210Bi (t1/2=5.01 d) is theoretically a radionuclide for tracing the particle cycle over a timescale of hours to days. However, it has been rarely investigated in marine environments due to its very short half-life and low activity. Here, 210Bi and 210Pb were examined in the water column on the shelf/slope of the northern South China Sea (SCS), as well as their atmospheric deposition. In rainwater, the 210Bi/210Pb ratio averaged 0.54±0.28, indicating the influence of atmospheric deposition on the disequilibrium between 210Bi and 210Pb in surface seawater. On the shelf, 210Bi/210Pb averaged 0.73±0.10 in the euphotic zone and 1.25±0.10 below, supporting a quick removal of 210Bi from the euphotic zone and regeneration in the twilight zone. On the slope, deficits in 210Bi (210Bi/210Pb of 0.81±0.07) were also observed in the productive low euphotic zone. The concurrence of 210Bi deficits and higher particulate organic carbon (POC) concentrations implied that POC largely dominates the deficit and excess of 210Bi. Based on a simple model, the removal fluxes of 210Bi at the euphotic base were 728±73 dpm m-2 d-1 and 216±89 dpm m-2 d-1 on the shelf and slope. The residence time of particulate 210Bi was 14±2 d. The 210Bi-derived export flux of POC was 1.7±0.7 mmol-C m-2 d-1 out of the euphotic zone over the slope. These results lay the foundation for 210Bi/210Pb to quantify the sinking and remineralization of particulate organic matter in coastal seas.
YANG Weifeng
The dataset includes daily precipitation data of Qinghai, Tibet, Sichuan, Gansu, Yunnan and Xinjiang stations near the Tibetan Plateau, with time series from 1979 to 2015. The data package contains daily precipitation data of 184 weather stations, the file name is the weather station number and the file extension is data. Each document has four columns, respectively representing: Year, Month, Day, Precipitation (unit: mm). The site information is described in the file stations_meta_SR.txt. The document consists of 6 columns, respectively representing: Station No., Latitude, Longitude, Altitude (unit: m), Station name and Province. The data comes from the data sharing network of China Meteorological Administration and conventional meteorological observation data. The data is the original data and has not been processed again. The default value of the data is - 99.
China Meteorological Data Network
The surface elevation of the ice sheet is very sensitive to climate change, so the elevation change of the ice sheet is considered as an important variable to evaluate climate change. The time series of long-term ice sheet surface elevation change has become a fundamental data for understanding climate change. The longest time series of ice sheet surface elevation can be established by combining the observation records of radar satellite altimetry missions. However, the previous methods for correcting the intermission bias still have error residue when cross-calibrating different missions. Therefore，we modify the commonly used plane-fitting least-squares regression model by restricting the correction of intermission bias and the ascending–descending bias at the same time to ensure the self-consistency and coherence of surface elevation time series across different missions. Based on this method, we use Envisat and CryoSat-2 data to construct the time series of Antarctic ice sheet elevation change from 2002 to 2019. The time series is the monthly grid data, and the spatial grid resolution is 5 km×5 km. Using airborne and satellite laser altimetry data to evaluate the results, it is found that compared with the traditional method, this method can improve the accuracy of intermission bias correction by 40%. Using the merged elevation time series, combining with firn densification-modeled volume changes due to surface processes, we find that ice dynamic processes make the ice sheet along the Amundsen Sea sector the largest volume loss of the Antarctic ice sheet. The surface processes dominate the volume changes in Totten Glacier sector, Dronning Maud Land, Princess Elizabeth Land, and the Bellingshausen Sea sector. Overall, accelerated volume loss in the West Antarctic continues to outpace the gains observed in the East Antarctic. The total volume change during 2002–2019 for the AIS was −68.7 ± 8.1 km3/y, with an acceleration of −5.5 ± 0.9 km3/y2.
