Citation:

PANGAEA.871920

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Abstract:

The COastal Sea level Tailored ALES (COSTA) dataset contains dedicated coastal altimetry sea level measurements based on the Adaptive Leading Edge Subwaveform (ALES) reprocessing. In this version, the missions involved are ERS-2 (1996-2002) and Envisat (2002-2010), and the data are available in the Mediterranean Sea and in the North Sea.

The dataset is generated by the application of the ALES fitting algorithm to the radar signal provided by the official products of the missions. The ALES algorithm selects only a portion of the altimetric signal (waveform), in order to estimate the distance between the satellite and the sea surface (range) while avoiding the noise in the tail of the signal. The algorithm is based on the relation between estimated sea state, achievable precision and width of the subwaveform. The sea state bias correction, which accounts for the effects of waves and the tracking errors, is recomputed for the ALES output.

Following this pre-processing, the data are post-processed with updated geophysical corrections, tidal and mean sea surface models. Finally, the sea level measurements are averaged at 1 Hz (one measurement every ~7 km along each track) after removing the outliers. To facilitate the temporal analysis, the sea level anomalies for each track are stored in matrices in which each row corresponds to the time series at one latitude-longitude location.

The validation work, presented at the 10th Coastal Altimetry Workshop (2017-02-21 - 2017-02-24, Florence, Italy), has shown a 15% decrease in the high-rate noise of the measurements if compared to the standard product, with larger improvements in the last 20 km from the coastline and a better precision also in the open ocean.

The COSTA dataset is made available to the scientific community in order to foster the application of coastal altimetry data by users, who are not necessarily trained in radar altimetry processing. Its objective is the provision of easy-to-use along-track sea level data that can be directly used for sea level and circulation studies not only in the open ocean, but also in the coastal regions.

Related to:

Passaro, Marcello; Calafat, Francisco M (2017): ALES Coastal Processing Applied to ERS: Extending the Coastal Sea Level Time Series. Presented at the 10th Coastal Altimetry Workshop, 21-24 February 2017, Florence, Italy

Further details:

Passaro, Marcello (2017): User Manual - COSTA v1.0 - DGFI-TUM Along Track Sea Level Product for ERS-2 and Envisat (1996-2010) in the Mediterranean Sea and in the North Sea. Deutsches Geodätisches Forschungsinstitut der Technischen Universität München (DGFI-TUM), München, 7 pp, hdl:10013/epic.50369.d001

Coverage:

Median Latitude: 45.345000 * Median Longitude: 9.465000 * South-bound Latitude: 36.000000 * West-bound Longitude: 2.930000 * North-bound Latitude: 54.690000 * East-bound Longitude: 16.000000

Event(s):

Mediterranean_Sea * Latitude: 36.000000 * Longitude: 16.000000 * Location: Mediterranean Sea * Comment: position describes the center of area

North_Sea * Latitude: 54.690000 * Longitude: 2.930000 * Location: North Sea * Comment: position describes the center of area

Parameter(s):

#	Name	Short Name	Unit	Principal Investigator	Comment
1	Event label	Event		Passaro, Marcello
2	Date/time start	Date/time start		Passaro, Marcello
3	Date/time end	Date/time end		Passaro, Marcello
4	File name	File name		Passaro, Marcello
5	File format	File format		Passaro, Marcello
6	File size	File size	kByte	Passaro, Marcello	zipped
7	Uniform resource locator/link to file	URL file		Passaro, Marcello

License:

Creative Commons Attribution 3.0 Unported (CC-BY-3.0)

Size:

24 data points

Data

Download dataset as tab-delimited text — use the following character encoding:

1 Event	2 Date/time start	3 Date/time end	4 File name	5 File format	6 File size [kByte]	7 URL file
Mediterranean_Sea	1996-01-01	2002-12-31	Med_ERS2	NetCDF	741857	Med_ERS2_netcdf.zip
Mediterranean_Sea	2002-01-01	2010-12-31	Med_Envisat	NetCDF	775592	Med_Envisat_netcdf.zip
North_Sea	1996-01-01	2002-12-31	Northsea_ERS2	NetCDF	370194	Northsea_ERS2_netcdf.zip
North_Sea	2002-01-01	2010-12-31	Northsea_Envisat	NetCDF	377253	Northsea_Envisat_netcdf.zip