Anthropogenic Heat Islands in the Arctic – Windows to the Future of the Regional Climates, Ecosystems and Societies

Highlight speech “Warmer climate of Arctic cities”, Bjerknes Annual Meeting, Bergen, Norway, 2019

The urban heat island (UHI) is one of the most evident local climate phenomena in urbanized areas. Although much is known about the UHI in low-and mid-latitude cities, knowledge about the UHI in high latitudes is still fragmentary. Understanding this urban climate phenomenon in the high latitudes is essential to support sustainability and resilience of northern settlements that experience accelerated Arctic warming. This study focuses on Fennoscandia, which is the most urbanized northern region. Here, small and medium sized cities are numerous. The urban population is expected to grow as well as the importance of the region for the global resource supply and geopolitical arena. This study includes all 57 cities located above 64° N in this complex region. Their combined urban population is of 1,700,000. The study is based on statistical analysis of Land Surface Temperature (LST) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data in the period 2001-2017. The analysis of the LST data determines a surface UHI or SUHI. We find strong and persistent winter and summer SUHIs in most of the studied cities. The SUHI intensity varies from city to city. It is remarkably heterogeneous due to bioclimatic and socioeconomic differences between the cities. The SUHI is particularly intense in the coastal cities of the Atlantic region. Our analysis shows that the cities with warmer rural background and larger fraction of land covered by more productive vegetation (low albedo) around the cities have lower SUHI intensity. Conversely, the cities with colder background rural climate and less fraction of land with more productive vegetation (high albedo) have higher SUHI. Large thermal inertia of water bodies additionally complicates the determination and interpretation of the SUHI as both the relative strength and the direction of the urban effects (cooling or warming) depend on the fraction of water surfaces in the rural background. In this maritime climate zone, neither population nor the city area size reveal strong correlations with the SUHI intensity. The size of the population is found to be the strongest SUHI predictor in cities with more continental climate. The mean SUHI intensity is found in the range 0-5 °C. The intensity is larger for the largest cities of Murmansk and Oulu (3-5 °C).

Although there is a growing body of research on Arctic urbanisation and the development of cities in harsh polar climate, few studies focus on the long-term interaction of urban environments with the natural world and society. As the search for determinative links between natural environmental characteristics and socio-cultural phenomena is exceedingly complex and obscured by human decision-making, it is more fruitful to adopt another perspective – one that views the city as an anthropogenic object combining natural, social, and cultural features and phenomena. The HIARC (Anthropogenic Heat Islands in the Arctic – Windows to the Future of the Regional Climates, Ecosystems and Society) project helps to fill this knowledge gap by bringing together traditional climate science that operates on large spatial and time scales; micro-level high-resolution studies that provide relevant practical details about the changing environment; bio-medical science that studies the physical adaptation of newcomers to the Arctic environment; and an array of social science approaches that range from political science on urban regimes to sociology and cultural anthropology that capture evolving human environments. This article offers a preliminary agenda for thinking about cities as an anthropogenic object in a polar context.

Satellite studies using the normalized difference vegetation index (NDVI) have revealed changes in northern Eurasian vegetation productivity in recent decades, including greening in tundra and browning in the boreal forests. However, apparent NDVI changes and relationships to climate depend on the temporal and spatial sampling and the biome and forest-land cover type studied. Here we perform a consistent analysis of NDVI and climate across four bioclimatic zones (tundra, forest-tundra, northern and middle taiga) in northern West Siberia (NWS), further stratified into eight forest-land cover types.We utilize NDVI data from the Moderate Resolution Imaging Spectroradiometer and climate reanalysis data from 2000 to 2016, a period including the record warm anomaly in 2016 (+2 °C–5 °C June–July surface air temperature (SAT) across NWS). Statistically significant (α = 0.05) correlations were found for two bivariate relationships at the biome level: between NDVImax and June–July surface air temperature (SAT)(r = +0.79), and between middle taiga NDVImax and July precipitation (r = +0.48).No significant statistical relationships were found for the northern taiga and forest-tundra biomes. However, within these biomes we found that deciduous needle-leaf (larch) NDVImax is significantly correlated with July temperature (r = +0.48). Qualitatively, spatial composites of NDVI and climate variables were effective for revealing insights and patterns of these relationships at the sub-regional scale. The spatial heterogeneity of NDVI patterns indicates divergent reactions of specific types of vegetation, as well as local effects that are clearly important on the background of a regional climate response.