ZHANG Baojun, WANG Zemin, YANG Quanming, LIU Jingbin, AN Jiachun, LI Fei, GENG Hong
The global high-resolution simulated near sea surface temperature precipitation SST data set from 1990 to 2020 is from the latest cmip6 project. Cmip6 is the sixth climate model comparison program organized by the world climate research project (WCRP). Original data source: https://www.wcrp-climate.org/wgcm-cmip/wgcm-cmip6 。 The data set includes the global near ocean surface temperature (TMP), precipitation (PR) and sea surface temperature (TOS). The air temperature and precipitation data include the rectangular combination of shared social economic path (SSP) and representative concentration path (RCP) of four different experimental scenarios of scenario MIP in cmip6. (1) Ssp126: upgrade rcp2.6 scenario based on ssp1 (low forcing scenario) (radiation forcing will reach 2.6w/m2 in 2100). (2) Ssp245: upgrade rcp4.5 scenario based on SSP2 (moderate forcing scenario) (radiation forcing will reach 4.5 w / m2 in 2100). (3) Ssp370: a new rcp7.0 emission path based on ssp3 (medium forcing scenario) (radiation forcing will reach 7.0 w / m2 in 2100). (4) Ssp585: upgrade rcp8.5 scenario based on ssp5 (high forcing scenario) (ssp585 is the only SSP scenario that can make radiation forcing reach 8.5 w / m2 in 2100). SST data provides ssp126 scenario data.
YE Aizhong
The atmospheric and oceanic thermal conditions over the Indian Ocean-Third Pole (Qinghai-Tibet Plateau) are important for affecting the Asian monsoon activity and pan-Third Pole climate. At seasonal and interannual timescales, the meridional atmospheric and oceanic heat sources are closely related to Indian monsoon, Bay of Bengal monsoon, and the sea surface temperature (SST) mode in the tropical Indian Ocean. Therefore, we calculate and establish the meridional atmospheric and oceanic heat sources dataset for the Indian Ocean-Third pole section. In order to obtain the horizontal distribution of atmospheric heating rate on each pressure level, we use the inverse algorithm from Yanai et al. (1973): Q_1=c_p [∂T/∂t+V ⃑∙∇T+(p/p_0 )^κ ω ∂θ/∂p] Q_1 is the atmospheric apparent heat source, which can be affected by temperature local variation, temperature advection and potential temperature vertical variation. T, θ, V ⃑, and ω respectively represent the temperature, potential temperature, horizontal wind vector, and vertical velocity. p_0=1013.25hPa. κ=R/c_p, R and c_p are the gas constant and specific heat of dry air at constant pressure respectively, κ≈0.286。 Based on the ERA5 Atmospheric Reanalysis data from 2000 to 2019, we calculate the monthly meridional (along 60°E, 70°E, 80°E, 90°E) atmospheric heating rate (unit: K/s) for the Indian Ocean-Third pole section (30°S-60°N) with horizontal resolution of 1°×1° and vertical range of 1000-100hPa at 27 levels. With reference to Hall and Bryden (1982), the vertical Ocean Heat Transport (OHT) at given longitudes can be calculated by the following formula: OHT=∮_(Θ=Θ_i)▒∫_(z_b)^(z_0)▒〖ρ_0 c_p (θ-θ_r ) 〗∙udz Where ρ_0, c_p, θ, θ_r, and u represent the density, specific heat, capacity potential temperature, reference temperature (0℃), and zonal velocity of sea water respectively. z_0 and z_b are the depths of sea surface and sea floor. Based on the CMEMS (Copernicus Marine Service) Oceanic Reanalysis data from 2000 to 2019, we calculate the monthly meridional (along 60°E, 70°E, 80°E, 90°E) OHT (eastward positive, unit: PW(1015W)) over the Indian Ocean-Third pole region (30°S-30°N) with horizontal resolution of 1°×1° and vertical range from sea surface to sea floor at a depth of about 5900m on 75 levels. This dataset can reflect the close relationship between meridional atmospheric and oceanic thermal conditions of Indo-Tibetan Plateau region and Indian monsoon, Bay of Bengal monsoon, and SST mode over tropical Indian Ocean. For example, from the monthly evolution of meridional atmospheric heating rate along 70°E for the Indian Ocean-Third pole section (Figure 1), the atmospheric heat source area above the tropical southern Indian Ocean gradually advances northward from Marth to May. In particular, from May to June, this tropical atmospheric heat source area moves to the tropical northern Indian Ocean with its intensity strengthened and scope expanded, at the same time, the Indian summer monsoon onsets. For instance, from the monthly evolution of meridional atmospheric heating rate along 90°E for the Indian Ocean-Third pole region (Figure 2), we can see that the atmospheric heat source area above the tropical Indian Ocean expands to the south of Qinghai-Tibet Plateau and increases significantly from April to June, coinciding with the onset and northward advance of the Bay of Bengal monsoon. Another example, from the monthly evolution of meridional OHT along 60°E and 90°E for the Indian Ocean-Third pole section (Figures 3 and 4), it can be found the ocean heat at the equatorial Indian Ocean subsurface transports from west to east, and its position is very close to the Equatorial undercurrent. And this subsurface OHT intensity in the west is obviously higher than that in the east, which is related to the wind-thermocline-SST feedback mechanism. It is also worth noting that this subsurface OHT is strong in spring (March-May), weakens in summer, and significantly strengthens in late autumn and early winter (October-December), interacting with the development and formation of Indian Ocean Dipole.
