CHAPTER 4

COASTAL HAZARDS

Introduction

The original CoastWatch and Coastal Hazards themes and the more recent Coastal Forecast System (CFS) program are becoming a single COP theme called “Coastal Forecast System.”10 The new theme includes CoastWatch, Ocean Color, Tsunami, Sea Level Rise, Hurricane Winds, Coastal Winds, Great Lakes Forecasting System (GLFS), and East Coast Forecast System Feasibility Experiment (ECFSFE) programs. Taken together, these programs constitute the precursor elements of a unified coastal forecast and analysis system designed to acquire, analyze, and disseminate information on the present and future physical state of the coastal environment.

Written reports and plans were made available to panel members prior to the formal review held in Washington, D.C. on November 1-2, 1993. This documentation included the FY 1993 Implementation Plans for CoastWatch (COP, 1993a) and the other Coastal Hazards programs, the published Strategic Plan for the Coastal Forecast System (NOAA, 1993), and the report resulting from the 1991 review of COP by the Panel on the NOAA Coastal Ocean Program (PoCO) (NRC, 1991). Much additional information on technical progress and status was contained in the presentations made by each program at the November 1993 review meeting. In addition to presentation

10  

The new theme was referred to as Coastal Hazards at the time of the review and will be referred to as such throughout this report.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) CHAPTER 4 COASTAL HAZARDS Introduction The original CoastWatch and Coastal Hazards themes and the more recent Coastal Forecast System (CFS) program are becoming a single COP theme called “Coastal Forecast System.”10 The new theme includes CoastWatch, Ocean Color, Tsunami, Sea Level Rise, Hurricane Winds, Coastal Winds, Great Lakes Forecasting System (GLFS), and East Coast Forecast System Feasibility Experiment (ECFSFE) programs. Taken together, these programs constitute the precursor elements of a unified coastal forecast and analysis system designed to acquire, analyze, and disseminate information on the present and future physical state of the coastal environment. Written reports and plans were made available to panel members prior to the formal review held in Washington, D.C. on November 1-2, 1993. This documentation included the FY 1993 Implementation Plans for CoastWatch (COP, 1993a) and the other Coastal Hazards programs, the published Strategic Plan for the Coastal Forecast System (NOAA, 1993), and the report resulting from the 1991 review of COP by the Panel on the NOAA Coastal Ocean Program (PoCO) (NRC, 1991). Much additional information on technical progress and status was contained in the presentations made by each program at the November 1993 review meeting. In addition to presentation 10   The new theme was referred to as Coastal Hazards at the time of the review and will be referred to as such throughout this report.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) material, several groups distributed reprints of papers. Some written responses to specific questions were obtained from presenters following the meeting. The panel's evaluations and recommendations are organized here according to the panel's charge. Overall assessments and recommendations are presented first, followed by more detailed technical summaries and recommendations for individual programs. Goals and Objectives The Coastal Hazards theme is evolving into a Coastal Forecast System. The panel endorses the development of a scientifically valid, operationally useful, and programmatically relevant Coastal Forecast and Analysis System (CFAS) to characterize and predict the physical state of the coastal environment. The present set of programs reviewed within this theme addresses many of the research and development needs required for a CFAS, but the theme management team has not yet linked the theme's programs into a coherent system. The basic elements of a CFAS are shown in Figure 4.1: environmental data are acquired, processed, and combined with models to produce nowcasts and forecasts of selected environmental variables. Basic CFAS scientific and engineering research and development includes: improvements in, or additions to, existing data acquisition; development of accurate nowcast/forecast models (including the associated infrastructure for input and output of data) incorporating an improved understanding of the dominant physical processes; and development of scientifically valid, policy-relevant data products and their timely dissemination to users. An approximate mapping of the present Coastal Hazards programs into a CFAS is shown in Figure 4.1 to illustrate how these programs contribute to the central goal of the theme.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) Figure 4.1 Incorporation of Coastal Hazards elements into a Coastal Forecast and Analysis System. SLOSH is the Sea, Lake and Overland Surges from Hurricanes; GLFS is the Great Lakes Forecasting System; and ECFSFE is the East Coast Forecast System Feasibility Experiment. Progress and Quality Significant scientific and technical progress has been achieved in most program areas since the 1991 panel review. Highlights include: development of an operational data acquisition and distribution system in the CoastWatch program; derivation and testing, as part of the Coastal Winds program, of refinements that will improve the accuracy of coastal winds significantly; acquisition by the Tsunami program of bottom pressure data in key regions needed to improve physical understanding of tsunami processes; and

