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| RAMMB CIRA 1st Quarter Report FY2008 |
October November December |
A real-time source of simulated Advanced Baseline Imager (ABI) data for infrared channels has been developed using an algorithm obtained from the GOES-R Algorithm Working Group (AWG). The ABI infrared channels are approximated using Meteosat Second Generation (MSG) data obtained from the NESDIS server. The simulated ABI data, Channels 7 – 16, are then made available via a MCIDAS server that facilitates the development of case studies; allowing the researcher to obtain the data in smaller areas over long periods of time as interesting events occur.
These same algorithms can be applied to the MSG datasets collected over the tropical Atlantic during the 2005, 2006 and 2007 hurricane seasons. An example of the simulated ABI imagery, channels 7 – 16, covering Tropical Cyclone Elnus (SH09) at 23UTC on 2 January is shown in Figure 1. (J. Knaff)
Figure 1: Example simulated ABI imagery created using the AWG algorithm and MSG data. Imagery is valid 2 January 2008 at 2300 UTC. The scene shows Tropical Cyclone Elnus (SH092008), which was experiencing strong to moderate westerly wind shear and has a nearly exposed low-level center. Imagery from the top left-to-right order shows simulated ABI imagery for channels 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16, which correspond to 3.9, 6.19, 6.96, 7.34, 8.50, 9.61, 10.35,11.2, 12.30, and 13.30 μm central wavelengths. Channels 8,9 and 10 are water vapor sensitive, channels 11,13 and 14 are near IR windows, channel 12 is sensitive to stratospheric ozone, Channel 15 is a dirty IR window that is sensitive to inhomogeneously mixed water vapor, and channel 16 is a dirty IR window, but sensitive to homogeneously mixed CO2.
A GPS dropwindsonde AIRS sounding match-up database for tropical cyclone studies is complete. The AIRS soundings have been compared to those dropwindsonds and statistics of the comparison have been created. In addition, statistics evaluating the utility of AIRS soundings relative to the GFS model first guess have been compiled. A manuscript describing these results is in preparation. However, since the NASA science team almost always masks out the eye of tropical cyclones as being cloud contaminated even when not very few AIRS eye soundings exist. An effort has begun to more AIRS sounding eye cases from NESDIS (Chris Barnet from StAR) using raw AIRS data. (J. Knaff)