Observational changes and trends in northeast Pacific wave records

Gemmrich, Johannes; Thomas, Bridget R.; Bouchard, Richard

doi:10.1029/2011gl049518

Cited by 95 publications

(83 citation statements)

References 13 publications

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“…Errors-primarily jumps in H s -of the sort recently documented by Gemmrich et al (2011), must at some level lead to corresponding errors in our calibration analyses. Some presumably account for the scatter in individual buoy β 1 estimates ( Figure 11).…”

Section: Discussionmentioning

confidence: 99%

“…These inconsistency problems among different in situ measurements are becoming widely appreciated, and a recent report has identified the critical need to assess and improve the quality of observations from the present networks of moored buoys (Swail et al, 2010). The recent work of Gemmrich et al (2011) should further emphasize this need.…”

Section: Buoy Inconsistenciesmentioning

confidence: 99%

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Calibration of Ocean Wave Measurements by the TOPEX, Jason-1, and Jason-2 Satellites

Ray

Beckley

2012

Marine Geodesy

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The calibration and validation of ocean wave height measurements by the TOPEX, Jason-1, and Jason-2 satellite altimeters is addressed by comparing the measurements internally among themselves and against independent wave measurements at moored buoys. The two six-month verification campaigns, when two of the satellites made near-simultaneous measurements along the same ground track, are invaluable for such work and reveal subtle aspects that otherwise might go undetected.The two Jason satellites are remarkably consistent; Topex reports waves generally 1-2% larger. External calibration is complicated by some systematic errors in the buoy data. We confirm a recent report by Durrant et al. that Canadian buoys underestimate significant wave heights by about 10% relative to U.S. buoys. Wave heights from all three altimetric satellites require scaling upwards by 5-6% to be consistent with U.S. buoys.

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Section: Discussionmentioning

confidence: 99%

Section: Buoy Inconsistenciesmentioning

confidence: 99%

Calibration of Ocean Wave Measurements by the TOPEX, Jason-1, and Jason-2 Satellites

Ray

Beckley

2012

Marine Geodesy

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“…In short, the empirical distributions of all detrended segments are matched. The software has shown promise in Gemmrich et al (2011) and Vincent et al (2012).…”

Section: B Rhtestsv4-homogenizationmentioning

confidence: 99%

Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges

et al. 2015

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Trends in marine wind speed and significant wave height are investigated using the global reanalysis ERAInterim over the period 1979-2012, based on monthly-mean and monthly-maximum data. Besides the traditional reanalysis, the authors include trends obtained at different forecast range, available up to 10 days ahead. Any model biases that are corrected differently over time are likely to introduce spurious trends of variable magnitude. However, at increased forecast range the model tends to relax, being less affected by assimilation. Still, there is a trade-off between removing the impact of data assimilation at longer forecast range and getting a lower level of uncertainty in the predictions at shorter forecast range. Because of the sheer amount of assimilations made in ERA-Interim, directly and indirectly affecting the data, it is difficult, if not impossible, to distinguish effects imposed by all updates. Here, special emphasis is put on the introduction of wave altimeter data in August 1991, the only type of data directly affecting the wave field. From this, it is shown that areas of higher model bias introduce quite different trends depending on forecast range, most apparent in the North Atlantic and eastern tropical Pacific. Results are compared with 23 in situ measurements, Envisat altimeter winds, and two stand-alone ECMWF operational wave model (EC-WAM) runs with and without wave altimeter assimilation. Here, the 48-h forecast is suggested to be a better candidate for trend estimates of wave height, mainly due to the step change imposed by altimeter observations. Even though wind speed seems less affected by undesirable step changes, the authors believe that the 24-48-h forecast more effectively filters out any unwanted effects.

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“…High-quality wind and wave observations in excess of 20 years are available for climate research. These include voluntary observations along shipping routes [Gulev et al, 2003], point measurements at buoys [e.g., Bromirski et al, 2005;Menendez et al, 2008;Gemmrich et al, 2011], and spatial patterns from altimeters [e.g., Young, 1999;Woolf et al, 2002;Chen et al, 2002;Hemer et al, 2010;Young et al, 2011]. Some of these studies supplemented the measurements with detailed wave data from numerical models to provide space-time connections of the observed processes.…”

Section: Introductionmentioning

confidence: 99%

Periodicity and patterns of ocean wind and wave climate

Stopa

Cheung

2014

JGR Oceans

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The Climate Forecast System Reanalysis (CFSR) provides a wealth of information spanning 1979-2009 for investigation of ocean wind and wave climate. Preprocessing of the data is necessary to remove the dominant seasonal signals and to create time series of semimonthly averaged wind speed and significant wave height over a 0.5 global grid. We perform an empirical orthogonal function (EOF) analysis to extract the dominant space-time patterns. The results for the three major ocean basins show strong zonal structures in the winds and saturation of the swells corroborating prior works with various data sets. We reexamine the CFSR data in the frequency domain to identify periodic signals associated with published climate indices. The Fourier transform of the preprocessed time series generates spectra ranging from 1 month to 15 years period for an EOF analysis. The results demonstrate the spatial structures and periods of climate phenomena. The Arctic Oscillation dominates the Atlantic basin with a broad range of intra-annual signals off the European coasts. The Indian and Pacific Oceans are strongly influenced by inter-annual cycles of the El Niño Southern Oscillation (ENSO) and the Antarctica Oscillation. The Indian Ocean also has strong intra-annual components ranging from 50 to 80 days period. The ENSO proves to be a ubiquitous signal around the globe, and in particular, saturates the Pacific with strong influences in the equatorial region and the Southern Hemisphere Westerlies. A commonality of all basins is that the magnitude and the spatial structure of the intra-annual and inter-annual signals are similar suggesting a wide range of periods in each of the climate cycles examined.

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Observational changes and trends in northeast Pacific wave records

Cited by 95 publications

References 13 publications

Calibration of Ocean Wave Measurements by the TOPEX, Jason-1, and Jason-2 Satellites

Calibration of Ocean Wave Measurements by the TOPEX, Jason-1, and Jason-2 Satellites

Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges

Periodicity and patterns of ocean wind and wave climate

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