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) the first successful demonstration of a regional Great Lakes Forecast System (GLFS) utilizing inputs from CoastWatch, the NOAA National Ocean Service (NOS), and National Weather Service (NWS) operational models and providing products to a wide variety of users. Although COP support for these programs has been quite small in monetary terms (13% of the total FY 1993 COP budget for CoastWatch and Ocean Color, 3% for the former Coastal Hazards theme and CFS planning), the investigators associated with the various programs have been resourceful in leveraging COP support. This has led to increased emphasis and focus, and in some cases redirection, of ongoing coastal research and development activities funded by the NOAA line offices. All activities have reported technical progress to colleagues through presentations at scientific meetings, technical reports, and open literature publications. The panel noted that those programs engaged in vigorous collaboration with outside (academic) scientists also had many publications in the refereed literature and demonstrated the most scientific progress. The infusion of new ideas and energy into Coastal Hazards programs by both outside scientists and new COP-funded post-doctoral investigators represents one major benefit of the agency-academic partnership approach adopted by COP. Utility of the Research All programs have identified specific customers for their environmental products. This was especially evident with the GLFS, CoastWatch, and Tsunami programs. Users of products span the range from academic researchers to policymakers, operational agencies, businesses, and secondary schools, underscoring the broad utility and potential impact of these COP-supported activities. For example, the CoastWatch system has formal agreements with 85 regular users of its system. Many external users obtain sea surface temperature data from the CoastWatch systems; other Coastal Hazards programs (e.g., GLFS) use CoastWatch products as inputs for their predictions. Another example of the utility of products of the Coastal Hazards theme is the series of maps prepared by the Tsunami program to predict the extent of tsunami inundation at several vulnerable U.S. Pacific Coast and island sites. Theme Management There was a disparity in the level of formal technical review instituted by the various programs. CoastWatch has an active Technical Advisory Committee (TAC), representing the interests and viewpoints of the relevant external communities. The

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) discipline provided by the reviews clearly helped to focus program objectives and approaches. Unfortunately, no other programs in the present Coastal Hazards theme have successfully established a similar review process, despite attempts to do so. In addition to providing input to COP management, formal reviews provide a forum for technical exchange between programmatically distinct, but scientifically related, program activities. Several NOAA participants in the November 1-2 panel meeting commented favorably on the technical benefits they derived from listening to the presentations of their colleagues. These contacts should lead to an increased awareness of relevant work within NOAA and to future cooperation. Responsiveness to Past Reviews The programs in the present Coastal Hazards theme were not organized into a single theme at the time of the 1991 panel review (NRC, 1991). Responsiveness to specific programmatic suggestions are thus examined below in the individual program reviews. However, the 1991 review did recommend that the programs identify more specifically their objectives, intended products, and potential customers. In addition, the 1991 review also stressed the benefits that could result from increased collaboration with academic scientists and infusion of recent graduates and/or postdoctoral investigators into COP programs. The panel is pleased to note that although there have been significant budget shortfalls, programmatic reorganizations, and redirections of focus in the last two years, the individual programs generally have followed the 1991 recommendations. Future Plans and Theme Recommendations Most of the panel's recommendations regarding future plans are best presented in the context of the individual program reviews. However, four areas of concern are identified here because of their overall importance to COP and/or their cross-cutting nature, impacting not only other Coastal Hazards programs but also programs in the other two COP themes: COP must organize the transition of mature products, algorithms, and systems from research-oriented development to operations managed by the NOAA line offices. In particular, CoastWatch has developed, tested, marketed, and established a reliable distribution system for a suite of important sea-surface temperature and reflectance products based on satellite measurements. Routine operation of the system requires significant resources. While most of the support for these activities is already