Satellite studies using the normalized difference vegetation index (NDVI) have revealed changes in northern Eurasian vegetation productivity in recent decades, including greening in tundra and browning in the boreal forests. However, apparent NDVI changes and relationships to climate depend on the temporal and spatial sampling and the biome and forest-land cover type studied. Here we perform a consistent analysis of NDVI and climate across four bioclimatic zones (tundra, forest-tundra, northern and middle taiga) in northern West Siberia (NWS), further stratified into eight forest-land cover types.We utilize NDVI data from the Moderate Resolution Imaging Spectroradiometer and climate reanalysis data from 2000 to 2016, a period including the record warm anomaly in 2016 (+2 °C–5 °C June–July surface air temperature (SAT) across NWS). Statistically significant (α = 0.05) correlations were found for two bivariate relationships at the biome level: between NDVImax and June–July surface air temperature (SAT)(r = +0.79), and between middle taiga NDVImax and July precipitation (r = +0.48).No significant statistical relationships were found for the northern taiga and forest-tundra biomes. However, within these biomes we found that deciduous needle-leaf (larch) NDVImax is significantly correlated with July temperature (r = +0.48). Qualitatively, spatial composites of NDVI and climate variables were effective for revealing insights and patterns of these relationships at the sub-regional scale. The spatial heterogeneity of NDVI patterns indicates divergent reactions of specific types of vegetation, as well as local effects that are clearly important on the background of a regional climate response.

The Arctic has rapidly urbanized in recent decades with 2 million people currently living in more than a hundred cities north of 65∘ N. These cities have a harsh but sensitive climate and warming here is the principle driver of destructive thawing, water leakages, air pollution and other detrimental environmental impacts. This study reports on the urban temperature anomaly in a typical Arctic city. This persistent warm anomaly reaches up to 11 K in winter with the wintertime mean urban temperature being 1.9 K higher on average in the city center than in the surrounding natural landscape. An urban temperature anomaly, also known as an urban heat island (UHI), was found using remote sensing and in situ temperature data. High-resolution (1 km) model experiments run with and without an urban surface parameterization helped to identify the leading physical and geographical factors supporting a strong temperature anomaly in a cold climate. The statistical analysis and modeling suggest that at least 50 % of this warm anomaly is caused by the UHI effect, driven mostly by direct anthropogenic heating, while the rest is created by natural microclimatic variability over the undulating relief of the area. The current UHI effect can be as large as the projected, and already amplified, warming for the region in the 21st century. In contrast to earlier reports, this study found that the wintertime UHI in the Arctic should be largely attributed to direct anthropogenic heating. This is a strong argument in support of energy efficiency measures, urban climate change mitigation policy and against high-density urban development in polar settlements. The complex pattern of thermal conditions, as revealed in this study, challenges urban planners to account for the observed microclimatic diversity in perspective sustainable development solutions.

The severe continental climate of the northern high latitudes is characterized by a generally negative surface heat balance and persistent strong static stability of the lower atmosphere. Such conditions favor localized surface temperature anomalies of large amplitude. It has been found that the locations of such anomalies correspond to urban areas, where artificial surfaces and anthropogenic heat raise air and surface temperatures – i.e., urban heat islands (UHIs). However, the magnitude and spatial extent of such anomalies – as well as the controlling factors in high latitudes – have not been well investigated. A recent advance using remote sensing is the identification of UHIs in 28 cities in northern West Siberia (Miles and Esau, 2017). Here we present results focused on a few case studies. The analysis is based on the MODerate Resolution Imaging Spectro-radiometer (MODIS) data from Terra and Aqua satellite platforms.

Warm urban climate anomalies are a challenging problem for city’s economy and ecology. This problem is even more pressing in boreal environment with its sensitive ecosystems and considerable anthropogenic urban heat flux. The boreal regions of Eurasia witness both rapid urbanization and accelerated regional warming in the twenty-first century. Still, local climate of boreal cities is only fragmentary studied. There were no studies addressing spatial and temporal variability of urban temperature anomalies in Eurasian cities with cold continental climate. There were many indirect reports indicating large temperature anomalies and longer growing season in boreal cities. This study considered a land surface temperature (LST) anomaly, frequently referred to as a surface urban heat island (SUHI), in a typical young mid-size boreal city of Nefteyugansk. This city exemplifies urban planning and energy use patterns of a pleiad of cities in this oil and gas region of northern West Siberia. The study is based on LST products from the MODerate resolution Imaging Spectro-radiometer (MODIS) onboard of the Terra and Aqua satellite platforms. The MODIS data for 14 years (2001–2015) were processed to reveal geographical extent and diurnal variations of the SUHI in summer (June, July, August) and winter (December, January, February) seasons. The study found that the mean annual SUHI has higher LST than the surrounding natural background by + 2.4 K. Considering the meridional temperature gradient in this region, such a strong SUHI makes the urban climate similar to climate found 600 km south of the city. The diurnal mean summer (+ 2.1 K) and winter (+ 2.4 K) SUHI intensities are rather similar in Nefteyugansk. The daytime (+ 2.1 K) and nighttime (+ 2.5 K) SUHI intensities are also similar in wintertime. In summertime, however, the daytime SUHI intensity (+ 3.3 K) is significantly larger than that in nighttime (+ 1.0 K). There is also larger interannual variability of the SUHI in the summer season, especially in nighttime. The SUHI statistics in Nefteyugansk discerns this cold continental city from previously studied cities in the temperate climate zone. Heating of apartment and industrial buildings maintains a large anthropogenic heat flux in the city (estimated to be on average of 15–20 W m⁻²) and therefore supports the persistent winter SUHI. Weak turbulent mixing in the stably stratified lower atmosphere traps the heat in the urbanized area. This study found that the SUHI footprint in Nefteyugansk is considerably (two to three times) larger than the area of the city proper itself.

