Assessment of ERA-Interim Reanalysis Data Quality for the Caspian Sea Area
- PDF / 823,734 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 81 Downloads / 161 Views
ssment of ERA-Interim Reanalysis Data Quality for the Caspian Sea Area G. S. Dyakonova*, R. A. Ibrayeva, b, c, and P. O. Shishkovad a
Shirshov Institute of Oceanology, Russian Academy of Sciences, Nakhimovskii pr. 36, Moscow, 117997 Russia b Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences, ul. Gubkina 8, Moscow, 119333 Russia c Moscow Institute of Physics and Technology, Institutskii per. 9, Dolgoprudny, Moscow oblast, 141700 Russia d Saint Petersburg State University, Universitetskaya nab. 7–9, St. Petersburg, 199034 Russia *e-mail: [email protected] Received July 31, 2018 Revised September 10, 2019 Accepted December 17, 2019
Abstract—The analysis of the ERA-Interim atmospheric circulation reanalysis data for the Caspian Sea area is carried out. The possibility of their use for specifying external forcing in a numerical model of thermo- and hydrodynamic processes in the Caspian Sea is considered. The quality of these data is estimated based on a comparison with the climate atlases of the sea. The most significant differences between the average long-term fields of ERA-Interim and climate data are revealed, the possible errors in the numerical simulation of the thermohaline circulation, water and heat budgets of the Caspian Sea are analyzed. It is concluded that, in general, the ERA-Interim fields are in relatively good agreement with the climate and can be used to simulate the dynamics of the Caspian Sea. Wind speed during the autumn-winter period is underestimated over the Absheron Sill by 1–1.5 m/s and is overestimated in the Northern Caspian Sea by 1–2 m/s, whereas deviations from climate data in the warm season are minimal. The direction of the resulting wind qualitatively coincides with the climate throughout the year. The discrepancies in the fields of air temperature and dew point during most of the year do not exceed 1°C and reach 2–3°C only in winter in the Northern Caspian. Quite large deviations from climatic data (up to 35%) are registered in radiation fields. However, most likely, they are associated with errors in climate atlases. According to reanalysis data, total precipitation is consistent with the existing quantitative estimates. The spatial and temporal distribution of precipitation qualitatively corresponds to the climate.
DOI: 10.3103/S106837392009006X Keywords: Caspian Sea, ERA-Interim, hydrodynamic modeling, climate data
1. INTRODUCTION The numerical simulation is one of the main tools for studying the dynamics and water balance of the Caspian Sea [4, 5, 10, 17, 20–22, 25, 29], which, due to the closeness of the water body, are almost completely determined by the interaction with the atmosphere and river runoff. The investigation of water circulation in the Caspian Sea using a numerical hydrodynamic model requires specifying correct boundary conditions, especially at the surface. This can be done in several ways. Firstly, it is possible to use the coupled ocean–regional atmosphere model; for this purpose, it is necessary to specify boundary conditions for the atm
Data Loading...
