scholarly journals Zum Problem der Stabilität der Klimabedingungen in Westsibirien während der Glaziale und Interglaziale

1960 ◽  
Vol 11 (1) ◽  
pp. 77-87
Author(s):  
W. Weischet
Keyword(s):  
Western Siberia ◽  
Meridional Circulation ◽  
Climatic Conditions ◽  
Summer Temperature ◽  
Deciduous Forests ◽  
The Arctic ◽  
Mean Annual Temperature ◽  
Last Glaciation ◽  
The Mean ◽  
Glacial Periods

Abstract. The depression values of the summer temperature and also of the mean annual temperature in Western Siberia during the last glaciation, have been deduced. This calculation has been based on the different position of the boreal boundaries of the tundra and the continental deciduous forests during the ice ages and at the present time. According to these calculations the following depressions of summer temperature have been obtained: 5-8° C near the arctic circle and 2-4° C in the latitude of 50° North, in comparison with the 10-12° C depression in Central Europe. Afterwards it has been discussed whether or not these relatively small depressions can be explained exclusively on the basis of the higher continentality of the central part of Eurasia in comparison with the western or eastern part of this continent. As this seems to be impossible, it is necessary to look for other facts that could be related to this problem. In the opinion of the author the relative stability of climatic conditions in Western Siberia during the whole Quaternary could be easily explained by the change between the meridional-circulation (low-index-type), prevailing during the glacial periods, and the reinforced zonal-circulation (high-index-type) during the interglacial and postglacial periods.

scholarly journals Paleosols of the Interglacial Climates in Canada

2007 ◽  
Vol 44 (3) ◽  
pp. 363-374 ◽  
Author(s):  
Charles Tarnocai
Keyword(s):  
Forest Soils ◽  
The Arctic ◽  
Interglacial Period ◽  
Mean Annual Temperature ◽  
Tree Line ◽  
Climatic Parameters ◽  
The Holocene ◽  
Paleoclimatic Reconstruction ◽  
Soil Features ◽  
The Mean

ABSTRACTAlthough paleosols are useful indicators of paleoclimates. it is first necessary to establish the relationships between the northern limits of the various contemporary soils and the pertinent climatic parameters. It is then necessary to determine the age of the various paleosols and, if possible, their northern limits. Comparison of the distribution and northern limits of the contemporary soils with the distribution and northern limits of the analogous paleosols then permits the reconstruction of the paleoenvironments. For the purposes of comparison the mean annual temperature of the Old Crow area during the Pliocene epoch was also determined (about 4°C) even though this was not an interglacial period. It was found that during the pre-lllinoian interglacial periods the central Yukon had a mean annual temperature of about 7°C while during the Sangamonian interglacial period it had a mean annual temperature of about - 3°C. During the Holocene epoch, the current interglacial period, the climate has been similar to or only slightly cooler than that existing during the Sangamonian interglacial period. The fluctuating position of the arctic tree line (and associated forest soils) during the Holocene epoch, however, indicates that the climate has also been fluctuating during this time. The paleoclimatic reconstruction presented in this paper also relies heavily on both diagnostic soil features and the soil development during the various interglacial periods.

Pollen-Derived Rainfall and Temperature Estimates from Lake Tanganyika and Their Implication for Late Pleistocene Water Levels

1993 ◽  
Vol 40 (3) ◽  
pp. 343-350 ◽  
Author(s):  
Annie Vincens ◽  
Françoise Chalié ◽  
Raymonde Bonnefille ◽  
Joel Guiot ◽  
Jean-Jacques Tiercelin
Keyword(s):  
Catchment Area ◽  
Lake Tanganyika ◽  
Climatic Conditions ◽  
Water Levels ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
A Value ◽  
Last Glaciation ◽  
Analogue Method ◽  
The Last Glacial

AbstractPalaeoclimatic estimates of mean annual temperature and rainfall in the southern Tanganyika basin between 25,000 and 9000 yr B.P. have been established from two pollen sequences based on the best-analogue method. The results give evidence of a mean temperature decrease of about 4.2°C during the last glaciation, a value consistent with that previously obtained in the catchment area on the Burundi Highlands. This cooling was synchronous with a decrease of mean annual precipitation of about 180 mm/yr. Postglacial climatic conditions were established by 12,700 yr B.P., with warming and wetness continuing to increase from this date onward. These new palaeoclimatic data will be useful for hydrological reconstructions of Lake Tanganyika, particularly during the last glacial age for which the magnitude of water-level fall has been a controversial issue; our rainfall estimates are more consistent with low values (-250 to -300 m fall) than with high ones (-600 m) previously proposed.

scholarly journals Characteristics of the weather and climatic conditions of the Arctic zone of the Krasnoyarsk Territory by bioclimatic indices

