1. Seminar: Snowmelt and Storm Events: Biogeochemical and Hydrological Responses

2. Why study: Snowmelt and Storm Events Provide information on physical and chemical attributes of catchments Important contributor to discharge and biogeochemical fluxes Events can have a major influence on physical, chemical and biological attributes of surface waters.

3. Storm Event Example Inamdar, S., P., S. F. Christopher, and M. J. Mitchell. 2003. Export mechanisms for dissolved organic carbon and nitrate during summer storm events in a glaciated forested catchment in New York, USA. Hydrological Processes (In Press).

4. The Archer Creek catchment and instrumentation

5. Arbutus Watershed

6. (a) (b) (c) (d) (e) Precipitation, streamflow, and solute concentrations for the Floyd storm events.

7. Perceptual model for NO 3 - and DOC evolution considering water and solute contributions from deep and near-surface flow paths and spatial connectedness of saturated areas. Note: Arrow on the hydrograph (inset) indicates position of the stage during the event.

8. Snowmelt Example Piatek, K.B., M.J. Mitchell, S.R. Silva and C. Kendall. 2003. Sources of nitrate in Adirondack surface water during dissimilar snowmelt events. (In review).

12. Terminology Changes in isotopic abundance are expressed as ratios of 15 N/ 14 N of sample to air or 18 O/ 16 O of sample to ocean water. Units: per mil ( o / oo ) δ 15 N x = {[( 15 N/ 14 N) x / ( 15 N/ 14 N)] air –1} * 1000 δ 18 O x = {[( 18 O/ 16 O) x / ( 18 O/ 16 O)] std –1} * 1000

13. Separation of nitrate sources using stable isotopes of nitrogen and oxygen Nitrate has different stable isotopic values. Atmospheric N-nitrate has 18-O values than N-nitrate derived from soil and ground waters.

14. precipitation Soil + groundwater General trends of 18-O and 15-N values of nitrate

15. Results of nitrate samples taken during snowmelt at Archer Creek Catchment, Huntington Forest

16. Episodic Acidification Mitchell, M.J. Episodic Acidification. In: Jay H. Lehr (ed). Encyclopedia of Water. John Wiley and Sons Publishing (In Press).

18. Biscuit Brook Catskill Mountains New York

19. Goals of Seminar Increase understanding of biogeochemical and hydrological responses of snowmelt and storm events Exploration of literature on hydrology and biogeochemistry Develop skills for oral presentations and discussions Prepare for workshop to be held on Feb. 27, 2003 on “Snowmelt and Storm Events: Biogeochemical and Hydrological Responses”