Synthetic satellite imagery Louie Grasso Cooperative Institute for Research in the Atmosphere NOAA/NESDIS CoRP 15-16 August 2006
Introduction Motivation 32-bit GOESR and NPOESS. 64-bit cluster. Simulations and synthetic imagery Summary.
Motivation 1)Better understand satellite imagery. That is, synthetic satellite imagery can be used with model output to understand the imagery. 2)Synthetic satellite data can be used to aid in algorithm development. 3)Synthetic imagery can be used for NWPmodel verification.
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. 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. 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 plentyI 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) Test RAMS43. (a) Reproduce a 32-bit run, (b) Exceed 4 GB of ram. 2) Repeat (6), this time do runs in parallel. 3) More ram added: 8GB 16GB 32GB. 32GB is hardware limit. 4) More disk space added: 500GB 1TB 2.5TB raid to 10TB raid. 5) Each time more ram was added, I re-ran the same job to take advantage of the extra memory by increasing the horizontal domain. 6) 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 dokill the job! 7) Fifteen minutes passed before RAMS43 wrote out 15 GB of initial data. I had no idea the files would be this large.
Simulations Grid 1Grid 2Grid 3Grid 4 8 May 2003 90x66192x162502x5221027x852 12 Feb 200390x66192x162502x522992x902 1 Oct 200290x66192x162932x7821002x1002 Table 1: Number of x and y points for each grid in each simulation. Start grids 1-3 Stop grids 1-3 Start grid 4 Stop grid 4 8 May 2003 12 z20 z17 z20 z 12 Feb 200300 z19 z17 z19 z 1 Oct 200212 z00 z 3 Oct18z 2 Oct00z 3 Oct Table 2: Start and stop times for each grid in each simulation.
Synthetic 2 km ABI Bands 7-16 8 May Severe Weather Case (19 UTC) 3.9 m 6.2 m 7.0 m 7.3 m 8.5 m 9.6 m 10.35 m 11.2 m 12.3 m 13.3 m
GOES-12 at 10.7m GOES-R at 10.35 m NPOESS VIIRS at 11.02 m 4 km 2 km 400 m Synthetic GOES-12, GOES-R, and NPOESS-VIIRS imagery. 2 Oct 2002 Hurricane Lili 12 February 2003 Lake effect snow 8 May 2003 Severe weather
Summary Motivation 32-bit GOESR and NPOESS. 64-bit cluster. Simulations and synthetic imagery