CryoSat ocean product quality status and future evolution

Bouffard, Jérôme; Naeije, Marc; Banks, Christopher J.; Calafat, Francesc; Cipollini, Paolo; Snaith, Helen; Webb, Erica; Hall, Amanda; Mannan, Rubinder; Féménias, Pierre; Parrinello, Tommaso

doi:10.1016/j.asr.2017.11.043

Cited by 24 publications

(17 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present work has found that the CryoSat‐2 data can be used to estimate tides with a precision comparable to that available from other data sources, even if they were not found useful for identifying topography or water column thickness. Improvements may be anticipated from innovations in processing CryoSat‐2 waveforms over ice surfaces (Nilsson et al, ) and ocean surfaces (Boy et al, ; Idzanovic et al, ), and a new version of the entire CryoSat‐2 geophysical data record is being prepared (Bouffard et al, ). Future efforts should aim to utilize these data more widely for mapping tides in the polar oceans.…”

Section: Discussion and Summarymentioning

confidence: 99%

“…A data set consisting of the combined SARin and SAR mode data, processed according to Baseline‐C standards, was provided by the Center for Topographic studies of the Ocean and Hydrosphere (CTOH) for this study. Detailed information about the radar echo processing and range determination may be found in McMillan et al (, ) for SARin mode and in Boy et al () and Bouffard et al () for SAR mode.…”

Section: Data Sourcesmentioning

confidence: 99%

See 1 more Smart Citation

Simultaneous Estimation of Ocean Tides and Underwater Topography in the Weddell Sea

Zaron

2019

JGR Oceans

View full text Add to dashboard Cite

A new model for the M2, S2, K1, and O1 tides in the Weddell Sea is developed by assimilating CryoSat‐2 data into a barotropic tide model. A variational approach is used, which explicitly allows for errors in the water depth, that is, the bottom topography in open water and the water column thickness under floating ice shelves, so that an optimized estimate of the topography is obtained together with the tidal fields. In preparation for assimilation, the sensitivity of the tidal elevation to the interfacial drag at the sea floor and the ice‐water interface (under the floating ice shelves) is investigated; this motivates the development of a new drag parameterization which is more accurate and physically plausible in comparison with the interfacial drag alone. The assimilation of CryoSat‐2 data into the model results in tidal elevations with essentially the same accuracy as previous estimates, which is demonstrated by comparisons with independent in situ data and withheld CryoSat‐2 data. The novelty of the present tidal estimates is that they are consistent with well‐defined dynamics based on the Laplace Tidal Equations—augmented with the new parameterization of drag—and modifications of the prior estimate of underwater topography and water column thickness. Analysis of the sensitivity to the topography finds that, at this level of precision, the topography is not uniquely determined by the observed data.

show abstract

Section: Discussion and Summarymentioning

confidence: 99%

Section: Data Sourcesmentioning

confidence: 99%

Simultaneous Estimation of Ocean Tides and Underwater Topography in the Weddell Sea

Zaron

2019

JGR Oceans

View full text Add to dashboard Cite

show abstract

“…Also relevant for coastal zone, but scarcely investigated in this area is the DDA interferometry (SARin), which permits to extract spatial and temporal derivatives of water levels, providing an entirely new observable area. Few studies in coastal zone so far use SARin CryoSat-2 data (see Bouffard et al, 2018 andParrinello et al, 2018 for a recent review). Idžanović et al (2017) selected Norwegian tide gauges close to CryoSat-2 tracks with data collected in SARin mode (Figure 7) and found that SARin data processed as SAR has higher correlation and better RMS with in situ on the rugged coast of Norway compared with conventional altimetry.…”

