HiWATER: The multi-scale observation experiment on evapotranspiration over heterogeneous land surfaces 2012 (MUSOEXE-12)-dataset of flux observation matrix ( No.1 eddy covariance system)

This dataset contains the flux measurements from site No.1 eddy covariance system (EC) in the flux observation matrix from 4 June to 17 September 2012. The site (100.35813° E, 38.89322° N) was located in a cropland (vegetable surface) in the Yingke irrigation district, which is near Zhangye, Gansu Province. The elevation is 1552.75 m. The EC was installed at a height of 3.8 m; the sampling rate was 10 Hz. The sonic anemometer faced north, and the separation distance between the sonic anemometer and the CO2/H2O gas analyzer (Gill&Li7500A) was 0.2 m. Raw data acquired at 10 Hz were processed using the Eddypro post-processing software (Li-Cor Company, http://www.licor.com/env/products/ eddy_covariance/software.html), including spike detection, lag correction of H2O/CO2 relative to the vertical wind component, sonic virtual temperature correction, angle of attack correction, coordinate rotation (2-D rotation), corrections for density fluctuation (Webb-Pearman-Leuning correction), and frequency response correction. The EC data were subsequently averaged over 30 min periods. Moreover, the observation data quality was divided into three classes according to the quality assessment method of stationarity (Δst) and the integral turbulent characteristics test (ITC), which was proposed by Foken and Wichura [1996]: class 1 (level 0: Δst<30 and ITC<30), class 2 (level 1: Δst<100 and ITC<100), and class 3 (level 2: Δst>100 and ITC>100), representing high-, medium-, and low-quality data, respectively. In addition to the above processing steps, the half-hourly flux data were screened in a four-step procedure: (1) data from periods of sensor malfunction were rejected; (2) data before or after 1 h of precipitation were rejected; (3) incomplete 30 min data were rejected when the missing data constituted more than 3% of the 30 min raw record; and (4) data were rejected at night when the friction velocity (u*) was less than 0.1 m/s. There were 48 records per day; the missing data were replaced with -6999. Moreover, suspicious data were marked in red. The released data contained the following variables: data/time, wind direction (Wdir, °), wind speed (Wnd, m/s), the standard deviation of the lateral wind (Std_Uy, m/s), virtual temperature (Tv, ℃), H2O mass density (H2O, g/m^3), CO2 mass density (CO2, mg/m^3), friction velocity (ustar, m/s), stability (z/L), sensible heat flux (Hs, W/m^2), latent heat flux (LE, W/m^2), carbon dioxide flux (Fc, mg/ (m^2s)), quality assessment of the sensible heat flux (QA_Hs), quality assessment of the latent heat flux (QA_LE), and quality assessment of the carbon flux (QA_Fc). In this dataset, the time of 0:30 corresponds to the average data for the period between 0:00 and 0:30; the data were stored in *.xlsx format. For more information, please refer to Liu et al. (2016) (for multi-scale observation experiment or sites information), Xu et al. (2013) (for data processing) in the Citation section.

WATER: Dataset of LST (land surface temperature) observations in the Yingke oasis and Huazhaizi desert steppe foci experimental areas

