ABSTRACT The bias adjustment of visually estimated ship winds in the International Comprehensive Ocean-Atmosphere Data Set
(ICOADS) is addressed through the comparison to the QuickSCAT scatterometer equivalent neutral winds. We assume that visually estimated
winds and satellite scatterometer winds share similar characteristics, which are a function of stress rather than wind speed, and treat
the estimated ship winds as equivalent neutral winds. Under such an assumption, we use statistical analyses to calculate the bias
correction for estimated ship winds. Because observation practices vary by country and data provider, ICOADS identifies datasets by "deck"
which is a number that allows for differentiating the source of the records (different deck numbers indicate different data collections
provided to ICOADS, each which may contain one or more sources/countries). Three ICOADS decks 792, 926, and 992 contain the vast majority
(~90%) of collocated visually estimated ship winds covering the time period November 1999-October 2009. The Root-Mean-Square difference
between these visually estimated ship winds and scatterometer winds are 3.0ms-1, 2.8ms-1 and 2.9ms-1 for each major deck respectively.
Following the methodology of Freilich (1997) and Freilich and Dunbar (1999), we numerically show that for lower wind speeds (0ms-1-5ms-1
in this case) that the random error in the component of the visually estimated ship winds causes an artificial appearance of an
overestimation relative to satellite scatterometer winds. We also extend this statistical artifact test to test higher wind speeds
(12ms-1-18ms-1 in this case) through a Monte Carlo approach. An apparent slight drop of the conditional sample means relative to reference
line is shown to be a statistical artifact. These artificial biases are properly accounted in this study. A new bias correction, LMS
correction, is calculated and also compared to prior corrections such as Lindau (1995). This new bias correction is available for wind
speeds ranging from 0ms-1 to 17ms-1, because there are too few spatial and temporal collocated matches at wind speed greater than 17ms-1.
We are limited in our ability to perform the adjustments required for intercallibration because when comparing visual winds to
scatterometer winds the necessary wind speed observations are rare and small in magnitude. / A Thesis submitted to the Department of Earth Oceanic and Atmospheric Science in partial fulfillment
of the requirements for the degree of Master of Science. / Spring Semester 2016. / March 29, 2016. / Beaufort winds, bias adjustment, ICOADS, Lindau's (1995) correction, LMS correction / Includes bibliographical references. / Mark A. Bourassa, Professor Directing Thesis; Shawn R. Smith, Committee Member; Guosheng Liu,
Committee Member; Jeffrey Chagnon, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_360400 |
| Contributors | Li, Keqiao (authoraut), Bourassa, Mark Allan (professor directing thesis), Smith, Shawn R. (Shawn Richard) (committee member), Liu, Guosheng (committee member), Chagnon, Jeffrey M. (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Earth, Ocean, and Atmospheric Science (degree granting department) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource (43 pages), computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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