Systematic errors in forecast near-surface air temperature (SAT) still constitute a considerable problem for numerical weather prediction (NWP) at high latitudes. Numerous studies in the past have attempted to reduce this problem through recalibration of physical parameterization schemes and better approximation of the surface energy budget. The errors, however, remain despite notable improvements in the overall weather forecast performance. This study looks at the problem from a different perspective. It analyzes asymmetries in the SAT forecast errors. The study reveals a statistical pattern of warm SAT biases under cold weather conditions and cold SAT biases under warm weather conditions. The largest errors were found in shallow atmospheric boundary layers (ABLs). The study attributes the problem to the modeled excessive ABL thickness in northern Eurasia (the NEFI region). The ABL thickness is considered as a scaling factor controlling the efficacy of the applied surface heating. Too thick an ABL damps the magnitude and agility of the SAT response. The study utilized the operational model SL-AV of the Russian Hydrometeorological Centre. Two turbulence schemes were evaluated in the northern European and western Siberian regions of Russia against observations from 73 meteorological stations. The pTKE (old) scheme is based on the local balance of the turbulence characteristics. The TOUCANS (new) scheme incorporated the total turbulence energy equations in an energy-flux balance approach. Neither scheme uses the ABL thickness as a prognostic parameter. The study reveals that the SAT errors are consistent with the damped response of temperature and reduced agility of temperature fluctuations in too thick ABLs. The TOUCANS scheme did not improve those features, probably because it links the turbulent fluxes and the ABL thickness. The SAT errors in shallow ABLs persist in the new scheme. This study emphasizes the need for a closer look at the ABL thickness in the NWP models.

A key finding of the research is the identification of contrasting trends for different species within the same bioclimatic zone.The most interesting observation is that larch-dominated (Larix) forest is only the forest type in northern West Siberia showing a positive “greening” trend, according to the study of 15 years record of a vegetation index based on satellite images. Among the various types of forest stands growing close to each other, only the Larix – which is a deciduous needle-leaf conifer – shows a positive change while the other six types show negative trends (see V.Miles and I. Esau, 2016: Spatial heterogeneity of greening and browning between and within bioclimatic zones in northern West Siberia. Environ. Res. Letter 11 (2016) 115002.).

Urban temperature anomalies, frequently referred to as the urban heat islands (UHIs), are of the most distinct and influential climatic factors with significant impact on urban life and environment. However, UHIs in high latitudes are still studied only fragmentary. There is a knowledge gap related to the urban temperature distinction with respect to local temperature anomalies of natural surface types. This study extends upon our recent high latitude regional-scale climatic survey in 28 cities in the Northern West Siberia (NWS) region. Based on MODIS land surface temperature (LST) products covering 15 years between 2001 and 2015, it was revealed that all 28 cities have significant surface urban heat islands (SUHIs). The strong statistical dependence (r = 0.73) on endogenous factors such as city size and the population was found. It was suggested that exogenous factors such as the background LC types could be significant as well. This study presents the analysis of the exogenous factors shaping the apparent SUHI intensities. The major contribution to the SUHI was revealed for water, sparse vegetation, grassland, and shrubland. There are no clear dependence between the partial SUHI intensity and the area fraction occupied by the given LC type. The mechanisms and pathways of the SUHI maintenance cannot be inferred solely from the remote sensing data. Further understanding requires numerical experiments with turbulence-resolving models.

The Arctic has rapidly urbanized in recent decades with two million people currently living in more than a hundred cities north of 65°N. These cities have a harsh but sensitive climate and warming here is the principle driver of destructive thawing, water leakages, air pollution, and other detrimental environmental impacts. This study reports on the urban temperature anomaly in a typical Arctic city. This persistent warm anomaly reaches up to 11 K in winter with the wintertime mean urban temperature being on average 1.9K higher in the city centre than in the surrounding natural landscape. An urban temperature anomaly, also known as an urban heat island (UHI), was found in remote sensing and in situ temperature data. High-resolution (1km) model experiments run with and without an urban surface parametrization helped to identify the leading physical and geographical factors supporting a strong temperature anomaly in a cold climate. The statistical analysis and modelling suggest that direct anthropogenic heating contributes at least 50% to the observed UHI intensity, and the rest is created by natural microclimatic variability over the undulating relief of the area. The current UHI effect can be as large as the projected, and already amplified, warming for the region in the 21st century. In contrast to earlier reports, this study found that the wintertime UHI in the Arctic should be largely attributed to direct anthropogenic heating. This is a strong argument in support of energy efficiency measures, urban climate change mitigation policy, and against high-density urban development in polar settlements. The complex pattern of thermal conditions, as revealed in this study, challenges urban planners to account for the observed micro-climatic diversity in perspective sustainable development solutions.