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) provided by line offices, COP must take care to avoid becoming burdened by essentially operational responsibilities to the detriment of its mission for research and development. COP managers must continue to stress the benefits of outside collaboration in all aspects of COP research and development and timely publication of results in the open literature. Peer review of research is essential. COP must support acquisition of SeaWiFS ocean color data for the Alaska coastal region. Although this was part of the original FY 1993 plan for the Ocean Color program, an Alaska site was not chosen in FY 1993, and funding constraints in FY 1994 have caused COP to delay for yet another year. The panel recommends that the implications of this gap in the national coastal ocean color data base be analyzed carefully to ensure that it does not devalue the investment being made in the other coastal ocean color sites. In addition, attention must be paid to the implications of this gap on the ongoing Bering Sea FOCI studies being conducted by the Coastal Fisheries Ecosystems (CFE) theme. COP must continue to foster improvements in the accuracies of coastal wind analyses and forecasts produced by operational models such as the ETA model. Given COP's severely limited resources, research on improving model predictions of coastal winds is anticipated to have greater short-term reward than investments in large-scale data acquisition systems for coastal winds. The Coastal Hazards theme should adopt as its overall goal the development of a scientifically valid, operationally useful coastal forecast and analysis system. COP has a clear and unique role within NOAA in identifying and supporting scientific research and development needed to develop such a system, and the adoption of a clear mission statement by the Coastal Hazards theme should help ensure that the different programs within the theme contribute to the overall goal. A coastal forecast and analysis system could provide ocean color and coastal winds data of great utility for coastal fisheries research (including CFE) and management. Formal technical review and advisory procedures should be incorporated as soon as possible at the theme planning level and when appropriate within individual programs. The theme TAC is necessary to help management evaluate the quality and appropriateness of individual programs, and to foster increased communication between theme programs. Some of the programs may be too small to support their own TACs.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) The panel further recommends that the Coastal Forecasting System program, having been successful in developing a conceptual design for a coastal forecast and analysis system (CFAS), now be charged with the evaluation and assessment of the other programs within the Coastal Hazards theme as well as continued planning for the CFAS. The new role of the CFS program would thus focus on identification and initiation of new scientific and engineering research and development programs needed to build a scientifically and technically sound CFAS. This would complement the developing NOAA-wide effort in this area. Individual Programs—Assessments and Recommendations CoastWatch Program The overall objective of the CoastWatch program is to support federal, state, and local decisionmakers and researchers by providing timely access to coastal data and products. Since 1989, CoastWatch activities have focused on supporting clients with near-real-time coastal and Great Lakes imagery products from (primarily NOAA) polar orbiting satellites. This task has involved developing an initial set of surface temperature and radiance products, establishing reliable communication networks both to acquire satellite data and to distribute the products to clients, and identifying and interacting with users/clients to insure that the products are scientifically and operationally useful. The CoastWatch program has been successful in establishing an operational demonstration system for data processing and distribution, involving a central operations support group and eight distributed nodes hosted at NOAA laboratories. Raw satellite data are received from the NOAA National Environmental, Satellite, Data and Information Service (NESDIS), and 1-km Local Area Coverage (LAC) radiances and multi-channel sea surface temperatures (MCSST) are generated. These data products are then forwarded electronically to the nodes by the Ocean Products Center of NOAA/NOS. Additional tailored products can be generated at the node, and each node also has a “help” desk manned by a trained analyst to provide background information in response to user requests. Nodes distribute products to local users, primarily via the Internet electronic communication network. Eighty-five users have signed formal Memoranda of Agreement and interact with the system on a regular basis. Funding from COP has allowed the development of a cohesive CoastWatch system, with COP providing linkages among several NOAA line offices. It is unlikely that the CoastWatch system would have been as successful, comprehensive, or useful if COP had not contributed its perspective and focused support to encourage the cooperation of several different NOAA groups in CoastWatch research and development.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) The CoastWatch goal of developing an operational demonstration data acquisition and distribution system is of crucial importance to the ultimate development of a CFAS. The utility of CoastWatch data products and the reliability of the system become clear when it is recognized that many research users rely upon CoastWatch as the primary means for acquiring coastal LAC and MCSST data for their own archives. In addition, near-real-time coastal forecast efforts such as the Great Lakes Forecast System and the new East Coast Forecast System Feasibility Experiment (both discussed below) rely upon CoastWatch products for portions of their routine input. The CoastWatch program has remained focused on system development, production, and dissemination of a limited, yet extremely useful, set of data products. This is consistent with relevant recommendations of the previous panel review in 1991. CoastWatch first convened a TAC in early 1992 to examine the program and to provide recommendations on its future course. The report of the TAC11 was primarily concerned with procedural and structural recommendations, which was appropriate considering the maturity of the program. Clear progress has been made on several of the TAC's recommendations, chiefly the involvement of the outside user community and the need for clear statements of the program's goals. As with the present review, the TAC identified a need for increased effort related to the development of science products and applications. The primary recommendation arising from the present review concerns the transition of CoastWatch operational costs from COP to other NOAA line offices. The panel feels strongly that the burden of continuing operations of CoastWatch should not be borne, even in part, by COP, but rather by the operational line offices (NESDIS and NOS). Having demonstrated the feasibility and utility of CoastWatch, COP support should now be focused on scientific and research issues associated with development and testing of new products. Tsunami Program The overall aims of the Tsunami program remain the mitigation of tsunami damage (economic, physical, and sociological) to Alaska, Hawaii, California, Oregon, 11   Letter dated July 10, 1993 to Kent Hughes (CoastWatch Program manager) from William Pearcy (Oregon State University), Eileen Hofmann (Old Dominion University), and Ronald Tipper (Joint Oceanographic Institutions, Inc.) and letter dated November 29, 1993 to Kent Hughes from Eileen Hofmann.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) and Washington. This work is in direct support of NOAA's responsibility as the primary national source for tsunami warnings and hazard mitigation. The program is managed by the NOAA Pacific Marine Environmental Laboratory, and has clear objectives in the areas of observations, modeling, and generation of user products, such as inundation maps. They are developing and deploying bottom pressure recorders (BPRs) with the dual aims of (1) acquiring accurate data supporting retrospective modeling of tsunami generation and propagation mechanisms, and (2) establishing the basis for a future system capable of providing real-time warnings, covering tectonically active regions off the coasts of Alaska, Oregon, and Washington. Modeling activities include the evaluation and refinement of sophisticated inundation models developed by Japanese scientists, and used in Japan, including tests based on actual recent tsunamis for which adequate data exist. The program has been especially aggressive in acquiring relevant data both from their BPRs and from post-inundation site visits. Modeling has also been broadened to take into account the relationship between background sea level (established independently of tsunamis) and the extent of inundation. User products are focused on the production of inundation maps for key U.S. coastal sites, including Hilo Bay, Hawaii; Eureka and Crescent City, California; and coastal Oregon. The program appears to be well managed, and there is significant progress being achieved in all areas. It has so far been successful in synthesizing the needs and approaches required by scientific research with the objectives dictated by the operational roles of NOAA and other federal and state agencies. The program is commended for its decision to base modeling work on the best established models, even though they were developed in Japan (rather than by U.S. researchers), and to fund U.S. academic experts to help evaluate and further refine the models (rather than building a separate capability within NOAA). BPR development and deployment efforts have been linked closely with the accuracy requirements of the modelers as well as the need to acquire measurements in previously data-sparse geographical regions. The new efforts aimed at developing a real-time reporting capability for the open-ocean BPR data directly supports operational needs. Throughout, there has been a strong emphasis on reporting research results in the refereed literature and at both scientific and programmatic conferences. The program has identified the ultimate federal and state users of its products [e.g., the NOAA National Weather Service (NWS), the Federal Emergency Management Agency (FEMA), and the California Seismic Safety Commission] and seems to have developed a good working relationship with them. The program reports that the new inundation maps being produced are of great utility to the ultimate users.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) Hurricane Winds Program NOAA, through the National Meteorological Center (NMC) and the National Hurricane Center (NHC), has the national responsibility for predicting the time, location, and intensity of landfalling hurricanes. Precise specification of the near-surface hurricane wind field is required to ensure that warnings are accurate. Economic and sociological consequences of overly conservative predictions are nearly as important as the consequences of underpredicting the magnitudes or extent of hurricane conditions. The Hurricane Winds program is aimed at developing techniques for accurately modeling surface wind fields in hurricanes through real-time data assimilation and analysis. Retrospective analyses are performed in support of these modeling activities, yielding wind fields that are useful for developing and testing storm surge and wave models used in other products of the Coastal Hazards theme. The landfalls in the United States of several large tropical storms and hurricanes in the past three years have provided an extensive data set illustrative of measurement and modeling capabilities. Program personnel have been analyzing these recent events intensively, and there is evidence that their surface wind field models and assimilation techniques are becoming more accurate. Some scientific results have been reported in the refereed literature and at various conferences. The Hurricane Winds program has been particularly aggressive in acquiring data from diverse sources and using all available data in their analyses. These activities have highlighted an institutional problem within NOAA/NMC/NHC; only small subsets of available measurements and model outputs are used operationally to generate forecasts. Program personnel credit the availability of COP support with allowing them to develop mechanisms for real-time data acquisition and products, as well as the communication links to the traditional operational organizations; previously, attention had been focused almost exclusively on retrospective analyses. Nonetheless, there was frustration expressed by the scientists that the operational organizations were not making effective (or, at times, any) use of the products. The scientific work being conducted appears to be valid and useful. COP can be credited with the change in emphasis from purely retrospective analyses to development of a system for real-time data acquisition and analysis. In addition to further scientific and engineering refinements, however, the theme management must ensure that the program is generating products that will be used by the clients. In this case, the problem appears to be on the clients' side, but strong support for continued COP funding will probably require agreement by the clients that the program's results are useful.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) Coastal Winds Program Accurate knowledge of near-surface winds over the coastal oceans is critical for modeling the coastal zone and predicting coastal hazards. Measurement and prediction of coastal surface winds, however, is extremely difficult. Operational atmospheric models typically have insufficient spatial resolution to allow accurate modeling of the wind field in coastal regions. Small-scale features of the coastal wind field are of relatively greater importance than similar-scale variations in the wind field over the open ocean. The nearby presence of land strongly influences the wind field, and the simplified topography used in many large-scale numerical weather prediction models is insufficient in coastal areas; in some instances, spectral truncation of land topography leads to coastal ocean areas being treated as land in the models! Despite the economic, sociological, and scientific importance of the near-surface coastal wind field, numerical weather prediction has not placed special emphasis on the accurate prediction of coastal winds. Several activities at NMC, supported in part by COP, have been initiated to improve the accuracy of coastal surface wind predictions and modeling. These include: The use and enhancement of a high resolution (40- and 80-km) regional model (ETA) for prediction of coastal atmospheric circulation; Verification of both global and regional models for numerical weather prediction in coastal as well as open-ocean regions; Operational daily verification using buoy (both coastal and open ocean) data in collaboration with the Marine Forecast Branch of NOAA/NMC; Production of SST fields for the ETA model (1/8 degree resolution) from analyses of satellite high-resolution (8-km) SST measurements; Validation and assimilation of low-resolution surface wind speed data derived from the operational measurements from Defense Meteorological Satellite Program (DMSP) satellites and an evaluation of ERS-1 scatterometer vector winds. The “ETA” model, covering the continental United States and adjacent coastal areas, is the highest resolution (yet spatially extensive) regional model in the NMC suite. Initial indications of the accuracy of the ETA model were not encouraging, and the near-surface winds predicted by the model did not appear to be sufficiently accurate to allow use in coastal sea level and hazard prediction systems. With COP

