scholarly journals Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

2017 ◽  
Author(s):  
Jean-Christophe Raut ◽  
Louis Marelle ◽  
Jerome D. Fast ◽  
Jennie L. Thomas ◽  
Bernadett Weinzierl ◽  
...  
Keyword(s):  
Black Carbon ◽  
Biomass Burning ◽  
Forest Fires ◽  
Large Scale ◽  
Large Fraction ◽  
Arctic Region ◽  
Horizontal Resolution ◽  
The Arctic ◽  
Svalbard Archipelago ◽  
Wet Removal

Abstract. During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10 day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6–8 km). A combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations are used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbard archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg−1 . During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TEBC ) in biomass burning plumes is about 60 %, which is impacted by small accumulated precipitation along trajectory (APT) (1 mm). In contrast TEBC is very small (

scholarly journals Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

2017 ◽  
Vol 17 (18) ◽  
pp. 10969-10995 ◽  
Author(s):  
Jean-Christophe Raut ◽  
Louis Marelle ◽  
Jerome D. Fast ◽  
Jennie L. Thomas ◽  
Bernadett Weinzierl ◽  
...  
Keyword(s):  
Black Carbon ◽  
Biomass Burning ◽  
Large Scale ◽  
Arctic Region ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Convective Precipitation ◽  
Svalbard Archipelago ◽  
Wet Removal ◽  
The Arctic Region

Abstract. During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10-day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6–8 km). A combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations is used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbard archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg−1. During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TEBC) in biomass burning plumes was larger (60 %), because it was impacted by small accumulated precipitation along trajectory (1 mm). In contrast TEBC was small (< 30 %) and accumulated precipitation amounts were larger (5–10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in northern Russia, resulting in transport to lower altitudes. TEBC due to large-scale precipitation is responsible for a sharp meridional gradient in the distribution of BC concentrations. Wet removal in cumulus clouds is the cause of modeled vertical gradient of TEBC, especially in the mid-latitudes, reflecting the distribution of convective precipitation, but is dominated in the Arctic region by the large-scale wet removal associated with the formation of stratocumulus clouds in the planetary boundary layer (PBL) that produce frequent drizzle.

scholarly journals Black Carbon Emissions from the Siberian Fires 2019: Modelling of the Atmospheric Transport and Possible Impact on the Radiation Balance in the Arctic Region

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 814
Author(s):  
Sergey Kostrykin ◽  
Anastasia Revokatova ◽  
Alexey Chernenkov ◽  
Veronika Ginzburg ◽  
Polina Polumieva ◽  
...  
Keyword(s):  
Black Carbon ◽  
Forest Fires ◽  
Radiative Forcing ◽  
Climate Model ◽  
Arctic Region ◽  
The Arctic ◽  
Radiation Balance ◽  
Climatic Effects ◽  
Fire Emissions ◽  
Trajectory Model

The work is devoted to the study of the climatic effects of black carbon (BC) transferred from forest fires to the Arctic zone. The HYSPLIT (The Hybrid Single-Particle Lagrangian Integrated Trajectory model) trajectory model was used to initially assess the potential for particle transport from fires. The results of the trajectory analysis of the 2019 fires showed that the probability of the transfer of particles to the Arctic ranges from 1% to 10%, and in some cases increases to 20%. Detailed studies of the possible influence of BC ejected as a result of fires became possible by using the climate model of the INMCM5 (Institute of Numerical Mathematics Climate Model). The results of the numerical experiments have shown that the maximum concentration of BC in the Arctic atmosphere is observed in July and August and is associated with emissions from fires. The deposition of BC in the Arctic increases by about 1.5–2 times in the same months, in comparison with simulation without forest fire emissions. This caused an average decrease in solar radiation forcing of 0.3–0.4 Wt/m2 and an increase in atmospheric radiation heating of up to 5–6 Wt/m2. To assess the radiation forcing from BC contaminated snow, we used the dependences of the change in the snow albedo on the snow depth, and the albedo of the underlying surface for a given amount of BC fallen on the snow. These dependences were constructed on the basis of the SNICAR (Snow, Ice, and Aerosol Radiative) model. According to our calculations, the direct radiative forcing from BC in the atmosphere with a clear sky is a maximum of 4–5 W/m2 in July and August.

