CCSLRI Blog

Storm Surge Forecast in Hampton Roads

2011-09-01T17:49:00.000-07:00

During the passage of Hurricane Irene I posted the forecast for storm surge. Since it looks like there will be more tropical storms this fall I'm posting how you can get the forecast yourself.

The official storm surge forecast produced by the National Oceanic and Atmospheric Administration is at this LINK

This link takes you to the homepage for the forecast system and has explanations of the graphic displays.

If you click the 'Mid-Atlantic' tab on the left you get a map of locations of NOAA tide gauges where the forecasts refer to.

This map itself shows a gross depiction of water level heights for the next 48 hours (see legend in lower left of map). In this screenshot maximum water level heights are above the maximum astronomical tide.

The Sewells Point site is often the one referred to on news casts but pick the site nearest your location of interest.

Note that water levels during storm surges often are significantly higher in the upper reaches of tidal rivers such as the Lafayette, Elizabeth, Nansemond, York, and others in the region.

If you select Sewells Point as an example the map will look like this.

Local time is on the bottom axis. Height in feet of the water level above the average (mean) lower low water is on the vertical axis.

Green Line - The predicted water level height based on astronomical calculations. This is the predicted tide height you see in the paper.

Dashed Black Line - The predicted water level height in feet from Mean Lower Low Water.

Dashed Red Line - The water level height.

For more information on the plot see the online manual.

So what does this mean? For comparison the following table shows water level heights for past storm surges. Water levels during Irene reached 7.5 feet at Sewells Point: a significant event.

Table - Storm surge water level heights at Sewells Point (from MLLW)

Storm	Date	Water Level (reference to Mean Lower Low Water) in Feet
Hurricane (unnamed)	August 23, 1933	9.03
Hurricane Isabel	September 18, 2003	7.9
Ash Wednesday Storm	March 7, 1962	7.81
Veterans Day Storm	November 12, 2009	7.75
Hurricane	September 18, 1936	7.68
Hurricane	September 16, 1933	7.12
Thanksgiving Nor’easter	November 22, 2006	6.72
Columbus Day nor’easter	October 6, 2006	6.52
Twin nor’easters #1	January 28, 1998	6.02
Hurricane Floyd	September 16, 1999	5.97
Twin nor’easters #2	February 5, 1998	5.88

Note – to adjust to Mean Higher High Water subtract 2.76 feet for Sewells Point

For reference local flooding in ODU neighborhoods starts at about 3.9 feet and Hampton Blvd at the D’Egg and Tastes Unlimited starts to flood at about 4.5 feet.

DOD - climate change, energy, and national security

2011-04-14T11:48:00.000-07:00

In this blog I'll review the current activities of the US Defense Department.
Larry Atkinson - latkinso@odu.edu

Quadrennial Review 2010

Over the past few years the Department of Defense has started to include threats of climate change in its planning. The 2010 Quadrennial Defense Review (LINK) stated:

"Crafting a strategic approach to climate and energy: Climate change and energy will play significant roles in the future security environment. The Department is developing policies and plans to manage the effects of climate change on its operating environment, missions, and facilities. The Department already performs environmental stewardship at hundreds of DoD installations throughout the United States, working to meet resource efficiency and sustainability goals. We must continue incorporating geostrategic and operational energy considerations into force planning, requirements development, and acquisition processes."

This report and those mentioned below show how DOD views climate change, energy security and national security as a package.

US Navy Task Force Climate Change and Task Force Energy

You might think the U.S. Navy in particular and DOD in general would be the last group to be looking at climate change and energy together with national security. That is not the case.

The Navy currently has two task forces: Task Force Climate Change and Task Force Energy formally addressing the issue. This is at the direction of the Chief of Naval Operations (CNO).

The climate change task force is looking at the effect of the opening of the Arctic to shipping and the effect of sea level rise on Navy facilities, among other things.

With a reduction in multi-year ice and a few ice-free months in the summer, the Arctic is opening to shipping and resource extraction. The Navy is working with the Coast Guard to assure the US has adequate capability in this "new ocean".

