In November 2007, the Argo program reached a coverage of 3000 simultaneously operating floats (one float in a 3° square) planned during the development of
the program (measurements with the Argo floats cover the majority of the Global
Ocean since 2005). Currently, 4000 Argo floats autonomously profile the upper
2000 m water column of the ocean from Antarctica to Spitsbergen with a 10-day
interval. Constantly increasing number of measurements (World Ocean temperature
and salinity database increases by 12,000 profiles every month) makes it possible to
reconstruct and study the Southern Ocean dynamics and variability.
The Argo-Based Model for Investigation of the Global Ocean (AMIGO) was
recently developed at the Shirshov Institute of Oceanology. It consists of a block for
variational interpolation of Argo profiles to a regular grid and a block for model
hydrodynamic adjustment of variationaly interpolated fields. It makes possible to
obtain a full set of oceanographic characteristics: temperature, salinity, and current
velocity from irregularly located Argo measurements [15]. The AMIGO technique
was used for the calculation of the North Atlantic circulation [17] and estimates of
the transports by oceanic currents [15, 21]. The analysis of model simulations and
their comparison with the drifter data showed that irregularly distributed temperature
and salinity data measured by the Argo floats variationaly interpolated on a regular
grid restore realistic velocity fields [17, 21]; the AMIGO thermo-hydrodynamic
information can be successfully used as the initial conditions in the ocean global
circulation models [17].
In this paper we analyze the AMIGO simulations results in the Southern Ocean
covering a 10-year period from 2005 to 2014. The spatial resolution of the data is 1°
by latitude and longitude, and the temporal resolution is one month. The data are
represented as monthly mean, seasonal, and annual means and climatological fields
and are freely available at the Shirshov Institute web site: http://argo.ocean.ru/.
Data and Methods
The AMIGO dataset is used to study the variability of large-scale circulation in the
Southern Ocean. The AMIGO is a new end-user oriented dataset compiled at the
Shirshov Institute of Oceanology based on the Argo measurements [2] and satellite
altimetry [6]. The most prominent features of this new method of Argo data processing are the application of variational interpolation of irregularly located Argo
measurements to a regular grid [13, 16] followed by model hydrodynamic
adjustment of the obtained fields with the concurrent use of satellite altimetry to
verify solutions when selecting the model parameters [15].
The principle of the variational interpolation technique is to minimize the misfit
between the interpolated fields defined on a regular grid and the irregularly distributed data, so that the optimal solution passes as close to the data as possible. The
method of hydrodynamic adjustment [8, 9, 14] makes it possible to obtain
hydrodynamically balanced oceanographic data using the ocean general circulation
488
K. V. Lebedev
the program (measurements with the Argo floats cover the majority of the Global
Ocean since 2005). Currently, 4000 Argo floats autonomously profile the upper
2000 m water column of the ocean from Antarctica to Spitsbergen with a 10-day
interval. Constantly increasing number of measurements (World Ocean temperature
and salinity database increases by 12,000 profiles every month) makes it possible to
reconstruct and study the Southern Ocean dynamics and variability.
The Argo-Based Model for Investigation of the Global Ocean (AMIGO) was
recently developed at the Shirshov Institute of Oceanology. It consists of a block for
variational interpolation of Argo profiles to a regular grid and a block for model
hydrodynamic adjustment of variationaly interpolated fields. It makes possible to
obtain a full set of oceanographic characteristics: temperature, salinity, and current
velocity from irregularly located Argo measurements [15]. The AMIGO technique
was used for the calculation of the North Atlantic circulation [17] and estimates of
the transports by oceanic currents [15, 21]. The analysis of model simulations and
their comparison with the drifter data showed that irregularly distributed temperature
and salinity data measured by the Argo floats variationaly interpolated on a regular
grid restore realistic velocity fields [17, 21]; the AMIGO thermo-hydrodynamic
information can be successfully used as the initial conditions in the ocean global
circulation models [17].
In this paper we analyze the AMIGO simulations results in the Southern Ocean
covering a 10-year period from 2005 to 2014. The spatial resolution of the data is 1°
by latitude and longitude, and the temporal resolution is one month. The data are
represented as monthly mean, seasonal, and annual means and climatological fields
and are freely available at the Shirshov Institute web site: http://argo.ocean.ru/.
Data and Methods
The AMIGO dataset is used to study the variability of large-scale circulation in the
Southern Ocean. The AMIGO is a new end-user oriented dataset compiled at the
Shirshov Institute of Oceanology based on the Argo measurements [2] and satellite
altimetry [6]. The most prominent features of this new method of Argo data processing are the application of variational interpolation of irregularly located Argo
measurements to a regular grid [13, 16] followed by model hydrodynamic
adjustment of the obtained fields with the concurrent use of satellite altimetry to
verify solutions when selecting the model parameters [15].
The principle of the variational interpolation technique is to minimize the misfit
between the interpolated fields defined on a regular grid and the irregularly distributed data, so that the optimal solution passes as close to the data as possible. The
method of hydrodynamic adjustment [8, 9, 14] makes it possible to obtain
hydrodynamically balanced oceanographic data using the ocean general circulation
488
K. V. Lebedev