Estimation of possible impact of black carbon emissions from 2019 large Siberian forest wildfires on the Arctic region

2020 ◽  
Author(s):  
Veronika Ginzburg ◽  
Sergey Kostrikin ◽  
Vladimir Korotkov ◽  
Anastasia Revokatovа ◽  
Polina Polumieva ◽  
...  
Keyword(s):  
Black Carbon ◽  
Forest Fires ◽  
Climate Model ◽  
Arctic Region ◽  
The Arctic ◽  
Fire Event ◽  
Greenhouse Gas Inventories ◽  
Ice Surface ◽  
Ipcc Guidelines ◽  
National Greenhouse Gas Inventories

&lt;p&gt;The presented study is aimed to estimate the probability of black carbon transportation from large forest wildfires in Russian boreal taiga occurred in the summer 2019 to Arctic region and to estimate its deposition to ice surface and contribution to shortwave radiative forcing.&lt;/p&gt;&lt;p&gt;The extreme forest fires were observed in 2019 over the territories of Krasnoyarskiy region and Yakutia republic. The Russian Informational Remote monitoring System of the Federal Forestry Agency provides data on the areas of forest lands damaged by different types of fires. These data were used to choose ten most intensive and ten most continuous fires for each region. Estimation of fuel mass available for combustion including biomass, litter and deadwood were made using the growing stock data of the State Forestry Register differentiated for the regions of the Russian Federation applying country specific conversion coefficients [Schepaschenko et al. 2018]. Emission of black carbon from forest fires was carried out using the methodology and combustion coefficients from the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the coefficient of black carbon emissions from Akagi et al. [2011].&lt;/p&gt;&lt;p&gt;The main factor determining the transfer of particles is the synoptic situation. Blocking anticyclones and cyclonic series affects the circulation regime and conditions for the transport of particles to the Arctic. For these regions climatic frequency of occurrence of Southern and South-Western winds in summer is about 30-40%. The probability of atmospheric trajectory transfer from each chosen fire event to the Arctic region was estimated by the trajectory model HYSPLIT, also real synoptic data for each chosen fire event were used to analyze the probability of emission cloud transfer to northern latitudes.&lt;/p&gt;&lt;p&gt;The black carbon effect including concentrations in the atmosphere, deposition on the ice surface, modification of surface albedo in the ice region of Arctic and influence of additional radiation forcing associated with BC emissions from forest fires were estimates using the climate model INMCM5 [Volodin et a.l., 2017]. Aerosol sources, advection, gravitational sedimentation, surface absorption, and scavenging by precipitation are taken into account to compute aerosol concentration variations. Radiation forcing caused by BC emission from forest fires was calculated using the SNICAR model.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;The study is supported by RFBR project No.18-05-60183.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;REFERENCES&lt;/p&gt;&lt;p&gt;Volodin E. M., Mortikov E. V., Kostrykin S. V., Galin V. Ya., Lykossov V. N., Gritsun A.S., Diansky N. A., Gusev A. V., Yakovlev N.G. Simulation of the present-day climate with the climate model INMCM5, Climate Dynamics, 2017, doi:10.1007/s00382-017-3539-7.&lt;/p&gt;&lt;p&gt;2006 IPCC Guidelines for National Greenhouse Gas Inventories, Vol. 4: Agriculture, Forestry and Other Land Use (IPCC, 2006&lt;/p&gt;&lt;p&gt;K. Akagi, R. J. Yokelson, C. Wiedinmyer, M. J. Alvarado, J. S. Reid, T. Karl, J. D. Crounse, and P. O. Wennberg, &amp;#8220;Emission factors for open and domestic biomass burning for use in atmospheric models,&amp;#8221; Atmos. Chem. Phys. 11 (9), 4039&amp;#8211;4072 (2011).&lt;/p&gt;&lt;p&gt;Schepaschenko D., Moltchanova E., Shvidenko A., Blyshchyk V., Dmitriev E., Martynenko O., See L., Kraxner F. (2018) Improved Estimates of Biomass Expansion Factors for Russian Forests // Forests. &amp;#8211; 9, 312. P. 1-23. &amp;#8211; https://doi.org/10.3390/f9060312&lt;/p&gt;

