Gridded polygon data for the seven classified risk variables. The risk variables areclassified versions of mean coastal elevation, geology, geomorphology, local subsidence trend, mean shoreline displacement, maximum tidal range, and maximum significant wave height. Supplemental point data for the stations used in calculating the sea-level trend and tidalrange data sets. These data include results from 41 legs of 11 ocean surveys conducted in the Atlantic, Pacific, Indian, and Southern oceans, as well as the Mediterranean and Red seas. The measurements were made by an automated high-precision shipboard gas chromatographic system that measures CO2 by flame ionization after quantitative reduction to methane in a stream of hydrogen.
Nitrous oxide is measured by a separate electron-capture detector.
These data constitute one of the most extensive records available of CO2 and, particularly, N2O in marine air and surface seawater. The data will be valuable in modeling the ocean's role in the global cycles of carbon and nitrogen, in studies of ocean-atmosphere dynamics, and in evaluations of other methods for determining pCO2. These data were originally collected for climate modelers so they could reduce the uncertainty associated with the magnitude and time course of historical land use change and of carbon release. Because of boundary changes through time and disparities between the validity, availability, and scale of the data for each country, the data were aggregated into 94 ecological zones. The resulting data base contains land use and carbon information for 94 ecological zones and national totals for 13 countries.