Dense meteorological networks are needed to advance understanding of urban climatology in the northern polar region where the global warming is rapid and amplified. High quality and density urban temperature datasets are required to monitor thawing processes in urban soils, properly assess and project climatic trends in human comfort, air quality and weather extremes. This study presents an Urban Heat Island Arctic Research Campaign (UHIARC) observational network, which has been deployed in several mid-sized cities (Salekhard, Vorkuta, Nadym, Novy Urengoy) of the Eurasian arctic region in the winter 2016-2017. The network comprises an array of air temperature loggers and one automatic weather station in each of these four cities. The UHIARC observations revealed strong warm temperature anomalies in all four cities. Such persistent temperature anomalies are frequently referred to as urban heat islands (UHIs). The mean wintertime magnitude of these temperature anomalies (the UHI intensity) was found to be between 0.8K and 1.4K. Extreme UHI intensities up to 7K were observed during cold anticyclonic weather conditions. Such a strong mediation of the cold temperature spills by the UHI might induce considerable socio-economic and environmental impact in the cities. The UHIARC dataset is available for further analysis from http://urbanreanalysis.ru/uhiarc.html

The main objective of the TRAKT-2018 (Transferable Knowledge and Technologies for High-Resolution Environmental Impact Assessment and Management) project is to implement a novel technology for the high-resolution environmental impact assessment. Responsible and sustainable environmental management requires accurate high-resolution environmental information on the user-relevant scales. Unfortunately, such information is fragmented and inconsistent. Traditionally, qualitative expert judgment is used to inform the decision-making process in these circumstances. Recent advances of observation and communication technologies have open a variety of open access data to support this process informing decisions on required 0.1-1 km scales. The critical challenge for any high-resolution technology is to obtain coherent data sets at the spatial and time resolution matching the modeling capacity. Therefore, the second project period has been focused on collection, qualification, analysis and transfer of data in a high-latitude urbanized and industrialized area. As other small and medium cities, the case study city Apatity (Noth-Western Russia, Kola Peninsula) does not maintain a sufficient number of regular or citizen observations to anchor remote sensing data product assessments and modeling projections. To overcome the problem, the project partners deployed a dense meteorological network of automatic weather stations (AWS) and temperature loggers (TLs) in and around the case study city. The Urban Heat Island Arctic Research Campaign (UHIARC) network successfully provided in situ data for the chosen wintertime periods. Figure 1 shows locations of the UHIARC stations and the mean temperature over the selected period 25-29 December 2017. The remote sensing data products from different satellite platforms are less accurate and more sensitive to the total cloudiness but provide better spatial data cover as well as variety of environmental characteristics consistent of longer periods of time. In this project, we utilized MODIS (Terra/Aqua platforms), AURA, LandSAT and ASTER satellite data products. We also make use of the gridded surface type data products ESA CCI 2015 and GlobaLand30-2010.

Anthropogenic heat and modified landscapes raise air and surface temperatures in urbanized areas around the globe. This phenomenon is widely known as an urban heat island (UHI). Previous UHI studies, and specifically those based on remote sensing data, have not included cities north of 60 • N. A few in situ studies have indicated that even relatively small cities in high latitudes may exhibit significantly amplified UHIs. The UHI characteristics and factors controlling its intensity in high latitudes remain largely unknown. This study attempts to close this knowledge gap for 28 cities in northern West Siberia (NWS). NWS cities are convenient for urban intercomparison studies as they have relatively similar cold continental climates, and flat, rather homogeneous landscapes. We investigated the UHI in NWS cities using the moderate-resolution imaging spectroradiometer (MODIS) MOD 11A2 land surface temperature (LST) product in 8-day composites. The analysis reveals that all 28 NWS cities exhibit a persistent UHI in summer and winter. The LST analysis found differences in summer and winter regarding the UHI effect, and supports the hypothesis of seasonal differences in the causes of UHI formation. Correlation analysis found the strongest relationships between the UHI and population (log P). Regression models using log P alone could explain 65–67% of the variability of UHIs in the region. Additional explanatory power—at least in summer—is provided by the surrounding background temperatures, which themselves are strongly correlated with latitude. The performed regression analysis thus confirms the important role of the surrounding temperature in explaining spatial–temporal variation of UHI intensity. These findings suggest a climatological basis for these phenomena and, given the importance of climatic warming, an aspect that deserves future study.