With all its bases naturally near sea level, the Navy is assessing vulnerability of these facilities to sea level rise and storm surges. Hampton Roads, being the largest Naval base in the world, is of particular concern, as are the commercial operations serving the Navy. A SERDP-funded report on these vulnerabilities will be out in 2012.

Information on the two task forces can be found at --

National Security

In the past year there have been two very relevant reports sponsored by DOD.

The first, which was recently published by the National Academies of Science, is titled "National Security Implications of Climate Change for U.S. Naval Forces". The link to the PDF is LINK

A quote from the press release: “Even the most moderate predicted trends in climate change will present new national security challenges for the U.S. Navy, Marine Corps, and Coast Guard,” said Frank L. Bowman, co-chair of the committee that wrote the report and a retired U.S. Navy admiral. “Naval forces need to monitor more closely and start preparing now for projected challenges climate change will present in the future.”

The second report was titled "National Security and the Threat of Climate Change" authored by 11 retired admirals and generals. The report is at LINK

To quote Vice Admiral (Ret) Truly: “I wasn’t convinced by a person or any interest group—it was the data
that got me.”

Water Security

The U.S. Army Corps of Engineers recently published a report and guidance for their projects.

The report "Addressing Climate Change in Long-Term Water Resources Planning and Management" was published in January 2011

The report can be seen at LINK

To quote from the introduction:

"Water resources underpin our quality of life and our national economy. Climate change impacts to water and water-dependent resources present new and complex challenges to the water resources management community. Meeting these challenges will require close collaboration between the water resources management community and the science community to develop and apply new and improved scientific information and technical tools."

Evidence for Sea Level Rise

2011-03-28T08:35:00.000-07:00

The evidence for sea level rise in the Hampton Roads area is from direct measurements of sea level carried out by the Department of Commerce, National Oceanic and Atmospheric Administrations, National Ocean Service. Interestingly, the group that installs and maintains these measuring stations is located in Chesapeake, VA. Their website has sea level trends for many locations in our region http://tidesandcurrents.noaa.gov/sltrends/sltrends.shtml

Here is the plot for Sewells Pt on the Norfolk Navy Base. What it shows that sea level is rising here at a rate that amounts to 1.46 feet per 100 years. The variation you see is caused by changes in the ocean and atmosphere. These changes cycle over years to decades with the occasional spike caused by a hurricane or northeaster.

The trends they have seen are as follows

Sewell's Point 4.44 mm/yr or 1.46 ft per century
Portsmouth 3.76 mm/yr or 1.23 ft per century
First Island (fishing pier) of the Chesapeake Bay Bridge Tunnel 6.05 mm/yr or 1.98 ft per century

In our region here are at least three reasons for this relatively rapid rise.

Reason 1 - The ocean's waters are slowing warming and as they warm they expand: the expansion causes sea level to rise because the volume of water is increasing.

Reason 2 - The last continental glaciation (18,000 years ago) was so heavy it pushed down the land in southern Canada and, like a teeter-totter, Virginia went up. Now, even long after the glaciers disappeared, southern Canada is rising and coastal Virginia is sinking. The same thing is happening in England and Holland for example.This process is called glacial fore-bulge subsidence.

Reason 3 - Chesapeake Bolide and other subsidence - There is a very small amount of subsidence in the lower Chesapeake Bay area related to the impact of a meteorite 35 million years ago. The land in that area is subsiding a bit more.There is also some subsidence near areas of significant ground water withdrawal.

A recent report has just been published - "Chesapeake Bay land subsidence and sea level change: an evaluation of past and present trends and future outlook". Boon, Brubaker and Forrest. Special Report No 425, Virginia Institute of Marine Science, Gloucester Point, VA 23062 Link to Report

Glacial fore bulge subsidence is described in "Glacioisostatic influences on Virginia's late Pleistocene coastal plain deposits" by Timothy W. Scott a, Donald J.P. Swift, G. Richard Whittecar, and George A. Brook in Geomorphology 116 (2010) 175–188. Link to report

The Chesapeake Bolide is described in Link

New CCSLRI Blog up and running

2011-03-23T10:22:00.001-07:00

We now have a place for me to post information and promote discussion of the CCSLRI.
More coming!