32-bit 1) 1997: AIX operating system, 196 Mbytes of ram, few hundred Mbytes of disk space, RAMS-3b.2) 1998: Linux operating system, 512 Mbytes of ram, 500 Mbytes of disk space, RAMS-429. Systems administration was done by user. Wow! Just think what I can do now.3) Upgrades! 1 Gbyte of ram 2 Gbytes of ram 3.3 Gbytes of ram. Standard Linux Kernel Bigman Kernel Experimental Kernel. Disk space increased to 100 Gbytes. RAMS-43. Systems administration done by systems administrator—not the user. Oh boy! Just think what I can do now.4) 32-bit cluster, 20 dual processor nodes, 2 Gbytes of ram, few hundred Gbytes of disk space. Test RAMS-43. Gee-wee what a fast machine! Just think what I can do now.

GOESR and NPOESS 1) Run RAMS43 and use output to make synthetic GOESR-ABI and NPOESS VIIRS images for three mesoscale weather events.2) 200 Gbytes of disk space should be plenty—I was in for a surprise!3) 32-bit 4 Gbyte ram too restrictive. GOESR-ABI has 2 km footprint, but I had to use 4 km horizontal grid spacings. NPOESS VIIRS has a horizontal footprint near 400 m, but I had to use 1 km horizontal grid spacings.4) Horizontal extent of domain too small to produce a realistic looking synthetic satellite image.5) Must move to 64-bit cluster: A whole new world!

64-bit 1) Purchase a ready-built machine or build one? We built one ($$$).2) How much ram should be put in the machine? Started with 8 GB.3) How much disk space? Started with 500 GB.4) How many nodes and what processor speed? 10 dual processor nodes.5) Get RAMS43 to run on the 64-bit cluster. This took six week. The issue was this: RAMS43(64-bit) but mpich(32-bit). That is, the 64-bit rams variables had to be changed to 32-bit variables before MPI subroutine calls then changed back to 64-bit after the suboutine.

6) Test RAMS43. (a) Reproduce a 32-bit run, (b) Exceed 4 GB of ram.7) Repeat (6), this time do runs in parallel. 8) More ram added: 8GB16GB32GB. 32GB is hardware limit.9) More disk space added: 500GB1TB2.5TB raid to 10TB raid.10) Each time more ram was added, I re-ran the same job to take advantage of the extra memory by increasing the horizontal domain.11) The first time I submitted a 25 GB job, a lot of time went by before the model wrote out the initial data. I thought something was wrong, so I did what any good scientist would do—kill the job!12) Fifteen minutes passed before RAMS43 wrote out 15 GB of initial data. I had no idea the files would be this large.

64-bit environment1) Where should the machine go?2) Fuses to room are blowing!3) Power outages!4) Air conditioning?5) Room too hot! The machine is overheating!6) Machine damaged!7) Results are expected, and quarterly reports are still due.8) Machine rebuilt; new systems administrator.

Synthetic GOES-R and NPOESS ImageryLouie Grasso, Manajit Sengupta, Jack Dostalek, and

Mark DeMaria

NPOESS VIIRS 11.02 µm

Hurricane Lili

Lake effect snow

Severe weather

GOES-12 10.7 µm GOES-R 10.35 µm

NOAA/NESDIS CoRP,15-16 August 2006, Hilton Fort Collins, Colorado

GOES-R 6.185 µm GOES-R 9.61 µm

GOES-R 10.35 µm GOES-R 13.3 µm