There are a number of asymmetries in the surface air temperature response to forcing, including polar amplification and changes to the diurnal and seasonal temperature ranges. We propose that such spatial–temporal signatures of climate change can, in part, be explained by differences in the effective heat capacity of the atmosphere. We have demonstrated that predictions arising from this hypothesis are simultaneously satisfied through the analysis of temperature records from daily to inter-decadal timescales using observational and reanalysis datasets. This mechanism can help to explain why we see the largest temperature trends in the winter months (0.42 K=decade in winter compared to 0.18 K=decade in summer) and why the diurnal temperature range decreases in a warming world, having decreased by �0.4 K since 1950.

В статье приводятся результаты исследования городского острова тепла (Urban Heat Island, UHI) г. Апатиты в зимний период, полученные по данным полевых метеорологических измерений и кос� мических снимков. По температуре поверхности, полученной из космических снимков, проведены расчеты температуры приземного слоя атмосферы. Экспериментальные данные о температуре воз� духа были получены в результате экспедиционных метеонаблюдений, а о температуре поверхности – по данным космической гиперспектральной системы MODIS (Moderate�Resolution Imaging Spectrora� diometer), каналы 31 и 32 (10.78–11.28 и 11.77–12.27 мкм соответственно). В результате анализа по� лей температур выявлен интенсивный (до 3.2°C) остров тепла, рассчитанный через температуру подстилающей поверхности, а его средняя интенсивность за период наблюдения заметно превыша�ет характерные данные для городов Европы в зимний период. Также установлено, что в зимних условиях температура воздуха, рассчитанная по данным MODIS, систематически выше температу�ры воздуха из данных прямых измерений.

Urban Heat Island (UHI) effect (Magee et al, 1999) in high latitudes is very poorly described in scientific literature. Actually, we know nothing about behavior of the heat islands during the polar night, while anthropogenic heat is the main source of thermal energy. This study is aimed to mitigate this lack of information about climatology of UHI formation in Russian cities of Arctic zone. In this paper, we consider the results of experimental research of the UHI of 4 biggest Arctic Cities (Murmansk, Norilsk, Apatity and Vorkuta), which were obtained during the expedition of Russian Geographic Society in 2013-2014. Due to severe climatic conditions, we ought to use three types of different measurements techniques: 1. Mounting of two automatic weather stations (AWS) in rural zone and city center 2. Development of small temperature sensors (iButton) network in the city and suburbs 3. Regular car-based temperature sounding of the city with AWS. 4. Using MTP-5 microwave temperature profiler. This research allowed to collect unique data about UHI in high latitudes. Analysis of the collected data showed the existence of UHI with the difference between city center and surrounding landscape up to 5-7 degrees Celcius. UHI characteristics in view of synoptic conditions was analyzed for several typical situations, for some cities (Norilsk) the negative correlation of the UHI power with air temperature was determined. References: 1. Magee N., Curtis J., Wendler G., The Urban Heat Island Effect at Fairbanks, Alaska// Theor. Appl. Climatol. 1999. V. 64, pp 39-47

This article presents the results of a study of the urban heat island (UHI) in the city of Apatity during winter that were obtained according to the data of field meteorological measurements and satellite images. Calculations of the surface layer temperature have been made based on the surface temperature data obtained from satellite images. The experimental data on air temperature were obtained as a result of expeditionary meteorological observations, and the experimental data on surface temperature were obtained based on the data of the space hyperspectral Moderate-Resolution Imaging Spectroradiometer (MODIS) system, channels 31 and 32 (10.78–11.28 and 11.77–12.27 micrometers, respectively). As a result of the analysis of temperature fields, an intensive heat island (up to 3.2°C) has been identified that was estimated based on the underlying surface temperature, and its mean intensity over the observation period significantly exceeds the representative data for European cities in winter. It has also been established that the air temperature calculated according to the MODIS data is systematically higher under winter conditions than the air temperature from direct measurement data.

