Connection Between Isotopes and Temperature/weather
18O is two neutrons heavier than 16O and causes the water molecule in which it occurs to be heavier by that amount. The addition of more energy is required to vaporize H218O than H216O, and H218O liberates more energy when it condenses. In addition, H216O tends to diffuse more rapidly.
Because H216O requires less energy to vaporize, and is more likely to diffuse to the liquid surface, the first water vapor formed during evaporation of liquid water is enriched in H216O, and the residual liquid is enriched in H218O. When water vapor condenses into liquid, H218O preferentially enters the liquid, while H216O is concentrated in the remaining vapor.
As an air mass moves from a warm region to a cold region, water vapor condenses and is removed as precipitation. The precipitation removes H218O, leaving progressively more H216O-rich water vapor. This distillation process causes precipitation to have lower 18O/16O as the temperature decreases. Additional factors can affect the efficiency of the distillation, such as the direct precipitation of ice crystals, rather than liquid water, at low temperatures.
Due to the intense precipitation that occurs in hurricanes, the H218O is exhausted relative to the H216O, resulting in relatively low 18O/16O ratios. The subsequent uptake of hurricane rainfall in trees, creates a record of the passing of hurricanes that can be used to create a historical record in the absence of human records.
Read more about this topic: Oxygen Isotope Ratio Cycle
Famous quotes containing the words connection between, connection, temperature and/or weather:
“The connection between our knowledge and the abyss of being is still real, and the explication must be not less magnificent.”
—Ralph Waldo Emerson (1803–1882)
“We will have to give up the hope that, if we try hard, we somehow will always do right by our children. The connection is imperfect. We will sometimes do wrong.”
—Judith Viorst (20th century)
“This pond never breaks up so soon as the others in this neighborhood, on account both of its greater depth and its having no stream passing through it to melt or wear away the ice.... It indicates better than any water hereabouts the absolute progress of the season, being least affected by transient changes of temperature. A severe cold of a few days’ duration in March may very much retard the opening of the former ponds, while the temperature of Walden increases almost uninterruptedly.”
—Henry David Thoreau (1817–1862)
“Family values are a little like family vacations—subject to changeable weather and remembered more fondly with the passage of time. Though it rained all week at the beach, it’s often the momentary rainbows that we remember.”
—Leslie Dreyfous (20th century)