Search Results
You are looking at 1 - 3 of 3 items for :
- Author or Editor: A. H. Gordon x
- Journal of Applied Meteorology and Climatology x
- Refine by Access: All Content x
Abstract
Anomalies from the respective decadal means of the monthly mean temperatures for central England covering a period of 250 years are ranked to form a quintile distribution. Contingency tables are then prepared which show the percentage frequencies of the changes in the temperature anomalies from one calendar month to the following calendar month for each quintile. Correlation coefficients for a lag of one month are computed for each calendar month-to-month change throughout the years, and for lags 1–12 months inclusive for the whole data series.
It is shown that persistence of extreme anomalies at certain times of the year are double the frequency which would be expected by chance, while the changes from one extreme quintile to the other occur with very low frequency compared with chance.
It is suggested that application of the tables would produce results as good, and perhaps a little better, at forecasting temperature anomalies for a month ahead than the official long-range forecasts supplied by the Meteorological Office for central and southeast England.
Abstract
Anomalies from the respective decadal means of the monthly mean temperatures for central England covering a period of 250 years are ranked to form a quintile distribution. Contingency tables are then prepared which show the percentage frequencies of the changes in the temperature anomalies from one calendar month to the following calendar month for each quintile. Correlation coefficients for a lag of one month are computed for each calendar month-to-month change throughout the years, and for lags 1–12 months inclusive for the whole data series.
It is shown that persistence of extreme anomalies at certain times of the year are double the frequency which would be expected by chance, while the changes from one extreme quintile to the other occur with very low frequency compared with chance.
It is suggested that application of the tables would produce results as good, and perhaps a little better, at forecasting temperature anomalies for a month ahead than the official long-range forecasts supplied by the Meteorological Office for central and southeast England.
Abstract
Recent changes in the National Weather Service's automated system of forecasting maximum and minimum surface temperatures are described and illustrated. Modifications include use of the primitive equation model, later surface reports, computer-analyzed isotherms, and climatologically-determined forecast limits. Verification figures are presented to show the improvement of the new system over the old and to justify the replacement of centralized subjective temperature forecasts by completely objective ones.
Abstract
Recent changes in the National Weather Service's automated system of forecasting maximum and minimum surface temperatures are described and illustrated. Modifications include use of the primitive equation model, later surface reports, computer-analyzed isotherms, and climatologically-determined forecast limits. Verification figures are presented to show the improvement of the new system over the old and to justify the replacement of centralized subjective temperature forecasts by completely objective ones.
Abstract
Reconstructions of winter (December-February) sea level pressure (SLP) from western North American tree-ring chronologies are compared with a proxy record of winter severity in Japan derived from the historically documented freeze dates of Lake Suwa. The SLP reconstructions extend from 1602 to 1961 and freeze dates from 1443 to 1954. The instrumental and reconstructed SLP for the 20th century reveal two distinct circulation regimes (teleconnection patterns) over the North Pacific that appear to be associated with severe and mild winters and, consequently, with early and late freezing of the lake. The reconstructed SLP anomaly map for severe winters prior to 1683 shows a pattern similar to those in the instrumental and reconstructed records of the 20th century. The analysis reveals that the reliability of the reconstruction may vary with the configuration of the actual SLP pattern as the mild winter pattern is not as well reconstructed as the severe winter pattern. That result illustrates the importance of testing the reliability of a reconstruction within the context of the intended interpretation. This analysis demonstrates how different types of proxy climate data can be compared and verified.
Abstract
Reconstructions of winter (December-February) sea level pressure (SLP) from western North American tree-ring chronologies are compared with a proxy record of winter severity in Japan derived from the historically documented freeze dates of Lake Suwa. The SLP reconstructions extend from 1602 to 1961 and freeze dates from 1443 to 1954. The instrumental and reconstructed SLP for the 20th century reveal two distinct circulation regimes (teleconnection patterns) over the North Pacific that appear to be associated with severe and mild winters and, consequently, with early and late freezing of the lake. The reconstructed SLP anomaly map for severe winters prior to 1683 shows a pattern similar to those in the instrumental and reconstructed records of the 20th century. The analysis reveals that the reliability of the reconstruction may vary with the configuration of the actual SLP pattern as the mild winter pattern is not as well reconstructed as the severe winter pattern. That result illustrates the importance of testing the reliability of a reconstruction within the context of the intended interpretation. This analysis demonstrates how different types of proxy climate data can be compared and verified.
