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Distribution and changes of active layer thickness(ALT) and soil temperature(TTOP) in the source area of the Yellow River using the GIPL model

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Science China Earth Sciences 2014年第8期57卷 1834-1845页

作者： LUO DongLiang JIN HuiJun Sergei MARCHENKO vladimir romanovsky State Key Laboratory of Frozen Soils Engineering Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Geophysical Institute University of Alaska FairbanksFairbanks Alaska 99775 USA

Active layer thickness（ALT） is critical to the understanding of the surface energy balance, hydrological cycles, plant growth, and cold region engineering projects in permafrost regions. The temperature at the bottom of the active layer, a boundary layer between the equilibrium thermal state（in permafrost below） and transient thermal state（in the atmosphere and surface canopies above）, is an important parameter to reflect the existence and thermal stability of permafrost. In this study, the Geophysical Institute Permafrost Model（GIPL） was used to model the spatial distribution of and changes in ALT and soil temperature in the Source Area of the Yellow River（SAYR）, where continuous, discontinuous, and sporadic permafrost coexists with seasonally frozen ground. Monthly air temperatures downscaled from the CRU TS3.0 datasets, monthly snow depth derived from the passive microwave remote-sensing data SMMR and SSM/I, and vegetation patterns and soil properties at scale of 1：1000000 were used as input data after modified with GIS techniques. The model validation was carried out carefully with in-situ ALT in the SAYR interpolated from the field-measured soil temperature data. The results of the model indicate that the average ALT in the SAYR has significantly increased from 1.8 m in 1980 to 2.4 m in 2006 at an average rate of 2.2 cm yr–1. The mean annual temperature at the bottom of the active layer, or temperature at the top of permafrost（TTOP） rose substantially from –1.1°C in 1980 to –0.6°C in 2006 at an average rate of 0.018°C yr–1. The increasing rate of the ALT and TTOP has accelerated since 2000. Regional warming and degradation of permafrost has also occurred, and the changes in the areal extent of regions with a sub-zero TTOP shrank from 2.4×104 to 2.2×104 km2 at an average rate of 74 km2 yr–1. Changes of ALT and temperature have adversely affected the environmental stability in the SAYR.

关键词： GIPL model active layer thickness TTOP degradation of permafrost

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Degrading permafrost and its impacts

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Advances in Climate Change Research 2021年第1期12卷 1-5页

作者： JIN Hui-Jun WU Qing-Bai vladimir E.romanovsky Northeast-China Observatory and Research Station of Permafrost Geological Environment(Ministry of Education) School of Civil EngineeringInstitute of Cold Region Scienceand TechnologyNortheast Forestry UniversityHarbin150040China State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China Geophysical Institute University of Alaska FairbanksFairbanks99775USA

*** Permafrost is present extensively in polar,high-plateau,alpine,and mountainous regions,with a model-estimated total extent of permafrost regions at 22.79 million km^(2)(Gruber,2012).However,among ever increasing modeling results,these estimates are based on applications of different permafrost models of various validity,but with a large range of *** affects terrestrial ecosystems and ground hydrothermal dynamics,biogeochemical cycles,engineered infrastructures,and socioeconomic development to varied *** a warming climate,permafrost has been degrading *** studies have been flourishing due to increasing concerns on the climatic feedbacks of permafrost carbon,ecological impacts from degrading permafrost,sustainable water supplies,and engineering ramifications.

关键词： terrestrial mountainous plateau

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Energy and mass changes of the Eurasian permafrost regions by multi-satellite and in-situ measurements

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Natural Science 2011年第10期3卷 827-836页

作者： Reginald R. Muskett vladimir E. romanovsky 不详

We investigate changes in total water equivalent mass, land-surface temperature and atmospheric CO2 by satellite-based measurements from August 2002 through December 2008. Our region of interest spans 75 to 165°E and 50 to 80oN centered on the Lena River watershed as a physical reference frame. We find energy and mass changes on the continuous and discontinuous permafrost zones indicating: 1) Arctic uplands such as the Siberian Plateau show strongly positive water equivalent mass and strongly negative land-surface temperature gradients during May months. 2) Arctic lowlands such as the thaw-lake regions of Kolyma, Lena Delta, and Taymyr show strongly negative water equivalent mass and strongly positive land-surface temperature gradients during September months. 3) Areas with strongly positive water equivalent mass and negative land-surface temperature gradients during May months have weakly positive CO2 gradients 4) Areas with strongly negative water equivalent mass and strongly positive land-surface temperature gradients during September months have strongly positive CO2 gradients. This indicates that continuous and discontinuous permafrost ecosystem responses are correlated in phase with energy and mass changes over the period. The Laptev and East Siberia Sea have increasing trends of CO2 atmosphere concentration 2.23 ± 0.15 ppm/yr and 2.40 ± 0.21 ppm/yr, respectively. Increasing trends and strong positive gradients of CO2atmosphere concentration during Aprils-Mays are evidence that the Arctic Ocean is a strong emitter of CO2 during springtime lead formation. We hypnotize that the increasing CO2 from land and ocean regions is from permafrost thawing and degradation and ecosystem microbial activity.

