Comparison of methods for argo drifters data assimilation into a hydrodynamical model of the ocean

Belyaev, Konstantin; Tanajura, Clemente Augusto Souza; Tuchkova, N. P.

doi:10.1134/s0001437012050025

Cited by 26 publications

(18 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Very little has been published to evaluate the impact of in situ profile data assimilation into HYCOM with a focus on the Atlantic Ocean (e.g., Thacker et al, 2004;Belyaev et al, 2012). In the present work, a data assimilation system for HYCOM was constructed, implemented and realized for the Atlantic Ocean for the first time.…”

Section: Introductionmentioning

confidence: 99%

Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean

et al. 2015

Self Cite

View full text Add to dashboard Cite

Abstract. An ocean data assimilation system to assimilate Argo temperature (T ) and salinity (S) profiles into the HYbrid Coordinate Ocean Model (HYCOM) was constructed, implemented and evaluated for the first time in the Atlantic Ocean (78 • S to 50 • N and 98 • W to 20 • E). The system is based on the ensemble optimal interpolation (EnOI) algorithm proposed by Xie and Zhu (2010), especially made to deal with the hybrid nature of the HYCOM vertical coordinate system with multiple steps. The Argo T -S profiles were projected to the model vertical space to create pseudoobserved layer thicknesses ( p obs ), which correspond to the model target densities. The first step was to assimilate p obs considering the sub-state vector composed by the model layer thickness ( p) and the baroclinic velocity components. After that, T and S were assimilated separately. Finally, T was diagnosed below the mixed layer to preserve the density of the model isopycnal layers. Five experiments were performed from 1 January 2010 to 31 December 2012: a control run without assimilation, and four assimilation runs considering the different vertical localizations of T , S and p. The assimilation experiments were able to significantly improve the thermohaline structure produced by the control run. They reduced the root mean square deviation (RMSD) of T and S calculated with respect to Argo independent data in 34 and 44 %, respectively, in comparison to the control run. In some regions, such as the western North Atlantic, substantial corrections in the 20 • C isotherm depth and the upper ocean heat content towards climatological states were achieved.The runs with a vertical localization of p showed positive impacts in the correction of the thermohaline structure and reduced the RMSD of T (S) from 0.993 • C (0.149 psu) to 0.905 • C (0.138 psu) for the whole domain with respect to the other assimilation runs.

show abstract

Section: Introductionmentioning

confidence: 99%

Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…The differential equations of the MHI model [16] were supplemented with two single-type equations similar to (6) for which the following boundary conditions were used: on the basin surface, on solid lateral boundaries and on the river banks and in the straits; besides, the dispersion flows at the bottom are equal to zero. At the initial time, the values of typical dispersions were preset.…”

Section: Basic Relations Of the Kalman Filter And The Methods Of Adaptmentioning

confidence: 99%

“…I II III REL1 REL1 3hr 6hr 12hr 24hr 36hr 12hr 3 5 10 15 20 25 30 40 50 63 75 88 100 113 125 150 175 200 250 300 400 Comparison of the actual and model dispersions of the forecast errors. The numerical experiments on the horizons within the 100-500 m layer have resulted in obtaining the model daily average dispersions of the temperature (salinity) fields' forecast errors calculated by the equations similar to (6) and corrected by the formulas similar to (9); also obtained are the dispersions of the differences (residuals) between the temperature (salinity) pseudo-measured value and the model one. It is seen in Fig.…”

Section: T a B L Ementioning

confidence: 99%

Application of the Adaptive Statistics Method for Reanalysis of the Black Sea Fields Including Assimilation of the Temperature and Salinity Pseudo-Measurements in the Model

Коротаев¹,

Knysh²,

Лишаев³

et al. 2018

PhO

View full text Add to dashboard Cite

To assimilate the thermohaline parameters' pseudo-measurements in the model, applied is the method of adaptive statistics, the characteristic feature of which consists in adjusting the three-dimensional errors' dispersions of the temperature and salinity forecast to the water circulation in the basin. The three-dimensional fields of the temperature and salinity pseudo-measurements are reconstructed in the 100-500 m layer based on the altimetry data and the Argo buoys' limited measurements. The method is approved and validated by comparing the sea fields reconstructed in the reanalysis for 2012 with the Argo measurements. It is revealed that on the horizons 100, 113 and 125 m, the dispersions of differences (residuals) between the temperature pseudo-measurements and its model values somewhat exceed the model dispersion; whereas on the horizons within the 150-500 m layer, they are smaller. The daily standard deviation of the model level (relative to that reconstructed using the altimetry data) is smaller than the deviation calculated in the forecast; and during the March -September period, it is lower than the standard deviation resulted from the pseudo-measurements' assimilation by the simplified method. Resolution of the mesoscale vortices in the currents' fields is higher in case the method of adaptive statistics is used.

show abstract

“…If one DA method does it better then another, it is obviously preferable. This method of comparison has been used earlier in papers (Belyaev et. al., 2012), where the standard method of objective interpolation, OI has been compared with the EnKF and method, based on the application of the Fokker-Planck equation (Tanajura et.…”

mentioning

confidence: 99%

A hybrid data assimilation method and its comparison with an Ensemble Optimal Interpolation scheme in conjunction with the numerical ocean model using altimetry data

Belyaev

Кулешов

Smirnov

et al. 2019

Preprint

View full text Add to dashboard Cite

An original hybrid data assimilation scheme recently developed is presented and tested. The scheme is based on the application of the theory of diffusion random processes. It is applied here in conjunction with the Hybrid-Coordinate Ocean Model (HYCOM) to assimilate altimetry data from the Archiving, Validating and Interpolating Satellite Oceanography Data (AVISO) in the Atlantic. Several numerical experiments were conducted and their results were analyzed. It is shown that the method is able to assimilate data and to produce analyses closer to observations. It also conserves the model balance. This 15 method allows calculating the confidence range of the analyses by estimating their errors The presented method is compared with the Ensemble Optimal Interpolation scheme (EnOI) and it is shown that it has several advantages, in particular, it provides a better forecast and requires less computational cost. literature for more than 50 years, since the beginning of the 1960s. A good review of the main achievements in this direction during the last century is presented in (Ghil et. al., 1991). From the beginning of the 2000s, the main progress is related to the development of computer facilities, explosion in observational data network, parallel computations and other technical novelties. This advance leads to the progress in new mathematical methods and algorithms, the construction and development of numerical models with very high resolution, the data exchange all over the world, etc. At the present time, the DA 35techniques, algorithms and methods have become the essential part of operational oceanography on the ocean shelf and coastal zones, especially in the oil and gas mining zones, as well as in the zones of pipeline transportation. Several national and international scientific projects are specially aimed to seek the optimal solution of the DA techniques in conjunction with the

show abstract

Comparison of methods for argo drifters data assimilation into a hydrodynamical model of the ocean

Cited by 26 publications

References 9 publications

Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean

Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean

Application of the Adaptive Statistics Method for Reanalysis of the Black Sea Fields Including Assimilation of the Temperature and Salinity Pseudo-Measurements in the Model

A hybrid data assimilation method and its comparison with an Ensemble Optimal Interpolation scheme in conjunction with the numerical ocean model using altimetry data

Contact Info

Product

Resources

About