Methane (CH₄) and carbon monoxide (CO) total column amounts (TCA) measured at the Research Institute of Physics of St. Petersburg State University (Russia) were used for: 1. study of temporal variability of CH ₄ and CO; 2. identification of source regions of CO and CH ₄ using trajectory analysis. CH₄ and CO showed distinct annual cycle with the amplitude of about 3% and 25% correspondingly. Period of 1999-2002 has a significant decline of CH₄ TCA for the St. Petersburg region. The suggested reason is hot and dry summers of 1998-2002. October 1998 - March 1999 is characterized by the strong irregular disturbances of CO TCA. Growth rates of CO TCA have changed at this period from (3.5±2.3)%/yr (for 1995-1998) up to (-2.1±1.5)%/yr (for 1999-2002). Enhanced CO and CH₄ TCA levels are observed for air masses originated from the sectors of the North Russia, continental Russia and the Eurasia. Europe can be classified as moderately polluted territory. Clean air comes from the Baltic Sea, Arctic Ocean and Scandinavia. Distribution of CO pollution levels over sectors repeats qualitatively situation for CH₄.