Global mapping of seasonal variations in tides from tide gauge and satellite altimeter data

2021 ◽  
Author(s):  
Inger Bij de Vaate ◽  
Henrique Guarneri ◽  
Cornelis Slobbe ◽  
Martin Verlaan
Keyword(s):  
Seasonal Variation ◽  
Sea Level ◽  
Seasonal Variations ◽  
Large Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Altimeter Data ◽  
Tide Gauges ◽  
Tidal Constituents ◽  
The Arctic Region

&lt;p&gt;The existence of seasonal variations in major tides has been recognized since decades. Where Corkan (1934) was the first to describe the seasonal perturbation of the M2 tide, many others have studied seasonal variations in the main tidal constituents since. However, most of these studies are based on sea level observations from tide gauges and are often restricted to coastal and shelf regions. Hence, observed seasonal variations are typically dominated by local processes and the large-scale patterns cannot be clearly distinguished. Moreover, most tide models still perceive tides as annually constant and seasonal variation in tides is ignored in the correction process of satellite altimetry. This results in reduced accuracy of obtained sea level anomalies. &lt;/p&gt;&lt;p&gt;To gain more insight in the large-scale seasonal variations in tides, we supplemented the clustered and sparsely distributed sea level observations from tide gauges by the wealth of data from satellite altimeters. Although altimeter-derived water levels are being widely used to obtain tidal constants, only few of these implementations consider seasonal variation in tides. For that reason, we have set out to explore the opportunities provided by altimeter data for deriving seasonal modulation of the main tidal constituents. Different methods were implemented and compared for the principal tidal constituents and a range of geographical domains, using data from a selection of satellite altimeters. Specific attention was paid to the Arctic region where seasonal variation in tides was expected to be significant as a result of the seasonal sea ice cycle, yet data availability is particularly limited. Our study demonstrates the potential of satellite altimetry for the quantification of seasonal modulation of tides and suggests the seasonal modulation to be considerable. Already for M2 we observed changes in tidal amplitude of the order of decimeters for the Arctic region, and centimeters for lower latitude regions.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;div&gt;Corkan, R. H. (1934). An annual perturbation in the range of tide. &lt;em&gt;Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character&lt;/em&gt;, &lt;em&gt;144&lt;/em&gt;(853), 537-559.&lt;/div&gt;

scholarly journals Multilevel Cloud Structures over Svalbard

2017 ◽  
Vol 145 (4) ◽  
pp. 1149-1159 ◽  
Author(s):  
Andreas Dörnbrack ◽  
Sonja Gisinger ◽  
Michael C. Pitts ◽  
Lamont R. Poole ◽  
Marion Maturilli
Keyword(s):  
Large Scale ◽  
Wave Structure ◽  
Horizontal Resolution ◽  
Temperature Fields ◽  
The Arctic ◽  
Mountain Waves ◽  
Air Masses ◽  
Flow Features ◽  
Stratospheric Clouds ◽  
Lidar Observations

Abstract The presented picture of the month is a superposition of spaceborne lidar observations and high-resolution temperature fields of the ECMWF Integrated Forecast System (IFS). It displays complex tropospheric and stratospheric clouds in the Arctic winter of 2015/16. Near the end of December 2015, the unusual northeastward propagation of warm and humid subtropical air masses as far north as 80°N lifted the tropopause by more than 3 km in 24 h and cooled the stratosphere on a large scale. A widespread formation of thick cirrus clouds near the tropopause and of synoptic-scale polar stratospheric clouds (PSCs) occurred as the temperature dropped below the thresholds for the existence of cloud particles. Additionally, mountain waves were excited by the strong flow at the western edge of the ridge across Svalbard, leading to the formation of mesoscale ice PSCs. The most recent IFS cycle using a horizontal resolution of 8 km globally reproduces the large-scale and mesoscale flow features and leads to a remarkable agreement with the wave structure revealed by the spaceborne observations.

