HDTenEightyP/NetNews huggingface dataset:
From: bennett@mp.cs.niu.edu (Scott Bennett)
Newsgroups: sci.geo.meteorology
Subject: Re: "Exact"-ness
Date: 11 Apr 92 04:22:51 GMT
Distribution: usa
Organization: Northern Illinois University

In article <1992Apr11.023107.477@midway.uchicago.edu> rtp1@midway.uchicago.edu writes:
>
>>found that meteorologists do not have a complete understanding
>>of the atmosphere.
>
>So what?  Cosmologists don't have a complete understanding of the
>origins of the universe or of the behavior of matter in the first
>three minutes.  Astrophysicists do not have a complete understanding
>of heat transport in convecting stellar envelopes.  Particle 
>physicists do not have a complete understanding of the behavior
>of the strong interactions.  
>
>The above statement does not imply that meteorology is not an
>"exact" science.  The implication is only that meteorology is
>a SCIENCE, plain and simple, like any other.  Since when
>does a subject have to be fossilized before it can count
>as an "exact science?"

     To which I would further add that there was a time when most
physicists assumed that Newtonian mechanics was pretty much the
last word.  But, a while later, physicists noticed some discrepancies
between electromagnetic theory and observations.  The fallout was the
modifications to electromagnetic theory for relativity, which in turn
required modifications for relativistic mechanics.
     That wasn't the last word either.  Now we have quantum mechanics
and relativistic quantum mechanics.
     Such revisions are part and parcel of science.  The fact that
the revisions to our understanding of the universe that will come
about in all future time are not known at the present has nothing
at all to do with exactness.  One could argue that we become aware
of discrepancies between observation and theory that require changes
to theory *because* of the exactness of the science; i.e. if it
weren't exact, we probably couldn't notice the discrepancies.


                                  Scott Bennett, Comm. ASMELG, CFIAG
                                  Systems Programming
                                  Computer Center
                                  Northern Illinois University
                                  DeKalb, Illinois 60115
**********************************************************************
* Internet:       bennett@cs.niu.edu                                 *
* BITNET:         A01SJB1@NIU                                        *
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*  "If it weren't for lawyers, we wouldn't need them."               *
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From: stricher@masig3.ocean.fsu.edu (Char Aznabul)
Newsgroups: sci.geo.meteorology
Subject: Re: "Exact"-ness
Date: 11 Apr 92 00:09:44 GMT
Distribution: usa

Robert Dale writes

+ causes of lightning are!  The fact that several different computer
+ models run daily can give dramatically different results tends
+ to show to me that we don't know the formulas that determine
+ what makes the atmosphere tick.
+ 
+ Hopefully some of the meterologists on the reasearch side could
+ add some input...

Well, maybe it's not the model's fault. A (to me) famous question that
one should ask is "Why did Richardson fail?". Who was Richardson? He tried
the first meteorological numerical experiment [among other things]. He failed
spectacularly. One of the reasons is poor data quality and relative lack of 
data.

Today, while the quality has gone up, the lack of data is still a sore spot.
Oceanic areas are (IMHO) incredibly important - but also the most data spare
regions! And now, as a cost cutting measure, NWS is proposing once per day
soundings. And so it goes.

James
Newsgroups: sci.geo.meteorology
From: rtp1@quads.uchicago.edu (raymond thomas pierrehumbert)
Subject: Re: Dateline : NBC
Reply-To: rtp1@midway.uchicago.edu
Organization: University of Chicago Computing Organizations
Distribution: usa
Date: Fri, 10 Apr 1992 02:47:01 GMT


>  meteorology is not an exact science

This statement has come up a number of times in this thread. I beg
to differ.  Meteorology IS an exact science.  At least, it is
at least as exact as the other physical sciences, and probably
more so than biology (from a quantitative standpoint).  It is
based on precise physical principles systematically applied.

I get peeved when "meteorology" is conflated with "weather prediction"
As a science, weather prediction holds a distinguished status,
because the consequences of (rather small, physically speaking)
errors in prediction are readily observable, and have a
big effect. I can think of hardly any other science dealing
with the natural world (as opposed to engineered constructs
like airplanes) that is held up to the standards of accuracy
of weather prediction. Sure, the chaotic nature of weather
implies that there are inherent limits to prediction of individual
events.  So what?  The same statement applies to just about
every physical system dealt with by science.  Including cosmology,
stellar structure (how about predictin the next sunspot?  The
next solar storm?), and yes, even celestial mechanics, taken
over a long enough time frame.

