Spatial variations in the Caspian Sea wave climate in 2002–2013 from satellite altimetry
The core properties of the wave climate and its changes in the Caspian Sea are established in terms of the annual mean significant wave height and its regional changes in 2002–2013 based on the outcome of the satellite altimetry mission JASON-1. Remotely estimated wave heights are validated against...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Estonian Academy Publishers
2019-11-01
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| Series: | Estonian Journal of Earth Sciences |
| Subjects: | |
| Online Access: | http://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2019/issue_4/earth-2019-4-225-240.pdf |
| _version_ | 1818587934368989184 |
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| author | Nadezhda Kudryavtseva Kuanysh Kussembayeva Zaure B. Rakisheva Tarmo Soomere |
| author_facet | Nadezhda Kudryavtseva Kuanysh Kussembayeva Zaure B. Rakisheva Tarmo Soomere |
| author_sort | Nadezhda Kudryavtseva |
| collection | DOAJ |
| description | The core properties of the wave climate and its changes in the Caspian Sea are established in terms of the annual mean significant wave height and its regional changes in 2002–2013 based on the outcome of the satellite altimetry mission JASON-1. Remotely estimated wave heights are validated against properties of the empirical distribution of instrumentally measured wave heights in the southern Caspian Sea and monthly averages of visually observed wave heights at three locations. A correction for systematic differences leads to very good correspondence between monthly averaged in situ and satellite data with a typical root mean square difference of 0.06 m. The average significant wave height in the Caspian Sea is 0.5–0.7 m in the northern basin of the sea, around 1.2 m in large parts of the central and southern basins and reaches up to 1.8 m in the northern segment of the central basin. The basin-wide average wave intensity varied insignificantly in the range of 1.02–1.14 m in 2002–2013. These estimates overestimate the wave heights by about 30% because low wave conditions are ignored. Substantial and statistically significant changes in the wave height occurred in certain areas. The wave height decreased by 0.019 ± 0.007 m/yr in the eastern segment of the central basin and by 0.04 ± 0.04 m/yr in the western segment of the southern basin. These changes can be explained by an increase in the frequency of westerly winds at the expence of southerly winds. Both basin-wide and regional extreme wave heights exhibit large interannual variations but do not show any significant trend. The patterns of changes in mean and extreme wave height are different. The average wave height has increased while the extreme wave height has decreased in the eastern segment of the southern basin. |
| first_indexed | 2024-12-16T09:16:45Z |
| format | Article |
| id | doaj.art-7be0c960b84e459fb02c2e5d2cbb33f7 |
| institution | Directory Open Access Journal |
| issn | 1736-4728 1736-7557 |
| language | English |
| last_indexed | 2024-12-16T09:16:45Z |
| publishDate | 2019-11-01 |
| publisher | Estonian Academy Publishers |
| record_format | Article |
| series | Estonian Journal of Earth Sciences |
| spelling | doaj.art-7be0c960b84e459fb02c2e5d2cbb33f72022-12-21T22:36:52ZengEstonian Academy PublishersEstonian Journal of Earth Sciences1736-47281736-75572019-11-0168422524010.3176/earth.2019.1610.3176/earth.2019.16Spatial variations in the Caspian Sea wave climate in 2002–2013 from satellite altimetryNadezhda Kudryavtseva0Kuanysh Kussembayeva1Zaure B. Rakisheva2Tarmo Soomere3Department of Cybernetics, School of Science, Tallinn University of Technology, Akadeemia tee 21, 12618 Tallinn, Estonia; nadezhda.kudryavtseva@taltech.eeAl-Farabi Kazakh National University, Department of Mechanics, al-Farabi av. 71, 050038 Almaty, KazakhstanAl-Farabi Kazakh National University, Department of Mechanics, al-Farabi av. 71, 050038 Almaty, KazakhstanDepartment of Cybernetics, School of Science, Tallinn University of Technology, Akadeemia tee 21, 12618 Tallinn, Estonia / Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, EstoniaThe core properties of the wave climate and its changes in the Caspian Sea are established in terms of the annual mean significant wave height and its regional changes in 2002–2013 based on the outcome of the satellite altimetry mission JASON-1. Remotely estimated wave heights are validated against properties of the empirical distribution of instrumentally measured wave heights in the southern Caspian Sea and monthly averages of visually observed wave heights at three locations. A correction for systematic differences leads to very good correspondence between monthly averaged in situ and satellite data with a typical root mean square difference of 0.06 m. The average significant wave height in the Caspian Sea is 0.5–0.7 m in the northern basin of the sea, around 1.2 m in large parts of the central and southern basins and reaches up to 1.8 m in the northern segment of the central basin. The basin-wide average wave intensity varied insignificantly in the range of 1.02–1.14 m in 2002–2013. These estimates overestimate the wave heights by about 30% because low wave conditions are ignored. Substantial and statistically significant changes in the wave height occurred in certain areas. The wave height decreased by 0.019 ± 0.007 m/yr in the eastern segment of the central basin and by 0.04 ± 0.04 m/yr in the western segment of the southern basin. These changes can be explained by an increase in the frequency of westerly winds at the expence of southerly winds. Both basin-wide and regional extreme wave heights exhibit large interannual variations but do not show any significant trend. The patterns of changes in mean and extreme wave height are different. The average wave height has increased while the extreme wave height has decreased in the eastern segment of the southern basin.http://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2019/issue_4/earth-2019-4-225-240.pdfsatellite altimetryvalidationcaspian seawave climateclimate changevisual wave observationswave measurements. |
| spellingShingle | Nadezhda Kudryavtseva Kuanysh Kussembayeva Zaure B. Rakisheva Tarmo Soomere Spatial variations in the Caspian Sea wave climate in 2002–2013 from satellite altimetry Estonian Journal of Earth Sciences satellite altimetry validation caspian sea wave climate climate change visual wave observations wave measurements. |
| title | Spatial variations in the Caspian Sea wave climate in 2002–2013 from satellite altimetry |
| title_full | Spatial variations in the Caspian Sea wave climate in 2002–2013 from satellite altimetry |
| title_fullStr | Spatial variations in the Caspian Sea wave climate in 2002–2013 from satellite altimetry |
| title_full_unstemmed | Spatial variations in the Caspian Sea wave climate in 2002–2013 from satellite altimetry |
| title_short | Spatial variations in the Caspian Sea wave climate in 2002–2013 from satellite altimetry |
| title_sort | spatial variations in the caspian sea wave climate in 2002 2013 from satellite altimetry |
| topic | satellite altimetry validation caspian sea wave climate climate change visual wave observations wave measurements. |
| url | http://www.kirj.ee/public/Estonian_Journal_of_Earth_Sciences/2019/issue_4/earth-2019-4-225-240.pdf |
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