scholarly journals Reviews and syntheses: Arctic fire regimes and emissions in the 21st century

2021 ◽  
Vol 18 (18) ◽  
pp. 5053-5083
Author(s):  
Jessica L. McCarty ◽  
Juha Aalto ◽  
Ville-Veikko Paunu ◽  
Steve R. Arnold ◽  
Sabine Eckhardt ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Black Carbon ◽  
Biomass Burning ◽  
Fire Regimes ◽  
Future Climate ◽  
The Arctic ◽  
Future Climate Change ◽  
Fire Emissions ◽  
Extreme Fire

Abstract. In recent years, the pan-Arctic region has experienced increasingly extreme fire seasons. Fires in the northern high latitudes are driven by current and future climate change, lightning, fuel conditions, and human activity. In this context, conceptualizing and parameterizing current and future Arctic fire regimes will be important for fire and land management as well as understanding current and predicting future fire emissions. The objectives of this review were driven by policy questions identified by the Arctic Monitoring and Assessment Programme (AMAP) Working Group and posed to its Expert Group on Short-Lived Climate Forcers. This review synthesizes current understanding of the changing Arctic and boreal fire regimes, particularly as fire activity and its response to future climate change in the pan-Arctic have consequences for Arctic Council states aiming to mitigate and adapt to climate change in the north. The conclusions from our synthesis are the following. (1) Current and future Arctic fires, and the adjacent boreal region, are driven by natural (i.e. lightning) and human-caused ignition sources, including fires caused by timber and energy extraction, prescribed burning for landscape management, and tourism activities. Little is published in the scientific literature about cultural burning by Indigenous populations across the pan-Arctic, and questions remain on the source of ignitions above 70∘ N in Arctic Russia. (2) Climate change is expected to make Arctic fires more likely by increasing the likelihood of extreme fire weather, increased lightning activity, and drier vegetative and ground fuel conditions. (3) To some extent, shifting agricultural land use and forest transitions from forest–steppe to steppe, tundra to taiga, and coniferous to deciduous in a warmer climate may increase and decrease open biomass burning, depending on land use in addition to climate-driven biome shifts. However, at the country and landscape scales, these relationships are not well established. (4) Current black carbon and PM2.5 emissions from wildfires above 50 and 65∘ N are larger than emissions from the anthropogenic sectors of residential combustion, transportation, and flaring. Wildfire emissions have increased from 2010 to 2020, particularly above 60∘ N, with 56 % of black carbon emissions above 65∘ N in 2020 attributed to open biomass burning – indicating how extreme the 2020 wildfire season was and how severe future Arctic wildfire seasons can potentially be. (5) What works in the boreal zones to prevent and fight wildfires may not work in the Arctic. Fire management will need to adapt to a changing climate, economic development, the Indigenous and local communities, and fragile northern ecosystems, including permafrost and peatlands. (6) Factors contributing to the uncertainty of predicting and quantifying future Arctic fire regimes include underestimation of Arctic fires by satellite systems, lack of agreement between Earth observations and official statistics, and still needed refinements of location, conditions, and previous fire return intervals on peat and permafrost landscapes. This review highlights that much research is needed in order to understand the local and regional impacts of the changing Arctic fire regime on emissions and the global climate, ecosystems, and pan-Arctic communities.

scholarly journals Climate change and forest management affect forest fire risk in Fennoscandia

2021 ◽  
Author(s):  
Keyword(s):  
Climate Change ◽  
Forest Management ◽  
Black Carbon ◽  
Forest Fire ◽  
Forest Fires ◽  
Fire Risk ◽  
The Arctic ◽  
Large Fires ◽  
Forest Fire Risk ◽  
Fire Ignition

