In the southwestern United States two important seasons influence stream flow: snowmelt in spring and summer monsoonal rainfall events. Flow patterns exhibit peak discharge from snowmelt runoff in the spring followed by pulsed increases in stream discharge during late summer monsoons. Molles and Dahm showed the intensity of the snowmelt discharge is linked to El Nino-Southern Oscillation (ENSO) conditions in the tropical Pacific. El Nino and La Nina climate patterns also may affect late summer monsoonal precipitation in New Mexico by intensifying the monsoon during La Nina years and weakening monsoons during El Nino years. Stage gage data show seasonal and interannual variability in the intensity of snowmelt and monsoonal runoof events in montane catchments in New Mexico. Further, in-situ YSI sonde, Satlantic Submersible Ultraviolet Nitrate Analyzer (SUNA) and CycleP instrumentation show physical and chemical constituents respond to higher flow events driven by climate variability, and the constituents these instruments measure can be used as a proxy to estimate whole stream metabolism and nutrient cycling processes.
Data Selection: Historical flux tower data from 2007 to 2011 was provided by UNM Marcy Litvak for two locations near our study site on the EFJR. Los Alamos National Lab provided flux data from 2005 to 2006. Flux towers provided photosynthetic active radiation (PAR) and barometric pressure in 30 minute time intervals. In-stream YSI sondes continuously monitored the Jemez and East Fork Jemez Rivers in 15 minute time intervals collecting water quality data (dissolved oxygen, pH, turbidity, specific conductance, water temperature).
Instrument Name: YSI Sonde Manufacturer: YSI IncorporatedModel Number: 6920V2-0
Sonde and flux data were QAQC'd using Aquarius software to delete suspicious data (or outliers) and to correct for drift from biofouling on probes.
Study Area Name: East Fork Jemez River
Study Area Location: Valles Caldera National Preserve, New Mexico
Study Area Description:
Elevation: 2582 meters
Landform: Montane grassland, caldera
Soils: Rich organic soils; Mollisols
Hydrology: snowpack(winter) and monsoonal rainfall (summer)
Vegetation: grassland, meadow
Site history: Domestic grazing of sheep from mid-1800's to 1940's, then cattle by 1940's.
Single Point: EFJR at Hidden Valley (from VCNP)
North Coordinate: 35.83666667
West Coordinate: -106.5013833