Subject: Doppler Sonar
From: rowe@ricochet.net
Date: Thu, 14 Nov 1996 15:21:12 -0600
I'm interested in finding a technology that can measure
ocean currents from a distance of 500-1,000 meters
away. If anyone has any info on doppler sonar/radar,
please let me know. Doppler Radar can measure wind
currents above ground from distances of >60 miles
from the radar. However, I can't find similar technology
for doing this in the ocean.
Any leads would be appreciated.
Richard Rowe, MD MPH
please e-mail me: rowe@ricochet.net
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Subject: Re: Global Warming: Effect on Sea Level
From: Leonard Evens
Date: Thu, 14 Nov 1996 16:59:25 -0600
Robert Evans wrote:
>
> Andy & Sophie Smout wrote:
> >
> > Greetings!
> >
> > I am interested in any information on the predicted change in sea-level as
> > a consequence of global warming. Does anyone know what the current climatic
> > models say? I think I have heard numbers up to 10 metres quoted, but don't
> > know the source of this information and whether it is in any sense recent
> > or reliable. Also, I would be interested to know wheter any rise in sea
> > level would be the same over the whole surface of the earth, or would be
> > greater near the equator.
> >
> > Does anyone know the current state of the art? Specifically, I would like
> > to move to the seaside in Scotland, but don't want to buy a house that will
> > be underwater after 25 years or so... :-)
> >
> > Andy Smout
>
> Andy & Sophie,
>
> The state of the models is not very good. The modelers will tell you that.
> If you move to the seaside, just make sure you are at a proper elevation
> and distance from the shore to avoid storm surge from any major storm.
>
> Maybe in 10-20 years the models will have most of the physics in them and
> the computers will be powerful enough to model the atmosphere. IMHO, we are
> not there yet.
>
> Bob Evans
>
> --
> ______________________________________
>
> all opinions expressed are mine and
> mine alone.
>
> ______________________________________
Might I beg to differ with you. From reading the IPCC Reports, I
think models aside, climatologists understand at least enough to more or
less rule out rises in sea level of ten meters in 25 years.
In any case, as I pointed out in a separate posting, the real
uncertainty has to do with the structure of the Antarctic ice cap and
what is likely to happen to that. That issue is different from the
question of modelling the atmosphere and global climate. I think you
are mixing apples and oranges in your comment.
--
Leonard Evens len@math.nwu.edu 491-5537
Department of Mathematics, Norwthwestern University
Evanston Illinois
Subject: Re: Global Warming: Effect on Sea Level
From: Leonard Evens
Date: Thu, 14 Nov 1996 16:52:25 -0600
Andy & Sophie Smout wrote:
>
> Greetings!
>
> I am interested in any information on the predicted change in sea-level as
> a consequence of global warming. Does anyone know what the current climatic
> models say? I think I have heard numbers up to 10 metres quoted, but don't
> know the source of this information and whether it is in any sense recent
> or reliable. Also, I would be interested to know wheter any rise in sea
> level would be the same over the whole surface of the earth, or would be
> greater near the equator.
>
> Does anyone know the current state of the art? Specifically, I would like
> to move to the seaside in Scotland, but don't want to buy a house that will
> be underwater after 25 years or so... :-)
>
> Andy Smout
In addition to the other sources recommended to you, look at Climate
Change 1995 by the Intergovernmental Panel on Climate Change.
Briefly, most projections place the increase at tens of centimeters,
not meters over the next century. A seaside house is not likely to be
under water in 25 years. However, if it is on low lying land which is
now just about at sea level, it could be affected more by storm surges
than in the past. There are of course a lot of uncertainties in these
projections. The joker in the deck is possible unstability in part of
the antarctic ice sheet. If that collapsed, there could be
catastrophic rises in sea level. However, the IPCC considers this
unlikely, at least in the short term.
--
Leonard Evens len@math.nwu.edu 491-5537
Department of Mathematics, Norwthwestern University
Evanston Illinois
Subject: Sterol standards for GC/coprostanol
From: "Edward D. Hudson"
Date: Thu, 14 Nov 1996 18:29:29 -0330
Dear All,
Does anyone out there know if anyone offers a mixed sterol
standard suitable for GC (either in the free or TMS ether forms)?
I'm looking at analysing sediment trap samples to determine
quantities of individual sterols. I could make up a standard
from pure individual sterols, but if someone offers a ready-made
mixed standard, it would be easier. Thanks in advance.
