Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges
Trends in marine wind speed and significant wave height are investigated using the global reanalysis ERA-Interim 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 u...
Published in: | Journal of Climate |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Meteorological Society
2015
|
Subjects: | |
Online Access: | https://hdl.handle.net/1956/9255 https://doi.org/10.1175/jcli-d-14-00470.1 |
id |
ftunivbergen:oai:bora.uib.no:1956/9255 |
---|---|
record_format |
openpolar |
spelling |
ftunivbergen:oai:bora.uib.no:1956/9255 2023-05-15T17:35:42+02:00 Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges Aarnes, Ole Johan Abdalla, Saleh Bidlot, Jean-Raymond Breivik, Øyvind 2015-01-15 application/pdf https://hdl.handle.net/1956/9255 https://doi.org/10.1175/jcli-d-14-00470.1 eng eng American Meteorological Society urn:issn:0894-8755 https://hdl.handle.net/1956/9255 https://doi.org/10.1175/jcli-d-14-00470.1 Copyright [date of publication] American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act September 2010 Page 2 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/) or from the AMS at 617-227-2425 or copyrights@ametsoc.org. Journal of Climate 28 2 819-837 Sea/ocean surface Waves oceanic Extreme events Wind Reanalysis data Trends Peer reviewed Journal article 2015 ftunivbergen https://doi.org/10.1175/jcli-d-14-00470.1 2023-03-14T17:38:50Z Trends in marine wind speed and significant wave height are investigated using the global reanalysis ERA-Interim 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. publishedVersion Article in Journal/Newspaper North Atlantic University of Bergen: Bergen Open Research Archive (BORA-UiB) Pacific Journal of Climate 28 2 819 837 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
Sea/ocean surface Waves oceanic Extreme events Wind Reanalysis data Trends |
spellingShingle |
Sea/ocean surface Waves oceanic Extreme events Wind Reanalysis data Trends Aarnes, Ole Johan Abdalla, Saleh Bidlot, Jean-Raymond Breivik, Øyvind Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges |
topic_facet |
Sea/ocean surface Waves oceanic Extreme events Wind Reanalysis data Trends |
description |
Trends in marine wind speed and significant wave height are investigated using the global reanalysis ERA-Interim 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. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Aarnes, Ole Johan Abdalla, Saleh Bidlot, Jean-Raymond Breivik, Øyvind |
author_facet |
Aarnes, Ole Johan Abdalla, Saleh Bidlot, Jean-Raymond Breivik, Øyvind |
author_sort |
Aarnes, Ole Johan |
title |
Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges |
title_short |
Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges |
title_full |
Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges |
title_fullStr |
Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges |
title_full_unstemmed |
Marine Wind and Wave Height Trends at Different ERA-Interim Forecast Ranges |
title_sort |
marine wind and wave height trends at different era-interim forecast ranges |
publisher |
American Meteorological Society |
publishDate |
2015 |
url |
https://hdl.handle.net/1956/9255 https://doi.org/10.1175/jcli-d-14-00470.1 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Journal of Climate 28 2 819-837 |
op_relation |
urn:issn:0894-8755 https://hdl.handle.net/1956/9255 https://doi.org/10.1175/jcli-d-14-00470.1 |
op_rights |
Copyright [date of publication] American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act September 2010 Page 2 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/) or from the AMS at 617-227-2425 or copyrights@ametsoc.org. |
op_doi |
https://doi.org/10.1175/jcli-d-14-00470.1 |
container_title |
Journal of Climate |
container_volume |
28 |
container_issue |
2 |
container_start_page |
819 |
op_container_end_page |
837 |
_version_ |
1766134955861082112 |