U.S. vulnerability to sea level rise

By: Dr. Jeff Masters , 4:04 PM GMT on June 23, 2009

Share this Blog
2
+

In the last century, sea level rose 5 - 6 inches (13 - 15 cm) more than the global average of 7 inches (18 cm) along the U.S. Mid-Atlantic and Gulf Coasts, because coastal lands there are sinking. Over 50% of the U.S. coastline is vulnerable or highly vulnerable to sea level rise, according to the Coastal Vulnerability Index (CVI) developed by the United States Geological Survey (USGS). In the U.S., relative sea level rise (the combined effects of global sea level rise plus the fact the land is sinking) is highest along the Mississippi River Delta in Louisiana, where relative sea level rises of 3.2 ft (.98 meters) have been observed during the 20th century. This is one of the highest relative sea level rises in the world. According to the NOAA Tides and Currents sea level rise interactive tool, the U.S. tide gauges that have shown the highest rates of sea level rise over the past century are at Grand Island, LA (1.8 ft rise since 1947), Galveston, TX (1.1 ft since 1957), and Chesapeake Bay, VA (0.6 feet since 1975). Alaska and some areas along the Pacific Northwest coast are at low risk of sea level rise, because the relative sea level is actually falling at present. Land in these regions is rising as it recovers from removal of the weight of the great ice sheets that covered much of North America during the last Ice Age. For example, relative sea level at Kodiak Island, Alaska has fallen by 1.1 feet since 1975, despite the fact global sea level has been increasing.


Figure 1. Twentieth century annual relative sea-level rise rates in mm/year along the U.S. coast. The higher rates for Louisiana (9.85 millimeters [mm] per year, about 3.3 ft/century) and the mid-Atlantic region (1.75 to 4.42 mm per year, 0.6 - 1.4 ft/century) are due to land subsidence. Sea level is stable or dropping relative to the land in the Pacific Northwest, as indicated by the negative values, where the land is tectonically active or rebounding upward in response to the melting of ice sheets since the last Ice Age. Image credit: Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region (data from Zervas, 2001).

U.S. Coastal Vulnerability
The Coastal Vulnerability Index (CVI) takes into account six factors:

1) The geology of the coast. Barrier islands, river deltas, and marshes are the most vulnerable to erosion and sea level rise, while steep, rocky cliff shores are the least. Sheltered bays like Galveston Bay and Tampa Bay are less vulnerable than the exposed coasts. (Note, however, that hurricane storm surges are typically higher in sheltered bays, at least for slow-moving storms).

2) How steep the land near the coast is. Gently sloping lands are the most vulnerable. In the Gulf Coast region, the slope variable has the highest risk ranking along the Louisiana coast, the Texas coast north of Corpus Christi, and the southwest Florida coast.

3) The local rate of sea level rise. The sea level is rising faster along the western Gulf of Mexico than the eastern Gulf. The highest rates of sea-level rise in the Gulf of Mexico (and in the United States) are in the Mississippi delta region (10 mm/yr, or 1 inch/2.5 years).

4) The amount of shoreline erosion going on. Most of the U.S. coast is moderately or severely eroding, and very few areas are gaining (Figure 2).

5) The mean tidal range. Shores that have a large difference between low and high tide are less likely to get a significant storm tide--the height above mean sea level of the sum of the storm surge plus the tide. For example, in a region like Maine, which has a 12 ft range between low and high tide, a storm having a 9 ft storm surge will have a storm tide below local high tide for a quarter of a tidal cycle. Shores with a very narrow tidal range (e.g., the 2 ft tidal range common along the Texas and Louisiana Gulf Coast) will get a storm tide of 8 - 10 feet with the 9 ft storm surge in the above example. Shorelines with a narrow tidal range always get high storm tides regardless of when the storm surge hits.

6) How high the waves at shore are. Obviously, shores that experience higher wave heights are at greater risk. In the Gulf of Mexico, wave energy is highest along sections of the Texas coast and on the southern tip of the Mississippi delta.