Section: Sarin Mode and Fully Focused Sar Altimetrymentioning

confidence: 99%

Requirements for a Coastal Hazards Observing System

et al. 2019

Self Cite

View full text Add to dashboard Cite

Coastal zones are highly dynamical systems affected by a variety of natural and anthropogenic forcing factors that include sea level rise, extreme events, local oceanic and atmospheric processes, ground subsidence, etc. However, so far, they remain poorly monitored on a global scale. To better understand changes affecting world coastal zones and to provide crucial information to decision-makers involved in adaptation to and mitigation of environmental risks, coastal observations of various types need to be collected and analyzed. In this white paper, we first discuss the main forcing agents acting on coastal regions (e.g., sea level, winds, waves and currents, river runoff, sediment supply and transport, vertical land motions, land use) and the induced coastal response (e.g., shoreline position, estuaries morphology, land topography at Frontiers in Marine Science | www.frontiersin.org 1 July 2019 | Volume 6 | Article 348Benveniste et al.Requirements for a Coastal Zone Observing System the land-sea interface and coastal bathymetry). We identify a number of space-based observational needs that have to be addressed in the near future to understand coastal zone evolution. Among these, improved monitoring of coastal sea level by satellite altimetry techniques is recognized as high priority. Classical altimeter data in the coastal zone are adversely affected by land contamination with degraded range and geophysical corrections. However, recent progress in coastal altimetry data processing and multisensor data synergy, offers new perspective to measure sea level change very close to the coast. This issue is discussed in much detail in this paper, including the development of a global coastal sea-level and sea state climate record with mission consistent coastal processing and products dedicated to coastal regimes. Finally, we present a new promising technology based on the use of Signals of Opportunity (SoOp), i.e., communication satellite transmissions that are reutilized as illumination sources in a bistatic radar configuration, for measuring coastal sea level. Since SoOp technology requires only receiver technology to be placed in orbit, small satellite platforms could be used, enabling a constellation to achieve high spatio-temporal resolutions of sea level in coastal zones.

show abstract

“…Details on the previous historic CryoSat Ice processing chain and main L1B and L2 processing steps are reported in Bouffard et al (2018b). CryoSat Ocean products are instead generated with the Baseline-C CryoSat Ocean Processor (more details in Bouffard et al, 2018a). An overview of the current CryoSat data products is reported in Fig.…”

Section: Introductionmentioning

confidence: 99%

CryoSat Ice Baseline-D validation and evolutions

Meloni¹,

Bouffard

Parrinello

et al. 2020

The Cryosphere

Self Cite

View full text Add to dashboard Cite

Abstract. The ESA Earth Explorer CryoSat-2 was launched on 8 April 2010 to monitor the precise changes in the thickness of terrestrial ice sheets and marine floating ice. To do that, CryoSat orbits the planet at an altitude of around 720 km with a retrograde orbit inclination of 92∘ and a quasi repeat cycle of 369 d (30 d subcycle). To reach the mission goals, the CryoSat products have to meet the highest quality standards to date, achieved through continual improvements of the operational processing chains. The new CryoSat Ice Baseline-D, in operation since 27 May 2019, represents a major processor upgrade with respect to the previous Ice Baseline-C. Over land ice the new Baseline-D provides better results with respect to the previous baseline when comparing the data to a reference elevation model over the Austfonna ice cap region, improving the ascending and descending crossover statistics from 1.9 to 0.1 m. The improved processing of the star tracker measurements implemented in Baseline-D has led to a reduction in the standard deviation of the point-to-point comparison with the previous star tracker processing method implemented in Baseline-C from 3.8 to 3.7 m. Over sea ice, Baseline-D improves the quality of the retrieved heights inside and at the boundaries of the synthetic aperture radar interferometric (SARIn or SIN) acquisition mask, removing the negative freeboard pattern which is beneficial not only for freeboard retrieval but also for any application that exploits the phase information from SARIn Level 1B (L1B) products. In addition, scatter comparisons with the Beaufort Gyre Exploration Project (BGEP; https://www.whoi.edu/beaufortgyre, last access: October 2019) and Operation IceBridge (OIB; Kurtz et al., 2013) in situ measurements confirm the improvements in the Baseline-D freeboard product quality. Relative to OIB, the Baseline-D freeboard mean bias is reduced by about 8 cm, which roughly corresponds to a 60 % decrease with respect to Baseline-C. The BGEP data indicate a similar tendency with a mean draft bias lowered from 0.85 to −0.14 m. For the two in situ datasets, the root mean square deviation (RMSD) is also well reduced from 14 to 11 cm for OIB and by a factor of 2 for the BGEP. Observations over inland waters show a slight increase in the percentage of good observations in Baseline-D, generally around 5 %–10 % for most lakes. This paper provides an overview of the new Level 1 and Level 2 (L2) CryoSat Ice Baseline-D evolutions and related data quality assessment, based on results obtained from analyzing the 6-month Baseline-D test dataset released to CryoSat expert users prior to the final transfer to operations.

show abstract

CryoSat ocean product quality status and future evolution

Cited by 24 publications

References 28 publications

Simultaneous Estimation of Ocean Tides and Underwater Topography in the Weddell Sea

Simultaneous Estimation of Ocean Tides and Underwater Topography in the Weddell Sea

Requirements for a Coastal Hazards Observing System

CryoSat Ice Baseline-D validation and evolutions

Contact Info

Product

Resources

About