SNBUDs Yes, this is referable to the nass of dust. WEILER: It depends on the sises. But about this stratospheric I agree with everything that Ben says abdcut the lower ee of the stratosphere which you might say is isotropically with the trcposphere. When you get up shove into the stratosphere, then the direct exchange between it and the lower ataosp becomes much more difficult to do because there are no i surfaces that really penetrate up. up there, They are mostly hori So, to get things way high up they are likely there except by a very slow process of diffusion or ¢ Very slow, but none of this very rapid quasi horisontel 1 scale of exchange that Ben was talking about. \ CEs How high? X would say that if you get up to 100,000 feet. Hy recollection is that in the case of Krakatoa is that observed brilliant sunsets in the Sahara desert and other WEXLER: places and they persisted for a matter of months and possibly a year. These things were such as to indicate the presence of dust as scattering at a very high altitude well above the tropo e That is right. ch the stuff went. GRIGGSs : That is how they estimated the height te : Sye-- ant GRIOUS: ee WEXLER: At least 100,000 feet. There was persistence of this dust in the high stratospherp a long time. gy r’saf Ener Diecoay aifice tems ARGHIVES 186