Meeting:Abstract 2013 CSDMS meeting-077: Difference between revisions

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{{CSDMS meeting personal information template-2013
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|CSDMS meeting first name=Jianwei
|CSDMS meeting first name=Irina
|CSDMS meeting last name=Han
|CSDMS meeting last name=Overeem
|CSDMS meeting institute=Tulane University
|CSDMS meeting institute=University of Colorado
|CSDMS meeting city=New Orleans
|CSDMS meeting city=Boulder
|CSDMS meeting country=United States
|CSDMS meeting country=United States
|CSDMS meeting state=Louisiana
|CSDMS meeting state=Colorado
|CSDMS meeting email address=jhan@tulane.edu
|CSDMS meeting email address=irina.overeem@colorado.edu
|CSDMS meeting phone=504-202-8350
|CSDMS meeting phone=303-492 6631
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{{CSDMS meeting abstract title template-2013
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|CSDMS meeting abstract title=Explore the mechanism of valley spacing for higher order fluvial channels with CHILD
|CSDMS meeting abstract title=Modeling of Waves and Storm Surge along the Arctic Coast of Alaska
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|CSDMS meeting coauthor first name abstract=Nicole
|CSDMS meeting coauthor first name abstract=Katy
|CSDMS meeting coauthor last name abstract=Gasparini
|CSDMS meeting coauthor last name abstract=Barnhart
|CSDMS meeting coauthor institute / Organization=Tulane University
|CSDMS meeting coauthor institute / Organization=University of Colorado
|CSDMS meeting coauthor town-city=New Orleans
|CSDMS meeting coauthor town-city=Boulder
|CSDMS meeting coauthor country=United States
|CSDMS meeting coauthor country=United States
|State=Louisiana
|State=Colorado
|CSDMS meeting coauthor email address=ngaspari@tulane.edu
|CSDMS meeting coauthor email address=katy.barnhart@colorado.edu
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{{CSDMS meeting authors template
|CSDMS meeting coauthor first name abstract=Robert
|CSDMS meeting coauthor last name abstract=Anderson
|CSDMS meeting coauthor institute / Organization=University of Colorado
|CSDMS meeting coauthor town-city=Boulder
|CSDMS meeting coauthor country=United States
|State=Colorado
|CSDMS meeting coauthor email address=r.s.anderson@colorado.edu
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|CSDMS meeting abstract=Many studies have found that the ratios between valley spacing and width of mountain range are relatively constant over the world. It seems like the magic of the nature which produces even and uniform ripples, dunes and valleys both in seascape and landscape. Perron et al. (2008) has found that the critical length (CL) between hillslope and fluvial processes play a key role in the valley spacing of first order fluvial channels. In this study, we’ll use landscape evolution model CHILD to further explore the mechanism of valley spacing for second and higher order fluvial channels, and to discuss the reason why the ratios between valley spacing and mountain width might fall into a narrow range for diverse natural settings.
|CSDMS meeting abstract=Arctic coasts have been impacted by rapid environmental change over the last 30 years. Warming air and water temperatures and the increased duration of the open water season, correlate with increases in the rate of already rapid erosion of ice-rich bluffs along the Beaufort Sea coast. To investigate longer-term changes in near-shore wave dynamics and storm surge set up as a result of sea-ice retreat, we coupled two simple modules.
 
Following Dean and Dalrymple (1991), we model wind-driven setup as a function of wind speed and direction, azimuth relative to the shore-normal, fetch and bathymetry. The wave module calculates the wave field for fetch-limited waves in shallow water based on the Shore Protection Manual (1984). For a given wind speed, dynamic water depth and fetch, we predict the significant wave height and wave period. Both modules require fetch as a controlling parameter. Sea-ice influenced coasts, are unique in that fetch is spatially variable due to the geometry of the shoreline and temporally variable as the location of the sea ice edge moves through the sea ice free season. We determine the distance to the sea ice edge using daily Nimbus 7-SMMR/SSM/I and DMSP SSMI Passive Microwave Sea Ice Concentration data. The sea ice edge is defined at a threshold sea ice concentration of 15%. We find a good match between the model predictions and our observed records of meteorological conditions and nearshore water level and waves along the Beaufort Coast in the summers of 2009 and 2010.
 
Over the period 1979-2012, fetch has increased significantly. In our study area near Drew Point, Alaska, the open water season itself lengthened from ~45 days to ~90 days. In the 1980’s and early 1990’s wave dynamics were fetch-limited during a significant period of the open water season. More recently, the distance from the coast to the sea ice edge shifts extremely rapidly (often 100’s of km over 1-2 weeks); fetch therefore only minimally influences wave dynamics as offshore distance exceeds the 140 km threshold over most of the open water season. Wave heights and surge set-up events on average have not changed in magnitude significantly, but storm surge set up events have increased in frequency.
 
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Revision as of 17:30, 8 February 2013

Browse  abstracts

CSDMS all hands meeting 2013

Modeling of Waves and Storm Surge along the Arctic Coast of Alaska

Irina Overeem, University of Colorado Boulder Colorado, United States. irina.overeem@colorado.edu
Katy Barnhart, University of Colorado Boulder Colorado, United States. katy.barnhart@colorado.edu
Robert Anderson, University of Colorado Boulder Colorado, United States. r.s.anderson@colorado.edu


[[Image:|300px|right|link=File:]]Arctic coasts have been impacted by rapid environmental change over the last 30 years. Warming air and water temperatures and the increased duration of the open water season, correlate with increases in the rate of already rapid erosion of ice-rich bluffs along the Beaufort Sea coast. To investigate longer-term changes in near-shore wave dynamics and storm surge set up as a result of sea-ice retreat, we coupled two simple modules.

Following Dean and Dalrymple (1991), we model wind-driven setup as a function of wind speed and direction, azimuth relative to the shore-normal, fetch and bathymetry. The wave module calculates the wave field for fetch-limited waves in shallow water based on the Shore Protection Manual (1984). For a given wind speed, dynamic water depth and fetch, we predict the significant wave height and wave period. Both modules require fetch as a controlling parameter. Sea-ice influenced coasts, are unique in that fetch is spatially variable due to the geometry of the shoreline and temporally variable as the location of the sea ice edge moves through the sea ice free season. We determine the distance to the sea ice edge using daily Nimbus 7-SMMR/SSM/I and DMSP SSMI Passive Microwave Sea Ice Concentration data. The sea ice edge is defined at a threshold sea ice concentration of 15%. We find a good match between the model predictions and our observed records of meteorological conditions and nearshore water level and waves along the Beaufort Coast in the summers of 2009 and 2010.

Over the period 1979-2012, fetch has increased significantly. In our study area near Drew Point, Alaska, the open water season itself lengthened from ~45 days to ~90 days. In the 1980’s and early 1990’s wave dynamics were fetch-limited during a significant period of the open water season. More recently, the distance from the coast to the sea ice edge shifts extremely rapidly (often 100’s of km over 1-2 weeks); fetch therefore only minimally influences wave dynamics as offshore distance exceeds the 140 km threshold over most of the open water season. Wave heights and surge set-up events on average have not changed in magnitude significantly, but storm surge set up events have increased in frequency.