While I'm at it- anyone know if there was ever a "last word"
in the debate on the value of coprostanol as a fecal marker? (Some
report it as an unambiguous sewage marker, others say it may also be
formed by bacterial delta-5 hydrogenation in sediments/sinking
particles, still others try to get around this by quoting ratios of
coprostanol to other sterols, etc., etc. )
Thank you. Cheers,
Ed :)
Ed Hudson
Department of Chemistry
Memorial University of Newfoundland
St. John's, NF A1B 3X7, Canada
Subject: Re: Global Warming: Effect on Sea Level
From: Aaron Brasket
Date: Thu, 14 Nov 1996 19:18:20 +0000
Leonard Evens wrote:
>
> Might I beg to differ with you. From reading the IPCC Reports, I
> think models aside, climatologists understand at least enough to more or
> less rule out rises in sea level of ten meters in 25 years.
>
> In any case, as I pointed out in a separate posting, the real
> uncertainty has to do with the structure of the Antarctic ice cap and
> what is likely to happen to that. That issue is different from the
> question of modelling the atmosphere and global climate. I think you
> are mixing apples and oranges in your comment.
>
> --
> Leonard Evens len@math.nwu.edu 491-5537
> Department of Mathematics, Norwthwestern University
> Evanston Illinois
This isn't entirely true. Besides the Antarctic ice sheets, another
possible cause of rapid climate change could be the oceanic thermohaline
circulation (deep water formation in the North Atlantic). Ice core
samples from the end of the last ice age (Younger Dryas event) show
rapid fluctuations in the climate system with multiple transitions from
near glacial to relatively warm conditions in periods as quick as a
decade.
This is not an ice sheet phenomenon rather an adjustment in the
large-scale ocean/atmosphere circulation. I agree the chances of rapid
climate change are close to nil for the immediate future but modeling
of these past climate changes and its application to future climate
change scenarios remains an open question. Whether the ice sheets or the
ocean is more important depends to some degree on whether you are
speaking to a geologist or an oceanographer. Comprehensive climate
models which have land processes, realistic topography, and dynamic
oceans exist but have considerable room for improvement. Don't wait for
them to improve before buying a house however.
Aaron Brasket
Program in Atmosphere and Ocean Sciences
University of Colorado
Subject: PhD : Tridi-flow and transport in coastal zone : numerical modeling (19/11/96 10h30 Grenoble FRANCE)
From: Stephane CHEVALIER
Date: Fri, 15 Nov 1996 15:43:25 +0100
=============================================================
FRANCAIS (for english version see below)
=============================================================
Soutenance de These :
Mardi 19 novembre 1996 a 10h30,
Salle de conférence de l'IRIGM
rue de la piscine
Universite de Grenoble (FRANCE)
--------------
Ecoulement et transport littoraux tridimensionnels :
application numerique
--------------
par Cristele BERTHET
pour le titre de Docteur en mecanique geophysique
These effectuee au LEGI
(Laboratoire d'Ecoulement Geophysique et Industriels)
Universite de Grenoble (FRANCE)
Resume :
L'utilisation d'un modele numerique tridimensionnel a permis d'etudier
d'une part un ecoulement caracteristique en zone cotiere a forte
bathymetrie, d'autre part, le transport de sediment.
L'influence de la bathymetrie et de la stratification sur l'evolution
d'un courant et de la surface libre est analysee. Cette etude se
concretise par une simulation realiste de la section du courant Nord
face a la baie de Monaco.
Le transport du sable et de la vase est considere sous l'action d'un
courant et de la houle. Puis, une etude sur le transport des particules
organique permet d'evaluer la production primaire dans la colonne d'eau.
=============================================================
ENGLISH
=============================================================
Tuesday 19 november 1996, 10h30,
conference room of IRIGM
University of Grenoble (FRANCE)
--------------
Tridi-flow and transport in coastal zone :
numerical modeling
--------------
by Cristele BERTHET
for the title of : Docteur en mecanique geophysique
PhD. carried out at the LEGI
(Laboratoire d'Ecoulement Geophysique et Industriels)
University of Grenoble (FRANCE)
Abstract :
We studied a characteristic flow in a deep coastal zone and the
transport of sediment using a three-dimensional numerical model.
The influence of bathymetry and stratification on flow and water level
was analysed. This study is applied in the simulation of a part of the
"North current" of the coast of Monaco.
The transfer of sand and clay was studied under the influence of flow
and waves. Then, a preliminary evaluation of the transfer and primary
production of the organic matter was presented.
