The Scientific Beaufort Equivalent Scale: Effects on Wind Statistics and Climatological Air-Sea Flux Estimates in the North Atlantic Ocean

Isemer, Hans-Jörg; Hasse, Lutz

doi:10.1175/1520-0442(1991)004<0819:tsbese>2.0.co;2

Cited by 51 publications

(49 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…WMO1100-estimated winds are thought to contain systematic errors that vary non-linearly with wind speed, due to the statistical method and limited data used to derive the scale (Isemer and Hasse, 1991), causing an underestimation of climatological monthly means. Various authors developed alternative Beaufort equivalent scales, although none was adopted operationally (Cardone, 1969;WMO, 1970;Kaufeld, 1981;Isemer, 1992;da Silva et al, 1995;Lindau, 1995a).…”

Section: Introductionmentioning

confidence: 99%

Trends in ship wind speeds adjusted for observation method and height

Thomas

Kent

Swail

et al. 2007

Intl Journal of Climatology

View full text Add to dashboard Cite

Globally averaged wind speeds from archived ship reports show an increasing trend since the 1940s, which previous studies attributed to the gradual shift from visually estimated to anemometer-measured winds, and an increase in mean anemometer height. To test this hypothesis, adjustments to account for these changes were applied to individual ship wind observations in the International Comprehensive Ocean-Atmosphere Data Set (ICOADS). Annual means calculated from adjusted reports were compared to reanalysis near-surface winds in consistently well-sampled regions for the period 1958-2002.The adjustments to individual ship wind reports for known biases improve the homogeneity over the entire period and remove trends, prior to the early 1980s. However, for the 21-year period 1982-2002, trends remain in the annual mean spatially averaged adjusted winds, of 0.4 ms −1 decade −1 (6% decade −1 ) for estimated speeds, and of 0.2 ms −1 decade −1 (3% decade −1 ) for measured speeds. In contrast, co-located reanalysis near-surface wind speeds show little change, 1% decade −1 or less. Anemometers were installed on increasing numbers of ships during the period of study, even as many of these ships continued to report estimated winds. Part of the trend in estimated wind speeds is probably spurious, most likely a result of observers being increasingly influenced by readings from anemometers located well above 10-m. This influence is indicated by the gradual reduction in the tendency to underestimate nighttime marine winds. Results confirm earlier findings that reanalysis near-surface winds were biased low. The paper summarizes methods that could be employed to account for remaining inhomogeneities and thereby improve the quality of the marine wind climate record.

show abstract

Section: Introductionmentioning

confidence: 99%

Trends in ship wind speeds adjusted for observation method and height

Thomas

Kent

Swail

et al. 2007

Intl Journal of Climatology

View full text Add to dashboard Cite

show abstract

“…Thus, disagreement results from data obtained by Quayle (1980) when compared to the WMO code 1100 (WMO 1970(WMO , 1973. These results are explained by Cardone et al (1990) and Isemer and Hasse (1991). Alternatively, our disagreement (Fig.…”

Section: A Climatological and Seasonal Meansmentioning

confidence: 66%

“…fixed positions, upper-air wind observations (Isemer 1994, and comparisons with pressure gradients and geostrophic wind hindcast (Ward 1992) indicate either significantly smaller trends or do not show any pronounced trends at all. However, the trend estimates are based on a quite short time series and should be always be considered in a view of 1) their statistical significance and 2) longer-scale climate variability, which may contain the observed trendlike changes as parts of, say, decadal and interdecadal variations.…”

Section: Volume 16 J O U R N a L O F A T M O S P H E R I C A N D O C mentioning

confidence: 91%

“…There has been considerable debate about the reliability of the Comprehensive Ocean-Atmosphere Dataset (COADS) winds-particularly the long-term wind speed trends (Ramage 1984;Peterson and Hasse 1987;Cardone et al 1990;Lindau et al 1990;Isemer and Hasse 1991;Ward 1992;Ward and Hoskins 1996;Bigg 1993;Isemer 1994, ranging from 0.1 to 0.5 m s Ϫ1 per decade with local maxima in the Tropics and in the Norwegian Sea . Change with time of the relative role of anemometer measurements is considered as one of the possible reasons of the unrealistically high COADS wind trends, although there is a number of other reasons that are still poorly understood.…”

