GEOG 272 Lecture Notes - Lecture 2: Transpiration, Industrial Revolution, Stoma
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Atmosphere is a delicate blanket that envelops the planet. Held to the surface by gravity: the early atmosphere, there are a lot of uncertainties. So(cid:373)e of the ideas ea(cid:396)th fo(cid:396)(cid:373)ed (cid:1008). (cid:1010) (cid:271)illio(cid:374) (cid:455)ea(cid:396)s ago. Ea(cid:396)th sta(cid:396)ted fof as this cloud of gas and dust and this cloud gradually compacted and under the influence of gravity. And very light gases, mostly hydrogen, some helium, some ammonia (traces), (traces of methane) formed the first primordial atmosphere. It existed just for about 0. 1 billion years. There were se(cid:448)e(cid:396)al theo(cid:396)ies as to (cid:449)h(cid:455) this at(cid:373)osphe(cid:396)e (cid:894)(cid:373)ostl(cid:455) h(cid:455)d(cid:396)oge(cid:374), so(cid:373)e heliu(cid:373), (cid:373)etha(cid:374)e, (cid:895) : earth gravity was not strong rnough to hold onto the atmosphere, 2nd idea is that ea(cid:396)th"s (cid:373)ag(cid:374)eti(cid:272) field had (cid:374)ot (cid:455)et fo(cid:396)(cid:373)ed. It is la(cid:396)gel(cid:455) (cid:272)(cid:396)eated (cid:271)(cid:455) the oute(cid:396) (cid:272)o(cid:396)e. Sli(cid:272)e th(cid:396)ough the ea(cid:396)th, (cid:449)e ha(cid:448)e the thi(cid:374) su(cid:396)fa(cid:272)e (cid:272)(cid:396)ust. That"s (cid:373)ost of the insde of the planet.