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) support, a postdoctoral scientist has been added to the NMC team refining the ETA model, focusing specifically on refining the model 's surface flux calculation and turbulence parameterization scheme. A new, more accurate, computationally-efficient scheme for turbulence parameterization has been developed and implemented, along with an increase in near-surface vertical resolution and a vertical nesting scheme for calculating fluxes over steps in the model topography (important near the coast). The work has been published extensively in the refereed literature, as well as in a variety of conference proceedings and World Meteorological Organization reports. The accuracies of model-produced surface winds must be quantified before the model outputs can be used as inputs to coastal hazard forecast, warning, and scientific analysis systems. The presentations indicated that, with COP support, such an operational validation program has been started. Unfortunately, the levels of analyses that were presented seemed insufficient to answer the scientific questions. Mere tabulation of differences in low order statistics (such as mean biases and root mean squares) between buoy measurements and interpolated model predictions) are insufficient. The scientific rigor and insight so clearly present in the previously discussed refinement of the ETA model is not evident here. Additional activities have involved analysis of remotely-sensed SST and near-surface wind data and their assimilation in regional and global atmospheric circulation models. The NMC standard blended product is a 15-day composite of all available in situ and satellite data, analyzed on a 1 × 1 degree grid and filtered and smoothed to an effective 3 × 3 degree resolution. With COP support, work has proceeded with developing high resolution SST products (1/8 degree resolution) for the ETA model domain, interpolating the 0.5 degree NESDIS products and merging the 1/8 degree coastal products where available. Beginning in May 1993, NESDIS produced a Great Lakes SST product with 1/8 degree resolution (compatible with the GLFS system) which included flagging of pixels contaminated by ice. These ETA SST products are presently being validated with buoy and ship data and are used to set surface boundary conditions in the regional ETA 40-km model (started in May 1993). Near-surface wind speed estimates with broad spatial coverage are available from the DMSP Sea Surface Microwave Imager (SSM/I) microwave radiometer instruments; more recently, wind velocity estimates (both speed and direction) have become available in near-real-time from the scatterometer flown on the European Space Agency's (ESA's) ERS-1 mission. After extensive analyses and conventional validation studies, SSM/I data began to be used operationally in the NMC Global Data Assimilation System in March 1993; ongoing studies are aimed at developing procedures to use full-resolution data to generate high-resolution surface wind and pressure fields. Data presented at the review suggest that inclusion of the SSM/I data significantly improved the quality of analyses and forecasts over the ocean (open

