Database DOI


Heat and Water Balance Measurement System


This system consists of a measurement field, measuring equipment, and data acquisition facilities. Its main purpose is to acquire long-term basic data for the heat and water balance of grassland. This grass-covered circular experimental field with a diameter of 160 m (more than 20,000 m2) has a 30 m high meteorological observation tower at its center. The field is covered with many types of weeds and is managed by mowing once every summer and winter. Wells are arranged on the measurement field to measure the groundwater level, and several meteorological sensors are set on the field as well. The measured data are transferred by wireless LAN to the data recording room and recorded in quasi-real time. Data from supersonic anemometer-thermometers are used to obtain heat and momentum fluxes by the eddy correlation method. These observation data are open to public and freely available through our website. See “Current Readings of Meteorological and Hydrological Variables at TERC” (renewed every minute)


General characteristics
Parameters: wind direction, wind speed, momentum flux, sensible heatflux, shortwave radiation, downward longwave radiation, net radiation, soil heat flux, air temperature, soil temperature, dew point temperature, ground water level, pan evaporation, precipitation, relative humidity, air pressure, sunshine duration.
Processing level:
Temporal resolution: 10sec (from 2003-04-26), 30min, 60min 24hour
Start date: 1981-08-01
Stop date:
Observatory Location
Observation site: University of Tsukuba, Japan
Latitude: (WGS84):36°06′35″N (36.1135)
Longitude: (WGS84):140°06′00″E (140.0949)
Elevation: 27.0 m
Data  Access:
Citation & Contact Information
How to Cite: Publications based on data acquired via Center for Research in Isotopes and Environmental Dynamics (CRiED) access services should cite the CRiED in the standard format outlined here. Proper citation ensures that source information is available for use by future researchers.


Researchers publishing analytical pieces using data obtained from the CRiED are encouraged to provide the Center with a copy of the work or its citation information for inclusion in the “Bibliography of publications using data from the CRiED”. Citations can be submitted by email at jimu”@” or by sending them to contact listed below.

Contact : Wenchao MA (orcid: 0000-0003-1470-8483)

Naomi Nakajima

E-mail  nakajima@ied.(add





Center for Research in Isotopes and Environmental Dynamics at University of Tsukuba, Environmental Dynamics & Prediction Web site:

Note: Available from, rather than Retrieved from, indicates that the URL takes you to a download site, rather than directly to the data set file itself.

Acknowledgements: The survey results reported here were provided by the Center for Research in Isotopes and Environmental Dynamics, Environmental Dynamics & Prediction, University of Tsukuba.
Provider Version
Ver. 1.1

Monthly  data     Annual data     Data item         Meta data

Ver. 1.0

Monthly  data      Annual data      Data item

Ver. 2.0

Hourly average     Monthly average        Annualaverage      data item

Rawdata (updating)

Update History


Description of Data Version 1.0, 1.1 and 2.0


Since May 2003, the data set with consistent quality control applied to raw data by the new system operated. The quality control includes removing error data due to maintenance troubles, and missing data caused by observed values out of the specified range. It was published at the end of the year, which was recorded in Bulletin of the Terrestrial Environment Research Center the University of Tsukuba”. The Ver. 1.1 data set are constituted by both of old and new versions that are in accordance with the new version data format. Descriptions of new system can be found from Bulletin of the TERC No. 5 (2004)”.



This data set followed a preceding system standard, which applied to the observed data until April 2003. It is necessary to pay attention about the difference of data quality control for certain observation period. The data format is integer. It was published at the end of the year, which was recorded in the Bulletin of the Environmental Research Center the University of Tsukuba (before 1999 筑波大学水理実験センター報告), and Bulletin of the Terrestrial Environment Research Center the University of Tsukuba (from 2001 to 2012 筑波大学陸域環境研究センター報告). After the new system is started (from May 2003), the data set was updated as Ver. 1.1, and the record of Ver. 1.0 were stopped meanwhile.



This data set is a comprehensive version with both of the Ver. 1.0 and Ver. 1.1, for the purpose of improving data reliability by performing quality evaluation and quality control. Currently, the Ver. 2.0 released including hourly data with highly consistent quality control, between August 1981 and December 2005. Details of quality control, monthly and annual statistics and graph of climate values were published in the Bulletin of TERC No. 7 (2006)”.



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