LI Delin , XIAO Ziniu, ZHAO Liang
This dataset contains daily 0.01°×0.01° land surface soil moisture products in the Qinghai-Tibet Plateau in 2005, 2010, 2015, 2017, and 2018. The dataset was produced by utilizing the multivariate statistical regression model to downscale the “SMAP Time-Expanded 0.25°×0.25° Land Surface Soil Moisture Dataset in the Qinghai-Tibet Plateau (SMsmapTE, V1)”. The auxiliary datasets participating in the multivariate statistical regression include GLASS Albedo/LAI/FVC, 1km all-weather surface temperature data in western China by Ji Zhou, and Lat/Lon information.
CHAI Linna, ZHU Zhongli, LIU Shaomin
This dataset contains monthly 0.05°×0.05° land surface soil moisture products in Qilian Mountain Area in 2005, 2010 and 2015. The dataset was produced by utilizing the multivariate statistical regression model to downscale the “AMSR-E and AMSR2 TB-based SMAP Time-Expanded Daily 0.25°×0.25° Land Surface Soil Moisture Dataset in Qilian Mountain Area (SMsmapTE, V1)”. The auxiliary datasets participating in the multivariate statistical regression include GLASS Albedo/LAI/FVC, 1km all-weather surface temperature data in western China by Ji Zhou and Lat/Lon information.
CHAI Linna, ZHU Zhongli, LIU Shaomin
This dataset contains daily 0.05°×0.05° land surface soil moisture products in Qilian Mountain Area in 2017. The dataset was produced by utilizing the multivariate statistical regression model to downscale the “AMSR-E and AMSR2 TB-based SMAP Time-Expanded Daily 0.25°×0.25° Land Surface Soil Moisture Dataset in Qilian Mountain Area (SMsmapTE, V1)”. The auxiliary datasets participating in the multivariate statistical regression include GLASS Albedo/LAI/FVC, 1km all-weather surface temperature data in western China by Ji Zhou and Lat/Lon information.
CHAI Linna, ZHU Zhongli, LIU Shaomin
This dataset contains the flux measurements from the Qinghai Lake eddy covariance system (EC) belonging to the Qinghai Lake basin integrated observatory network from January 1 to December 31 in 2021. The site (100° 29' 59.726'' E, 36° 35' 27.337'' N) was located on the Yulei Platform in Erlangjian scenic area, Qinghai Province. The elevation is 3209m. The EC was installed at a height of 16.1m, and 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 about 0.17 m. The raw data acquired at 10 Hz were processed using the Eddypro post-processing software, including the spike detection, lag correction of H2O/CO2 relative to the vertical wind component, sonic virtual temperature 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. 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): class 1-3 (high quality), class 4-6 (good), class 7-8 (poor, better than gap filling data), class9 (rejected). 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 collected 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, and the missing data were replaced with -6999. The released data contained the following variables: DATE/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/m3), CO2 mass density (CO2, mg/m3), friction velocity (ustar, m/s), stability (z/L), sensible heat flux (Hs, W/m2), latent heat flux (LE, W/m2), carbon dioxide flux (Fc, mg/ (m2s)), 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). The quality marks of sensible heat flux, latent heat flux and carbon flux are divided into three levels (quality marks 0 have good data quality, 1 have good data quality and 2 have poor data quality). 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 *.xls format. Detailed information can be found in the suggested references.