2021 ◽  
Vol 7 (3) ◽  
pp. 7-13
Author(s):  
R. S. Rakhmanov ◽  
E. S. Bogomolov ◽  
D. A. Narutdinov ◽  
S. A. Razgulin ◽  
M. V. Ashina
Keyword(s):  
Climatic Conditions ◽  
The Body ◽  
The Arctic ◽  
Cold Environment ◽  
Arctic Zone ◽  
Bioclimatic Indices ◽  
Relative Air Humidity ◽  
The Mean ◽  
Body Cooling ◽  
Safe Working

Aim. Assess the health risk of a cold environment by bioclimatic indices characterizing weather and climatic conditions in the Arctic zone of the Krasnoyarsk Territory.Materials and methods. The mean monthly daily ambient temperature, wind speed and relative air humidity were determined. The body cooling conditions integral index (BCCII) and the wind-cold index (WCI) were calculated.Results and their discussion. Using the BCCII from 4 to 6 months a year at Cape Chelyuskin, the critical risk of frostbite in exposed areas of the body determined at Dixon Island from 4 to 5 months a year; in July and August, the indicator values reached the lower border of the “moderate risk”. Using the WCI, an uncomfortable cold environment was determined, respectively, 2 months and 4 months, a very cold — 3 months and 2 months, and an extremely cold — 3 months and 2 months.Conclusion. The advantage of using BCCII rather than WCI is shown, since on its basis the criteria for safe working conditions in an open area are determined. To interpret the value of “no risk” while using WCI, it is necessary to know the period of the year, in which the weather and climatic conditions are assessed as a cold environment.

scholarly journals Permafrost Distribution in Peatlands of West-Central Canada During the Holocene Warm Period 6000 Years BP

2007 ◽  
Vol 49 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Stephen C. Zoltai
Keyword(s):  
Land Surface ◽  
Floristic Composition ◽  
Climatic Conditions ◽  
Warm Period ◽  
Tree Cover ◽  
The Arctic ◽  
Mean Annual Temperature ◽  
The North ◽  
West Central ◽  
Central Canada

ABSTRACTThe extent and distribution of permafrost in peatlands 6000 years ago was investigated in the present discontinuous and continuous permafrost zones of west-central Canada. Permafrost peatlands were cored at 161 locations and the floristic composition of the peat was determined from macrofossil analysis. The reconstructed paleoenvironments were used to indicate the presence or absence of permafrost at the time of peat formation. Chronological control was provided by radiocarbon dating of substantial changes in the peat sequences and by dates of basal peat deposits. Peatland formation began after glacial ice disappeared from the land surface of west-central Canada. Macrofossils indicate that most peatlands were fens without permafrost at 6 ka, except in the far north. Permafrost was already present in many areas of the Arctic, and peat accumulation occurred under permafrost conditions. In the southern area, permafrost development in peatlands began about 4 ka as the middle Holocene warm period came to a close. Permafrost development in the fens was associated with the development of a Sphagnum-dominated surface on the fens, caused by the onset of a cooler and moister climate. The insulation provided by the surface peat layer and by the associated tree cover initiated permafrost development in small lenses that coalesced into large permafrost bodies according to the prevailing climatic conditions. At the target date, 6 ka, permafrost was present in some peatlands, but the distribution zones shifted 300 to 500 km to the north, relative to the present zonation. It is estimated that this corresponds to a mean annual temperature that was about 5°C warmer than at present.

scholarly journals Relationships between the distribution of Galba truncatula (Gastropoda: Lymnaeidae) climatic conditions and the altitude of municipalities in Haute Vienne (France)

2018 ◽  
Vol 54 ◽  
pp. 19
Author(s):  
Gilles Dreyfuss ◽  
Philippe Vignoles ◽  
Daniel Rondelaud
Keyword(s):  
Retrospective Study ◽  
Habitat Type ◽  
Acid Soils ◽  
Climatic Conditions ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Galba Truncatula ◽  
Mean Annual Rainfall ◽  
The Mean

A retrospective study on 7407 populations of Galba truncatula found in the department of Haute Vienne for 37 years (1970–2006) was carried out to determine if altitude and climate on acid soils had an effect on the distribution of populations and the characteristics of their habitats. Out of a total of 13 478 water points surveyed in 179 municipalities, the overall frequency of snail populations was 54.9% but varied with the habitat type and the municipality on which these water points are located. The frequency of snail populations significantly decreased when the mean altitude of municipalities or their mean annual rainfall increased. Conversely, this frequency significantly increased with increasing mean annual temperature. The characteristics of habitats were analysed for 6281 populations in relation to the mean altitude of municipalities. The area of G. truncatula habitats and the density of overwintering snails per m2 of habitat significantly decreased with increasing altitude. On the acid soils of Haute Vienne, the distribution of G. truncatula populations is closely related to the altitude and climatic conditions of municipalities.

scholarly journals Сравнение эколого-климатических ниш двух видов ковылей – Stipa sareptana A.K. Becker и S. krylovii Roshev. (Poaceae)

