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Site: Twitchell Alfalfa (TA) aka US-Tw3

2013-05-24 - 2018-06-13

The Twitchell Alfalfa site is an alfalfa field owned by the state of California and leased to third parties for farming. The tower was installed on May 24, 2013. This site and the surrounding region are part of the San Joaquin - Sacramento River Delta drained beginning in the 1850's and subsequently used for agriculture. The field has been alfalfa for X years…., Crop rotation occurs every 5-6 years. The site is harvested by mowing and bailing several times per year. The field is fallow typically between November and February. The site is irrigated by periodically-flooded ditches surrounding the field. The site is irrigated by raising, and subsequently lowering the water table??

Ameriflux BADM Site Info

Last field site visit: more fieldnotes

2018-06-13 09:00:00

Decommissioning of the site. Everything was removed from the field.

Latest data processing: more processing notes

2018-07-23

Processed: Met, L3 for dates: 2018-04-04 - 2018-06-04

Processor of record: 2013-07-01 - Cove Sturtevant 2015-08-18 - Patty Oikawa 2016-10-31 - Sam Chamberlain

Ameriflux Author: 20130524 - Cove Sturtevant 20130524 - Joseph Verfaillie 20130524 - Dennis Baldocchi 20150818 - Patty Oikawa 20161031 - Samuel D Chamberlain 20161200 - Daphne Szutu

Data Digital Object Identifier (DOI)
FLUXNET-CH4: https://doi.org/10.18140/FLX/1669697
AmeriFlux: https://doi.org/10.17190/AMF/1246149
FLUXNET2015: https://doi.org/10.18140/FLX/1440110
FLUXNET: https://doi.org/10.17190/AMF/1881594

Equipment Locations more details

Data Streams: more data

Code	First Day	Last Day	Description
TA_arable	2017-09-07	2018-06-13	Data from Arable Mark device. Raw times are in UTC, hourly averages with the time at the beginning of the averaging period beginning 2019-04-01 30min averages PST at the end of the averaging period - stored in PST at end of averaging period.
TA_cam	2013-05-24	2018-06-05	RGB digital number data extracted from autocam photos from four photos from 13:25 to 14:45 Phenocam archive
TA_fd	2016-07-15	2018-06-05	Soil respiration data from the second generation Forced Diffusion chamber from Eosense. The raw data is collected at 5min intervals and averaged to 30min values.
TA_flux	2013-05-24	2018-06-05	30 minute averages of the 10Hz raw flux data.
TA_met	2013-05-24	2018-06-05	30 minute average soil temperature, soil moisture, soil heat flux, air temp, RH and pressure.
TA_processed	2013-05-24	2018-06-04	Fluxes and derived values from Level 1 processing
TA_processed3	2013-05-24	2018-09-04	Gap filling and partitioned data from Level 3 processing
TA_rad	2013-05-24	2016-12-21	30 min average PAR in and reflected, SW in and reflected, LW in and reflected, LED NDVI
TA_soilco2	2014-08-12	2018-06-05	Soil CO2 data from Vaisala probes in gradients and forced diffusion chamber.

Metadata and Data Sets: more data

Id	Type	Site	Dates	Frequency	Title	Description
16	LAI	BC, BA, TA	2017-07-26 - 2020-07-30	Approx. monthly during growing season with field visits	Optical LAI measured in-situ	~10 measurements taken each time with a LAI-2200C. Most of the measurements were taken with the 2-wand method, where an "above" wand was set up on a tripod and took measurements every 5 sec, and a "below" wand was used to collect data below the crop canopy. The data were processed in the Licor software FV2200, where each "below" measurement was paired with the "above" measurement closest in time; LAI was calculated and corrected for scattering (based on 4A scattering data). Twitchell Alfalfa: 2017 (2), 2018 (2) Bouldin Alfalfa: 2017 (3), 2018 (9) Bouldin Corn: 2017 (5), 2018 (7)
26	Lidar	BA, BC, EE, MB, SB, SW, TA, WP	2016-12-01 - 2017-03-07	Once	Delta-wide USGS Lidar flight	Winter time Lidar flight commissioned by the USGS and flown by Woolpert. Horizontal datum: NAD83 (NSRS2007) Epoch 2017.95, UTM Zone 10N, meters. Vertical datum: NAVD88, GEOID12B, US Survey Feet, Orthometric. Includes classified point cloud, features shape files, bare earth DEM, orthometric imagery (0.3-meter16-bit 4-band RGB-IR tiles in TIFF format with World Files). The entire Delta is covered by 8 points per m2, 0.5m DEM.
3	Lidar	BA, BC, WP, EP, EE, TA, TW, MB, SB, SW	2018-09-20	Once	NCALM Lidar Flight	Lidar flight data collection from Kyle Hemes NCAL project: Ecosystem Structure as a Driver of Climatic, Habitat, and Hydrological Services in Heterogeneous Restored Wetlands. Point clouds (*.las files), 1m resolution DEM and DSM (arcgis GridFloat files), visible imagery (*.tif files) of Sherman, Twitchel and Bouldin Islands. UTM Zone 10N, meters, NAD83(2011) epoch 2010.00 / NAVD88 (GEOID12B)
30	Soils	SB, BC, Bouldin 1, Staten	2016-08-01 - 2018-03-15	Once	%C, %N sampled by Tyler Anthony	Tyler Anthony (Whendee Silver's lab) analyzed %C and %N from shallow soils: -Sherman Barn (Tyler refers to it as "Sherman Pasture"), 0-10cm, probably sampled in Spring 2018 -Bouldin Corn, 0-15cm, sampled 2017-05-16 -Bouldin 1 (Tyler's alfalfa auto-chamber site by the barn), 0-15cm?, sampled 2016-08-01 -Staten ("taken from a corn field west of the road), 0-10cm, sampled 2018-03-15

Documents:
Cospectra_Comparison_Delta.pdf - Plots of cospectra from the Delta sights
HMP RH and AirT Comparison 12-2017
Delta SW PAR Comparison 10-2016
Twitchell Alfalfa - NDVI (SRS, Arable)