Atmospheric sciences Atmospheric sciences Atmospheric sciences are the study of the Earth's atmosphere, its processes, the effects other systems have on the atmosphere, and the effects of the atmosphere on these other systems. Meteorology includes atmospheric chemistry and atmospheric physics with a major focus on weather forecasting. Climatology is the study of atmospheric changes (both long and short-term) that define average climates and their change over time, due to both natural and anthropogenic climate variability. Aeronomy is the study of the upper layers of the atmosphere, where dissociation and ionization are important. Atmospheric science has been extended to the field of planetary
Long-term effects of cannabis to prove causal associations of marijuana with many physical health conditions". Imaging studies suggest that long-term exposure does not lead to decreases in white matter or grey matter volume, but may lead to reductions in hippocampal volume. Variations in the methodologies used lend some uncertainty to this conclusion. The acute effects of cannabis use in humans include a dose-dependent increase in heart rate, typically accompanied by a mild increase in blood pressure while lying down and postural hypotension - a drop in blood pressure when standing up. These effects may vary depending on the relative concentration of the many different