2017 ◽  
Vol 7 (4) ◽  
pp. 263-269 ◽  
Author(s):  
P. D. Gudkova ◽  
M. V. Olonova ◽  
D. S. Feoktistov
Keyword(s):  
Related Species ◽  
Significant Contribution ◽  
Climatic Conditions ◽  
Ecological Niches ◽  
Mean Annual Temperature ◽  
Morphological Pattern ◽  
Closely Related Species ◽  
The Mean ◽  
Gis Methods ◽  
Subordinate Role

Each species besides of having the unique morphological pattern also has an unique ecologo-climatic niche and geographical range. The study of ecologico-climatic and geographic divergence can make significant contribution to understanding of the species genesis and its volume. The purpose of this paper was to compare the ecologo-climatic niches of the closely related species Stipa sareptana and S. krylovii in order to reveal their identity. The research allowed specifying the areas of both species. Using GIS methods and based on the points of presence and six independent bioclimatic characters, their potential ranges – areas where the climatic conditions are favorable for growth – were identified and ecologo-climatic niches revealed. It was established that the most important factors determining the distribution of S. krylovii and S. sareptana are the mean annual temperature and seasonality of precipitation. Other factors play a subordinate role. The comparison of ecological niches, generated by MaxEnt, showed their differences at a statistically significant level.

scholarly journals Towards Understanding Variability in Droughts in Response to Extreme Climate Conditions over the Different Agro-Ecological Zones of Pakistan

2021 ◽  
Vol 13 (12) ◽  
pp. 6910
Author(s):  
Adil Dilawar ◽  
Baozhang Chen ◽  
Arfan Arshad ◽  
Lifeng Guo ◽  
Muhammad Irfan Ehsan ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Principal Component ◽  
Mitigation Strategies ◽  
Precipitation Extremes ◽  
Climate Mitigation ◽  
Mean Annual Temperature ◽  
Climate Extreme ◽  
Ecological Zones ◽  
The Mean ◽  
Agro Ecological Zones

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.

scholarly journals Paleocene-Eocene volcanic segmentation of the Norwegian-Greenland seaway reorganized high-latitude ocean circulation

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Jussi Hovikoski ◽  
Michael B. W. Fyhn ◽  
Henrik Nøhr-Hansen ◽  
John R. Hopper ◽  
Steven Andrews ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
High Latitude ◽  
Seismic Reflection ◽  
Arctic Region ◽  
Climatic Conditions ◽  
The Arctic ◽  
Early Eocene ◽  
Subaerial Exposure ◽  
Thermal Maximum ◽  
Volcanic Facies

AbstractThe paleoenvironmental and paleogeographic development of the Norwegian–Greenland seaway remains poorly understood, despite its importance for the oceanographic and climatic conditions of the Paleocene–Eocene greenhouse world. Here we present analyses of the sedimentological and paleontological characteristics of Paleocene–Eocene deposits (between 63 and 47 million years old) in northeast Greenland, and investigate key unconformities and volcanic facies observed through seismic reflection imaging in offshore basins. We identify Paleocene–Eocene uplift that culminated in widespread regression, volcanism, and subaerial exposure during the Ypresian. We reconstruct the paleogeography of the northeast Atlantic–Arctic region and propose that this uplift led to fragmentation of the Norwegian–Greenland seaway during this period. We suggest that the seaway became severely restricted between about 56 and 53 million years ago, effectively isolating the Arctic from the Atlantic ocean during the Paleocene–Eocene thermal maximum and the early Eocene.

scholarly journals High-time resolved radon-progeny measurements in the Arctic region (Svalbard Islands, Norway): results and potentialities

2017 ◽  
Author(s):  
Roberto Salzano ◽  
Antonello Pasini ◽  
Antonietta Ianniello ◽  
Mauro Mazzola ◽  
Rita Traversi ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Atmospheric Stability ◽  
Arctic Region ◽  
Climatic Conditions ◽  
The Arctic ◽  
Radon Emanation ◽  
Radon Progeny ◽  
Time Resolved ◽  
Scientific Challenge ◽  
The Arctic Region

Abstract. The estimation of radon progeny in the Arctic region represents a scientific challenge due to the required low limit of detection in consideration of the limited radon emanation associated with permafrost dynamics. This preliminary study highlighted, for the first time, the possibility to monitor radon progeny in the Arctic region with a higher time resolution. The composition of the radon progeny offered the opportunity to identify air masses dominated by long-range transport, in presence or not of near-constant radon progeny instead of long and short lived progenies. Furthermore, the different ratio between radon and thoron progenies evidenced the contributions of local emissions and atmospheric stability. Two different emanation periods were defined in accordance to the permafrost dynamics at the ground and several accumulation windows were recognized coherently to the meteo-climatic conditions occurring at the study site.

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