CHANGES IN SUNSHINE DURATION ARE CORRELATED WITH CHANGES IN DAILY TEMPERATURE-RANGE THIS CENTURY - AN ANALYSIS OF SWISS CLIMATOLOGICAL DATA

Analyses of the relationship between trends in daily temperature range and those of sunshine duration in the Swiss Alps show a strong correl ation at lower elevation sites. The decrease in daily temperature rang e is associated with a corresponding decrease in sunshine duration. At high elevations, however, this relationship is absent. The decrease i n daily temperature range observed this century at lower elevation sit es is inferred to be a consequence of an increase in low-level cloudin ess. Higher elevation sites lie above the low-level cloud layers and t he moisture-laden lower atmospheric boundary layer and as a result do not exhibit the same trends.