Figure 2. Shoreline change around the United States based on surveys over the past century. All 30 coastal states are experiencing overall erosion due to natural processes (e.g., storms, sea-level rise) and human activity. If the shoreline is uncolored, no data was available. Image credit: USGS, 1985, and taken from Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region).

The Coastal Vulnerability Index (CVI) web page gives detailed maps of each section of the U.S. coast, along with specific reasons why each portion of the coast was assigned the ranking it got. A brief summary:

The Gulf Coast
The Gulf Coast has 55% of its length in the "very high" or "high" vulnerability range. Fully 41% of the coast falls in the "very high" range, far more than the 28% in that category along the Pacific coast and 23% along the Atlantic coast. The region around New Orleans is the most vulnerable region of the entire U.S. coast. The Florida Panhandle, as well as the West Florida coast, are at low to moderate risk because the land is not sinking much, wave heights are lower, and the slope of the land is relatively steep near the coast. The Texas coast is considered to be at a high to very high risk because of the relatively high mean wave height, sinking land, and shallow coastal slope.

The East Coast
The East Coast has 50% of its length in the "very high" or "high" vulnerability range. The highest vulnerability areas are typically high-energy coastlines where the regional coastal slope is low and where the major landform type is a barrier island. A significant exception to this is found in the lower Chesapeake Bay. Here, the low coastal slope, vulnerable landform type (salt marsh) and high rate of relative sea-level rise combine for a high CVI value. The coastline of northern New England, particularly Maine, shows a relatively low vulnerability to future sea-level rise. This is primarily due to the steep coastal slopes and rocky shoreline characteristic of the region, as well as the large tidal range.

The Pacific Coast
The Pacific Coast has 50% of its length in the "very high" or "high" vulnerability range. Areas of very high vulnerability include the San Francisco - Monterey Bay coast and in southern California from San Luis Obispo to San Diego, where the coast is most highly populated. The highest vulnerability areas are typically lower-lying beach areas. The low risk, least vulnerable areas generally occur at rocky headlands along cliffed coasts where the coastal slope is steep, relative sea-level is falling, tide range is large, and wave energy is lower. Examples of these areas are the northern coast of Washington, Monterey, and Cape Mendocino, California.


Figure 3. The Coast Vulnerability Index (CVI) for the U.S.

References
Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region.

National Assessment of Coastal Vulnerability to Sea-Level Rise: Preliminary Results for the U.S. Gulf of Mexico Coast (USGS, 2000).

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 677 - 627

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28Blog Index

677. IKE
Quoting scottsvb:
I would never consider the NAM in the tropics... only continental lows or upper wind patterns!


I don't think any of them are worth a flip on the tropics in 2009.

I've read enough discussions from mets at weather offices that have stated so about how bad their performing.

Didn't the GFDL and HWRF have Andres going inland....turning north? Wrong.

Member Since: Posts: Comments:
Quoting CycloneOz:


That's my main concern...

I'm working with the owner of the system to see what kind of shielding will work during "xtreme" conditions. There is hope...


Be careful with overheating if you alter it. That can possibly bring the same result, darkness :)
Member Since: Posts: Comments:
LOL That didn't take long!
000
WTPZ32 KNHC 241455
TCPEP2
BULLETIN
TROPICAL DEPRESSION ANDRES ADVISORY NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP022009
800 AM PDT WED JUN 24 2009

...ANDRES WEAKENS TO A TROPICAL DEPRESSION...

AT 800 AM PDT...1500 UTC...THE CENTER OF TROPICAL DEPRESSION ANDRES
WAS LOCATED NEAR LATITUDE 20.3 NORTH...LONGITUDE 107.7 WEST OR ABOUT
130 MILES...210 KM...WEST OF CABO CORRIENTES MEXICO AND ABOUT 230
MILES...370 KM...SOUTHEAST OF THE SOUTHERN TIP OF BAJA CALIFORNIA.

THE DEPRESSION IS MOVING TOWARD THE NORTHWEST NEAR 9 MPH...15 KM/HR.
ANDRES IS FORECAST TO CONTINUE MOVING NORTHWESTWARD UNTIL IT
DISSIPATES.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER
GUSTS. CONTINUED WEAKENING IS FORECAST TODAY AND ANDRES IS EXPECTED
TO DISSIPATE LATER TODAY OR TONIGHT.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB...29.68 INCHES.

