How often does CPDN upload my results? Is it only after I\'ve run an entire model? If I stop running the model prior to completion, is all the work on that model lost? Thanks in advance,

Rob

Rob,

CPDN operates a little differently to the other BOINC projects, because of the long runs. It uploads data at relatively short intervals and larger amounts of data (in a Zip file) less frequently.

The slab models (HADSM3) submit 72 \'trickles\' over 45 model years, and a Zip file at the end of each 15-year phase.

The coupled models (HADCM3) submit 160 trickles over 160 model years (i.e. one per model year), and a Zip file every 10 years. There are also 80-year coupled models.

The regional models (HADAM3) submit 72 trickles over 1 model year, and a large Zip file at the end.

So, all is not lost if a model is stopped before its natural end - the project can get something out of the model\'s results. It\'s entirely understandable if someone has to give up on a coupled model, which could take many months to finish.

Hope that helps.

Iain

Hi,

Depending on the type of model, it is uploaded at different times:

* HadCM3 (coupled) - every 10 model years
* HadSM3 (slab) - 3 times (i.e., at the end of each of the 3 phases)
* HadAM3 (SAP) - at the end only


-- Edit:

Iain got there first :-)

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Iain et al,

Thanks much. One more question.... does a trickle convey some data, or is it just a status update? I infer from your answer there is some data in the trickle but I\'m not sure.

Rob

Rob,

CPDN operates a little differently to the other BOINC projects, because of the long runs. It uploads data at relatively short intervals and larger amounts of data (in a Zip file) less frequently.

The slab models (HADSM3) submit 72 \'trickles\' over 45 model years, and a Zip file at the end of each 15-year phase.

The coupled models (HADCM3) submit 160 trickles over 160 model years (i.e. one per model year), and a Zip file every 10 years. There are also 80-year coupled models.

The regional models (HADAM3) submit 72 trickles over 1 model year, and a large Zip file at the end.

So, all is not lost if a model is stopped before its natural end - the project can get something out of the model\'s results. It\'s entirely understandable if someone has to give up on a coupled model, which could take many months to finish.

Hope that helps.

Iain

Iain et al,

Thanks much. One more question.... does a trickle convey some data, or is it just a status update? I infer from your answer there is some data in the trickle but I\'m not sure.

Rob

It depends. Coupled model trickles contain some data, which is how the temperature graph is updated on the Web site between Zip uploads; the Zip file contains more data and a full restart dump. Slab models send a \"hey, I\'m here\" trickle on starting as well as the 72 progress trickles, but no information appears on the Web site between phases - so the science data is all in the Zip file. (Slab models also send a lot of junk trickles at phase changes, but I think these are being excised from the latest slab model version.) The HADAM3 models adopt the same general approach as the slabs, though there is only one Zip at the end; because both models are relatively short the probability of completing ought to be much higher.