Historical Climatology
Abstract
A methodology for evaluation of past climates in historic times has been examined from a theoretical basis and its evaluation has been initiated. The principle is that the ratios of stable isotopes in a tree depend on the temperature at which its wood is manufactured as well as on the temperature at which precipitation, which nourishes the tree is produced. By measuring stable isotope ratios in a chronological sequence of dated tree rings, changes in climate may be evaluated. A tree has been so measured for the years 1700-1950 and compared with the thermometer record for those years to obtain phenomenological (numerical) temperature coefficients for the ratios of hydrogen, carbon, and oxygen. A second tree has been measured for the years 1500-1800 and found to show the low temperatures of the Little Ice Age with warm brief intervals at about 1570, 1650, 1730 and 1790. A theoretical study of various aspects of the total carbon inventory on the earth's surface has been initiated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1974
- Accession Number
- AD0780121
Entities
People
- Leona M. Libby