Prediction of individual events is not synonymous with "understanding"
or "explaining" the behavior of the system.  Weather prediction
is about the only science I can think of where the measure
of success is the prediction of individual events (as opposed
to the general behavior of large numbers of events).

That is a matter of sociology.

But, meteorology is an exact science.

Newsgroups: sci.geo.meteorology
From: gmcmanus@reepicheep.gcn.uoknor.edu (Gary McManus)
Subject: Re: Weather forecasting (was: Re: Dateline : NBC)
Keywords: Beamwidth 
Organization: CIMMS/The University of Oklahoma, Norman
Date: Wed, 15 Apr 1992 18:37:31 GMT

In article <1992Apr15.140520.28797@nsslsun.nssl.uoknor.edu> hondl@nsslsun.nssl.uoknor.edu (Kurt Hondl) writes:
>>>>
>>miles NW of Woodward, but not of that magnitude.  I do believe,     
>>however, that this weatherperson's radar has a smaller beamwidth
>>than the 88D due to the large dish. 
>
>LARGER DISH = SMALLER BEAMWIDTH
>
>beamwidth =~ 140 * wavelength / Diameter of dish
>
Yes, this is what I was trying to say.  GARY ENGLAND's Doppler 9000
system has a larger dish than the 88D.  Also, I think GARY ENGLAND'S
Doppler 9000 is a 5 cm. radar, whereas the 88D is 10 cm.

G.Mc.
Newsgroups: sci.geo.meteorology
From: rmg3@grebyn.com (Robert Grumbine)
Subject: Re: modeling (was: "Exact"-ness)
Organization: Grebyn Timesharing
Distribution: usa
Date: Mon, 13 Apr 1992 00:05:21 GMT

In article <8177@sun13.scri.fsu.edu> stricher@masig3.ocean.fsu.edu (Char Aznabul) writes:
>Harold_Brooks writes
>+ The big thing that hurt Richardson was that the numerical scheme he used was 
>+ unstable.  Even with 'perfect' data, his model would have blown up.
>
>Of course. Anyone taking a 12 hour time step is asking for trouble... :)
>
>Let's see, he failed because:
>
>1) too large a time step
>2) errors in the intitial data
>3) numerical errors (round off, computational - it was done by hand)
>
>What else? Refresh my memory!

  Perhaps the best source to look at is a pair of articles by George
Platzman, written when Dover released reproductions of L.F. Richardson's
book "Weather Forecasting by Numerical Means" 1922.  (Title
approximate).  The full citations are:

  Platzman, G. W.  A retrospective view of Richardson's book on weather
prediction"  Bulletin of the AMS, 48, 514-550, 1967.

  Platzman, G. W. Richardson's Weather Prediction  Bulletin of the AMS,
49, 496-500, 1968.

  The numerical instability was _not_ a problem for his forecast.  He
took only 1 step (remember that this was by hand), so there was no 
chance for the 2 step instabilities to blow the forecast.  Insufficient
data was also not a particular problem.  He had observations for each 
of his grid points.  

  The thing which was a major problem is that he was computing his 
pressure tendency by using the observed winds directly to compute a
divergence.  This was compounded by a problem with his method (or
lack thereof) for exchanging mass between layers.  Basically he didn't,
while the atmosphere does.  Namely, the lowest layer developed a mass
loss of something like 100 mb.  In the real atmosphere, the upper layers
would generally notice this, and become sites of mass convergence.  So
the total mass loss in the vertical column would be less than this.

  Those were Platzman's conclusions as I recall them.  I also spent
some time reproducing his forecast, exactly as Richardson had layed out.
It turns out that his arithmetic was _not_ a problem.  I was taking
advantage of somewhat more refined computational instruments and his
answers generally checked out to the recorded precision.  Any interest
in seeing this written up for the Bulletin?

