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Questions fréquentes concernant le projet |
| Voila quelques questions
posées par des personnes souhaitant prendre part au projet climateprediction.net.
Nous espérons qu'elles vous seront utiles. Cependant, si vous ne
trouvez pas l'information recherchée, vous pouvez poser votre question
ou vos suggestions à partir de la zone
Utilisateur de climateprediction.net,
ou via la page Contact
& support page. Les questions ci-dessous sont organisées
en trois catégories:
- S'enregistrer en tant qu'utilisateur
- Exécuter le modèle climatique
- En apprendre plus sur le climat & la zone utilisateur interactive
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- Quelle donnée dois-je vous donner pour m'enregistrer?
- Allez-vous vendre mon adresse email ou d'autre données me concernant?
- Quand le logiciel sera-t-il disponible?
- La climatologie est une science en pleine évolution; allez-vous fournir des mises à jour pendant le déroulement du projet?
- Ca m'intéresse... par où commencer?
- Le formulaire d'enregistrement ne contient pas la plate-forme XYZ!
- I downloaded the model, filled
in the registration form, and received confirmation email. However,
I can't log in to the user forum; it keeps telling me "email address
not recognized". What's wrong??
- Quelle donnée dois-je vous donner
pour m'enregistrer?
- Pour participer au projet, nous vous demandons de vous enregistrer
sur le portail de climateprediction.net. Vous devez entrer
votre nom, votre adresse email, un nom d'utilisateur et un mot de passe.
Les autres informations (telles que âge, location...) sont facultatives.
Les nom d'utilisateur, email et mot de passe permettent de vous identifier
de façon unique, pour vous envoyer un modèle unique et
vous permettre d'interagir avec les autres participants depuis le portail.
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- Allez-vous vendre mon adresse
email ou d'autre données me concernant?
- Jamais! Nous vous demandons votre adresse email dans le seul but de
pouvoir vous contacter lorsque le logiciel client climateprediction.net
sera disponible, et de vous vous tenir informé de la progression du
projet. Nous utiliserons votre nom d'utilisateur pour personnaliser
les pages auxquelles vous accéder sur notre site, sur la partie interactive
et pour diverses statistiques.
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- Quand le logiciel sera-t-il
disponible?
- MAINTENANT! Nous avons fini de tout assembler et à présent
(depuis le 3 septembre) le logiciel fonctionne. Nous avons effectué
le bêta-test pour nous assurer que tout fonctionne sans problème.
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- La climatologie est une science
en pleine évolution; allez-vous fournir des mises à jour pendant le
déroulement du projet ?
- Pas dans un premier temps. Le but premier de ClimatePrediction.net
est d'évaluer l'incertitude associée à un modèle
climatique donné. Le modèle sera à jour lors du
lancement, mais doit rester inchangé pendant le déroulement
du projet pour pouvoir fournir des résultats utiles. Bien sûr,
les évolutions de ClimatePrediction.net intégreront les
derniers développements en climatologie.
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- Ca m'intéresse... par où commencer?
- Merci d'être intéressé dans le projet. D'abord,
lisez
les spécifications
techniques pour être sûr que le modèle tournera
bien sur votre ordinateur. Ensuite, il vous faudra télécharger
le logiciel, vous enregistrer, etc. Pour vous enregistrer, suivez le
lien Comment Participer
. Une fois que le modèle s'exécute, de temps en temps
il vous demandera de se connecter à Internet pour renvoyer des
résultats. A la fin de l'exécution, il enverra également
des informations scientifiques importantes pour la finalité du
projet climateprediction.net.
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- Le formulaire d'enregistrement
ne contient pas la plate-forme XYZ!
- Il y a trop de plates-formes différentes pour pouvoir toutes
les inclure dans le formulaire d'enregistrement. Nous avons essayé
d'inclure les principales, mais savons bien que nous en avons laissé
beaucoup de côté. De toute évidence nous ne pourrons
pas créer un logiciel client pour chaque plate-forme. N'hésitez
pas à nous contacter si nous avons négligé une
plate-forme et nous essaierons d'en tenir compte.
