EOSC 112 Lecture Notes - Lecture 3: Geostrophic Wind, Solar Thermal Collector

• School: UBC
• Department: Earth and Ocean Sciences
• Course: EOSC 112
• Professor: Roger Francois

Document Summary

Let"s exa(cid:373)i(cid:374)e this fro(cid:373) a pressure gradie(cid:374)t perspe(cid:272)ti(cid:448)e. Last class, we discussed how horizontal pressure gradients drive atmospheric wind patterns. As you go up from the ground as it rose, you find that the vertical distance between isobars is also expanded (see notes last class). The isobars in this image are the gray lines labeled 800 mb, 900 mb, and 1000 mb. The warmer, expanded air column over land puts the 800 mb isobar at a higher altitude over land than o(cid:448)er the o(cid:272)ea(cid:374). Whe(cid:374) (cid:449)e"re looki(cid:374)g for the horizo(cid:374)tal pressure gradie(cid:374)t, (cid:449)e"re (cid:272)o(cid:373)pari(cid:374)g the pressure at t(cid:449)o differe(cid:374)t lo(cid:272)atio(cid:374)s, but at the same altitude. Note that the (cid:862)h(cid:863) aloft, o(cid:448)er la(cid:374)d, is (cid:272)loser to the 8(cid:1004)(cid:1004) mb li(cid:374)e tha(cid:374) the (cid:862)l(cid:863) aloft, o(cid:448)er the ocean. This means that, in relative terms, at that altitude, the pressure over land is higher than the pressure aloft over the ocean.