Exploration and exploitation of oil and gas reserves of northern West Siberia has promoted rapid industrialization and urban development in the region. This development leaves significant footprints on the sensitive northern environment, which is already stressed by the global warming. This study reports the region-wide changes in the vegetation cover as well as the corresponding changes in and around 28 selected urbanized areas. The study utilizes the normalized difference vegetation index (NDVI) from high-resolution (250 m) MODIS data acquired for summer months (June through August) over 15 years (2000–2014). The results reveal the increase of NDVI (or “greening”) over the northern (tundra and tundra-forest) part of the region. Simultaneously, the southern, forested part shows the widespread decrease of NDVI (or “browning”). These region-wide patterns are, however, highly fragmented. The statistically significant NDVI trends occupy only a small fraction of the region. Urbanization destroys the vegetation cover within the developed areas and at about 5–10 km distance around them. The studied urbanized areas have the NDVI values by 15 to 45 % lower than the corresponding areas at 20–40 km distance. The largest NDVI reduction is typical for the newly developed areas, whereas the older areas show recovery of the vegetation cover. The study reveals a robust indication of the accelerated greening near the older urban areas. Many Siberian cities become greener even against the wider browning trends at their background. Literature discussion suggests that the observed urban greening could be associated not only with special tending of the within-city green areas but also with the urban heat islands and succession of more productive shrub and tree species growing on warmer sandy soils.

Modern human societies have accumulated considerable power to modify their environment and the earth's system climate as the whole. The most significant environmental changes are found in the urbanized areas. This study considers coherent changes in vegetation productivity and land surface temperature (LST) around four northern West Siberian cities, namely, Tazovsky, Nadym, Noyabrsk and Megion. These cities are located in tundra, forest-tundra, northern taiga and middle taiga bioclimatic zones correspondingly. Our analysis of 15 years (2000–2014) Moderate Resolution Imaging Spectroradiometer (MODIS) data revealed significantly (1.3 °C to 5.2 °C) warmer seasonally averaged LST within the urbanized territories than those of the surrounding landscapes. The magnitude of the urban LST anomaly corresponds to climates found 300–600 km to the South. In the climate change perspective, this magnitude corresponds to the expected regional warming by the middle or the end of the 21 st century. Warmer urban climates, and specifically warmer upper soil layers, can support re-vegetation of the disturbed urban landscapes with more productive trees and tall shrubs. This afforestation is welcome by the migrant city population as it is more consistent with their traditional ecological knowledge. Survival of atypical, southern plant species encourages a number of initiatives and investment to introduce even broader spectrum of temperate blossoming trees and shrubs in urban landscapes. The unintended changes of the urban micro-climates in combination with knowledgeable urban planning could transform the Siberian pioneer settlements into places of belonging.

This article is devoted to investigation of the urban heat island phenomenon of Norilsk city, which is on of the biggest polar cities, under the polar night conditions with usage of automatic weather stations, iButton compact temperature sensors and MODIS remote sensing data. It was found that during the polar night anthropogenic heat flux forms significant urban heat island in Norilsk with the intensity up 6-7 ⁰C in spite of the completely absence of solar light, which absorption and accumulation by urban surface is considered as important factor forming the urban heat island. Methods of researches, features of temperature distribution in Norilsk region according experimental measurements and remote sensing data, which shows the presence of the urban heat island, and also assessment of economic effect of this phenomenon are considered.

Modern human societies have accumulated considerable power to modify their environment and the earth’s system climate as the whole. The most significant environmental changes are found in the urbanized areas. This study considers coherent changes in vegetation productivity and land surface temperature (LST) around four northern West Siberian cities, namely, Tazovsky, Nadym, Noyabrsk and Megion. These cities are located in tundra, forest-tundra, northern taiga and middle taiga bioclimatic zones correspondingly. Our analysis of 15 years (2000–2014) Moderate Resolution Imaging Spectroradiometer (MODIS) data revealed significantly (1.3 °C to 5.2 °C) warmer seasonally averaged LST within the urbanized territories than those of the surrounding landscapes. The magnitude of the urban LST anomaly corresponds to climates found 300–600 km to the South. In the climate change perspective, this magnitude corresponds to the expected regional warming by the middle or the end of the 21st century. Warmer urban climates, and specifically warmer upper soil layers, can support re-vegetation of the disturbed urban landscapes with more productive trees and tall shrubs. This afforestation is welcome by the migrant city population as it is more consistent with their traditional ecological knowledge. Survival of atypical, southern plant species encourages a number of initiatives and investment to introduce even broader spectrum of temperate blossoming trees and shrubs in urban landscapes. The unintended changes of the urban micro-climates in combination with knowledgeable urban planning could transform the Siberian pioneer settlements into places of belonging.

The Climate Processes Group – GC Rieber Climate Institute (GCR) at the Nansen Environmental and Remote Sensing Centre is developing a coherent research strategy to address the scientific challenges of the rapidly warming high latitudes of the Earth. This workshop summarized the available expertise in the GCR and drafted ideas for perspective research directions compatible with the international Pan-Eurasian Experiment (PEEX) (Lappalainen et al., 2015). PEEX (https://www.atm.helsinki.fi/peex/) is a multidisciplinary, multi-scale bottom-up open scientific initiative. The PEEX approach emphasizes that solving challenges related to climate change, air quality and cryospheric change requires large-scale coordinated co-operation of the international research communities. A scientific workshop was hosted at the Nansen Center (GCR) on 29 the September 2015. The workshop presentations discussed both the large- and small-scale components of the climatology of the high-latitudes. A particular attention has been given to the links between climate scales as well as to the scales shaping the climate impact on society.