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- I downloaded the model, filled
in the registration form, and received confirmation email. However,
I can't log in to the user forum; it keeps telling me "emails address
not recognized". What's wrong?
- There are two different authentication systems - one for you as a
participant running a climate model, and another one for user wanting
to take part in the discussion forums. If you want to post messages
to the Forum, you need to register with the forum (at www.climateprediction.net/board. This mode of operation
has been chosen so that even people who cannot or don't want to run
a model have a chance to discuss things with other members of our community.
For additional info, see also Forum FAQs.
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- I have an old 286 computer with 4 Mb of memory and Windows
3.1, will there be a client I can run?
- How long will the modelling take?
- Is your model running as a screensaver or a background client?
- What should I do if I have a dual-processor machine?
- Will running climate model interfere with other processes?
Can I run it together with SETI@Home or Folding projects?
- If there's a power failure or my Windows freezes up, how much
data have I lost?
- Are you going to port to the Linux/Mac platforms?
- Will climateprediction.net be Open Source?
- What will the software do to my machine?
- I have an old 286 computer with
4 Mb of memory and Windows 3.1, will there be a client I can run?
- We're afraid not. Although not yet cast in stone, the climateprediction.net
client will most likely require at least 128MB of memory, and 500MB
of free disk space. In order for results to be produced in 12-18 months,
one will need at least a 200MHz processor. This is a scientific research
project based on a full-scale climate model, representing decades of
research in super-computing centres. Although it would be a great idea
to have a simpler model available for anyone to run on any old PC, and
we don't like being CPU-elitist, our primary goal is the science, for
which we need to use a state-of-the-art model.
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- How long will the modelling
take?
- Quite a while. We are anticipating at least six weeks of CPU time
on fast machines, perhaps three or four months on slower machines. Serious
climate science requires serious computer time. The flipside of this
is that the fact we can conduct this sort of experiment at all is one
of the minor miracles of the computer age: general circulation climate
models are among the most sophisticated computer models in the world.
They have always been run on supercomputers because of their complexity
and the intensity of the number-crunching involved. It's yet another
(if more were needed) testament to the phenomenal development of personal
computing that you can run such a model on the machine you have in front
of you.
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- Is your model running as a screensaver
or a background client?
- Many people have complained about the screensaver aspect of the climateprediction.net
client, and rightfully so. Screensavers only run when a computer has
been idle for a period of time, are resource-hungry and place a limit
on the platforms that can be supported. A background client will run
whenever there is spare processing power, can be made more efficient
than a screensaver and will support many more platforms. Following all
of your suggestions, the climateprediction.net client has been
designed to run in the background. An additional client will be provided
to view the progress of your climate simulation, and that will be able
to be run in screensaver mode if the user desires it.
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- What should I do if I have a
dual-processor machine?
- Right now, just register it as 2 independent CPUs. The most efficient
use you could make of a multi-processor machine would be to run several
models (assuming you have the memory to do so). If you want to get fewer
answers out faster, we may be able to get it working for a multi-processor
PC environment, but we aren't making any promises.
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- Will running climate model interfere
with other processes? Can I run it together with SETI@Home or Folding projects?
- Almost certainly there should be no interference with other applications on your
computer - e.g. Word, Excel, Lotus, etc. In developing the package we have made every
effort to fit in with other sorts of Windows-based software, such as
Powerpoint, Word, Excel, and even games. Those of you who use other
systems (such as reasonably tuned Linux-box) don't need to worry at
all. However, applications like SETI@Home and Folding use a similar strategy as
we do - re-use as much of your spare/idle CPU time as possible. From this reason
they would 'compete' for a scarce resource (your computer memory and processor), and
this may result into poor performance of climate model and/or SETI@Home. We would
advise not to run climate model together with any other distributed computing project.
