HARMONIC ANALYSIS OF PRECIPITATION.
Abstract
Periodicities in monthly precipitation over North America are investigated using harmonic analysis. The long term means are expressed by a trigonometric function (cosine or sine) with periods of 12, 6, and 4 months. Amplitudes and phase angles are examined with the goodness of fit determined by analyzing the residual variances after the application of one, two, and three harmonics. The variation of precipitation in the interior of North America may be satisfactorily expressed as a simple cosine curve with a summer maximum and an amplitude of about one inch. Adding the second and third harmonic reduces the residual variance to less than 20% in all but three small scattered areas. The physical reasoning behind this mathematical technique is not immediately evident since synoptic phenomena occurring at three-month intervals are not clear. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1967
- Accession Number
- AD0666772
Entities
People
- Marvin J. Lowenthal
Organizations
- United States Army Communications-Electronics Command