##General study design
The Tromble Watershed is a small experimental watershed located in the East Bajada geomorphic unit of the Jornada Basin in southern New Mexico, USA. We have instrumented this watershed, which consists of a mixed Chihuahuan Desert shrubland, and have on-going measurements and modeling studies of hydrological, meteorological and phenological processes. The instrument network consists of 20 soil moisture profiles around an eddy covariance tower and 15 soil moisture profiles arranged along hillslope transects. A network of rain gauges and channel runoff flumes is also deployed.
The Tromble Watershed eddy covariance tower is listed as an AmeriFlux site (US-Jo2; http://ameriflux.lbl.gov/sites/siteinfo/US-Jo2) and flux data from the location is archived in AmeriFlux standard formats at the link below (see "AmeriFlux data access"). This data package contains only metadata pertaining to these AmeriFlux data (the same metadata should be available at the link below). The included data files list and describe the data entities held at AmeriFlux ("JRN_338005_US-Jo2_data_entities.csv") and the variables that should be available in those data files ("JRN_338005_TrombleEC_AmeriFlux_US-Jo2_variables.csv\"). Variables available at AmeriFlux include 30 minute average fluxes that have been processed from the 20 Hz raw measurements at the Tromble watershed eddy covariance tower.
##AmeriFlux data access
Data are archived at the AmeriFlux repository under this DOI:
https://doi.org/10.17190/AMF/1617696
Visit this link and follow prompts to download archived data files (.zip format), which will include 2010-current data as a csv, and metadata in AmeriFlux format (BADM form Excel sheet).
##Instruments and flux processing methods
Data from the three-dimensional sonic anemometer (CSAT3, Campbell Scientific) and open-path gas analyzer (LI-7500, LiCOR Biosciences) on the eddy covariance tower were first filtered to remove rainfall periods and periods of equipment malfunction. Despiking, corrections, and 30 min flux calculations are performed using the software EddyPro 7.0 (Li-Cor Biosciences). An initial raw data quality check was performed, consisting of spike detection and removal based on a maximum of three consecutive outliers [Vickers and Mahrt, 1997] and outliers greater than three standard deviation for gas concentrations and five standard deviations for wind components [Schimd et al., 2000], amplitude resolution with a range of variation above seven standard deviations [Vickers and Mahrt, 1997] and initial absolute limits from -30 to 30 m s-1 for zonal velocity (u), from -5 to 5 m s-1 for meridional velocity (v), from -20 to 50°C for sonic temperature (Ts), from 200 to 600 µmol mol-1 for CO2 and from 0 to 40 mmol mol-1 for H2O. Flux processing included detrending by block averaging and time lag compensation by covariance maximization [Moncrieff et al., 1997; Massman, 2001], axis rotation by double rotation [Wilczak et al., 2001], low-frequency correction using the analytic correction of high-pass filtering effects [Moncrieff et al., 2004], low-cut frequency corrections [Moncrieff et al., 1997], corrections for stability and density fluctuations [Webb et al., 1980; Foken et al., 2006], , and estimates of sensible heat were obtained from the sonic temperature [Paw U et al., 2000].
##Specifics and related publications
The specifics of the Tromble Watershed site, instrumentation, and research methods used can be found in the following publications:
Templeton, Ryan C., Enrique R. Vivoni, Luis A. Méndez-Barroso, Nicole A. Pierini, Cody A. Anderson, Albert Rango, Andrea S. Laliberte, and Russell L. Scott. "High-resolution characterization of a semiarid watershed: Implications on evapotranspiration estimates." Journal of Hydrology 509 (2014): 306-319. https://doi.org/10.1016/j.jhydrol.2013.11.047
Schreiner-McGraw, A. P., E. R. Vivoni, G. Mascaro,and T. E. Franz. "Closing the water balance with cosmic-ray soil moisture measurements and assessing their relation to evapotranspiration in two semiarid watersheds." Hydrology and Earth System Sciences 20 (2016):329–345. https://doi.org/10.5194/hess-20-329-2016
##Related data packages
Complementary data, such as standard meteorology at the Tromble micromet tower, can be found in other data packages on EDI.
knb-lter-jrn.210338002 - Tromble Watershed rain gauges (co-located with transects and tower)
knb-lter-jrn.210338004 - Soil volumetric water content along 3 transects of instrumented soil profiles in the Tromble Watershed
knb-lter-jrn.210338006 - Standard meteorology and ancillary data at the Tromble micromet tower