Li Xiaoyan
This dataset (version 1.5) is derived from the complementary-relationship method, with inputs of CMFD downward short- and long-wave radiation, air temperature, air pressure, GLASS albedo and broadband longwave emissivity, ERA5-land land surface temperature and humidity, and NCEP diffuse skylight ratio, etc. This dataset covers the period of 1982-2017, and the spatial coverage is Chinese land area. This dataset would be helpful for long-term hydrological cycle and climate change research. Land surface actual evapotranspiration (Ea)，unit: mm month-1. The spatial resolution is 0.1-degree; The temporal resolution is monthly; The data type is NetCDF; This evapotranspiration dataset is only for land surface.
MA Ning, MA Ning, Jozsef Szilagyi, ZHANG Yinsheng, LIU Wenbin
This data set is the global high accuracy global elevation control point dataset, including the geographic positioning, elevation, acquisition time and other information of each elevation control point. The accuracy of laser footprint elevation extracted from satellite laser altimetry data is affected by many factors, such as atmosphere, payload instrument noise, terrain fluctuation in laser footprint and so on. The dataset extracted from the altimetry observation data of ICESat satellite from 2003 to 2009 through the screening criteria constructed by the evaluation label and ranging error model, in order to provide global high accuracy elevation control points for topographic map or other scientific fields relying on good elevation information. It has been verified that the elevation accuracy of flat (slope<2°), hilly (2°≤slope<6°), and mountain (6°≤slope<25°) areas meet the accuracy requirements of 0.5m, 1.5m, and 3m respectively.
XIE Huan, LI Binbin, TONG Xionghua, TANG Hong, LIU Shijie, JIN Yanmin, WANG Chao, YE Zhen, CHEN Peng, XU Xiong, LIU Sicong, FENG Yongjiu
This data set includes the statistical data of water resources in Tibet and Qinghai. The data comes from Tibet water resources bulletin and Qinghai water resources bulletin. The statistical scale is the municipal unit scale, including Xining City, Haidong City, Haibei Prefecture, Hainan prefecture, Huangnan Prefecture, Guoluo Prefecture, Yushu prefecture and Haixi Prefecture in Qinghai Province, Lhasa, Changdu, Shannan, Shigatse, Naqu and other municipal units in Tibet Ali, Linzhi and other municipal units; Variables include annual precipitation, surface water resources, groundwater resources, repeated calculation, total water resources, per capita water resources, water production modulus, surface water supply, groundwater supply, total water supply, agricultural water consumption, industrial water consumption, domestic water consumption, ecological environment water consumption and total water consumption. The data set can be used in the fields of water resources management and ecological environment protection in the Qinghai Tibet Plateau.
LIU Zhaofei, YAO Zhijun
This data set is the summary of the survey results of rural small hydropower in Tibet in 2018. The main contents include the name, installed capacity, start-up time and completion time of small hydropower stations in different districts and counties of each prefecture and city in Tibet Autonomous Region, as well as the operation status of each hydropower station. The hydropower development in Tibet Autonomous Region has an early history. There are not many large and medium-sized hydropower stations, mainly in rural areas. With the development of social economy, most of the small hydropower stations in Tibet Autonomous Region have been shut down. At present, the development of large and medium-sized hydropower projects is the main one. In plateau areas where Hydropower Survey data are scarce, this data set reflects the history and current situation of small hydropower in Tibet Autonomous Region, and can provide a certain data basis for hydropower development survey and evaluation in Tibet Autonomous Region.
