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- Path: sparky!uunet!gatech!concert!fletcher!pisgah.unca.edu!unca.edu!strauss
- Newsgroups: sci.geo.meteorology
- Subject: Hot humid/dry and Cold humid/dry?
- Message-ID: <1993Jan23.095958.1@unca.edu>
- From: strauss@unca.edu
- Date: 23 Jan 93 09:59:58 -0500
- Organization: University of North Carolina at Asheville
- Lines: 33
-
- Here's a question that might interest some of you. I have had rather heated (no
- pun intended) discussions about it from time to time.
-
- A warm, humid day feels "hotter" i.e., less comfortable, than a warm dry day.
- Personally, I believe that a cold, humid day is "warmer" than a cold dry day,
- but others might disagree. I think cloud cover and wind, often associated with
- the humidity, can make it feel cooler, but all thing being equal, a cold muggy
- day is more comfortable--to me.
-
- This is discussed by Stephen Sargent Visher in his 1924 book (recently reissued
- by AMS): Climatic Laws ....
-
- His "Law 89" states: "The temperature often feels warmer or colder than the
- thermometer indicates." He believed that BELOW ABOUT 50 [deg] F, dry air feels
- warmer, but above 50F, humid air feels warmer.
-
- This is very interesting! On what physics is this based? I can see something
- with either body temperature (~98F) or skin temperature (~60-80?), but I would
- like to see this contention based upon physical laws, if possible. If warm
- humid is "hotter: than warm dry, and cold humid is "colder" than cold dry, then
- there MUST be a point (temperature) at which there is no difference between dry
- and humid effects. If that is true, then on what laws is it based?
-
- Any answers would be appreciated. I prefer messages sent directly to me (at
- least in duplicate), since I miss lots of usenet (our VAX is small and gets
- frequently purged).
- Thanks,
-
- Bob Strauss
- Ramsey Library
- UNC-Asheville
- strauss@uncavx.unca.edu
-
-