MONGOLIA SOIL MOISTURE DATA

Plant Available Soil Moisture Gravimetric Observations and Maps, 1964-2002

Alan Robock  and  Haibin Li
Department of Environmental Sciences
Rutgers, The State University of New Jersey

Erdenetsetseg Divaa
National Agency of Meteorology, Hydrology and Environment Monitoring
Ulaanbaatar, Mongolia

Jared Entin 
NASA Headquarters, Washington, DC

Konstantin Vinnikov
Department of Meteorology, University of Maryland

A. Namkhai
Environmental Consulting and Assessment Company, Ulaanbaatar, Mongolia

Ts. Adyasuren
Ministry of Nature and the Environment, Ulaanbaatar, Mongolia

1. DESCRIPTION OF THE DATA SET

The Mongolian data set consists of 44 stations for the period 1964-2002. Twenty-eight sites have pasture vegetation and sixteen have wheat. All the observations were taken using the gravimetric technique for each 10-cm layer down to a depth of 1 m, with the first layer divided into two 5-cm layers. The data are volumetric plant-available soil moisture. Soil moisture was observed three times a month, on the 8th, 18th and 28th of the month from April through the end of October. The data set is described in Robock et al. (2000). The data were used by Entin et al. (2000) to study the scales of soil moisture variations. Observations at some stations began as early as 1964. A majority of them began observations during 1970. Time series data corresponding to each individual layer are available for downloading in both GrADS and ASCII formats.
Please note that the current data set includes corrections to our previous data, such as station locations and various formatting errors.  Latitudes and longitudes are now correct (correcting a confusion between decimals and degrees/minutes).  11 of the previously released 42 stations (numbered from 17 to 27) had a mixed formatting problem, which has now been corrected. In order to keep the data format consistent, the first two layers (0- to 5-cm and 5- to 10-cm) are combined and reported as a single 0- to 10- cm layer.  Please use this data set for future analyses and discard previous versions.


Click here for a location map of the 44 stations

Click here for a sample time series plot

2. DATA PROCESS PROCEDURE

To produce plant-available soil moisture, wilting levels were subtracted from total soil moisture. In case the wilting levels are not available for some stations , we used the mean value of the minimum 3 as substitutions. This method produced homogenous soil moisture for those Mongolian stations without measured wilting levels. By examining the plant-available data, it seemed to us that the wrong wilting level may have been used, as even during dry periods the plant-available soil moisture was still quite high. Therefore, we have subtracted the apparent excess from the data for some of our analyses.

3. DATA FORMATS

Mongolian data sets are available in both ASCII and BINARY formats. Some GrADS scripts are also prepared to display time series. Please contact us to work with them
.

4. REFERENCES

Entin, Jared K., Alan Robock, Konstantin Y. Vinnikov, Steven E. Hollinger, Suxia Liu, and A. Namkai, 2000: Temporal and spatial scales of observed soil moisture variations in the extratropics. J. Geophys. Res., 105, 11,865-11,877. ABSTRACT, PDF file

Robock, Alan, Konstantin Y. Vinnikov, Govindarajalu Srinivasan, Jared K. Entin, Steven E. Hollinger, Nina A. Speranskaya, Suxia Liu, and A. Namkhai, 2000: The Global Soil Moisture Data Bank. Bull. Amer. Meteorol. Soc., 81, 1281-1299. ABSTRACT, PDF file ( Copyright 2000 AMS)

5. IF YOU HAVE ANY PROBLEMS OR QUESTIONS YOU CAN CONTACT US FOR ASSISTANCE:

Haibin Li OR Prof. Alan Robock
Department of Environmental Sciences   Department of Environmental Sciences
Rutgers University   Rutgers University
New Brunswick, New Jersey 08901 USA   New Brunswick, New Jersey 08901 USA
Phone: (732) 932-9478   Phone: (732) 932-9478
Fax: (732) 932-8644    Fax: (732) 932-8644 
E-mail: hli@envsci.rutgers.edu   E-mail: robock@envsci.rutgers.edu

OR
Dr. Erdenetsetseg Divaa
National Agency of Meteorology, Hydrology and Environment Monitoring (NAMHEM)
Khudaldaany gudamj-5
Ulaanbaatar-46, Mongolia
Phone: 976-11-926592
Fax: 976-11-326611
E-mail: edivaa@yahoo.com


Prepared by Alan Robock (robock@envsci.rutgers.edu) and Haibin Li (hli@envsci.rutgers.edu)

Last updated on April 19, 2005