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) ocean buoys are used as comparisons). It is less clear whether the coastal forecasts and analyses were influenced to the same extent. Significant errors associated with vector wind data from the ERS-1 scatterometer instrument (mainly at low wind speeds and directional errors associated with ambiguity removal) have hindered the utility of these data. The validation process continues, although it appears that the most recent fast-delivery data produced by ESA are of high quality. No information was presented about ongoing activities related to assimilation procedures for these scatterometer data; previous studies both in the United States and abroad indicate that near-surface wind data must be assimilated in a very sophisticated manner in order for additional data to make a marked positive impact on the forecast. Results pertaining to operational model validation, SST, and wind speed/velocity products have been reported extensively at professional conferences. However, no open-literature papers have apparently been submitted. The scientific community would benefit from knowledge of the ongoing work through the open literature, and significant scientific input may be obtained from associated reviews. In the long term, both the Coastal Winds program and the Hurricane Winds program should communicate extensively, and strive for a common model of the coastal environment. Ocean Color Program The Ocean Color program was started in FY 1993, with the aims of acquiring, processing, and promoting the scientific use of SeaWiFS data from U.S. coastal waters. At the time the program was initiated, SeaWiFS was scheduled to be launched in late 1993 and the primary objective was to assure that a complete set of SeaWiFS coastal data was acquired off the U.S. Gulf, West, Alaskan, and Hawaiian coasts and adjacent waters the U.S. East coast and the Great Lakes were to be covered by NASA-funded facilities). In addition to acquiring the data, processing it to Level 1 (radiances), archiving it locally, and transmitting it to a NASA-funded archive at Goddard Spaceflight Center, each NOAA station funded by the Ocean Color program was asked to propose science-related activities involving higher-level processing, algorithm development, and/or application demonstrations. Proposals were solicited from four existing NOAA facilities, close to or co-located with CoastWatch nodes (to take advantage of existing data acquisition, processing, and communications facilities). The science-related and algorithm development portions of the proposed work were to be done in collaboration with non-NOAA investigators. Three of the four desired sites were chosen in FY 1993 (Hawaii, West Coast, and Gulf Coast); in each case, approximately half the funding was allocated to the

