Covariance Analysis Technique Based on Bivariate Log-Normal Distribution with Weather Modification Applications

Abstract A statistical technique based on the bivariate log-normal distribution is presented for analyses of treatment (cloud seeding) effects on measurements (precipitation amounts) when appropriate covariates (correlated control area measurements) are available. An example is given which evaluates effects of seeding on specific 500 mb temperature partitions of 24 h precipitation amount data from the 1964–70 Wolf Creek Pass wintertime orographic cloud seeding experiment. In addition, an appendix includes an analogous analytic technique based on the bivariate log-normal distribution for cross-over designs.