390
G. Kallos et al.
winds over waves. Different wave characteristics have an influence in surface winds,
with an imposed oceanic drag expressed as sea surface roughness.
Thermodynamical processes, involve heat exchanges between the air and water
surfaces and moisture transfers, expressing condensation and evaporation. Additionally, due to wave breaking and bubble bursting sea droplets and aerosols appear in
the air surface above sea. Sea spray participates in the thermodynamic system of
the air-sea interface zone through the exchange of heat and moisture between water
droplets emerged in the lower atmosphere and the surrounding air. The release of
sea droplets leads to a moistening of the near sea surface air and adds heat into the
atmosphere. These thermodynamical interactions are expressed as heat fluxes. The
effects influence temperature and moisture profiles near sea surface. This can alter
buoyancy which affects non-linearly the near surface wind patterns [4].
Concurrently, the particles formed in the sea surface, noted as sea salt aerosols,
have a significant impact on various processes of the marine atmosphere. This consists
of interaction with short and long wave radiation, the role of CCN influencing marine
clouds and further climate effects. The production, concentration, transportation and
time scales in which sea salt particles remain in the atmosphere are highly depended
on the prevailing atmospheric-wave characteristics.
For the description of the air-sea environment all the aforementioned processes are
essential and necessary. The strength of links and feedback between atmosphere and
ocean might deviate based on the meteorological conditions and the characteristics
of the area where those occur. The air-sea interaction mechanisms lead to a cascade
of effects in several meteorological features. This work focuses on investigating
the role of mechanical and thermodynamical air-sea interaction processes in marine
boundary layer and their feedback effects in sea salt aerosols.
62.2 Models and Methodology
To model efficiently the dynamical processes taking part in the air-sea regime, a
combination of an atmospheric with a wave model is used. The RAMS/ICLAMS
model [5] is interfaced with the WAM wave model under the OASIS-MCT coupler,
used for communication. Parameterizations for sea surface roughness, sea spray
fluxes and salt production are implemented. Precisely, sea surface conditions are
considered in the atmospheric model by the dynamic sea surface roughness with
Charnock parameter z ch given by the fraction of wave induced stress τ w with the total
stress τ , as described in [3]. Sea spray fluxes derive from the difference in temperature
and specific humidity, between the lifted water droplets and the surrounding air. In
the current work, the sea spray model method described in [1], has been adopted.
For sea salt production, a whitecap fraction parameterization is employed based on
surface wind speed and relative humidity [2].
G. Kallos et al.
winds over waves. Different wave characteristics have an influence in surface winds,
with an imposed oceanic drag expressed as sea surface roughness.
Thermodynamical processes, involve heat exchanges between the air and water
surfaces and moisture transfers, expressing condensation and evaporation. Additionally, due to wave breaking and bubble bursting sea droplets and aerosols appear in
the air surface above sea. Sea spray participates in the thermodynamic system of
the air-sea interface zone through the exchange of heat and moisture between water
droplets emerged in the lower atmosphere and the surrounding air. The release of
sea droplets leads to a moistening of the near sea surface air and adds heat into the
atmosphere. These thermodynamical interactions are expressed as heat fluxes. The
effects influence temperature and moisture profiles near sea surface. This can alter
buoyancy which affects non-linearly the near surface wind patterns [4].
Concurrently, the particles formed in the sea surface, noted as sea salt aerosols,
have a significant impact on various processes of the marine atmosphere. This consists
of interaction with short and long wave radiation, the role of CCN influencing marine
clouds and further climate effects. The production, concentration, transportation and
time scales in which sea salt particles remain in the atmosphere are highly depended
on the prevailing atmospheric-wave characteristics.
For the description of the air-sea environment all the aforementioned processes are
essential and necessary. The strength of links and feedback between atmosphere and
ocean might deviate based on the meteorological conditions and the characteristics
of the area where those occur. The air-sea interaction mechanisms lead to a cascade
of effects in several meteorological features. This work focuses on investigating
the role of mechanical and thermodynamical air-sea interaction processes in marine
boundary layer and their feedback effects in sea salt aerosols.
62.2 Models and Methodology
To model efficiently the dynamical processes taking part in the air-sea regime, a
combination of an atmospheric with a wave model is used. The RAMS/ICLAMS
model [5] is interfaced with the WAM wave model under the OASIS-MCT coupler,
used for communication. Parameterizations for sea surface roughness, sea spray
fluxes and salt production are implemented. Precisely, sea surface conditions are
considered in the atmospheric model by the dynamic sea surface roughness with
Charnock parameter z ch given by the fraction of wave induced stress τ w with the total
stress τ , as described in [3]. Sea spray fluxes derive from the difference in temperature
and specific humidity, between the lifted water droplets and the surrounding air. In
the current work, the sea spray model method described in [1], has been adopted.
For sea salt production, a whitecap fraction parameterization is employed based on
surface wind speed and relative humidity [2].