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) science portion of the investigation. No site was chosen covering the Alaskan region. Due to technical problems, including the ability of the SeaWiFS color sensor to sample near shore, the SeaWiFS mission launch was delayed by NASA until mid-1994. The Ocean Color program correctly recognizes that a prominent scientific use of ocean color data involves retrospective analysis, and that such processing and analysis is possible (and will be pursued aggressively by the scientific community) only if a comprehensive data set is available. As no other agency has taken responsibility for coastal data (NASA and the U.S. Navy are concentrating on global, open-ocean data sets), COP and the Ocean Color program are commended for moving actively to assure that, initially, all available data are collected and archived. The emphasis on linking the acquisition and low-level processing activities to local academic research, that applies the ocean color data, is admirable. It is difficult to assess progress, given the relatively recent inception of this activity and the delay in the SeaWiFS launch. In particular, the presentations to the panel did not address details of the various algorithm development activities. As noted above, acquisition and archiving of the data will at least preserve it for retrospective analysis by the scientific community. At present, neither the accuracies of the coastal algorithms under development, nor the capabilities of the SeaWiFS instrument in coastal regions, is known. The extent to which the Ocean Color program has identified and is interacting with user groups beyond the research community is not clear. An early June 1992 review of the embryonic Ocean Color program by the Nutrient Enhanced Productivity advisory committee raised issues regarding the availability of near-real-time Ocean Color products via CoastWatch and emphasized that a broad class of users require such rapid delivery. The presentation to PoCO (this review) also suggested that there was little formal interchange between NASA and the Ocean Color program. This is especially critical, as the whole East Coast and Great Lakes portion of the SeaWiFS data set will be acquired by NASA's Wallops Flight Facility, and incompatibilities between the NOAA and NASA portions of the data would degrade its scientific utility. On the other hand, the January 11-12, 1994 Interagency Coastal Water Color Workshop, co-sponsored by NOAA, NASA, and the Office of Naval Research in Silver Spring, Maryland, is a very positive step in the right direction. The present fiscal climate will not allow the planned Alaska site to be established in FY 1994. Although this will surely diminish the value of the Ocean Color data set, its impacts on researchers and other COP activities that represent potential users of the Ocean Color products have not been quantified.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) Coastal Storm Surge Modeling Program The prediction and understanding of inundation of low-lying coastal areas due to hurricane and extratropical storm surges continues to be a pressing societal concern. For example, barring only the recent California earthquake, Hurricane Andrew was the costliest natural disaster in U.S. history, accounting for $30 billion in damage. The extratropical (“Halloween”) storm of 1991 was also costly, causing an estimated $ 168 million in damage to property and loss of life along the northeast U.S. coast. The overall goal of this program is to develop operational storm surge models capable of delivering accurate storm surge estimates in both real-time and hindcast situations. The existing model for tropical storms, the Sea, Lake and Overland Surges from Hurricanes (SLOSH) model, has been in existence for some time, and (though the available literature is scant) appears generally to be capable of producing useful estimates of storm surge if provided with accurate predictions of hurricane strength, trajectory, and size. The systematic improvement of hurricane wind field predictions anticipated from the COP Hurricane Winds program should therefore materially improve SLOSH performance. These impacts should be documented in the refereed literature. Unlike fast-moving tropical storms, which cause rapid rise and fall of sea level in the immediate vicinity of landfall, extratropical storms are of significantly longer duration and larger spatial scale. As a consequence, the simple linear wave dynamics built into the SLOSH model may not be entirely satisfactory for the case of extratropical storms, and the issue of lateral boundary condition specification becomes especially problematic. Nonetheless, because present NOAA forecasting practices depend on statistical methods for issuing coastal flood warnings for extratropical storms, more reliable dynamical models of extratropical storm surges clearly are required. The FY 1993 Implementation Plan for Coastal Hazards (COP, 1993b), the most recent plan available to the panel, calls for the development of an extratropical storm surge model capable of real-time application in an operational NOAA setting. The development of an extratropical storm surge modeling capability seems well justified. As planned, development of the new extratropical storm surge model will proceed in several stages. First, a baseline model, based on SLOSH, will be implemented for the purposes of parameter and boundary condition exploration, and for eventual comparison with other candidate models. Second, complete sets of data will be developed, based on two storms that struck the U.S. east coast (the Halloween storm of 1991 and the January storm of 1992), for systematic testing of extratropical storm surge models. Third, the performance of the baseline model on these test problems will be

