Fog!                                               12/5

     1.  In earlier times, when the earth's axial tilt was higher, were climates different?
             Yes, but since climatic changes can be linked to axial tilt, to orbital eccentricity (shape) and to the direction of the axial
                tilt, as well as being possibly linked to a number of other variable causes, none of which fluctuate in lockstep with any
                other cause, sorting out the relative importance of each of the possible causes, is a very difficult problem.

    2.  Was the Sahara ever a jungle?
             Not in the recent past.  Prior to 10 500 years ago, and through much of the ice age, the Sahara was as dry as it is
                today.  However about 10 500 years ago the summer monsoon rains which currently and then fell on the Sahel
                abruptly began to penetrate much farther to the north, transforming the Sahara into a savannah with abundant
                grass, some wildlife, human inhabitants, and even rivers.  The Sahara again dried out about 5 500 years ago,
                returning to a climate similar to today's.

    3.  Where is the nicest, mildest place to live in terms of climate?  Is there a latitude zone that is most pleasant?
             This is at least partly a subjective question since various people would disagree as to what constitutes a "nice climate."
                There is really no well-defined "nicest" latitude at which to live since other factors, e.g., continental versus maritime
                influences, low elevation versus high elevation, etc., cause wide variations in the types of climate which occur at any
                latitude.

                Many people like the small temperature ranges which occur in maritime locations.  Given a maritime location where
                the mean temperature is pleasant and the maritime influence keeps temperature extremes from departing far from
                those means, the climate is usually regarded as very pleasant.  Such locations have what is known as a
                Mediterranean climate.  Examples of such locations include the coastal valleys of southern California, the French
                and northern Italian Mediterranean coasts (the Riviera), most of Greece, and much of the rest of the
                Mediterranean coast, southwestern coastal Australia, the northern half of coastal Chile and a number of other
                locations.  Such climates can have problems however.  The cold California current, which keeps coastal California
                pleasantly cool in the summer stabilizes the atmosphere to the extent that, with the influx of a large population,
                severe air pollution became a problem early in the 20th century.  The same population influx soon could not all find
                room close enough to the coast to enjoy the ideal coastal climate so they settled a little farther inland, e.g., in the
                San Fernando Valley which makes up much of the northern part of Los Angeles and is only 15-20 miles from the
                ocean, but because of the intervening Hollywood Hills, experiences a  minimized maritime influence, so that
                summer and fall temperatures there often exceed 100°F.  Some locations in southern California, aided by local
                geography, have maintained a nearly ideal climate.  Santa Barbara, for example, is located where the coastal plain
                is so narrow that there is not room for a large population and narrow enough that nighttime land breezes are able
                to blow most of each day's pollution out to sea.

                Other "nice" places to live include high valleys at low latitudes where the latitude minimizes the temperature
                variations and the altitude keeps the temperature relatively cool.  Mexico City is such a location.  Maximum
                temperatures there are in the 70s most months of the year.  Unfortunately, like Los Angeles, the pleasant climate
                brought in such an influx of people that air pollution is a major problem.  Other cities in the highlands of southern
                Mexico and Central America and equatorial east Africa have very pleasant climates, but with less of a pollution
                problem.

     4.  I believe I have seen the aurora borealis in Oregon.  Is this possible or am I crazy?
                Oregon is farther north than northern Utah, but also farther west which puts it about the same distance from the
                north magnetic pole (which is in Canada, north of Hudson Bay).  Since auroral displays are generally centered on
                the north magnetic pole, and occur with greater frequency, closer to the pole, Oregon should experience aurorae
                about as often as northern Utah.  So you may see them there, but not very often.

    5.  In the movie, "The Day after Tomorrow," it was so cold that persons going outside without covering
         their skin would have it freeze?  Is that possible?
                Yes.  The elapsed time before freezing would begin would depend on both temperature and wind speed.  Frostbite,
                the freezing of flesh (and attached skin), would begin, under calm conditions, in about 7 minutes at -50°F, in about
                31 minutes at -10°F.  At the world record temperature of -129.6°F frostbite would begin within seconds after the
                exposure of skin.