CEOP/EOP-1 CAMP Himalayas Hourly Surface Meteorology, Flux, and Radiation Data Set 1.0 Contact Information 1.1 UCAR/JOSS Contact Steven F Williams Data Specialist UCAR/JOSS P.O. BOX 3000 Boulder, CO, USA, 80307-3000 Telephone: 303-497-8987 Facsimile: 303-497-8158 E-Mail Address: sfw@ucar.edu 1.2 Himalayas Contact Massimo Bollasina & Laura Bertolani Epson Meteo Center via Pisa 250 I-20099 Sesto S. Giovanni, Milan, ITALY massimo.bollasina@epson-meteo.org laura.bertolani@epson-meteo.org Telephone: +39 02 26265440/09 Faxsimile: +39 02 24410777 2.0 General Description This data set contains the Coordinated Enhanced Observing Period (CEOP) Enhanced Observing Period 1 (EOP-1) CEOP related Asian Monsoon Experiment (CAMP) Himalayas Hourly Surface Meteorology, Flux, and Radiation Data Set. This data set contains hourly data from a single station (Pyramid) for the CEOP EOP-1 time period (01 July 2001 to 30 September 2001). The University Corporation for Atmospheric Research/ Joint Office for Science Support (UCAR/JOSS) did not perform quality control processing on this data set. 3.0 Detailed Data Description 3.1 CAMP Himalayas Algorithms 3.1.1 Native format data Intensive meteorological observations in the Khumbu Valley, Nepal Himalayas, are conducted since the middle 90.s (Ueno et al., 1996; Tartari et al., 1999; Bertolani et al., 2000; Bollasina et al., 2002) in order to provide long-term monitoring of the monsoon at high altitude. This area, being located on the windward side of the Range with respect to the Indian monsoon, is well exposed to the summer winds and it is one of the main ways of the monsoon toward Tibet. The studies conducted by means of Automated Weather Stations (AWS) datasets and gridded data provided by GCMs have demonstrated that the region is a significant point of observation both of local climate and large-scale circulation. In fact, it has been possible to clearly outline the main characteristics of the monsoon at high altitude (onset and withdrawal mean dates, description of the type of monsoon precipitation and of the prevalent circulation and its relation with synoptic forcing) and to highlight large-scale features, such as intraseasonal (active and break phases) and interannual variability (the Tropospheric Biennial Oscillation) of the monsoon. Moreover, a network of stations located at different altitudes will permit to study in detail the spatial rainfall distribution and the importance of surface heating as a driving mechanism of the monsoon. These data were collected with a Lastem AWSs 5 m mast. This mast contains the following sensors provided by LSI-LASTEM, Italy. Parameter Sensor Type Accuracy Height (m) ---------------------- ----------------- ----------- ---------- Air Temperature Thermoresistance 0.2°C 2 Precipitation Tipping Bucket 1% 1.5 Relative Humidity Capacitive Plate 2% 2 Atmospheric Pressure Slice of Silica 0.3 hPa 2 Wind Speed 3-cup anemometer 1.5% 5 Wind Direction Potentiometer 0.5% 5 Global Solar Radiation Temperature Difference 0.5% 2 Calibration is done in Italy. Collection of ground heat flux, surface temperature, snow depth, soil moisture, incoming and outgoing shortwave and longwave radiation are currently being implemented at the Pyramid site and will be available in the near future. 3.1.2 CEOP/EOP-1 Hourly Surface Meteorology, Flux, and Radiation format data This CEOP/EOP-1 CAMP Himalayas Hourly Surface Meteorology, Flux, and Radiation data set was formed by extracting the hourly observations from the native format data. The data are in UTC time. The U and V wind components were computed from wind speed and direction. Dew point was computed from the relative humidity and temperature using formulas from Bolton (1980). Specific humidity was computed from the surface pressure and dew point using formulas from Wexler and Wildhack (1963). More information regarding this site can be found under the "CEOP Reference Site Station Characteristics" link on the UCAR/JOSS CEOP Data Management page at http://www.joss.ucar.edu/ghp/ceopdm/ . 