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) published, and comparisons undertaken with comparable models from academia and industry. Second- and future-generation extratropical surge models will be chosen based on such systematic testing. The success of a surge model is intimately tied to good surface wind analyses and predictions. Therefore, this program has links to the Coastal Winds and Hurricane Winds programs. In the long term, the improved coastal winds should improve the surge model. The panel urges that COP avoid developing a surge model that is adjusted to a different wind data set. These specific plans and objectives seem quite sensible. The panel is particularly pleased to see in the plan an increased role for collaboration with academia and industry and for communication through peer-reviewed channels. Both are in conformity with the recommendations made in our previous review (NRC, 1991). The panel also encourages NOAA to keep abreast of the excellent research on storm surge modeling ongoing in Europe. In the future, some thought must be devoted to the approach for merging NOAA's storm surge modeling capabilities within the Coastal Forecast System. However, the immediate needs and modeling concerns of the storm surge and CFS programs are rather different, so that independent pursuit of these two projects is desirable at this early stage. Nonetheless, technical and informational exchange between the two programs should be instituted and strengthened. Great Lakes Forecasting System (GLFS) The Great Lakes Forecasting System (GLFS) is a coastal prediction system designed to analyze the present state of each of the Great Lakes and to provide up to 2-day forecasts of their physical states. A variety of input meteorological observations, remotely-sensed radiance and SST data, and meteorological forecasts are used as input, and predictions and analyses (nowcasts) of the 3-dimensional (3-D) circulation and thermal structure are planned. In its present implementation, the system produces nowcasts for Lake Erie only, assimilating wind stress and thermal forcing fields into the Blumberg-Mellor 3-D circulation model (Blumberg and Mellor, 1987) (the model can also be used presently to generate up to 1-day forecasts with 2-km horizontal resolution when run on a CRAY-YMP computer and 5-km resolution when run on a workstation). A shallow water wave prediction model is also used to predict the lake-wide wave field. Output products are transmitted as images upon request from users; transmissions to underway boats can be accommodated via portable telephone. Selected input data are obtained from, and all products are made available to, the local CoastWatch node.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) GLFS is a cooperative effort between the NOAA Great Lakes Environmental Research Laboratory (GLERL) and the Department of Civil Engineering at Ohio State University (OSU). GLERL is responsible primarily for overall system design, analysis and assimilation of meteorological data and NWP products, and calibration of GLFS model output. Operational GLFS model runs are conducted at OSU, which also has responsibility for development of visualization and user interface tools, and selected enhancements of the overall model (such as the addition of tributary flows). Support comes primarily from the NOAA Environmental Research Laboratories, COP, and the Sea Grant program, although a host of other agencies and private concerns provide funding or in-kind support. The GLFS effort represents an important scientific and programmatic accomplishment for NOAA, and for COP in particular. As it utilizes routinely many of the components of a future coastal forecasting system (such as the NMC ETA model for near-surface winds, CoastWatch for thermal data input and product distribution, and the Blumberg-Mellor circulation model), it provides an excellent proof-of-concept and testbed for future coastal ocean prediction systems. At the same time, the careful attention paid to product development and system (including model) verification has made the actual products themselves useful to researchers and federal, state, and local resource users and policymakers. COP support has had a direct influence on the present form of GLFS. Before COP involvement and the existence of a COP-supported, functioning CoastWatch system, GLFS was an ad hoc collection of independent process models and data acquisition systems, with products generated only on a sporadic and “as-needed” basis. Funding support from COP provided stability for planning and operations, and CoastWatch provided a stable source of data as well as an operational distribution system for products. East Coast Forecast System Feasibility Experiment (ECFSFE) The objective of this activity is to determine the feasibility of an operational East Coast coastal nowcast/forecast system, providing information on temperatures, salinities, currents, and waves/sea-level in response to astronomical and atmospheric forcing. The activity is a joint effort involving the Princeton University Geophysical Fluid Dynamics Laboratory (GFDL), NMC, and NOS. The core of the system is the Blumberg-Mellor ocean model, with atmospheric forcing provided by the NMC ETA model. The system is being developed at NMC, where it will also reside. Since the project was initiated in late April 1993, the Blumberg-Mellor model has been transferred successfully to NMC, and ETA model and astronomical (tidal)