Bob Grumbine
From: gmcmanus@reepicheep.gcn.uoknor.edu (Gary McManus)
Subject: Re: Weather forecasting (was: Re: Dateline : NBC)
Keywords: Beamwidth 
Organization: CIMMS/The University of Oklahoma, Norman
Date: Thu, 16 Apr 1992 22:23:42 GMT

In article <1992Apr16.185318.27240@nsslsun.nssl.uoknor.edu> skaggs@nsslsun.nssl.uoknor.edu (Gary Skaggs) writes:
>In article <1992Apr15.140520.28797@nsslsun.nssl.uoknor.edu> hondl@nsslsun.nssl.uoknor.edu (Kurt Hondl) writes:
>>
>>beamwidth =~ 140 * wavelength / Diameter of dish
>>
>
>Correct me if I'm wrong, Kurt.  Here are some rough figures for the various
>radars in the OKC Metro area...
>
>KOUN - WSR88-D -- 10 meter dish, 10 cm wavelength = 1.4 deg beamwidth
>KWTV - Enterprise 9000 (whatever) -- ~4 m dish, 5 cm wvl = 1.75 deg beamwidth
>KOCO - Enterprise whatever -- ~3 m dish, 5cm wvl = 2.3 deg beamwidth
>KFOR - Ummmmmm.  Not sure of size, but it is a 5cm radar
>
>For comparison, a WSR74-C (5cm) would be 140*.05m/10m= 0.7 deg beamwidth
>
>However, the penetration capabilities offset the wider beamwidth of the 
>10 cm government radar.  And besides, the VAST majority of 5cm radars 
>were installed with a smaller dish to save cost on the radar pedestal.
>Doppler was not an issue when these were installed.

Actually, the formula I've been familiar with is 
   beamwidth=~73*wavelength / Diameter of dish
which would give the actual beamwidth for the 88D, which is I 
believe ~.95 degrees.  I thought an employee of KWTV told me
 that their dish was around 25 feet, or around 8 meters.  
 I obtained this formula from Doviak and Zrnic Doppler Radar and
 Weather Observations.  The WSR74-C has a 1.6 degree beamwidth, I
 believe.  Oh well.

 G.Mc.
From: tag@ecl.psu.edu
Newsgroups: sci.geo.meteorology
Subject: Re: Big BOOMS over east coast in 1970's - what were they?
Date: 6 Apr 92 16:44:46 EDT
Organization: Engineering Computer Lab, Pennsylvania State University

 
> I hear these booms quite regularly in the spring, summer and fall off Nova 
> Scotia's east coast. I never hear them at night, but sometimes three times a 
> day. Almost always in two or three groups of double booms. Sometimes they 
> shake the windows, at times they can be felt as a pulse of air. They always 
> appear to come from over the ocean. The sounds appearing in groups of 
> double booms, from over the water, appear similar to the reports in Corliss'
> book. He does not ascribe the noises to magic or extraterrestials, but 
> gives only sober accounts from thorough research. The same booms have been 
> reported in Nova Scotia from as early as the 1800's, and were apparently 
> much discussed in Nature magazine way back then. 
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> Rick Ballard                 | rballard @ fox.nstn.ns.ca
> Halifax, Nova Scotia, Canada |

According to my sources (i.e. somebody who was involved in discovering the
cause of these booms in the 1970's), they were caused by inbound Concorde
flights to New York.  The Concorde was deaccelerating to subsonic too
close to land, and shock waves produced by the (still) supersonic craft were
propagating along the ocean as a surface wave.  The surface wave was
audible at far greater distances than direct sound from the aircraft's
Mach cone.  The solutin, or modification to the Concorde's flight
plans to quiet the anomalous booms heard along the New England/Nova Scotia
coast, involved bringing the Concorde down to subsonic speed at a position
further away from land.

Tom Gionfriddo
Penn State Univ.
n









Newsgroups: sci.geo.meteorology
From: kwthomas@nsslsun.nssl.uoknor.edu (Kevin W. Thomas)
Subject: Re: Dateline : NBC
Organization: National Severe Storms Laboratory
Distribution: usa
Date: Fri, 10 Apr 1992 17:07:32 GMT

In article <1992Apr10.024701.16022@midway.uchicago.edu> rtp1@midway.uchicago.edu writes:
>
>>  meteorology is not an exact science
>
>This statement has come up a number of times in this thread. I beg
>to differ.  Meteorology IS an exact science.
>
>But, meteorology is an exact science.

Do you understand everything there is to know about thunderstorms and tornadoes?
Can you explain with 100% accuracy how they form, why they exist, and when
they will die.

I thought not.  Until you do, you can't say "meteorology is an exact science".

By the way, are you a meteorologist?