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- If there's a power failure or
my Window freezes up, how much data have I lost?
- We, of course, do ensure the model state is saved to disk at least
once per day (real time) so as little information as possible is lost
in the event of an interruption -- if all goes to plan, you should be
able to copy the re-start file over to a new PC if you decide to upgrade
while running the experiment. More frequent dumps would simply slow
the integration down and eventually wear out your hard disk.
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- Are you going to port to the
Linux/Mac platforms?
- Our industry partners Tessella
Support Services plc. have begun work on a Linux/UNIX port. See the
Climate News for details.
We'll keep you posted on its status. We also have plans to include a
Mac version of the client, and we'll let you know how these develop. We apologize
that initially only Win32 version is released, but the model is a hugely complex
code originally designed for supercomputers and human supervision. Our version of
the model runs automatically, without any major assistance needed thanks to the
'user interface/model manager'. It is this particular piece of code that requires
significant work in order to port it to other platforms.
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- Will climateprediction.net
be Open Source?
- The source code of any model used in climate research is accessible
to the academic community -- we would never contemplate using a model
for which the authors were not prepared to disclose the source. On the
other hand, some of the most advance climate models are "dual use",
meaning they are used for operational weather forecasting as well as
for research. As a result, the source code has considerable commercial
value, so anyone who wants access to it (to port it to a different platform,
for example) would need to sign a specific agreement with the model's
developers stating the purpose for which it was to be used and guaranteeing
that it would not be passed it on to a third party.
We recognise this is not fully Open Source, but since anyone who wishes
to verify that the model is doing what we claim it is doing, could access
the source in this way (free of charge, of course) it's close -- not
all Sources are Open, but some are more Open than others...
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- What will the software do to
my machine?
- As long as you leave the computer on (after having closed other applications
for the night, for instance) the model will run. You don't even need
to close the model down when you start new processes (such as Word or
Powerpoint or Explorer) because the climateprediction.net software
is set to be a background process - all other processes will automatically
be given priority over the model, so it won't slow up your other work.
However, as stated above, if
you are going to use your company's computer, please DO ask for permission
to do so. We cannot accept any liability or responsibility for
any breaches in your company's code of conduct and/or Internet usage!
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- Won't all those computers left on for 24 hours a day have
a detrimental impact on the climate system?
- Okay, so I'm running the model. How can I find out what is
going on in my model run?
- My model turns into an ice-ball/mass of boiling oceans,
yet you guys reckon this is a reasonable representation of 21st century climate. Should I be
alarmed or is your model just rubbish?
- I want to particpate in the climateprediction.net community.
How do I go about it?
- What peer to peer services do you provide to the user?
- My model does not finish all three phases, and uploads data
prematurely. This may be accompanied by a message about 'instable climate' and 'repeated calculation'.
What went wrong?
- Won't all those computers left
on for 24 hours a day have a detrimental impact on the climate system?
- Assume a computer running 24hrs/day requires, on average, 50W of power.
If 100,000 computers join the climateprediction.net project, the project
will require 5,000kW of power. There are 24 hours in a day, so each
day the project will consume 120,000kW-hrs, or 432,000,000kJ of electrical
energy.
That's a big number, so let's try and put it in perspective by calculating
how much energy is necessary to boil water for a cup of tea. Let's use
a tiny bit of physics to do it. Assuming a specific heat of water of
4.19 kJ/(kg-K), 0.237kg/cup of water, a necessary temperature rise from
20 degrees Celsius to 100 degrees Celsius, and that only one cup of
water is boiled for each cup of tea, then about 80kJ/cup of energy are
necessary (assuming our kettle is 100% efficient). This means that running
the climateprediction.net project for one day is equivalent
to boiling water for 5,400,000 cups of tea!
Is five and a half million cups of tea a lot? According to the Tea Council,
some 37 million people in the United Kingdom drink, on average, 3.4
cups of tea per day. That's nearly 126 million cups of tea per day in
the UK alone!!!
