The most intensive warming is typical for the winter months. The analysis of changes in precipitation over the study area demonstrates the stable increase of annual sums, deviation of which from the climatic norm in the first decade of XXI century is about 50-100 mm

scholarly journals Seasonal Climate Impacts on Vocal Activity in Two Neotropical Nonpasserines

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 319
Author(s):  
Cristian Pérez-Granados ◽  
Karl-L. Schuchmann
Keyword(s):  
Air Temperature ◽  
Daily Rainfall ◽  
Climatic Conditions ◽  
Dry Season ◽  
Climate Impacts ◽  
Calling Behavior ◽  
Wet Season ◽  
Focal Species ◽  
Calling Activity ◽  
Vocal Activity

Climatic conditions represent one of the main constraints that influence avian calling behavior. Here, we monitored the daily calling activity of the Undulated Tinamou (Crypturellus undulatus) and the Chaco Chachalaca (Ortalis canicollis) during the dry and wet seasons in the Brazilian Pantanal. We aimed to assess the effects of climate predictors on the vocal activity of these focal species and evaluate whether these effects may vary among seasons. Air temperature was positively associated with the daily calling activity of both species during the dry season. However, the vocal activity of both species was unrelated to air temperature during the wet season, when higher temperatures occur. Daily rainfall was positively related to the daily calling activity of both species during the dry season, when rainfall events are scarce and seem to act as a trigger for breeding phenology of the focal species. Nonetheless, air temperature was negatively associated with the daily calling activity of the Undulated Tinamou during the wet season, when rainfall was abundant. This study improves our understanding of the vocal behavior of tropical birds and their relationships with climate, but further research is needed to elucidate the mechanisms behind the associations found in our study.

Modeling soil temperature using air temperature features in diverse climatic conditions with complementary machine learning models

2021 ◽  
Vol 185 ◽  
pp. 106158
Author(s):  
Maryam Bayatvarkeshi ◽  
Suraj Kumar Bhagat ◽  
Kourosh Mohammadi ◽  
Ozgur Kisi ◽  
M. Farahani ◽  
...  
Keyword(s):  
Machine Learning ◽  
Soil Temperature ◽  
Air Temperature ◽  
Climatic Conditions ◽  
Learning Models ◽  
Machine Learning Models

scholarly journals Changes in Air Temperature and Snow Cover in Winter in Poland

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Arkadiusz M. Tomczyk ◽  
Ewa Bednorz ◽  
Katarzyna Szyga-Pluta
Keyword(s):  
Snow Cover ◽  
Air Temperature ◽  
Winter Season ◽  
Primary Objective ◽  
Climatic Conditions ◽  
Cover Depth ◽  
North Eastern ◽  
Northern Regions ◽  
Maximum Air Temperature ◽  
Snow Cover Depth

The primary objective of the paper was to characterize the climatic conditions in the winter season in Poland in the years 1966/67–2019/20. The study was based on daily values of minimum (Tmin) and maximum air temperature (Tmax), and daily values of snow cover depth. The study showed an increase in both Tmin and Tmax in winter. The most intensive changes were recorded in north-eastern and northern regions. The coldest winters were recorded in the first half of the analyzed multiannual period, exceptionally cold being winters 1969/70 and 1984/85. The warmest winters occurred in the second half of the analyzed period and among seasons with the highest mean Tmax, particularly winters 2019/20 and 1989/90 stood out. In the study period, a decrease in snow cover depth statistically significant in the majority of stations in Poland was determined, as well as its variability both within the winter season and multiannual.

Sign in / Sign up

Export Citation Format

Share Document