Forest and wildland fires are a natural part of ecosystems worldwide, but large fires in particular can cause societal, economic and ecological disruption. Fires are an important source of greenhouse gases and black carbon that can further amplify and accelerate climate change. In recent years, large forest fires in Sweden demonstrate that the issue should also be considered in other parts of Fennoscandia. This final report of the project “Forest fires in Fennoscandia under changing climate and forest cover (IBA ForestFires)” funded by the Ministry for Foreign Affairs of Finland, synthesises current knowledge of the occurrence, monitoring, modelling and suppression of forest fires in Fennoscandia. The report also focuses on elaborating the role of forest fires as a source of black carbon (BC) emissions over the Arctic and discussing the importance of international collaboration in tackling forest fires. The report explains the factors regulating fire ignition, spread and intensity in Fennoscandian conditions. It highlights that the climate in Fennoscandia is characterised by large inter-annual variability, which is reflected in forest fire risk. Here, the majority of forest fires are caused by human activities such as careless handling of fire and ignitions related to forest harvesting. In addition to weather and climate, fuel characteristics in forests influence fire ignition, intensity and spread. In the report, long-term fire statistics are presented for Finland, Sweden and the Republic of Karelia. The statistics indicate that the amount of annually burnt forest has decreased in Fennoscandia. However, with the exception of recent large fires in Sweden, during the past 25 years the annually burnt area and number of fires have been fairly stable, which is mainly due to effective fire mitigation. Land surface models were used to investigate how climate change and forest management can influence forest fires in the future. The simulations were conducted using different regional climate models and greenhouse gas emission scenarios. Simulations, extending to 2100, indicate that forest fire risk is likely to increase over the coming decades. The report also highlights that globally, forest fires are a significant source of BC in the Arctic, having adverse health effects and further amplifying climate warming. However, simulations made using an atmospheric dispersion model indicate that the impact of forest fires in Fennoscandia on the environment and air quality is relatively minor and highly seasonal. Efficient forest fire mitigation requires the development of forest fire detection tools including satellites and drones, high spatial resolution modelling of fire risk and fire spreading that account for detailed terrain and weather information. Moreover, increasing the general preparedness and operational efficiency of firefighting is highly important. Forest fires are a large challenge requiring multidisciplinary research and close cooperation between the various administrative operators, e.g. rescue services, weather services, forest organisations and forest owners is required at both the national and international level.

scholarly journals Sources of Springtime Surface Black Carbon in the Arctic: An Adjoint Analysis

2017 ◽  
Author(s):  
Ling Qi ◽  
Qinbin Li ◽  
Daven K. Henze ◽  
Hsien-Liang Tseng ◽  
Cenlin He
Keyword(s):  
Natural Gas ◽  
Black Carbon ◽  
Biomass Burning ◽  
Transport Model ◽  
Lower Troposphere ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Anthropogenic Source ◽  
Gas Flaring ◽  
Arctic Front

Abstract. We quantify source contributions to springtime (April 2008) surface black carbon (BC) in the Arctic by interpreting surface observations of BC at five receptor sites (Denali, Barrow, Alert, Zeppelin, and Summit) using a global chemical transport model (GEOS-Chem) and its adjoint. Contributions to BC at Barrow, Alert, and Zeppelin are dominated by Asian anthropogenic sources (40–43 %) before April 18 and by Siberian open biomass burning emissions (29–41 %) afterward. In contrast, Summit, a mostly free tropospheric site, has predominantly an Asian anthropogenic source contribution (24–68 %, with an average of 45 %). We compute the adjoint sensitivity of BC concentrations at the five sites during a pollution episode (April 20–25) to global emissions from March 1 to April 25. The associated contributions are the combined results of these sensitivities and BC emissions. Local and regional anthropogenic sources in Alaska are the largest anthropogenic sources of BC at Denali (63 %), and natural gas flaring emissions in the Western Extreme North of Russia (WENR) are the largest anthropogenic sources of BC at Zeppelin (26 %) and Alert (13 %). We find that long-range transport of emissions from Beijing-Tianjin-Hebei (also known as Jing-Jin-Ji), the biggest urbanized region in Northern China, contribute significantly (~ 10 %) to surface BC across the Arctic. On average it takes ~ 12 days for Asian anthropogenic emissions and Siberian biomass burning emissions to reach Arctic lower troposphere, supporting earlier studies. Natural gas flaring emissions from the WENR reach Zeppelin in about a week. We find that episodic, direct transport events dominate BC at Denali (87 %), a site outside the Arctic front, a strong transport barrier. The relative contribution of direct transport to surface BC within the Arctic front is much smaller (~ 50 % at Barrow and Zeppelin and ~ 10 % at Alert). The large contributions from Asian anthropogenic sources are predominately in the form of ‘chronic’ pollution (~ 40 % at Barrow and 65 % at Alert and 57 % at Zeppelin) on 1–2 month timescales. As such, it is likely that previous studies using 5- or 10-day trajectory analyses strongly underestimated the contribution from Asia to surface BC in the Arctic. Both finer temporal resolution of biomass burning emissions and accounting for the Wegener-Bergeron-Findeisen (WBF) process in wet scavenging improve the source attribution estimates.