The Climate Processes Group – GC Rieber Climate Institute (GCR) at the Nansen Environmental and Remote Sensing Centre is developing a coherent research strategy to address the scientific challenges of the rapidly warming high latitudes of the Earth. This workshop summarized the available expertise in the GCR and drafted ideas for perspective research directions compatible with the international Pan-Eurasian Experiment (PEEX) (Lappalainen et al., 2015). PEEX (https://www.atm.helsinki.fi/peex/) is a multidisciplinary, multi-scale bottom-up open scientific initiative. The PEEX approach emphasizes that solving challenges related to climate change, air quality and cryospheric change requires large-scale coordinated co-operation of the international research communities. A scientific workshop was hosted at the Nansen Center (GCR) on 29 the September 2015. The workshop presentations discussed both the large- and small-scale components of the climatology of the high-latitudes. A particular attention has been given to the links between climate scales as well as to the scales shaping the climate impact on society.

Exploration and exploitation of oil and gas reserves of northern West Siberia has promoted rapid industrialization and urban development in the region. This development leaves significant footprints on the sensitive northern environment, which is already stressed by the global warming. This study reports the region-wide changes in the vegetation cover as well as the corresponding changes in and around 28 selected urbanized areas. The study utilizes the normalized difference vegetation index (NDVI) from high-resolution (250 m) MODIS data acquired for summer months (June through August) during 15 years (2000–2014). The results reveal the increase of NDVI (or “greening”) over the northern (tundra and tundra-forest) part of the region. Simultaneously, the southern, forested part shows the widespread decrease of NDVI (or “browning”). These region-wide patterns are, however, highly fragmented. The statistically significant NDVI trends occupy only a small fraction of the region. Urbanization destroys the vegetation cover within the developed areas and at about 5–10 km distance around them. The studied urbanized areas have the NDVI values by 15 % to 45 % lower than the corresponding areas at 20–40 km distance. The largest NDVI reduction is typical for the newly developed areas, whereas the older areas show recovery of the vegetation cover. The study reveals a robust indication of the accelerated greening near the older urban areas. Many Siberian cities become greener even against the wider browning trends at their background. Literature discussion suggests that the observed urban greening could be associated not only with special tending of the within-city green areas but also with the urban heat islands and succession of more productive shrub and tree species growing on warmer sandy soils.

Modern human societies have accumulated considerable power to modify their environment and the earth's system climate as the whole. The most significant environmental changes are found in the urbanized areas. This study considers coherent changes in vegetation productivity and land surface temperature (LST) around four northern West Siberian cities, namely, Tazovsky, Nadym, Noyabrsk and Megion. These cities are located in tundra, forest-tundra, northern taiga and middle taiga bioclimatic zones correspondingly. Our analysis of 15 years (2000–2014) Moderate Resolution Imaging Spectroradiometer (MODIS) data revealed significantly (1.3 °C to 5.2 °C) warmer seasonally averaged LST within the urbanized territories than those of the surrounding landscapes. The magnitude of the urban LST anomaly corresponds to climates found 300–600 km to the South. In the climate change perspective, this magnitude corresponds to the expected regional warming by the middle or the end of the 21 st century. Warmer urban climates, and specifically warmer upper soil layers, can support re-vegetation of the disturbed urban landscapes with more productive trees and tall shrubs. This afforestation is welcome by the migrant city population as it is more consistent with their traditional ecological knowledge. Survival of atypical, southern plant species encourages a number of initiatives and investment to introduce even broader spectrum of temperate blossoming trees and shrubs in urban landscapes. The unintended changes of the urban micro-climates in combination with knowledgeable urban planning could transform the Siberian pioneer settlements into places of belonging.

The degree and spatial distribution of boreal forest ecosystem degradation in Russia are not well known. The objective of this study is to develop an interpretation basis for analysis of satellite remote sensing data using a set of indicators characterizing the ecological situation and the degree of industrial pollution. European Remote Sensing Satellite (ERS) Synthetic Aperture Radar (SAR) and Landsat Multi-Spectral Scanner (MSS) data are used in combination for this purpose, along with an exceptionally extensive in situ data set of ground measurements of spectral radiance of pine biocenose components, and the results of moss chemistry and bio-indicator studies from the ecologically stressed St Petersburg region. It is shown that ERS SAR images provide an assessment of forested area distribution and forest type classification. The main factors of variability in parameters such as Normalized Difference Vegetation Index (NDVI) that are most strongly related to in situ indicators reflecting the state of the forest are identified. A supervised classification of forest degradation was performed on the basis of the NDVI values from the Landsat images. The results obtained make it possible to specify the areas at a local level and perform regional assessments. The potential for multi-temporal ERS SAR and multi-spectral sensor observations to trace the dynamics of changes in forest ecosystems is evaluated.