...SUMMARY OF 800 AM PDT INFORMATION...
LOCATION...20.3N 107.7W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...NORTHWEST OR 305 DEGREES AT 9 MPH
MINIMUM CENTRAL PRESSURE...1005 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
200 PM PDT.

$$
FORECASTER BROWN

Member Since: July 8, 2005 Posts: 259 Comments: 23012
Quoting IKE:


Even the areas of interest are a little benign.


The proper term is... boring
Member Since: Posts: Comments:
Quoting STORMTHRILLA:


Name this major hurricane that formed in a well-below average hurricane season as the only true entity of the year. It formed under high wind shear and followed a gummyworm-like path in the Atlantic...stormthrilla


I want to say Hurricane Erika because I remember seeing that on the weather channel in 1997.
Member Since: July 8, 2005 Posts: 259 Comments: 23012
I would never consider the NAM in the tropics... only continental lows or upper wind patterns!
Member Since: Posts: Comments:
671. IKE
Quoting scottsvb:



really?? is that why now on the 12z run it shows almost nothing? and the wave going into Mexico. 86!


Looks like you looked at it.

He's just talking about it...no big deal.
Member Since: Posts: Comments:
Quoting leftovers:
thank gosh for the nam or there would not be much to think about. stalled out fronts over warm water with a tropical wave mingling nearby nam might be on to something.



really?? is that why now on the 12z run it shows almost nothing? and the wave going into Mexico. 86!
Member Since: Posts: Comments:
Quoting Ossqss:
Oz, most low end units have exposed bulbs that don't do well with cold horizontal rain. Check the specs before you go forward with one to ensure it is capable of handling the exposure.


That's my main concern...

I'm working with the owner of the system to see what kind of shielding will work during "xtreme" conditions. There is hope...
Member Since: August 26, 2006 Posts: 10 Comments: 3420
668. IKE
Quoting hurricane2009:
The NAM is not a tropical model. The only time I use it is if it shows tropical development close to the US that comes from fronts that move off the US. I have found it does a decent job showing the moisture that eventually becomes a tropical system, but it isnt used to determine when tropical systems form directly.


It is good at showing where moisture will be at. It spinning up lows and backing off is similar to the 2009 version of the GFS and to some extent, the ECMWF.

I'll go this far....I think they'll be an increase in moisture in the SE GOM by this weekend...then a cold front should sag into the SE by the first of next week.
Member Since: Posts: Comments:


Name this major hurricane that formed in a well-below average hurricane season as the only true entity of the year. It formed under high wind shear and followed a gummyworm-like path in the Atlantic...stormthrilla
Member Since: Posts: Comments:
Good morning everyone! I sure do hope some of that convection in the gulf can push back east a little. It would make for a very stormy day here in Tampa
Member Since: Posts: Comments:
what is this system 8 n 51 w ?


Link
Member Since: August 22, 2006 Posts: 0 Comments: 2552
Oz, most low end units have exposed bulbs that don't do well with cold horizontal rain. Check the specs before you go forward with one to ensure it is capable of handling the exposure.
Member Since: Posts: Comments:
661. Mikla
FYI... this is what I sent to my Senator in case other want to do the same or similar...
------------------------------------------
Please read the following link:

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1204&tstamp=#commenttop

The House of Representatives recently passed the FY 2010 CJS Appropriations Bill which included language urging NASA and NOAA to work together to provide upgraded capability for storm prediction through an upgrade to the next generation QuikSCAT satellites.

As severe storms are a common and dangerous occurrence in FL, I urge you to support the Next Generation QuikSCAT replacement project by including similar language in the Senates FY2010 Appropriations Bill and push for as early a launch as is possible. The ~$750M price tag could easily be offset by the reduction in damage/injury such a two satellite system could provide.
Member Since: Posts: Comments:
'morning all! :)

Over at XtremeHurricanes.com, PensacolaDoug has found and posted a most excellent video of Hurricane Ivan produced by Mark Suddath of hurricanetrack.com back in 2004.

