BIOL 1055 Lecture Notes - Lecture 22: Harvest Records, Palynology, Atomic Number
Document Summary
Climate: the conditions in the atmosphere over relatively long periods of time. Usually refers to conditions across large regions or the entire earth. Weather: the conditions of the atmosphere over relatively short periods of time. Usually refers to conditions at a specific site. Global warming: warming of the planet, based on average temperatures. Actual measurements: thermometers, satellites take ocean and air temperatures at many locations all over the planet. Historical records: logs/diaries, harvest records, ice break-up dates, tree blossoming records. Proxies: don"t give actual measurements, but give data that can be extrapolated to temperature estimates. Ex: isotope ratios, coral reef layers, tree rings, pollen analysis. Stable isotopes: atom"s identity is determined by the number of protons it has (atomic number). An atom"s weight is determined by the sum of protons and neutrons (electrons are so small their weight is negligible) Isotope: same atomic number, different number of neutrons in nucleus. Stable isotope: doesn"t exhibit radioactive decay over time.