Exploration and exploitation of oil and gas reserves of northern West Siberia has promoted rapid industrialization and urban development in the region. This development leaves significant footprints on the sensitive northern environment, which is already stressed by the global warming. This study reports the region-wide changes in the vegetation cover as well as the corresponding changes in and around 28 selected urbanized areas. The study utilizes the normalized difference vegetation index (NDVI) from high-resolution (250 m) MODIS data acquired for summer months (June through August) over 15 years (2000–2014). The results reveal the increase of NDVI (or “greening”) over the northern (tundra and tundra-forest) part of the region. Simultaneously, the southern, forested part shows the widespread decrease of NDVI (or “browning”). These region-wide patterns are, however, highly fragmented. The statistically significant NDVI trends occupy only a small fraction of the region. Urbanization destroys the vegetation cover within the developed areas and at about 5–10 km distance around them. The studied urbanized areas have the NDVI values by 15 to 45 % lower than the corresponding areas at 20–40 km distance. The largest NDVI reduction is typical for the newly developed areas, whereas the older areas show recovery of the vegetation cover. The study reveals a robust indication of the accelerated greening near the older urban areas. Many Siberian cities become greener even against the wider browning trends at their background. Literature discussion suggests that the observed urban greening could be associated not only with special tending of the within-city green areas but also with the urban heat islands and succession of more productive shrub and tree species growing on warmer sandy soils.

Studies of the normalized difference vegetation index (NDVI) have found broad changes in vegetation productivity in high northern latitudes in the past decades, including increases in NDVI (‘greening’) in tundra regions and decreases (‘browning’) in forest regions. The causes of these changes are not well understood but have been attributed to a variety of factors.Weuse Moderate Resolution Imaging Spectrometer (MODIS) satellite data for 2000–2014 and focus on northern West Siberia—a hot spot of extensive landcover change due to rapid resource development, geomorphic change, climate change and reindeer grazing. The region is relatively little-studied in terms of vegetation productivity patterns and trends. This study examines changes between and within bioclimatic sub-zones and reveals differences between forest and treeless areas and differences in productivity even down to the tree species level. Our results show that only 18% of the total northern West Siberia area had statistically significant changes in productivity, with 8.4% increasing (greening) and 9.6% decreasing (browning).We find spatial heterogeneity in the trends, and contrasting trends both between and within bioclimatic zones. A key finding is the identification of contrasting trends for different species within the same bioclimatic zone. Browning is most prominent in areas of denser tree coverage, and particularly in evergreen coniferous forest with dark (Picea abie, Picea obovata) or light (Pinus sylvestris) evergreen and evergreen-majority mixed forests. In contrast, low density deciduous needleleaf forest dominated by larch (Larix sibirica), shows a significant increase in productivity, even while neighboring different species show productivity decrease. These results underscore the complexity of the patterns of variability and trends in vegetation productivity, and suggest the need for spatially and thematically detailed studies to better understand the response of different northern forest types and species to climate and environmental change.

Studies of the normalized difference vegetation index (NDVI) have found broad changes in vegetation productivity in high northern latitudes in the past decades, including increases in NDVI ('greening') in tundra regions and decreases ('browning') in forest regions. The causes of these changes are not well understood but have been attributed to a variety of factors. We use Moderate Resolution Imaging Spectrometer (MODIS) satellite data for 2000–2014 and focus on northern West Siberia—a hot spot of extensive landcover change due to rapid resource development, geomorphic change, climate change and reindeer grazing. The region is relatively little-studied in terms of vegetation productivity patterns and trends. This study examines changes between and within bioclimatic sub-zones and reveals differences between forest and treeless areas and differences in productivity even down to the tree species level. Our results show that only 18% of the total northern West Siberia area had statistically significant changes in productivity, with 8.4% increasing (greening) and 9.6% decreasing (browning). We find spatial heterogeneity in the trends, and contrasting trends both between and within bioclimatic zones. A key finding is the identification of contrasting trends for different species within the same bioclimatic zone. Browning is most prominent in areas of denser tree coverage, and particularly in evergreen coniferous forest with dark (Picea abie, Picea obovata) or light (Pinus sylvestris) evergreen and evergreen-majority mixed forests. In contrast, low density deciduous needle-leaf forest dominated by larch (Larix sibirica), shows a significant increase in productivity, even while neighboring different species show productivity decrease. These results underscore the complexity of the patterns of variability and trends in vegetation productivity, and suggest the need for spatially and thematically detailed studies to better understand the response of different northern forest types and species to climate and environmental change.