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) input has been used for experiments. Skill assessments are still being developed, centered initially around system predictions of sea level and SST. Initial experiments have shown that the ETA model winds associated with hurricane-strength events are inaccurate, and thus lead to significant underpredictions of sea level excursions. Although not presently operational, it is expected that near-real-time altimeter sea level data from the ERS-1 satellite will be assimilated into the model in the near future. Additional near-term enhancements include upgraded skill assessment (comparisons with NOS Next Generation Water Level data and Ocean Products Center-analyzed SST data), completion of the tidal capability, sensitivity studies with respect to surface and lateral boundary conditions, coupling the present model to an estuary model, and completion of predictability studies. ECFSFE is a follow-on to GLFS, which will require dealing with an open oceanic boundary, a complication not encountered in the Great Lakes study, and will provide an opportunity to utilize remotely-sensed ocean surface height information. ECFSFE has been identified by CFS as the second major prototype forecast system that should be examined prior to establishment of a national system. Not only will ECFSFE products be useful, but the “lessons learned” in its development at an operational site (NWS) will prove valuable in future development efforts. Although the program has only recently been initiated, significant progress has already been achieved. From the start, a Steering Committee composed of four members (two from NOS, and one each from Princeton/GFDL and NMC) was established to oversee and help plan the project, and to assure coordination among the various organizational elements. The plan for expanding the scope of the activity appears reasonable and achievable. At present, the activity does not include facilities for outside groups to contribute modules or process models. The panel recommends that the program examine whether such a facility must be “built-in” from the start in order to ensure efficiency and accuracy. It is noted that NMC is adding a similar “model testbed” facility for use by the outside community. Coastal Forecast System (CFS) As noted above, the ultimate goal of CFS is the development of a modern, flexible, end-to-end system that provides data and forecasts to a wide range of coastal users. The CFS program is uniquely suited for developing the requirements for a full, national coastal forecast system and justifies both the scientific and operational requirements and the associated costs. The broad perspective of the CFS activity allows it to identify key short- and long-term gaps in ongoing work; in addition, this perspective allows evaluation of the results of other projects in the context of a future forecast system.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) CFS has documented the philosophy of a future observing system (NOAA, 1993), and developed its structure sufficiently to allow realistic planning budgets to be presented. They sponsored a workshop at the Woods Hole Oceanographic Institution in June 1993, at which an economic cost-benefit analysis of a future CFS was conducted (Marine Policy Center, 1993). Both of these activities are vital for the successful initiation of a full-scale CFS program within NOAA. The CFS activity has not actively evaluated the products of the other Coastal Hazards programs, nor have they to date addressed issues such as the overlap in approaches for calculating storm-induced sea level rise. The panel was informed that negotiations are underway with other NOAA line offices, including NWS and NOS, for a NOAA-wide CFS activity. In this expanded activity, the role of COP will be to identify and conduct research and development activities required to refine models. System and forecast validation will be conducted by NOS prior to transition of CFS to full operations at NWS. Aggressive evaluation of ongoing Coastal Hazards programs and analyses of the needs to develop new data sources, or expand present ones, will increasingly become a part of the COP-CFS role. References Blumberg, A.F. and G.L. Mellor. 1987. A description of a three-dimensional coastal ocean circulation model . In: Three Dimensional Coastal Ocean Models, N.M. Heaps (ed.). American Geophysical Union, Washington, D.C. pp. 1-17. Coastal Ocean Program. 1993a. CoastWatch FY 1993 Implementation Plan Contract. National Oceanic and Atmospheric Administration, Washington, D.C. 48 pp. Coastal Ocean Program. 1993b. FY 1993 Implementation Plan—Coastal Hazards. National Oceanic and Atmospheric Administration, Department of Commerce , Washington, D.C. 56 pp. Marine Policy Center, Woods Hole Oceanographic Institution. 1993. Preliminary Analysis of Benefits and Costs of a Proposed Coastal Forecast System. A Report on a Workshop held at the Woods Hole Oceanographic Institution. National Oceanic and Atmospheric Administration. 1993. A Strategic Plan for a Coastal Forecast System. Department of Commerce, Washington, D.C. 31 pp.

OCR for page 61
A Review of the Accomplishments and Plans of the NOAA Coastal Ocean Program (1994) National Research Council. 1991. A Review of the NOAA Coastal Ocean Program. National Academy Press, Washington, D.C. 24 pp.