METREX This directory contains all the data files and technical reports associated with the Metropolitan Tracer Experiment (METREX). The data files are simple ASCII (.dat) while the report files are either compressed using Pkzip (.zip) or compressed unix tar format (tar.Z). Each report contains detailed discussion of the file data formats. The reports have been scanned and each page is saved as a .PCX file. The can be viewed and printed using Microsoft Paintbrush under Windows or through a variety of shareware programs available for unix systems. The pages are named according the following format: vol?-a##.pcx, where for instance vol2-a14.pcx might be the page preceeding vol3-a01.pcx. Here ? represents the scanning session and ## represent the sequential pages scanned in that session. ------------------------------------------------------------------------ DATA REPORT arl-140.tar.Z - NOAA Tech Memo ERL ARL-140 arl-140.zip ---------------------------------------------------------------------------- The data format has been standardized as much as possible. The descriptors used are given below. Each letter represents one digit on the data record with the exception of the decimal point, which is implied by its position. A letter represents a data type as follows: Y - Year (83/84/85) S - Wind speed (m/s) M - Month (00-12) W - Wind direction (deg) D - Day (00-31) F - Wind direction fluctuation (deg) H - Hour (00-24) P - Pressure (mb) M - Minute (00-59) Q - Moisture (dew point, K) Z - Height (m) T - Temperature (K) C - Air concentration (g/m3 10-11) X - Any other number Data types that do not fit the standard format are discussed with the appropriate file. Spaces in the descriptions of each file mean nothing, although there may be spaces on the tape if a number does not fill its field. Each letter represents one digit and a number within parentheses before the field represents a multiplier. All times are in Eastern Standard Time. Missing data are indicated by a -1 for concentrations and 9's for meteorological variables. The order of information on a data record for several stations is in the same sequence (or position) as those stations that are identified in the various tables in the text. The file descriptions follow. --------------------------------------------------------------------------- Tracer emissions data (emission.dat) release sites 1601 1602 1603 YYMMDDHH XXXX XXXX XXXX The release rate for each 6-h release for the three sites is expressed in g/h. The releases are assumed to be uniform over the 6-h period. Each record is identified by the start time of the release and the rate at each of the three release sites. Of course, for any period only two sites have non-zero rates, one for PMCH (pp2) and one for PDCH (pp3). There are no missing data. --------------------------------------------------------------------------- Sequential sampling concentration data (sequential.dat) sampling sites 1701 1702 1703 pp2 pp3 pp2 pp3 pp2 pp3 YYMMDDHH CCCC CCCC CCCC CCCC CCCC CCCC The sequential sampling data are sorted by increasing time, and concentrations for both tracers for the three sampling sites are given on each record. The time identifies the starting time of the 8-h sample. --------------------------------------------------------------------------- Passive sampling concentration data (passive_pp1, passive_pp2, passive_pp3) Station Latitude Longitude Concentration by month XXXXX XXX.XX XXX.XX 14 (CCCC) The passive sampling data are recorded as one station per record sorted by increasing station number. The position is given in hundreds of degrees. The concentrations are given for the 14 months from November 1983 through December 1984. --------------------------------------------------------------------------- Passive sampling start times (passive_start.dat) Station Latitude Longitude Start time by month XXXXX XXX.XX XXX.XX 14 (MMDD) The format is similar to the concentration files. --------------------------------------------------------------------------- Tower meteorological data (met_tower.dat) YYMMDDHHMM 5( 2( TTT.T SS.S WWW FF.F ) ) The meteorological data from the five-tower network are sorted by time with all observations from all towers on one line or data record. Each observation contains temperature, wind speed, wind direction, and standard deviation of direction for the upper level followed by the lower level for tower 1 through tower 5 (Woodbridge, Springfield, Bells Mill, Takoma, Fairfax) as indicated by the position in Table 6 of the data report. --------------------------------------------------------------------------- NOAA surface data (met_noaa.dat) YYMMDDHH (EEEE) 2[ PPPP TTT.T QQQ.Q SS.S WWW (LIQ) (FRZ) (CEL) (N) (X)) ] The surface observations at the local airports contain only an extraction of the complete observation. These data records are also sorted by increasing time, and all observations for both stations are on one record. The special fields include solar elevation angle (E) in degrees, current weather observations for the type of liquid (LIQ) and frozen (FRZ) precipitation in coded form*, cloud ceiling (CEL) in meters x 100,total cloud cover in tenths (N), and Turner stability category (X). --------------------------------------------------------------------------- Supplemental surface data (met_local.dat) YYMMDDHH 9( TTT.T SS.S WWW ) Each record of the supplemental surface data, collected by local air quality agencies, contains the temperature, wind speed, and wind direction for the nine stations as indicated by the position in Table 9 (Takoma, Smith, Rockville, Suitland, Mt. Vernon, Occoquan, Lewinsville, Gt- Falls, 7-Corners). --------------------------------------------------------------------------- Intensive meteorological data (met_intensive.dat) YYMMDDHHMM (XX) (NR) identification record ZZZZ PPPP TT.T SS.S WWW QQ.Q data record The intensive data are composed of an identification record: time of observation, station identification, and number of data records to follow. The data record consists of height, pressure, temperature, wind speed, wind direction, and dewpoint depression (*C). The station identifications (XX) are as follows: Sterling rawinsonde -01 Woodward H.S. tethersonde -02 Gallaudet Coll. tethersonde -03 National Airport pibal -04 --------------------------------------------------------------------------- *See WBAN hourly surface observations reference manual (144), National Climatic Data Center.