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Posts by Sarah Sparrow

Posts by Sarah Sparrow

1) Message boards : Number crunching : Upload 11 status (Message 62595)
Posted 18 days ago by Sarah Sparrow
Dear all,

There have been issues at the facility where Upload 11 is located and so we are not able to take uploads there at present. We will let you know as soon as this is resolved and normal service is resumed.

Best wishes,
2) Message boards : Number crunching : "No tasks sent" (Message 61605)
Posted 25 Nov 2019 by Sarah Sparrow

Just to let you know we are currently dev testing new batches of windows tasks which should be released on the main site in the next few weeks.

Best wishes,
3) Questions and Answers : Unix/Linux : HadAM4 at N216 resolution (Message 61180)
Posted 4 Oct 2019 by Sarah Sparrow
We are about to launch 3000 workunits of our new ‘hadam4h’ application running on linux. This will have a global resolution of ~60km and a higher vertical resolution than before as well which should enable us to do some new and interesting science. We wanted to make volunteers aware that currently this model has a longer time between checkpoints and they will be larger than the N144 checkpoints. We have tested the application and believe the model should run smoothly but wanted to give advance notice that if there are any large scale issues associated with this batch it may be necessary for us to abort these simulations from client machines. Please do let us know via forum posts if there are any major problems. We look forward to sharing the results with you in due course.
4) Message boards : Science : AFlame PROJECT (Message 60915)
Posted 13 Sep 2019 by Sarah Sparrow
Just to give some more details on AFLAME. This is a belated announcement of the project, which actually started in April this year. This will be run under CPDN with the weather@home2 application using the South America region. Some of the initial WU have already been sent out (batches 813, 814, 815 and 822) with more planned when we have the appropriate land use forcing files available.
5) Message boards : News : Project news: Introducing the AFLAME project (Attributing Amazon Forest fires from Land-use Alteration and Meteorological Extremes) (Message 60909)
Posted 12 Sep 2019 by Sarah Sparrow
The AFLAME project is funded through the Newton Fund Climate Science for Services Partnership Brazil via the Met Office and works collaboratively with scientists in the UK and Brazil.

There is an emerging realization that Amazonian wildfires that were formerly driven by deforestation and agricultural expansion, are now growing to unprecedented magnitudes because of meteorological extremes. These escaped agricultural fires are rapidly degrading remaining forests in the Legal Brazilian Amazon (LBA).

Within this project we aim to attribute the change in wildfire risk due to human induced climate change and predict how these wildfire occurrences may change in possible future climates. Other factors besides increased greenhouse gas emissions may affect wildfire incidence, for instance, large-scale natural variability in the climate system from events such as the El Nino Southern Oscillation (ENSO) as well as how the land is being used and deforested. We will be performing a series of sensitivity studies to determine the relative influence of each of these factors alone on Amazon wildfire outbreaks. To do this we will analyse the results from the distributed computing simulations for the occurrence of weather conducive to wildfire outbreaks and parse this output into a statistical wildfire module.
6) Message boards : Number crunching : Project Losing it's Way? (Message 60019)
Posted 26 Apr 2019 by Sarah Sparrow
Just to respond to some of your concerns and hopefully reassure you that as a project we are still heading in the right direction.

Although we are looking at running some higher resolution models our aim with these is that they should still be suitable to run on an average computer. We are aware that otherwise we will not be able to do the analysis that we wish to. One of the initial tests we do when considering new models is to check resource requirements and we intend to keep the bulk of work units within reasonable constraints otherwise we will reject bringing the model within the project. There are a couple of projects coming out that are of higher resolution (but still run ok on our test machines which are setup to represent an "average" system). These will be a minority of the runs that we send and will be sent out as a new distinct app so that people can choose whether to run these or not. In many cases initially they will be limited to a single OS as well.

We do gratefully receive all contributions of simulations that are run. However if we have enough simulations in place to do the analysis that we need to do then it seems more efficient to use peoples computing time on simulations that are needed so we close batches. This also allows us to do essential cleanup processes on our servers here. Generally batches are not closed until we have around 80% of the simulations successfully returned to us. We aim to send work units that do not take too long to run, although realise that in many cases these simulations may still take several weeks.