FU Bin
This dataset contains the ground surface water (including liquid water, glacier and perennial snow) distribution in Qilian Mountain Area in 2020. The dataset was produced based on classical Normalized Difference Water Index (NDWI) extraction criterion and manual editing. Landsat images collected in 2020 were used as basic data for water index extraction. Sentinel-2 images and Google images were employed as reference data for adjusting the extraction threshold. The dataset was stored in SHP format and attached with the attributions of coordinates and water area. Consisting of 1 season, the dataset has a temporal resolution of 1 year and a spatial resolution of 30 meters. The accuracy is about 1 pixel (±30 meter). The dataset directly reflects the distribution of water bodies within the Qilian Mountain in 2020, and can be used for quantitative estimation of water resource.
Li Jia, Li Jia, LI Jia, LI Jia, LI Jianjiang, LI Xin, LIU Shaomin
The Land Surface Temperature in China STC dataset contains land surface temperature data for China (about 9.6 million square kilometers of land) during the period of 2003-2017, in Celsius, in monthly temporal and 5600 m spatial resolution. It is produced by combing MODIS daily data(MOD11C1 and MYD11C1), monthly data(MOD11C3 and MYD11C3) and meteorological station data to reconstruct real LST under cloud coverage in monthly LST images, and then a regression analysis model is constructed to further improve accuracy in six natural subregions with different climatic conditions.
ZHAO Changming, ZHANG Renyi
The ages of glacial traces of the last glacial maximum, Holocene and little ice age in the Westerlies and monsoon areas were determined by Cosmogenic Nuclide (10Be and 26Al) exposure dating method to determine the absolute age sequence of glacial advance and retreat. The distribution of glacial remains is investigated in the field, the location of moraine ridge is determined, and the geomorphic characteristics of moraine ridge are measured. According to the geomorphic location and weathering degree of glacial remains, the relationship between the new and the old is determined, and the moraine ridge of the last glacial maximum is preliminarily determined. The exposed age samples of glacial boulders on each row of moraine ridges were collected from the ridge upstream. This data includes the range of glacier advance and retreat in Karakoram area during climate transition period based on 10Be exposure age method.
ZHAO Changming, ZHANG Renyi
This dataset includes data recorded by the Qinghai Lake integrated observatory network obtained from an observation system of Meteorological elements gradient of the Alpine meadow and grassland ecosystem Superstation from August 31 to December 24, 2018. The site (98°35′41.62″E, 37°42′11.47″N) was located in the alpine meadow and alpine grassland ecosystem, near the SuGe Road in Tianjun County, Qinghai Province. The elevation is 3718m. The installation heights and orientations of different sensors and measured quantities were as follows: air temperature and humidity profile (HMP155; 3, 5, 10, 15, 20, 30, and 40 m, towards north), wind speed and direction profile (windsonic; 3, 5, 10, 15, 20, 30, and 40 m, towards north), air pressure (PTB110; 3 m), rain gauge (TE525M; 10m of the platform in west by north of tower), four-component radiometer (CNR4; 6m, towards south), two infrared temperature sensors (SI-111; 6 m, towards south, vertically downward), photosynthetically active radiation (PQS1; 6 m, towards south, each with one vertically downward and one vertically upward, soil heat flux (HFP01; 3 duplicates below the vegetation; -0.06 m), soil temperature profile (109; -0.05、-0.10、-0.20、-0.40、-0.80、-1.20、-2.00、-3.00 and -4.00m), soil moisture profile (CS616; -0.05、-0.10、-0.20、-0.40、-0.80、-1.20、-2.00、-3.00 and -4.00m). The observations included the following: air temperature and humidity (Ta_3 m, Ta_5 m, Ta_10 m, Ta_15 m, Ta_20 m, Ta_30 m, and Ta_40 m; RH_3 m, RH_5 m, RH_10 m, RH_15 m, RH_20 m, RH_30 m, and RH_40 m) (℃ and %, respectively), wind speed (Ws_3 m, Ws_5 m, Ws_10 m, Ws_15 m, Ws_20 m, Ws_30 m, and Ws_40 m) (m/s), wind direction (WD_3 m, WD_5 m, WD_10 m, WD_15 m, WD_20 m, WD_30m, and WD_40 m) (°), air pressure (press) (hpa), precipitation (rain) (mm), four-component radiation (DR, incoming shortwave