	Kevin W. Thomas
	National Severe Storms Laboratory
	Norman, Oklahoma
Newsgroups: sci.geo.meteorology
From: hbrooks@uiatma.atmos.uiuc.edu (Harold_Brooks)
Subject: Re: "Exact"-ness
Organization: NSSL
Distribution: usa
Date: Sat, 11 Apr 1992 14:01:36 GMT

In article <8169@sun13.scri.fsu.edu> stricher@masig3.ocean.fsu.edu (Char Aznabul) writes:
>Well, maybe it's not the model's fault. A (to me) famous question that
>one should ask is "Why did Richardson fail?". Who was Richardson? He tried
>the first meteorological numerical experiment [among other things]. He failed
>spectacularly. One of the reasons is poor data quality and relative lack of 
>data.

The big thing that hurt Richardson was that the numerical scheme he used was 
unstable.  Even with 'perfect' data, his model would have blown up.

The constraints placed on operational models lead to problems beyond any data
difficulties.  The worst thing an operational NWP model can do isn't a poor
forecast, it's _no_ forecast.  Having a model run late or not produce a
product causes havoc in the communications system.  Partially as a result
of this, physical accuracy is not necessarially the primary goal.  If a
problem is detected, such as the LFM's precipitation bias, NMC doesn't
always go back and try to fix what's wrong.  In the LFM precip. case, 
instead of doing anything with the way the model generated precip., they just
multiply the predicted amount by 2 to eliminate the bias.  There is a strong
tendency to look for 'engineering' solutions, rather than 'science' solutions.

As we move towards using higher-resolution models, e.g., the current generation
of research mesoscale models and their successors, these problems may well
become more acute.  Efforts to use even higher-resolution models, e.g., the 
current generation of research cloud-scale models and their successors, in a
mode where detailed storm evolution is predicted explicitly may be doomed to
failure.  Note that in the latter case, we'll have the large amount of data
coming in from the WSR-88D network.  

WARNING:  Unabashed, self-serving reference follows:

(For a lengthier discussion, see the "Forecaster's Forum" article in the
March, 1992 issue of _Weather and Forecasting_ by Brooks, Doswell, and Maddox
entitled "On the use of mesoscale and cloud-scale models in operational fore-
casting.")

Harold
-- 
Harold Brooks (NSSL)    hbrooks@nsslsun.nssl.uoknor.edu
Celebrating the arrival of a daughter and new Cardinal fan-
Sarah Elizabeth Brooks (born 18 Feb 92)
Newsgroups: sci.geo.meteorology
From: okabe@unixg.ubc.ca (Ian Okabe)
Subject: Re: Dateline : NBC
Organization: University of British Columbia, Vancouver, B.C., Canada
Date: Sat, 11 Apr 1992 22:57:52 GMT

Well I managed to see the Dateline story. Looks like NBC is trying hard
to find viewers. In any case, you guys are extremely lucky/blessed to
have the equipment that you do. Up here in the Great White North we have
two, count them two Doppler radars. Both in locations where many deaths
occurred from tornadoes. Thats how politics and the system works. Response
is always after the fact.

You guys have television stations that have better equipment than many
of our weather offices in Canada. You want to see a primitive satellite
loop? Try flipping through hard copies of satellite pictures for that
animation effect, or run by the pixs when posted on the wall. I kid you not!
But like others have said before we do the best job we can with the 
resources we have. And thats the way it will always be...
-- 
Ian T. Okabe (okabe@unixg.ubc.ca)
Atmospheric Sciences, University of British Columbia, Vancouver, Canada
From: pfgarvey@bsu-cs.bsu.edu (Patrick F. Garvey)
Newsgroups: sci.geo.meteorology
Subject: chaos tornado
Keywords: chaos, tornado
Date: 15 Apr 92 03:47:37 GMT
Organization: CS Dept, Ball St U, Muncie, Indiana


 hi, i am a novice. i know nothing about meteorology, and i dont know if 
there is a FAQ for this group... but i have 2 questions:

1- do buildings implode due to the pressure changes incurred during a
tornado, or is it due to the shear forces of the wind. also, should one
close their windows during a tornado?

2- has anyone used non-linear dynamic models to explain/ describe weather
forecasting?  the lorenz equations were fascinating to me, but i would like
to know if anyone has used these ideas to any practical benefit.

       i would appreciate any response ( usenet or e-mail or even direction
to a possible FAQ)

       thanks, 
         pat garvey
From: paul@kuhub.cc.ukans.edu
Newsgroups: sci.geo.meteorology
Subject: Johnston vortmax?
Date: 17 Apr 92 19:50:50 GMT
Article-I.D.: kuhub.1992Apr17.145050.39444
Organization: University of Kansas Academic Computing Services

What sort of vortmax is a Johnston vortmax? Is that a convectively
spawned vorticity? Thanks!
From: ajs@hpfcso.FC.HP.COM (Alan Silverstein)
Date: Tue, 14 Apr 1992 00:28:49 GMT
Subject: Electronic Lake Powell water levels?
Organization: Hewlett-Packard, Fort Collins, CO, USA
Newsgroups: sci.geo.meteorology

I'm looking for...  an electronic source of Lake Powell (Utah) water
levels on a periodic basis.  If you know of one, please send me mail.

