Profile six Visible CFC charge dates created when the: (a) younger water for the harmony with 1993 air offers with drinking water charged during the 1940; and you can (b) young liquid from inside the harmony that have 1993 heavens mixes that have water charged for the 1975. Calculations at 10°C and you will step 1 atm. overall tension.
Hydrodynamic dispersion
By the simple and generally expanding characteristics of the atmospheric mix ratios 
, hydrodynamic dispersion is not likely to keeps a serious impact on CFC levels otherwise noticeable CFC years during the groundwater. Having fun with a-one-dimensional logical solution to this new advection-dispersion equation when you look at the steady-state move occupation (van Genuchten and Alves, 1982), Plummer mais aussi al. (1993) artificial the fresh transportation and you may resulting ages uncertainties having CFC-eleven and CFC-several to own liquid billed away from 1940 by way of 1991 (Profile 7).
Contour seven Errors for the CFC-11 and you will CFC-twelve obvious age calculated for one-dimensional circulate, that have dispersivities out-of 0 so you can dos yards (of Plummer ainsi que al., 1993).
from the 1975 is always to come slightly over the age of the newest advective age. Water charged prior to about 1970 would seem to be a bit younger compared to the advective age. A great dispersivity out of 0.step one yards has actually little or no affect CFC-eleven and you may CFC-several levels along side relationship directory of the new tracers. In the event that dispersivity is step 1.0 yards, liquid energized from inside the 1960 you may are available young according to the fresh advective age by as much as five years to have CFC-11 and you will from the three years considering CFC-several.
The result away from dispersion with the obvious years vary to possess tracers having other shapes to their atmospheric input properties, significantly 3 H/ step 3 The guy (Solomon and you can Make, Part thirteen). Theoretically, it can be it is possible to to utilize variations in noticeable age derived regarding various other tracers to identify surroundings where tracer concentrations is highly impacted by hydrodynamic dispersion (Plummer mais aussi al., 1993; Ekwurzel mais aussi al., 1994), even when used this type of brief differences is masked because of the most other process. An assessment off CFC and you will 3 H/ 3 He noticeable age to have seas co-dated about sand aquifers of your Delmarva Peninsula (Ekwurzel mais aussi al., 1994) shows absolutely nothing proof having extreme effects of hydrodynamic dispersion throughout these tracers. Similarly, Szabo mais aussi al. (1996) discover an effective contract anywhere between step 3 H/ 3 He and you may CFC decades in a mud aquifer from inside the southern area Nj, more an age range away from almost 40 years spanning both sides of one’s step three H bomb level, indicating one to dispersion did not have a significant influence on groundwater years obtained with this tracers from the data town. Reilly ainsi que al. (1994) used CFC relationships in order to refine an excellent groundwater disperse model having a great superficial exotic aquifer on Delmarva Peninsulaparison regarding mentioned tritium with tritium concentrations modelled having fun with a great solute transportation design substantiated the brand new circulate design and demonstrated you to outcomes of hydrodynamic dispersion was basically minimal for the brand new sand aquifer.
Field Advice
Though much of the study with CFC matchmaking has actually focused on testing the newest reliability of one’s strategy (look for, particularly, Dunkle ainsi que al., 1993; Ekwurzel ainsi que al., 1994; Szabo et al., 1996), additionally there is an evergrowing books out of profitable software away from CFCs into the hydrologic evaluation. This section summarises specific results from chose field studies, and gift suggestions short-term interpretations of CFC analyses out of ten liquid products picked from an array of field websites.
Katz ainsi que al. (1995) put CFCs to analyze leakage out of good sinkhole river from inside the northern Florida and take to predictions out-of a three-dimensional groundwater circulate design to own transient and steady state disperse standards. To help with the latest comparison away from Yucca Mountain, Vegas, because a possible webpages getting a top-height radioactive waste repository, Thorstenson mais aussi al. (1998) made use of CFC size of unsaturated-region air over the mountain crest to show that take a trip lifetime of shallow, advecting energy was =five years.
