the chemical and physical transformation during their lifetime. Aerosol sources are
numerous and can be of natural or anthropogenic origin. They can occur in the
atmosphere as particles (primary aerosols) or can be formed in the atmosphere
from their precursors in the gas phase through physical and chemical reactions
(secondary aerosol formation). Physical processes, in particular the vertical transport and removal of particles by dry deposition to the surface, depend on particle
size and thus their deposition velocity. Very small particles are involved in the
processes of growth by condensation and coagulation. Their atmospheric transport
is based on turbulence and Brownian diffusion. Very large particles are subject to
gravitational forces resulting in rapid sedimentation. These processes, plus the
formation by direct emission and secondary formation, chemical transformations
and in-cloud processing, have decisive influence on the number concentrations of
aerosol particles. These concentrations differ by 10 orders of magnitude.
Aerosol particle size is one of the fundamental quantities needed to determine
the role of aerosols in climate forcing, modifying the hydrological cycle, and
affecting human health and to separate natural from man-made aerosol components
(Viana et al. 2014). Information on aerosol sizes is retrieved from remote-sensing
instruments including satellite sensors such as Moderate Resolution Imaging
Spectroradiometer (MODIS) and ground-based radiometers such as Aerosol
Robotic Network (AERONET) (Kleidman et al. 2005; Christopher et al. 2006; Yu
et al. 2009). The role of aerosols in climate change from the regional perspective is
described in the paper by Strzalkowska et al., while Pakszys et al. write about the
climate implications connected with the Arctic aerosols. Markuszewski, on the
other hand, pays attention to the quantification of the role of sea salt aerosols.
Climate changes influence largely the biogeochemical cycles in the marine
environment. Among the most important, climate related drivers affecting dynamics
and structure of the biogeochemical processes are: temperature increase, changes in
the atmospheric circulation and hydrological regimes, intensification of storm surges
etc. (Emerson and Hedges 2008; IPCC 2013). Observed (and predicted in the future)
increase of seawater temperature affects directly many biogeochemical processes
taking place in seawater, usually by accelerating them. The good example is respiration, which, to some degree, is directly proportional to the temperature. Seawater
temperature is responsible also for the solubility of gaseous substances, e.g. those
crucial for marine biota: O 2 and CO 2 . CO 2 being product of respiration and substrate
in photosynthesis is at the same time one of the most important drivers of present
climate changes. Moreover, CO 2 behaves like a weak acid in seawater and thus
contributes to pH—an important factor controlling number of biogeochemical cycles
and determining existence and functioning of marine organisms. As a consequence,
there is a complex net of feedback mechanisms between climate changes and their
effects and biogeochemical functioning of the marine ecosystems. This example
indicates that there is a need for more holistic approaches in studying marine environment in the context of climate and global changes (Emerson and Hedges 2008).
Another consequence of climate changes for marine biogeochemistry are regional
shifts in hydrological regimes (Dragoni and Sukhija 2008). Since water is the major
medium for transportation of chemical substances, changes in precipitation (in both
Introduction
3
numerous and can be of natural or anthropogenic origin. They can occur in the
atmosphere as particles (primary aerosols) or can be formed in the atmosphere
from their precursors in the gas phase through physical and chemical reactions
(secondary aerosol formation). Physical processes, in particular the vertical transport and removal of particles by dry deposition to the surface, depend on particle
size and thus their deposition velocity. Very small particles are involved in the
processes of growth by condensation and coagulation. Their atmospheric transport
is based on turbulence and Brownian diffusion. Very large particles are subject to
gravitational forces resulting in rapid sedimentation. These processes, plus the
formation by direct emission and secondary formation, chemical transformations
and in-cloud processing, have decisive influence on the number concentrations of
aerosol particles. These concentrations differ by 10 orders of magnitude.
Aerosol particle size is one of the fundamental quantities needed to determine
the role of aerosols in climate forcing, modifying the hydrological cycle, and
affecting human health and to separate natural from man-made aerosol components
(Viana et al. 2014). Information on aerosol sizes is retrieved from remote-sensing
instruments including satellite sensors such as Moderate Resolution Imaging
Spectroradiometer (MODIS) and ground-based radiometers such as Aerosol
Robotic Network (AERONET) (Kleidman et al. 2005; Christopher et al. 2006; Yu
et al. 2009). The role of aerosols in climate change from the regional perspective is
described in the paper by Strzalkowska et al., while Pakszys et al. write about the
climate implications connected with the Arctic aerosols. Markuszewski, on the
other hand, pays attention to the quantification of the role of sea salt aerosols.
Climate changes influence largely the biogeochemical cycles in the marine
environment. Among the most important, climate related drivers affecting dynamics
and structure of the biogeochemical processes are: temperature increase, changes in
the atmospheric circulation and hydrological regimes, intensification of storm surges
etc. (Emerson and Hedges 2008; IPCC 2013). Observed (and predicted in the future)
increase of seawater temperature affects directly many biogeochemical processes
taking place in seawater, usually by accelerating them. The good example is respiration, which, to some degree, is directly proportional to the temperature. Seawater
temperature is responsible also for the solubility of gaseous substances, e.g. those
crucial for marine biota: O 2 and CO 2 . CO 2 being product of respiration and substrate
in photosynthesis is at the same time one of the most important drivers of present
climate changes. Moreover, CO 2 behaves like a weak acid in seawater and thus
contributes to pH—an important factor controlling number of biogeochemical cycles
and determining existence and functioning of marine organisms. As a consequence,
there is a complex net of feedback mechanisms between climate changes and their
effects and biogeochemical functioning of the marine ecosystems. This example
indicates that there is a need for more holistic approaches in studying marine environment in the context of climate and global changes (Emerson and Hedges 2008).
Another consequence of climate changes for marine biogeochemistry are regional
shifts in hydrological regimes (Dragoni and Sukhija 2008). Since water is the major
medium for transportation of chemical substances, changes in precipitation (in both
Introduction
3