3.2 Station Information The following is a complete description of the station information provided with this CEOP CAMP Himalayas data set. The actual station information is given at the end of this section. Table 1 details the station list parameters. The beginning and ending dates for the period of coverage are in Universal Time Coordinated (UTC). The Identification Type field is network dependent and indicates the source of the Identification field. The Occurrence field is an integer value used to indicate co-located stations. Note that when a particular parameter is unknown for a station, either a blank, a question mark, or all 9's will appear in that parameter's position. For a complete list of Country, State, and County values, refer to the document in the references (Section 5.0). Possible platform types and frequency values are listed in Tables 2 and 3, respectively. Note that only those platform types present in the CEOP EOP-1 data have been listed. Table 4 contains the station information for this CEOP CAMP Himalayas data set. Table 1 Parameter Description --------- ----------- Identification ID in data Identification Type Internal ID number type Latitude Station Latitude Longitude Station Longitude Occurrence Station occurrence Lat/Lon Accuracy Number of digits accuracy in lat/lon values Name Expanded station name Commissioned Flag `(C)' indicates commissioned station, `(N)' indicates station which is NOT commissioned Begin Period of Coverage Beginning date of period of coverage (YYYYMMDD) End Period of Coverage End date of period of coverage (YYYYMMDD) Country Country in which station is located State State code County County code UTC offset Hour Offset from UTC time DST switch 'y' indicates station does switch to Daylight Savings Time (DST). 'n' indicates station does not switch to DST Platform type Collection Platform. See Table 2 Reporting Frequency Frequency of data collection Elevation Station elevation Fixed/Mobile flag Flag indicating if station has fixed location. 'f' indicates a fixed station. 'm' indicates a mobile station Table 2 Platform Type Description ------------- ----------- 264 CEOP Reference Site Platform Table 3 Reporting Frequency ------------------- hourly Table 4 Station Information ------------------- Pyramid 53 27.96000 86.81000 0 2 Pyramid Station (N) 20010630 20010930 NP 99 ??? 0.00 n 264 hourly 5035.0 f 3.3 Detailed Format Description The CEOP EOP-1 CAMP Himalayas Hourly Surface Meteorology, Flux, and Radiation Data Set contains 10 metadata parameters and 22 data parameters. The metadata parameters describe the station location and time at which the data were collected. The time of observation is reported both in Universal Time Coordinated (UTC) Nominal and UTC actual time. Days begin at UTC 0100 and end at UTC 0000 the following day. Note that missing parameter values are indicated by "-999.99". The table below details the data parameters in each record. Parameters Units ---------- ----- Date of Observation UTC Nominal Time of Observation UTC Nominal Date of Observation UTC Actual Time of Observation UTC Actual CSE Identifier Abbreviation of CSE name Reference Site Identifier Abbreviation of Site name Station Identifier Reference Site Dependent Latitude Decimal degrees, South is negative Longitude Decimal degrees, West is negative Station Elevation Meters Station Pressure Hectopascals (mb) Dry Bulb Temperature Celsius Dew Point Celsius Relative Humidity Percent Specific Humidity g/kg Wind Speed m/s Wind Direction Degrees U Wind Component m/s V Wind Component m/s Total Precipitation mm Snow Depth cm Sensible Heat Flux W/m2 Latent Heat Flux W/m2 Incoming Shortwave Radiation W/m2 Outgoing Shortwave Radiation W/m2 Incoming Longwave Radiation W/m2 Outgoing Longwave Radiation W/m2 Net Radiation W/m2 Skin Temperature Celsius CO2 Flux uMoles/m2/s Incoming PAR uMoles/m2/s Outgoing PAR uMoles/m2/s 3.4 Data Remarks This data set contains hourly observations for the CEOP EOP-1 time period for a single station (Pyramid). This data set is also available on-line in native format at http://www.joss.ucar.edu/ghp/ceopdm/ under the link CEOP EOP-1 Reference Site Data Sets. There are three other stations in this network. Currently, data is not available for these other stations. The relative humidity sensor has a known delayed reduction from saturation conditions. The sensors are not heated. Wind sensors can freeze during cold and wet conditions, especially at the highest station (Pyramid). Solid precipitation melts with some delay. 4.0 Quality Control Processing UCAR/JOSS performed limited gross limit and visual checks on this data set. No data values have been changed. 5.0 References Bolton, D., 1980: The computation of equivalent potential temperature., Mon. Wea. Rev., 108, pp 1046-1053. Department of Commerce - National Institute of Standards and Technology (NIST), 1985: Federal Information Processing Standards Publication 10-3 Countries, Dependencies, & Areas of Special Sovereignty. Department of Commerce - NIST, Washington, DC. Wexler, A., and W. A. Wildhack, 1963: Humidity and Moisture. Vol. 3: Fundamentals and Standards. Reinhold Publ. Corp., 562 pp.