Climate change in the City of Àlmaty during the past 120 years

The temporal trends of the mean annual temperature and the mean annual precipitation in the City of Almaty during meteorological observational period of the past 120 years were assessed. The results show that the temperature harmonics had periodicities of 53, 33, and 23 years and the temperature had an overall increasing trend with the rate becoming faster after 1982. Our comparison of the temperatures between much more urbanized Almaty and much less urbanized Issyk shows that the temperature difference between these two sites remained more or less constant, suggesting that the temperature increase in Almaty primarily resulted from the large-scale external forcing factors rather than from the local urban effects. Precipitation harmonics had periodicities of 78, 28 and 18 years and precipitation started its decreasing trend at the beginning of last century, reaching its minimum around 1925. The precipitation reached a maximum around 1958 and the trend became a nearly flat line from 1958 to 2010 with a noticeable trough around 1990. Our comparison of precipitation in Almaty with that in nearby Issyk shows that precipitation variation over the observational period has been geographically coherent. Urban effects (i.e., enhancement in precipitation) on precipitation in Almaty were detected.