This is really cool. If I knew the slightest bit about Fortran, I'd be distracted for weeks.
Global Forecast System source code
11–20 of 29 posts
Re: Global Forecast System source code
#12Do they also make raw sensor data available for free? I.e. if I wanted to build my own forecast system based on this code, I would still need all the data they collect with weather balloons, right?
To create a global NWP system from this code you would need observations (soundings, SST, satellite measurements) as well as a super computer.
WCOSS (Tide & Gyre): IBM iDataPlex/Intel Sandy Bridge/Linux
208 trillion calculations/sec; 10,048 processing cores; 2,590 trillion bytes of storage
Re: Global Forecast System source code
#13Fortran 90 is still the language computational stuff is made in today. I'm not convinced, however, that that choice is really for performance reasons over cultural reasons. Still, Fortran 90 is hell of a lot better than Fortran 77, which unfortunately is the language of choice for some of the people I'm being asked to work with.
I'm a part of this community. I assure you speed in number crunching is a huge reason this is written in F90.
Indeed, automatic (and largely implicit) use of SIMD and OpenMP by the compiler is very very good with F90 compared to almost all other widely used languages.
Re: Global Forecast System source code
#14Earlier quoted context omitted.
To create a global NWP system from this code you would need observations (soundings, SST, satellite measurements) as well as a super computer.
WCOSS (Tide & Gyre): IBM iDataPlex/Intel Sandy Bridge/Linux 208 trillion calculations/sec; 10,048 processing cores; 2,590 trillion bytes of storage [xref: http://www.emc.ncep.noaa.gov/GFS/doc.php#comopesys ]
Here's a really interesting read about the trials of upgrading to WCOSS: http://www.washingtonpost.com/blogs/capital-weather-gang/wp/...
Re: Global Forecast System source code
#15Earlier quoted context omitted.
To create a global NWP system from this code you would need observations (soundings, SST, satellite measurements) as well as a super computer.
WCOSS (Tide & Gyre): IBM iDataPlex/Intel Sandy Bridge/Linux 208 trillion calculations/sec; 10,048 processing cores; 2,590 trillion bytes of storage [xref: http://www.emc.ncep.noaa.gov/GFS/doc.php#comopesys ]
You can get 1.5% of that processing power in a single graphics card now. So in 7 years, we should be able to buy that much power for about $350 :)
Re: Global Forecast System source code
#16Earlier quoted context omitted.
To create a global NWP system from this code you would need observations (soundings, SST, satellite measurements) as well as a super computer.
WCOSS (Tide & Gyre): IBM iDataPlex/Intel Sandy Bridge/Linux 208 trillion calculations/sec; 10,048 processing cores; 2,590 trillion bytes of storage [xref: http://www.emc.ncep.noaa.gov/GFS/doc.php#comopesys ]
More details here: http://www.nwas.org/committees/waf/new_supercomputer.php
Re: Global Forecast System source code
#17Earlier quoted context omitted.
I'm a part of this community. I assure you speed in number crunching is a huge reason this is written in F90.
Indeed, automatic (and largely implicit) use of SIMD and OpenMP by the compiler is very very good with F90 compared to almost all other widely used languages.
[deleted]
Re: Global Forecast System source code
#18Fortran 90 is still the language computational stuff is made in today. I'm not convinced, however, that that choice is really for performance reasons over cultural reasons. Still, Fortran 90 is hell of a lot better than Fortran 77, which unfortunately is the language of choice for some of the people I'm being asked to work with.
I'm a part of this community. I assure you speed in number crunching is a huge reason this is written in F90.
I'm curious (really curious, although this might sound like a troll), have you ever tried a benchmark test on this? Things like this [0] come up every so often, and make me wonder about the efficiency advantage for coding in Fortran.
This is also relevant and insightful [1]. The top answer talks about Fortran's strict aliasing semantics.
[0] http://unriskinsight.blogspot.com/2014/06/fast-functional-go...
[1] http://stackoverflow.com/questions/146159/is-fortran-faster-...
Re: Global Forecast System source code
#19Do they also make raw sensor data available for free? I.e. if I wanted to build my own forecast system based on this code, I would still need all the data they collect with weather balloons, right?
You don't want the "raw sensor data". You need it after it's been processed to the appropriate level, to retrieve geophysically-relevant quantities (like temperatures and wind speeds) from the data that is measured. That is not done by the forecasters.
Re: Global Forecast System source code
#20Earlier quoted context omitted.
I'm a part of this community. I assure you speed in number crunching is a huge reason this is written in F90.
I'm curious (really curious, although this might sound like a troll), have you ever tried a benchmark test on this? Things like this [0] come up every so often, and make me wonder about the efficiency advantage for coding in Fortran. This is also relevant and insightful [1]. The top answer talks about Fortran's strict aliasing semantics. [0] http://unriskinsight.blogspot.com/2014/06/fast-functional-go... [1] http://s…
[0] is a classic example of comparing programming languages attacking a problem with different algorithms.
I see that the author insults Fortran a couple of times, and I don't seen any indication that they tried to implement the better algorithm in Fortran. Did I miss something?