1 Introduction
The Arctic region is especially sensitive to climate change and its climate is
modulated, in part, by atmospheric aerosols that affect the distribution of radiative
energy passing through the atmosphere (Rozwadowska and Górecka 2012).
Aerosols affect the surface-atmosphere radiation balance directly through interactions with solar and terrestrial radiation and indirectly through interactions with
cloud particles. In Polar regions, where the surface albedo can exceed 0.85 (in VIS)
in snow and ice covered areas, aerosols may cause significant warming at the
ground (Tomasi et al. 2007; Engvall et al. 2008). While such effects are due mainly
to the direct scattering and absorption of incoming solar radiation, exchanges of
thermal radiation between the surface and the atmosphere enhance heating below
aerosol layers (Stohl 2006; Fisher et al. 2010).
Atmospheric aerosols originate from a wide variety of sources in both marine
and continental environments and their content varies significantly depending upon
the air mass source and history (Petelski et al. 2014). These species are, in general,
poorly accounted for in climate models. Better quantification of the radiative
forcing by different types of aerosol is needed to improve predictions of future
climate (Brock et al. 2011).
During the last century the temperature increase in the Arctic has been observed
to be larger than the global average (IPCC 2013). The reason for this “Arctic
amplification” relates to both the complex feedbacks that are active in the Arctic
environment as well as the overall environmental conditions that are characteristic
of the Arctic environment (Quinn et al. 2007). This increased warming results in
positive feedback which further impacts the radiative balance via reduced surface
albedo (Hudson 2011). Future changes in the Arctic are projected to progress
rapidly and the projections show that the Arctic Ocean may be seasonally ice free in
the next several decades. This will result in a more pronounced impact on atmospheric aerosol sources and sinks and on cloud properties and their distribution in
the area (Petelski and Piskozub 2006).
Methods commonly used for monitoring atmospheric pollution (including
aerosols) are optical ones, which collect data from a given point or a small area
(Labow 1996; Dixon 1998; Drollette 2000; Smirnov et al. 2002). Studies using
ground-based sun photometry are very effective in investigations of aerosol optical
properties. Aerosol optical depth measured at different wavelengths is one of the
key parameters in aerosol studies (Dubovik et al. 2002; Zielinski 2004; Markowicz
et al. 2008; Mazzola et al. 2012; Zielinski et al. 2012). Also satellite remote sensing
is a good approach to obtain the aerosol information over the Arctic region, for
which appropriate aerosol models are required.
In this paper we describe the aerosol optical depth and Ångström exponent
values measured at three locations in Spitsbergen. These stations include Hornsund
in the south of the island, Longyearbyen in the center of the island and Ny-Alesund,
in the north.
24
P. Pakszys et al.
The Arctic region is especially sensitive to climate change and its climate is
modulated, in part, by atmospheric aerosols that affect the distribution of radiative
energy passing through the atmosphere (Rozwadowska and Górecka 2012).
Aerosols affect the surface-atmosphere radiation balance directly through interactions with solar and terrestrial radiation and indirectly through interactions with
cloud particles. In Polar regions, where the surface albedo can exceed 0.85 (in VIS)
in snow and ice covered areas, aerosols may cause significant warming at the
ground (Tomasi et al. 2007; Engvall et al. 2008). While such effects are due mainly
to the direct scattering and absorption of incoming solar radiation, exchanges of
thermal radiation between the surface and the atmosphere enhance heating below
aerosol layers (Stohl 2006; Fisher et al. 2010).
Atmospheric aerosols originate from a wide variety of sources in both marine
and continental environments and their content varies significantly depending upon
the air mass source and history (Petelski et al. 2014). These species are, in general,
poorly accounted for in climate models. Better quantification of the radiative
forcing by different types of aerosol is needed to improve predictions of future
climate (Brock et al. 2011).
During the last century the temperature increase in the Arctic has been observed
to be larger than the global average (IPCC 2013). The reason for this “Arctic
amplification” relates to both the complex feedbacks that are active in the Arctic
environment as well as the overall environmental conditions that are characteristic
of the Arctic environment (Quinn et al. 2007). This increased warming results in
positive feedback which further impacts the radiative balance via reduced surface
albedo (Hudson 2011). Future changes in the Arctic are projected to progress
rapidly and the projections show that the Arctic Ocean may be seasonally ice free in
the next several decades. This will result in a more pronounced impact on atmospheric aerosol sources and sinks and on cloud properties and their distribution in
the area (Petelski and Piskozub 2006).
Methods commonly used for monitoring atmospheric pollution (including
aerosols) are optical ones, which collect data from a given point or a small area
(Labow 1996; Dixon 1998; Drollette 2000; Smirnov et al. 2002). Studies using
ground-based sun photometry are very effective in investigations of aerosol optical
properties. Aerosol optical depth measured at different wavelengths is one of the
key parameters in aerosol studies (Dubovik et al. 2002; Zielinski 2004; Markowicz
et al. 2008; Mazzola et al. 2012; Zielinski et al. 2012). Also satellite remote sensing
is a good approach to obtain the aerosol information over the Arctic region, for
which appropriate aerosol models are required.
In this paper we describe the aerosol optical depth and Ångström exponent
values measured at three locations in Spitsbergen. These stations include Hornsund
in the south of the island, Longyearbyen in the center of the island and Ny-Alesund,
in the north.
24
P. Pakszys et al.