The dataset of Land Surface Temperature (LST) observations was obtained in the Yingke oasis and Huazhaizi desert steppe foci experimental areas. (1) The time-continuous surface radiative temperature by the automatic thermometer (FOV: 10°; six from BNU with emissivity 0.95; two from Institute of Remote Sensing Applications with emissivity 1.00, observing at nadir at an intervals of one second. The maize canopy, the bare land and the wheat canopy in Yingke oasis maize field, the wheat canopy in Yingke oasis wheat field, the maize canopy in Huazhaizi desert maize field, vegetation and the bare land in Huazhaizi desert No. 1 and 2 plots and three intensive plots (Huazhaizi desert No. 3 plot, the barley field and the maize field near the resort) were measured on May 20, 24, 28, 30 and 31, Jun. 1, 3, 4, 16, 29 and 30, Jul. 1, 7, 9 and 11, 2008. The dataset of ground truth measurement was synchronizing with WiDAS (Wide-angle Infrared Dual-mode line/area Array Scanner), OMIS-II, TM, ASTER, MODIS, Hyperion and CHRIS. Diurnal variation in the radiative temperature was recorded as well. Raw data, blackbody calibrated data and processed data were archived in Excel format. (2) the surface radiative temperature by the handheld infrared thermometer (FOV:1°; accuracy: 0.1°C) in Yingke oasis maize field and wheat field, Huazhaizi desert maize field, No. 1 and 2 plots, and the maize field at the resort on May 20, 28, 30 and 31, Jun. 1, 4, 16 and 29, Jul. 4, 7 and 11, 2008. Besides, the four component temperature was also measured in Yingke oasis maize field and wheat field, Huazhaizi desert maize field. Raw data and processed data on the surface radiative temperature were archived.

WATER: Dataset of airborne WiDAS mission in the Zhangye-Yingke-Huazhaizi flight zone on June 1, 2008

The dataset of airborne WiDAS mission was obtained in the Zhangye-Yingke-Huazhaizi flight zone on Jun. 1, 2008. Data available for general users include Level-2C data (after geometric, radiometric and atmospheric corrections). Level-1B browse image (after intra-band matching) and Level-2B browse image (intra-band after registration). The raw data, Level-1A, and data processing parameters were filed; applications would be evaluated prior to access. Data processing started Aug. 2008 and ended Apr. 2009, and in Nov. 2009, CCD data were reprocessed to adjust radiometric calibration. The raw data set included 12 flight routs, some of which were repeated. There was discrepancy about 1.4s between exposure time of CCD images at 650nm/750nm and that of 550nm/700nm. Images in different bands has been matched during pre-processing. However, in areas with large elevation changes, intra-bands match error still existed. The flying time of each route was as follows: {| ! id ! flight ! relative height ! starttime ! endtime ! data size ! data state ! data quality ! ground targets |- | 1 || 3#15 || 1500m || 13:35:46 || 13:39:37 || 59 || incomplete || incomplete |- | 2 || 3#13 || 1500m || 13:43:21 || 13:51:33 || 75 || incomplete || incomplete |- | 3 || 3#11 || 1500m || 13:54:41 || 14:03:17 || 41 || incomplete || incomplete || the resort, Yingke oasis maize field, and wheat field |- | 4 || 3#11a || 1500m || 14:07:23 || 14:14:46 || 111 || incomplete || incomplete || the resort, Yingke oasis maize field, and wheat field |- | 5 || 3#9 || 1500m || 14:18:21 || 14:26:17 || 119 || processed;complete || good || wetland park, Zhangye city, Yingke oasis maize field, and wheat field, Huazhaizi desert maize plot |- | 6 || 3#7 || 1500m || 14:31:01 || 14:38:25 || 112 || processed;complete || good |- | 7 || 3#5 || 1500m || 14:42:05 || 14:50:01 || 120 || incomplete || incomplete || Huazhaizi desert plot 1 |- | 8 || 3#3 || 1500m || 14:53:49 || 15:02:41 || 134 || processed;complete || good || Huazhaizi desert plot 2 |- | 9 || 3#1 || 1500m || 15:07:01 || 15:14:41 || 116 || processed;complete || good |- | 10 || 3#11b || 1500m || 15:20:05 || 15:26:37 || 99 || processed;complete || good || the resort, Yingke oasis maize field, and wheat field |- | 11 || 3#13a || 1500m || 15:30:45 || 15:39:01 || 125 || processed;complete || good |- | 12 || 3#5a || 1500m || 15:42:48 || 15:50:05 || 111 || processed;complete || good || Huazhaizi desert plot 1 |}