Apportionment of Wye

   Wye, Maryland, is another location in the Chesapeake Watershed that is near Elms and Prince George. Thus we would expect one or both of these signatures to enter into its North American solution. The final map of steps in the apportionment confirms that the solution is North American and that Elms is in fact the first to enter (after crust and sea, of course). Although moderately high F-ratios appeared at step 2 for Europe and Japan/Korea, their full apportionments proved unsatisfactory. For a quick trip through the three threads (North American, European, Japanese/Korean), just click on the links in the table below. For discussion of the North American solution, see below. For the other two threads, click on Europe and Japan/Korea.

    The rest of this page follows the North American thread, shown in red italic in the table just below. It has two distinctive characteristics: it very quickly becomes an excellent fit and it eventually includes our new signature for Shenandoah. The important aspect of Shenandoah working is that it is a fine-particle signature, as opposed to full aerosol (coarse plus fine, or TSP) in all our other signatures. We believe that it is working only because the floating crustal signature allows it to. If so, it would vindicate the principle behind the floating signatures more aggressively than we have been able to up to now. We shall see.

   Step 0 in the Wye apportionment, nothing chose, is shown below. Three groups of possible sources appear: eastern North America, Europe, and Japan/Korea. Eastern North America appears the most likely, consistent with location of Wye.

    Step 2 enters the sea and the best crust (NAIC) into the solution. The three potential source regions remain, in roughly their relation from step 0. All three must be tried.

    Step 3 adds Elms, the source in North America with the highest F-ratio (by far). In improves the fit to a respectable 0.99, and reduces most of the other NA sources. Potential European sources now dominate potential Japan/ Korea.

    In keeping with the restriction of the North American thread, step 4 adds New York City (NYC), the highest of the remaining NBA signatures. This improves the fit to 0.61 and reduces the JK signatures and most of those from Europe, although one high European F-ratio remains. If we were thinking seriously about the European thread at this point, we would still discount that one high signature because more than one would have to qualify from such a distant region in order to indicate that the region as a whole would have to be taken seriously. Thus we would not have to worry about that lone signature as a matter of principle. 

    Step 4 raised several NA signatures to the level of NYC. Step 5 follows that up by adding the highest of them, Allegheny Mountain, a high-Se signature that seems to represent coal burning in Appalachia or something like that. (Its exact meaning has never been clear.) The fit improves to an excellent 0.38. Virtually all sources other an North American fall away, except for that one in Europe.

    Step 6 adds Sudbury, a smelter town in NW Ontario. It improves the fit to 0.26 but still leaves more NA signatures to be tapped.

    Step 7 adds Shenandoah, the highest of the remaining NA signatures, and improves the fit to 0.23. As noted at the top, this step is a bit radical (at least for now) because Shenandoah is a fine-particle signature among total-aerosol signatures, a lonely little petunia in an onion patch, as some might say. The act of including it may be more important than the small amount by which it increases the fit (0.26 to 0.23). Should we truly be able to use fine-aerosol signatures, the way so many people are measuring aerosol these days, we could tap into a rich new source of data that we have previously considered unusable.

    The final North American solution for Wye aerosol is then Elms, NYC, Sudbury, Allegheny, and Shenandoah (plus sea and crust, of course). This seems to be the richest of the solutions found for North American so far.

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