scholarly journals Increase in Aerosol Black Carbon in the 2000s over Ny-Ålesund in the Summer

2015 ◽  
Vol 73 (1) ◽  
pp. 251-262 ◽  
Author(s):  
Liqi Chen ◽  
Wei Li ◽  
Jianqiong Zhan ◽  
Jianjun Wang ◽  
Yuanhui Zhang ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Black Carbon ◽  
Atmospheric Circulation ◽  
Yellow River ◽  
The Arctic ◽  
Radiative Energy ◽  
Back Trajectory ◽  
Significant Implication ◽  
Svalbard Archipelago ◽  
Local Emissions

Abstract To investigate the concentrations, sources, and temporal variations of atmospheric black carbon (BC) in the summer Arctic, routine ground-level observations of BC by optical absorption were made in the summer from 2005 to 2008 at the Chinese Arctic “Yellow River” Station (78°55′N, 11°56′E) at Ny-Ålesund on the island of Spitsbergen in the Svalbard Archipelago. Methods of the ensemble empirical-mode decomposition analysis and back-trajectory analysis were employed to assess temporal variation embedded in the BC datasets and airmass transport patterns. The 10th-percentile and median values of BC concentrations were 7.2 and 14.6 ng m−3, respectively, and hourly average BC concentrations ranged from 2.5 to 54.6 ng m−3. A gradual increase was found by 4 ng m−3 a−1. This increase was not seen in the Zeppelin Station and it seemed to contrast with the prevalent conception of generally decreasing BC concentration since 1989 in the Arctic. Factors responsible for this increase such as changes in emissions and atmospheric transport were taken into consideration. The result indicated that BC from local emissions was mostly responsible for the observed increase from 2005 to 2008. BC temporal variation in the summer was controlled by the atmospheric circulation, which presented a significant 6–14-day variation and coherent with 1–3- and 2–5-day and longer cycle variation. Although the atmospheric circulation changes from 2005 to 2008, there was not a marked trend in long-range transportation of BC. This study suggested that local emissions might have significant implication for the regional radiative energy balance at Ny-Ålesund.

The Frontier Research System for Global Change—The International Arctic Research Center (Frontier-IARC): its Origin and Tentative Science Plan

1999 ◽  
Vol 33 (1) ◽  
pp. 81-84
Author(s):  
Jinro Ukila ◽  
Moloyoshi Ikeda
Keyword(s):  
Climate Change ◽  
Global Change ◽  
Global Climate Change ◽  
Large Scale ◽  
Global Climate ◽  
Research Effort ◽  
Arctic Region ◽  
Research Center ◽  
The Arctic ◽  
Research System

The Frontier Research System for Global Change—the International Arctic Research Center (Frontier-IARC) is a research program funded by the Frontier Research System for Global Change. The program is jointly run under a cooperative agreement between the Frontier Research System for Global Change and the University of Alaska Fairbanks. The aim of the program is to understand the role of the Arctic region in global climate change. The program concentrates its research effort initially on the areas of air-sea-ice interactions, bio-geochemical processes and the ecosystem. To understand the arctic climate system in the context of global climate change, we focus on mechanisms controlling arctic-subarctic interactions, and identify three key components: the freshwater balance, the energy balance, and the large-scale atmospheric processes. Knowledge of details of these components and their interactions will be gained through long-term monitoring, process studies, and modeling; our focus will be on the latter two categories.

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