WATER LEVEL MEASUREMENTS IN THE POLAR REGIONS 

 STATUS AND TECHNOLOGY 



E. M. Russin, H. H. Shih and R. F. Edwing 

 National Ocean Service, NOAA 



ABSTRACT 



Continuous sea level measurements have been made and recorded for more than 100 years, 

 but their importance has increased dramatically in the past few years due to the great international 

 interest for monitoring global levels in anticipation of climate warming. Since the National Ocean 

 Service (NOS) is the primary agency for measuring and recording water levels in the United States, 

 it is being encouraged to increase the number of permanent sea level measuring stations especially 

 in the polar regions where the data are extremely sparse. 



Personnel from the Physical Oceanography Division (POD) and the Ocean Systems Division 

 (OSD) of the Office of Oceanography and Marine Assessment (OOMA) have been researching the 

 status of the technology and the requirements for water level measurements in the polar regions 

 with special emphasis on the needs of NOAA's Climate and Global Change Program and The Global 

 Sea Level Observing System, known as GLOSS. It is called GLOSS because it measures the global 

 level of the sea surface, a smooth level after averaging out waves, tides and meteorological events. 

 GLOSS, co-ordinated by the Intergovernmental Oceanographic Commission (IOC), provides high 

 quality standarized data from which valuable sea level products are prepared for international and 

 regional research programs as well as for practical national applications. 



This report includes a survey of the work that NOS and others are or have been doing in this 

 area and also assesses the state-of-the-art of the technology involved, the potential for future 

 development, and provides recommendations for near and long-term projects. The report con- 

 cludes that the technology and techniques exist for making sea level measurements in polar regions 

 but that they must be site-specific; also, that stable bench mark connections and atmospheric 

 pressure measurements are mandatory; that the field measurement system should be as 

 automated as possible; and that near real-time transmission of data is highly desirable to ensure 

 proper system operation and early availability of information to users. The report recommends the 

 use of thermal bench marks in certain polar areas and the further development of acoustic and 

 electromagnetic means of transmitting data from underwater sensors through the ice or land to 

 nearby shore stations. It also recommends that Prudhoe Bay, AK be established as a pilot station 

 for further investigations into the measurement requirements of other Arctic stations and that a 

 cooperative program be initiated with the National Science Foundation for establishing stations in 

 Antarctica. 