Each day, about 23 times more energy will be spent boiling water for
tea in the United Kingdom than would be used by the computers involved
in the climateprediction.net project. More seriously, a rough
calculation suggests that 100,000 computers running 24hrs/day for one
year at a power consumption of 50W will contribute approximately 0.0001%
of the total amount of CO2 generated in one year. This is
not an insignificant amount, but seems (to us) a worthwhile investment
to better understand the climate system.
Assuming you are convinced this experiment needs to be done, there are
basically two options: to buy a hangar-full of PCs and run it ourselves
(not even an option right now, since the climate research community
doesn't have the resources); or to recycle spare CPU out in the community,
as we propose to do under the climateprediction.net experiment.
Since the main environmental impact of a PC is in manufacture and disposal,
not the power consumed in running it (never mind the air-conditioning
costs and visual impact of that hangar on some innocent rural community),
environmentalists will, we hope, approve of our strategy.
Nevertheless, this would be an interesting topic for further discussion,
and we warmly invite you to go to the interactive parts of this portal
and make your voice and/or opinion heard in the climateprediction.net
community. See also the question on joining the user community further
down.
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- Okay, so I'm running the model.
How can I find out what is going on in my model run?
- The client interface displays a variety of information about your
model. It tells you how far through the experiment you are, including
the timestep number and model date, and gives you information about
what sort of processing is going on (eg., it warns you if it needs to
do some file processing between different phases of the experiment).
Menus on the client interface allow you to open your browser at the
climateprediction.net help pages or user profile pages, as
well as giving you the option of opening the visualisation package,
through which you can see various fields (temperature, cloud/snow/ice
fields, etc) which are read directly from the model as it runs.
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- My model turns into an ice-ball/mass
of boiling oceans, yet you guys reckon this is a reasonable representation
of 21st century climate. Should I be alarmed or is your model just rubbish?
- No need to worry. We're making changes to the physics of the model,
and we expect (and want!) to probe a range of climates beyond that which
we currently observe. So we fully expect some strange climates (and
a few very strange climates). These are actually pretty interesting
because although they probably can't tell us much about the earth, they
can tell us a lot about the model.
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- I want to particpate in the
climateprediction.net community. How do I go about it?
- Over the next few months we're going to develop our user community/interactive
area. You'll be able to personalise your own user profile and see how
your model fits into the experiment as a whole. You'll also be able
to participate in various teams: friends and neighbours, countries and
regions, and neighbours in parameter space.
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- What peer to peer services do
you provide to the user?
- Basically, the services provided by our User Portal fall into two
categories. First, community-wide services such as newsletter, discussion
forums and similarly, where you are going to interact with many participants
in this experiment. Second category contains so-called peer to peer
services, by which we mean those tools that enable a contact between
limited number of individual participants - usually friends, colleagues,
fellow students, etc.
We start with a provision of a specially enhanced instant messaging
(IM) tool called BuddySpace
that puts you in touch with your mates using the leading IM networks
(e.g. MSN, ICQ, Jabber, Yahoo!), and in addition provides map-based
interface that will later be embedded directly into our climate model,
so you can have all the benefits at your fingertips. Later, we intend
to extend peer to peer services to include collaborative visualisation
of the results, result comparison between the peers, and similarly.
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- My model does not finish all
three phases, and uploads data prematurely. This may be accompanied by
a message about 'instable climate' and 'repeated calculation'.
What went wrong?
- Nothing went wrong. Only this particular combination of parameters that
was used for your personal model might be physically impossible (e.g. too hot
or too cold). Therefore, the model evolves a behaviour that gets 'out of control'.
This is shortly called 'instability'. When such instability is observed repeatedly,
we learn that the particular parameters are not realistic. Hence, your model stops
calculating, uploads the partial results, and downloads another parametrisation.
Don't worry, even these 'instable' models count towards the statistics of completed
runs...
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