MadSci Network: Earth Sciences |
MadSci Network: Earth Sciences |
Dear Neil:
Sorry that it has taken so long for me to respond to your question.
I was away on vacation for a while and then tried to research your question for the past week or so. Unfortunately, I have not met with success.
I have two meteorology texts that specifically cover marine weather and sailing. Neither mentioned progressive and oscillating wind systems. I also contacted several friends who sail but they had no advice on the subject.
I am familiar with the concept but concerning recognizing one vs. the other, I know of no rules-of-thumb or weather signs for distinguishing them.
The difference between them is to some degree a question of time. For example, a land-sea breeze system is progressive over a 12 hour period, but over a 24 hour period it oscillates. This is probably true of many winds along the coast: over a short time period they appear progressive; if you wait long enough though the wind will reverse itself and will then be oscillatory.
So in a sense, for many winds, whether they are progressive or oscillating depends on the time interval for which you observe them.
I wish that I could be of more help.
Clay Harris Dept. of Geography/Geology Middle TN State University cdharris@frank.mtsu.edu
Try the links in the MadSci Library for more information on Earth Sciences.