Eruptions of the Yellowstone volcanic system have included the two largest volcanic eruptions in North America in the past few million years; the third largest was at Long Valley in California and produced the Bishop ash bed.
On the diesel Passat, the TDI badge stands for Turbocharged Direct Injection, which isn't really all that helpful as the gasoline-powered Passat is also turbocharged and also uses direct injection. Volkswagen attempts to clear this up by calling this Passat the Passat TDI Clean Diesel.
2009 Jetta TDI and 2010-2012 Audi A3 TDI have the CBEA engine. 2010 and newer Jetta, Golf, and wagons have the CJAA engine. The most noticeable difference is in the oil pump/balance shaft and 2 piece DPF/NOx catalyst. See this forum thread for more details.