Section: Introductionmentioning

confidence: 99%

“…However, measurements at most OWSs were stopped in mid-1970s. Observations at OWS C were continued until 1990, but the homogeneity of record is questionable due to occupation of the OWS C by Soviet research vessels starting in July 1975 (Isemer 1994). The recently completed Voluntary Ship Observing Programme in the North Atlantic (VSOP-NA) (Kent et al 1993) provides data from voluntary observing ships G U L E V (VOSs) along a number of ship tracks in the North Atlantic midlatitudes.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Comparison of COADS Release 1a Winds with Instrumental Measurements in the Northwest Atlantic

Gulev¹

1999

J. Atmos. Oceanic Technol.

View full text Add to dashboard Cite

The reliability of the Comprehensive Ocean-Atmosphere Dataset (COADS) Release 1a 2Њ monthly winds is tested by comparing it with instrumental measurements in the northwest Atlantic from 1981 to 1991. The instrumental dataset contains anemometer measurements of a very high homogeneity and quality, which were taken by six research sister ships with known anemometer heights in the northwest Atlantic. Special data processing was made with instrumental samples to provide compatibility with the COADS winds. Comparison shows overestimation of the COADS winds in the low ranges and underestimation of the strong and moderate winds. Application of the alternative equivalent Beaufort scales does not remove this bias and makes it even more pronounced. Thus, the conclusion is made that the disagreement obtained results primarily from the uncertainties of anemometer measurements in COADS, especially from the incorrect evaluation of the true wind. Instrumental data also do not indicate significant long-term interannual changes, which are pronounced in the COADS dataset for the 1980s. Some regional features of the comparison are discussed.

show abstract

Wind speed measurements and forest damage in Canton Zurich (Central Europe) from 1891 to winter 2007

Usbeck

Wohlgemuth

Pfister

et al. 2009

Intl Journal of Climatology

View full text Add to dashboard Cite

ABSTRACT:The most severe damage to forests in central Europe occurs during winter storms that are caused by Northern Hemispheric mid-latitude cyclones. These winter storms have caused several catastrophic windthrows during the past four decades. Amounts of forest storm damage are believed to be a function of both the size of the forest and the storm intensity. To test this hypothesis, the Zurich region (city and canton) was chosen because long-term climate observation data is available for the region. The relationships between forest attributes, wind speed and forest damage were explored by comparing data on forests and wind speed from 107 winters with forest damage. Storm damage was defined as the proportion of damaged forests with respect to the growing stock. The variables: daily wind run (91 years), daily maximum hourly average wind speed (107 years) and peak gust wind speed (74 years) were homogenized with respect to high wind speed and related to levels of forest damage.High maximum wind speed at the end of the 19th century and at the beginning of the 20th century was followed by low maximum wind speed in the 1940s, 1960s and 1970s. Since then, maximum values have increased. Gusts (extremes of the maximum wind speed) increased from the beginning of the recordings in 1933 and peaked in the early 1990s.Forest damage due to winter storms is best correlated with peak wind speed. Gusts exceeding 40 m/s and resulting in catastrophic windthrow have increased in recent winters.

show abstract

The Scientific Beaufort Equivalent Scale: Effects on Wind Statistics and Climatological Air-Sea Flux Estimates in the North Atlantic Ocean

Cited by 51 publications

References 0 publications

Trends in ship wind speeds adjusted for observation method and height

Trends in ship wind speeds adjusted for observation method and height

Comparison of COADS Release 1a Winds with Instrumental Measurements in the Northwest Atlantic

Wind speed measurements and forest damage in Canton Zurich (Central Europe) from 1891 to winter 2007

Contact Info

Product

Resources

About