It's a 30-minute program and really captures the problems associated with video taping during a night storm.

After watching it several times, I'm now thinking about getting one of these things for the XtremeTeam...


Portable Construction Lighting

This system has 4 lamps...so in the event of a night storm, I'd turn two of the lamps to light up the scene for the live web cam and I'd use the other two lamps to light up our work in the storm. This means the XtremeTeam would have to stay close to the RHWS in the night...which is actually fine by me...as I don't venture out during night storms.

Member Since: August 26, 2006 Posts: 10 Comments: 3420
I really dont know why.....scratch that... I do know why some of you are looking @ a NAM model!

I wouldnt bother!
Member Since: Posts: Comments:
Quoting CybrTeddy:
I thought a QuickSCAT was going up on a Delta rocket down at Vandenburg AFB in 2013?


It has to be funded then built before it can be launched. Hence the request for contacting your rep to make it happen.

Quote from Dr. Jeffs blog on 3-26-09.

The second best solution: a QuikSCAT replacement
A second, cheaper solution that is being considered is to launch a replacement QuikSCAT satellite that has similar capabilities to the current one. NOAA and NASA are exploring a partnership with the Japanese Space Agency (JAXA) to fly a QuikSCAT instrument on their GCOM-Water Cycle satellite, scheduled to launch in 2016. Funding must begin in 2010 in order to meet this launch deadline. The proposed QuikSCAT replacement would be able to measure winds as high as 100 mph (Category 2 hurricane strength), and have improved ability to measure winds in heavy rain. The new satellite would have a 20% improvement in spatial resolution. The cost would be less than that of a next-generation QuikSCAT, since the rocket and and satellite are already paid for. However, there are additional costs involved in adapting QuikSCAT to the Japanese engineering requirements. The final costs of such a replacement QuikSCAT have not been determined yet, but would probably be several hundred million dollars.

This is the type of cause that it is important for we as citizens to lobby Congress for. Write your Senators and Representatives! The earliest a new QuikSCAT could get launched is 2015, and the current satellite is probably going to die well before then. Feel free to use the information above, or come up with your own. Thanks!


QuickScat blog 3-26-09
Member Since: Posts: Comments:
656. IKE
Quoting Orcasystems:
Blog Update
Reflector site for those at work, which now also includes Weather456, daily updates


AOI #1

AOI #2


Even the areas of interest are a little benign.
Member Since: Posts: Comments:
Dr. M,

Letters written and sent, although support of the space program (and especially hurricane forecasting) is usually a given, since NASA is based in the Houston area. Every little bit helps!

Glad to hear you are enjoying your vacation!
Member Since: Posts: Comments:
Dr. JM,

What a relief even though it is several years off.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Blog Update
Reflector site for those at work, which now also includes Weather456, daily updates


AOI #1

AOI #2
Member Since: Posts: Comments:
I thought a QuickSCAT was going up on a Delta rocket down at Vandenburg AFB in 2013?
Member Since: July 8, 2005 Posts: 259 Comments: 23012
Quoting hurricanemaniac123:
Where is everybody?


Hiking on the Appalachian Trail in Argentina with Mark Sanford. Link
Member Since: July 31, 2006 Posts: 56 Comments: 8112
Where is everybody?
Member Since: September 21, 2008 Posts: 9 Comments: 688
Here is the link to the previous QuickScat blog referenced above. Contact info for the appropriate representative is imbedded in the entry at the bottom. You have a chance to help this happen. Make it so !

QuikSCAT blog
Member Since: Posts: Comments:
Thx Doc... glad you're enjoying your PT. :) I wish I was there too... hehe.
Member Since: Posts: Comments:
646. JeffMasters (Admin)
Hi all, I'm having a great time sea kayaking here on Kafalonia Island, Greece, and found this in my email from last week. I encourage those of you with Senators on the appropriate committee to write to them about a new QuikScat satellite this week. Here's the email I got from Dr. Paul Chang on the QuikScat team:

The House of Representatives passed the FY 2010 CJS Appropriations Bill
at ~6:30 pm yesterday (June 19). The Report language accompanying this
Bill included the following statement:

The Committee directs NOAA, together with NASA which is similarly
directed, to continue co-funding joint studies
within available funds that should lead to a fiscal year 2011
request to build and fly an operational scatterometer
providing sea surface vector wind measurements. NOAA should
aggressively pursue negotiations to secure a flight
opportunity for this instrument that is both reliable and timely.

