Climate variability and trends: drivers

This chapter describes how climate varies by location, by considering the effects of altitude, latitude and other aspects of geography on the climate. Weather and climate can vary considerably at almost all timescales, but the amount they do vary differs considerably from place-to-place, and at different times of the year. Sea-surface temperature anomalies affect evaporation and heating or cooling of the overlying air, and the effect can last for weeks, months or even longer, because it takes so much energy to change the temperature of water. Spatial and temporal variations of temperature are much simpler than those of rainfall at virtually all scales. It is important to understand these scales of variability in space and time to obtain some idea of the necessary resolution of data for any analyses of climate–health relationships. The North Atlantic Oscillation is a large-scale pattern of natural climate variability characterized by a seesaw difference in air pressure between the Azores and Iceland