This is just for fun.  I own a share of a houseboat at the lake (sorry,
sorry :-) and would enjoy watching and plotting the numbers.

Uh, thanks to owning the houseboat (among other things), I don't have
time to read this group, so please send me mail.  The usual apologies if
this is a frequent topic, etc.  Thank you in advance!

Alan Silverstein -- ajs@hpfcajs.fc.hp.com
Newsgroups: sci.geo.meteorology
From: corprew@nssdca.gsfc.nasa.gov (Frank)
Subject: satellite images - again
News-Software: VAX/VMS VNEWS 1.41    
Keywords:  images, MAC IIci, grid overlay, hurricane gifs
Organization: NASA - Goddard Space Flight Center
Date: Thu, 16 Apr 1992 00:08:00 GMT


Once again I'm calling on the wisdom of the people in this 
group.  A while back I asked if anyone knew of a way to 
overlay the continental outlines of the USA on the satellite
images retrieved from vmd.cso.uiuc.edu.  I received a few 
replies for sharing info or explaining the complexity, but
no one had the solution.   If anyone out there knows of a 
way to display these satellite images with continental 
outlines (useful for locating where things are occuring),
I would greatly appreciate the help.  As for my situation,
I download my images from vmd.cso.uiuc.edu on to a VAX 9410, 
and then transfer them via telnet to my MAC IIci, running system 
7.0.1.  I have several gif viewers.  I have viewed the images 
seperately, but my real need is to attach location information 
to the image.


I also have the need for hurricane gifs or any other situation
with interesting cloud structure.  I have the one Hugo gif from
the above named site, but it will not work for my purposes. 
Any hurricane Gilbert image sequences? Hugo? Others?


Thanks for any and all help,


Frank Corprew
From: gary@isis.cgd.ucar.edu (Gary Strand)
Newsgroups: sci.geo.meteorology
Subject: Saving a house from a tornado (was Re: chaos tornado)
Date: 17 Apr 92 02:50:45 GMT
Reply-To: strandwg@ncar.ucar.edu (Gary Strand)
Organization: Rarely

> Patrick F. Garvey

> Do buildings implode due to the pressure changes incurred during a tornado,
> or is it due to the shear forces of the wind. also, should one close their
> windows during a tornado?

  [This is advice from Thomas Grazulis' "Significant Tornadoes Vol. I"]

  Whether windows are opened are closed during a tornado doesn't make much
  difference. If windows are closed, they will surely be broken by the vast
  amount of flying debris. If they're open, it's possible that some small 
  benefit could be had, but if the roof isn't securely anchored and becomes
  damaged or blown away (resulting in the collapse of the walls) the state
  of the windows won't make much difference. Also, if the windows on the lee-
  ward side of the house are closed, the wind rushing in through the (open)
  windward windows could blow the house up like a balloon and destroy it.

  In any case, one's time is *far* better spent seeking shelter rather than
  worrying about the windows. It's pretty stupid to put your life at such
  risk when the potential benefit is so negligible.

--
Gary Strand                      Opinions stated herein are mine alone and are
strandwg@ncar.ucar.edu            not representative of NCAR, UCAR, or the NSF
From: privette@samwise.colorado.edu (Jeff Privette)
Newsgroups: sci.geo.meteorology
Subject: 1-D Boundary layer model
Date: 16 Apr 92 16:37:59 GMT
Article-I.D.: colorado.1992Apr16.163759.14994
Organization: Colorado Center for Astrodynamics Research

Hi,
A coworker and I would like to couple a boundary
layer model to a canopy evapotranspiration model
we are adapting.  We need only a very simplistic 1-d
model that computes wind velocity profile, plus
some humidity and temperature information.  This is
vague, but we can probably adapt something if we
are given a skeleton model.  If anyone knows of
one, please email me.  If there is sufficient interest,
I will post a summaries of replies.
Thanks,
Jeff