radiation; UR, outgoing shortwave radiation; DLR_Cor, incoming longwave radiation; ULR_Cor, outgoing longwave radiation; Rn, net radiation) (W/m^2), infrared temperature (IRT_1 and IRT_2) (℃), soil heat flux (Gs_1, Gs_2, and Gs_3) (W/m^2), soil temperature (Ts_5cm、Ts_10cm、Ts_20cm、Ts_40cm、Ts_80cm、Ts_120cm、Ts_200cm、Ts_300cm、Ts_400cm) (℃), soil moisture (Ms_5cm、Ms_10cm、Ms_20cm、Ms_40cm、Ms_80cm、Ms_120cm、Ms_200cm、Ms_300cm、Ms_400cm) (%, volumetric water content), photosynthetically active radiation of upward and downward (PAR_D_up and PAR_D_down) (μmol/ (s m-2)). The data processing and quality control steps were as follows: (1) The AWS data were averaged over intervals of 10 min for a total of 144 records per day. The missing data were denoted by -6999. (2) Data in duplicate records were rejected. (3) Unphysical data were rejected. (4) The data marked in red are problematic data. (5) The format of the date and time was unified, and the date and time were collected in the same column, for example, date and time: 2018/8/31 10:30. Moreover, suspicious data were marked in red.
Li Xiaoyan
This dataset contains the flux measurements from the Qinghai Lake eddy covariance system (EC) belonging to the Qinghai Lake basin integrated observatory network from January 2 to October 18 in 2018. The site (100° 29' 59.726'' E, 36° 35' 27.337'' N) was located on the Yulei Platform in Erlangjian scenic area, Qinghai Province. The elevation is 3209m. The EC was installed at a height of 16.1m, and 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 about 0.17 m. The raw data acquired at 10 Hz were processed using the Eddypro post-processing software, including the spike detection, lag correction of H2O/CO2 relative to the vertical wind component, sonic virtual temperature 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. 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): class 1-3 (high quality), class 4-6 (good), class 7-8 (poor, better than gap filling data), class9 (rejected). 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 collected 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, and the missing data were replaced with -6999. Data during October 13 to December 31, 2018 were absent due to the unavailable collecting condition in winter. 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/m3), CO2 mass density (CO2, mg/m3), friction velocity (ustar, m/s), stability (z/L), sensible heat flux (Hs, W/m2), latent heat flux (LE, W/m2), carbon dioxide flux (Fc, mg/ (m2s)), 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 *.xls format. Detailed information can be found in the suggested references.
Li Xiaoyan
This dataset contains the flux measurements from the Alpine meadow and grassland ecosystem Superstation superstation eddy covariance system (EC) belonging to the Qinghai Lake basin integrated observatory network from September 2 to December 18 in 2018. The site (98°35′41.62″E, 37°42′11.47″N) was located in the alpine meadow and alpine grassland ecosystem, near the SuGe Road in Tianjun County, Qinghai Province. The elevation is 3718m. The EC was installed at a height of 4.5 m, and 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 (CSAT3A &EC150) was about 0.17 m. The raw data acquired at 10 Hz were processed using the Eddypro post-processing software, including the spike detection, lag correction of H2O/CO2 relative to the vertical wind component, sonic virtual temperature 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. 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): class 1-3 (high quality), class 4-6 (good), class 7-8 (poor, better than gap filling data), class9 (rejected). 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 collected 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, and the missing data were replaced with -6999. Data during December 18 to December 24, 2018 were missing due to the data collector failure. 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/m3), CO2 mass density (CO2, mg/m3), friction velocity (ustar, m/s), stability (z/L), sensible heat flux (Hs, W/m2), latent heat flux (LE, W/m2), carbon dioxide flux (Fc, mg/ (m2s)), 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 *.xls format. Detailed information can be found in the suggested references.
Li Xiaoyan
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