As for the analysis that we do, we do look at past events as part of validation but in many of the analyses we include possible future likelihoods of extreme events to make these relevant to policy and decision makers. Increasingly the studies we do are focussed not just on the extreme event that occurs (heatwaves, floods, droughts etc) but on also on the extended impacts (e.g. public health, infrastructure and economics), and likely change in risk of these, making them "more relevant to the real world". A lot of these are still in the pipeline, but you should hopefully see some of these appearing in the future on the publications page.
7) Message boards : Science : Project announcements (Message 59688)
Posted 27 Feb 2019 by Sarah Sparrow
Here is a message on behalf of project scientist Dr Peter Watson:

We are in the final stages of developing a new pair of global atmospheric models for use in CPDN. These have a big resolution upgrade compared to the existing global model used by Weather@Home, meaning that the spacing between grid points is being reduced, making use of the larger memory and processor power available in modern computers. The purpose of this is to address the fact that the high-impact weather events that CPDN is often used to study (like extreme heatwaves and heavy rainfall) usually involve extreme "dynamical" phenomena, like storms and blocking anticyclones. So it is very important to be able to simulate these events faithfully, and increasing the model resolution helps with this.

The resolution sets how much fine detail the model can resolve through calculations of the fundamental fluid dynamics of the atmosphere, and increasing it reduces the reliance on more approximate parameterisations of sub-grid processes. These models will have resolutions of 0.83x0.5 degrees (~60km in middle latitudes) and 1.25x0.83 degrees (~90km). The global atmospheric model that is currently used has a resolution of only 1.875x1.25 degrees (~150km). The number of vertical levels will also be doubled. Studies that have been done over the past few years have found that reducing the grid spacing below 100km starts making substantial improvements to the quality of simulated weather phenomena such as those previously mentioned.

The model with the higher resolution has a grid spacing close to that of the 50km regional model, but simulates features at this scale for the whole globe, effectively simulating the results for all of those regional models simultaneously. Whilst the regional models that are currently used help to capture fine details, they are dependent on the winds simulated by the 150km-resolution global model at large scales. The new higher resolution models will also simulate these large-scale winds more faithfully, giving further improvements in the results for small regions. The regional models may still be more appropriate for some projects, though, and are likely to still be used.

Our initial tests have found that the quality of weather simulations from these models appears similar to that in the current state-of-the-art model used at the Met Office. So with the ability to produce multi-thousand member ensembles with these models, there will be many opportunities to do cutting-edge science.

For now, these models are only going to be run on Linux systems. Some of you will already have received work units using the model with ~90km resolution. This work is pushing at the boundaries of what it is possible to achieve in a project like this, so please bear with us as there may be quite high failure rates at first as issues are ironed out.
8) Message boards : Science : Project announcements (Message 59682)
Posted 26 Feb 2019 by Sarah Sparrow
This is a new thread where we will post information about the scientific objectives of different batches of work that are released along with project developments.
9) Message boards : Number crunching : Credits (Message 59637)
Posted 14 Feb 2019 by Sarah Sparrow
Hi Randi,

Just to reassure you we are looking at implementing improvements to our feedback to volunteers on these sort of issues and we are taking this very seriously.

Best wishes,
10) Message boards : Number crunching : New Model Type HadAM4 (Message 59625)
Posted 13 Feb 2019 by Sarah Sparrow
Hello all,

Firstly I just wanted to say a big thank you for all your useful posts on this model. They have been very gratefully received and trying to resolve issues such as this would be much harder without your input.

To give you a quick update we are still trying to resolve the BAD BUFFIN error to identify what is happening. My initial tests trying to ensure that ancillary information is read when the model starts do not appear to have fixed the problem so this is proving to be a more complicated issue and I will need to think further how to fix it.

I will talk to Andy about the machines with missing 32-bit libraries so we can clear those sort of errors for this model.
11) Questions and Answers : Macintosh : No Tasks Available for Mac? (Message 54238)
Posted 2 Jun 2016 by Sarah Sparrow
I can confirm that the upload zips that we have on the upload server from mac builds are monthly uploads from simulations that are still running.

CPDN Applications Co-ordinator