关键词： Permafrost GRACE MODIS AIRS

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The Use of Geophysical Methods to Discriminate between Brine Layers and Freshwater Taliks in Permafrost Regions

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冰川冻土 2004年第S1期26卷 301-309页

作者： Kenji Yoshikawa vladimir romanovsky Nataria Duxbury Jerry Brown Alexandre Tsapin Water and Environmental Research Center Institute of Northern Engineering University of Alaska Fairbanks PO Box 755860 Fairbanks AK 99775-5860 USA Geophysical Institute University of Alaska Fairbanks 903 Koyukuk Drive P.O. Box 757320 Fairbanks AK 99775-7320 USA Jet Propulsion Laboratory 4800 Oak Grove Drive MS 183-301 Pasadena CA 91109 USA International Permafrost Association P.O. Box 7 Woods Hole MA 02543 USA

Direct current resistivity and ground penetrating radar surveys were employed to obtain the value of the resistivity and dielectric constant in the brine near the Barrow, Alaska. The geophysical surveys were undertaken together with the permafrost drilling program for the measuring of the ground temperature regime and for the core sampling. The sampled cores were measured for their physical and chemical properties in the laboratory under different temperature conditions ((-60) to (20) ℃). Laboratory results support field observations and led to the development of a technique for distinguishing freshwater taliks and brine layers in permafrost. These methods were also employed in freshwater taliks near Council, Alaska. The electrical resistivity is a powerful and sensitive parameter for brine detection. However, the resistivity is a less sensitive indicator of the soil type or water content under highly saline conditions. High frequency dielectric constant is an ideal second parameter for the indication of the soil type, liquid water content and other physical properties. The imaginary part of the dielectric constant and resistivity have a significant dependence upon salinity, i.e. upon freezing temperature. The ground temperature regime and the freezing point of the brine layer are important parameters for studying the electric properties of permafrost terrain.

关键词： geophysical method resistivity and dielectric constant talik Barrow,Alaska

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The closed Lake Issyk-Kul as an indicator of global warming in Tien-Shan

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Natural Science 2013年第5期5卷 608-623页

作者： vladimir V.romanovsky Saadat Tashbaeva Jean-Francois Crétaux Stephane Calmant Vanessa Drolon IWPH BishkekKyrgyzstan CNES/Legos ToulouseFrance IRD/Legos ToulouseFrance CNRS/Legos ToulouseFrance

Lake Issyk-Kul is the seventh deepest lake in the world situated inCentral Asiain theTien-ShanMountainsat the elevation of 1607 m above sea level. This area belongs toKyrgyzstan. From 1927 to 1997 the water level decreased by 3.4 m, and increased by 0.93 m from 1997 to 2011. The article analyzes the impact of the global warming on the Lake Issyk-Kul thermal regime and the components of its water balance: river discharge, precipitation, evaporation and lake level variations. It shows that the global warming has entailed the increase of the Lake Issyk-Kul water temperature down to the maximum depths, and river discharge increase due to the glaciers melting and the evaporation from the lake surface. The air temperature increase of 1 ℃ results in river discharge increas and lake level rise of 44 mm/year and surface evaporation increase of 88 mm/year. TheLakeIssyk-Kullevel increase after 1997, which takes place in the situation of global warming, was caused by the activation of the West air masses transport and increase of precipitation in autumn.

关键词： Issyk-Kul Lake Tyup Jyrgalan Chon-Kyzylsuu Juuku Rivers Karabatkak Glacier Watershed Glacier Discharge Discharge Formation Zone Water Balance

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Active-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 through 2014

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International Journal of Geosciences 2015年第1期6卷 12-41页

作者： Reginald R. Muskett vladimir E. romanovsky William L. Cable Alexander L. Kholodov Geophysical Institute University of Alaska Fairbanks Fairbanks USA Tyumen State Oil and Gas University Tyumen Russia

Soil moisture is a vital physical parameter of the active-layer in permafrost environments, and associated biological and geophysical processes operative at the microscopic to hemispheric spatial scales and at hourly to multi-decadal time scales. While?in-situ?measurements can give the highest quality of information on a site-specific basis, the vast permafrost terrains of North America and Eurasia require space-based techniques for assessments of cause and effect and long-term changes and impacts from the changes of permafrost and the active-layer. Satellite-based 6.925 and 10.65 GHz sensor algorithmic retrievals of soil moisture by Advanced Microwave Scanning Radiometer-Earth Observation System (AMSR-E) onboard NASA-Aqua and follow-on AMSR2 onboard JAXA-Global Change Observation Mission—Water-1 are ongoing since July 2002. Accurate land-surface temperature and vegetation parameters are critical to the success of passive microwave algorithmic retrieval schemes. Strategically located soil moisture measurements are needed for spatial and temporal co-location evaluation and validation of the space-based algorithmic estimates. We compare on a daily basis ground-based (subsurface-probe) 50- and 70-MHz radio-frequency soil moisture measurements with NASA- and JAXA-algorithmic retrieval passive microwave retrievals. We find improvements in performance of the JAXA-algorithm (AMSR-E reprocessed and AMSR2 ongoing) relative to the earlier NASA-algorithm version. In the boreal forest regions, accurate land-surface temperatures and vegetation parameters are still needed for algorithmic retrieval success. Over the period of AMSR-E retrievals, we find evidence of at the high northern latitudes of growing terrestrial radio-frequency interference in the 10.65 GHz channel soil moisture content. This is an important error source for satellite-based active and passive microwave remote sensing soil moisture retrievals in Arctic regions that must be addressed.