To the extent that there is interest in NOAA being able to offer a
Dual-Frequency Scatterometer for launch on the Japasese GCOM-W2 in
January 2016 (possibly November 2015), new funding will be required in
its FY2011 budget to enable the development and delivery of this
instrument to meet this launch schedule. I understand that the Senate
will start its mark up of the FY2010 Appropriations Bill early this
coming week. Therefore, it could be very helpful for interested parties
to make this opportunity known via email to their Senator who sits on
the Appropriations Committee and request that similar language be
inserted in the Report language for the Senate Appropriations Bill.

This is the next best thing to the actual provision of funds for NOAA.

In your blog several months ago you encouraged your readers to contact
their representatives. If you are so inclined a follow-up note of
encouragement for folks to do so again might be beneficial in an effort
to get this language in the Senate Appropriations Bill also.


Jeff Masters
640. Weather456

Hehe... yeah.
Member Since: Posts: Comments:
Great to see ya too Storm!
Member Since: Posts: Comments:
good morning...milder at 9:30 a.m. but still a scorcher. have a good day everyone.
Daytona Beach (Ponce Inlet), FL, Daytona Beach, Florida (PWS)
Updated: 1 sec ago
86.3 °F
Scattered Clouds
Humidity: 74%
Dew Point: 77 °F
Wind: 0.0 mphfrom the ESE
Wind Gust: 4.0 mph
Pressure: 29.80 in (Rising)
Heat Index: 98 °F
Visibility: 10.0 miles
UV: 3 out of 16
Clouds: Scattered Clouds 2000 ft
(Above Ground Level)
Elevation: 12 ft

Member Since: Posts: Comments:
At this point I'll take any area of disturbed weather.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Ike,
you wanted an Invest yesterday remember, I think you might get one next week somewhere, lol.
Member Since: Posts: Comments:
Its groundhog day here in the northeast.

Fog/Mist

60 °F
(16 °C) Humidity: 96 %
Wind Speed: NE 14 G 17 MPH
Barometer: 29.77" (1009.3 mb)
Dewpoint: 59 °F (15 °C)
Visibility: 1.50 mi.
Member Since: Posts: Comments:


high of 86 with heat index of 95 today gonna be a little warm
Member Since: July 15, 2006 Posts: 163 Comments: 52216
604. That is a big blob.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
635. IKE
Hold Your Head Up!

High today only 97!
Member Since: Posts: Comments:
634. IKE
Quoting DaytonaBeachWatcher:
Ike the low that the NAM is forcasting has been in the long range gfs for the 27th of the month for a long time now. i have been wondering if it would come to pass or not. the nogaps was picking it up the other day for a few runs, havent checked to see if it still is. I think something will be there, what it is, still remains to be seen.


NAM is almost alone on forecasting anything there. I would discount it for now.

Not sure on the GFS Cape Verde "storm'.....if it's legit.
Member Since: Posts: Comments:
Ike the low that the NAM is forcasting has been in the long range gfs for the 27th of the month for a long time now. i have been wondering if it would come to pass or not. the nogaps was picking it up the other day for a few runs, havent checked to see if it still is. I think something will be there, what it is, still remains to be seen.
Member Since: Posts: Comments:

AOI #1

AOI #2

Member Since: Posts: Comments:
thanks IKE...
Member Since: September 1, 2008 Posts: 0 Comments: 315
630. IKE
In between >Link and the <. You'll see where it says Link. Delete that and type in what you want.

It's at the end of the linked item.
Member Since: Posts: Comments:
Link

tried to post a pic ... wouldnt work. so tried to do link .. how do you name it?
Member Since: September 1, 2008 Posts: 0 Comments: 315

Viewing: 677 - 627

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28Blog Index

Top of Page

About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.