lO 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. no 



/ \ 



cr 1 1 ^ 



-9-7-5-3-10 1 3 5 7 9 



Fig. 4. — Washington temperatures depressed by severe magnetic storms. 

 Abscissae, days before and after height of storm ; ordinates, degrees centigrade 

 of departures from normal. 



Table 3. — Effect of magnetic storms on Washington temperature 



—I 01234567 



-4 —3 



8 



Days from zero day. — 9 — 8 — 7 — 6 

 Mean departure from 



normal temperature. o!37 o!63 iTas i?8i i!48 i?70 i!74 2° 2% o'.^j — itsS o?93 o?70 o?04 oTag i°i2 i?6o o!o7 o!6i ( 

 Mean of first 8 =: i?4i Mean of last 8 = o!64 



OTHER CASES OF TEMPERATURE CHANGE CAUSED BY 

 VARIATION OF SOLAR RADIATION 



Simpson, in his classical investigation of the temperature of the 

 earth's atmosphere, and its relation to radiation, computed the the- 

 oretical effect of a rise of i percent in the solar constant. For eastern 

 North America he found that such a rise in radiation would depress 

 temperatures at the earth's surface. Clayton, by statistical studies 

 of actual changes in solar radiation to temperature, had also arrived 

 at the same result. Indeed his isothermal lines, corresponding to 

 a rise of i percent in the solar constant, very nearly map out the 

 extension of Pleistocene glaciation in North America. See, for in- 

 stance, figure 21, Smithsonian Miscellaneous Collections, volume yy, 

 No. 6, 1925. 



