FIRE_ACE_UTRECHT_BALLOON Readme File 1.0 Introduction This readme file provides information on the FIRE_ACE_UTRECHT_BALLOON data set. This data set was obtained during the FIRE.ACE field campaign from the Utrecht University Tethered Balloon deployed at the SHEBA site. The data were taken from May 2-25, 1998. For more information on the FIRE.ACE Project, visit the following web site: http://eosweb.larc.nasa.gov/ACEDOCS If users have questions, please contact the Langley DAAC Science, Users and Data Services Office at: NASA Langley Atmospheric Sciences Data Center Science, Users and Data Services Office NASA Langley Research Center Mail Stop 157D 2 South Wright Street Hampton, Virginia 23681-2199 U.S.A. E-mail: larc@eos.nasa.gov Phone: (757)864-8656 FAX: (757)864-8807 URL: http://eosweb.larc.nasa.gov This document includes the following sections: Section 2.0 - Data Set Description Section 3.0 - Data Format and Packaging Section 4.0 - Science Parameter Information Section 5.0 - Description of Sample Read Software Section 6.0 - Implementing Sample Read Software Section 7.0 - Sample Output Section 8.0 - Additional Data Information 2.0 Data Set Description 2.1 Data Quality The quality of the visible actinic flux data is very good between 2 May and 12 May. After this date the actinic fluxes were not always consistent with data measured with an identical surface-installed actinometer. Therefore it is not recommended to use actinic flux data measured from the tethered balloon after 12 May. Temperature measurements were good throughout the experiment. The quality of the wind data varied. During low wind conditions the wind direction is not very accurate (wind velocity < 1 m/s). Soundings which contain questionable wind data are summarized below. fire_ace_utrecht_090598_0408 Wind direction bad fire_ace_utrecht_090598_0728 Wind direction bad fire_ace_utrecht_100598_0035 Wind velocity between 970 and 940 hPa questionable. fire_ace_utrecht_110598_1418 Wind velocity questionable. All wind data measured after 16 May are questionable. It is not recommended to use these data. 2.2 Science Contact Stephan R. de Roode Princetonplein 5 Phone: 31 30 2532815 FAX: 31 30 2543163 E-mail: roode@phys.uu.nl URL: http://www.phys.uu.nl/~roode 3.0 Data Format and Packaging Some days contain more that one file. For ease of downloading the data, the individual files have been "zipped" together into one file. To unzip the files with Info-Zip software, download the freeware and information from the following URL: http://www.cdrom.com/pub/infozip/ 3.1 File Naming Convention FIRE_ACE_UTRECHT_BALLOON files are named according to the following convention: fire_ace_utrecht_MMDDYYYY.zip where YYYY is the 4 digit year, DD is the 2 digit day and MM is the 2 digit month. When the original file is unzipped as described above, the files produced are named according to the following convention: fire_ace_utrecht_MMDDYYYY_HHMM.zip where YYYY is the 4 digit year, DD is the 2 digit day, MM is the 2 digit month, HH is the 2 digit UTC hour and MM is the 2 digit UTC minute. 4.0 Science Parameter Information Each file contains 1 line of header information followed by the data in ASCII format. The fill values are -100. for pressure and -99.99 for all other parameters. The parameters contained within the file are: Field Units Description time[UTC] UTC Julian day and time (day.decimaltime) pres[hPa] mb pressure temp[C] degrees Celsius temperature ff[m/s] meters/second wind velocity dd[deg] degrees wind direction af[microA] microampere visible actinic flux - raw af[W/m2/nm] watts/meter^2/nanometer visible actinic flux - calibrated 5.0 Description of Sample Read Software These data are in ASCII format and no read software is provided. Last Updated: August 10, 2000