关键词： Soil Moisture Active Layer Radio Microwave Remote Sensing AMSR-E AMSR2 NASA JAXA Alaska Russia

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Equilibrium Arrivals to Preemptive Queueing System with Fixed and Random Population Size

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Journal of the Operations Research Society of China 2024年第1期12卷 77-92页

作者： Julia Chirkova vladimir Mazalov Institute of Applied Mathematical Research Karelian Research Centre of RASPetrozavodsk185910Russia School of Mathematics and Statistics Qingdao UniversityQingdao266071ShandongChina

A single-server queueing system with preemptive access is *** customer has one attempt to enter the system at its working interval[0,T].As soon as the customer request enters the system,the server immediately starts the *** when the next request arrives in the system,the previous one leaves the system even he has not finished his service *** study a non-cooperative game in which the customers wish to maximize their probability of obtaining service within a certain period of *** characterize the Nash equilibrium and the price of anarchy,which is defined as the ratio between the optimal and equilibrium social *** models are *** the first model the number of players is fixed,while in the second it is random and obeys the Poisson *** demonstrate that there exists a unique symmetric equilibrium for both ***,we calculate the price of anarchy for both models and show that the price of anarchy is not monotone with respect to the number of customers.

关键词： Service system Preemptive priorities Strategic users Random number of players Optimal arrivals Kolmogorov backward equations Nash equilibrium Price of anarchy

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Study of asphaltene reaggregation in toluene/heptane mixture by dynamic and static light scattering

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Petroleum Research 2024年第1期9卷 48-54页

作者： vladimir N.Kuryakov Oil and Gas Research Institute of RAS(OGRI RAS) Gubkina Str.3119333MoscowRussian Federation

This paper presents the study of the effect of multiple ultrasonic impacts on submicron asphaltene aggregates in a toluene/heptane solution,conducted with dynamic light scattering *** objects of the study were four samples of asphaltenes obtained from four different *** all samples,the change in the average size of the asphaltene submicron aggregates with time was measured after the addition of a precipitant(heptane)to a solution of asphaltenes in toluene at an amount above the threshold *** aggregates formed in solution after the addition of the precipitant and were subjected to ultrasonic treatment,which led to the destruction of the asphaltene *** of destroyed asphaltenes was *** kinetics of this aggregation were similar to the kinetics of aggregation of asphaltenes after the addition of a *** iterations of asphaltene aggregate destruction in the sample led to a significant change in the kinetics of aggregation:the growth of aggregates slowed and stabilized at a size of approximately 200 nm and 30 nm for the different studied samples.

关键词： Asphaltenes Aggregation Sonication Dynamic light scattering Re-aggregation Colloidal stability Resins

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On Differential Equations of Integrable Billiard Tables

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Acta Mathematica Sinica,English Series 2024年第1期40卷 417-424页

作者： vladimir DRAGOVIC Andrey E.MIRONOV Department of Mathematical Sciences The University of Texas at DallasRichardson TXUSA Mathematical Institute SANU BelgradeSerbia Novosibirsk State University NovosibirskRussia Sobolev Institute of Mathematics of the Siberian Branch of the Russian Academy of Sciences NovosibirskRussia

We introduce a method to find differential equations for functions which define tables,such that associated billiard systems admit a local first *** illustrate this method in three situations:the case of(locally)integrable wire billiards,for finding surfaces in R^(3)with a first integral of degree one in velocities,and for finding a piece-wise smooth surface in R^(3)homeomorphic to a torus,being a table of a billiard admitting two additional first integrals.

关键词： Polynomial first integrals wire billiards piece-wise smooth surfaces

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Attempts to restore loss of function in damaged ACD cells open the way to non-mutational oncogenesis

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Genes & Diseases 2024年第3期11卷 5-6页

作者： vladimir F.Niculescu 86420 Diedorf Germany Kirschenweg

This correspondence to Gene&Diseases calls attention to the controversy between proponents of genetic modification in carcinogenesis and supporters of non-mutational *** from molecular cancer research and findings from evolutionary cancer cell biology support the latter claim and provide no rationale for the mutational origin of sporadic *** is more conceivable that the general susceptibility of asymmetric cell division(ACD)phenotypes to oxygen leads to irreparable DNA defects and dysregulated defective symmetric cell division(DscD)phenotypes.

关键词： rational latter finding

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