CLAMS_CERES_CHESLIGHT_SONDE Readme File 1.0 Introduction This readme file provides information on the CLAMS_CERES_CHESLIGHT_SONDE data set. This data set was obtained during the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) field campaign located 25 km East of Virginia (near the mouth of the Chesapeake Bay). The data were taken from July 10 - August 3, 2001. For more information on the CLAMS Project, visit the following web site: http://eosweb.larc.nasa.gov/PRODOCS/clams/table_clams.html If users have questions, please contact the Langley ASDC, Users and Data Services Office at: NASA Langley Atmospheric Science 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 - Sample Data File 2.0 Data Set Description The CLAMS_CERES_CHESLIGHT_SONDE data set was collected by Vaisala RS-80 Radiosonde at the Chesapeake Lighthouse, which is a Coast Guard platform located 25 km East of Virginia (near the mouth of the Chesapeake Bay). It is located outside of the surf zone and far enough away from shore to make it an excellent validation site for space-borne retrievals of cloud and aerosol microphysics. The platform itself is small enough (25x25 meters) that the usual "island effect" associated with oceanic sites is negligible. Aerosol climatology at this location indicates optical depths and Angstrom exponents that are consistent with polluted urban aerosols, which is not surprising given its close proximity to Virginia Beach and Norfolk, VA. These urban aerosols will also have an impact on the marine clouds at the site. Not all air masses at Chesapeake Lighthouse are polluted, however, as Easterly winds from occasional synoptic systems and frequent sea breezes provide a marine aerosol source. Hence, the Chesapeake Lighthouse is an excellent location to study the impact of anthropogenic aerosols on cloud microphysical properties (i.e., the indirect effect). The parameters in the data set are listed below: time, minutes time, seconds acceleration rate, m/s height(MSL), m pressure, hPa temperature, deg C relative humidity, % dewpoint, deg C 2.1 Data Quality No known problems. 2.2 Science Point of Contact Jay Madigan 1 Enterprise Pkwy Suite 300 Hampton, Virginia 23666-5845 U.S.A Telephone: 757-827-4665 Fax: 757-825-8659 Email: j.j.madigan@larc.nasa.gov URL: http://cove.larc.nasa.gov 3.0 Data Format and Packaging The radiosonde data for each launch is in a single ASCII file. 3.1 File Naming Convention CLAMS_CERES_CHESLIGHT_SONDE_DATA files are named according to the following convention: CLAMS_CERES_CHESLIGHT_SONDE_YYYYMMDDHHSS.txt where YYYY is the 4 digit year, MM is the 2 digit month, DD is the 2 digit day, HH is the 2 digit hour, and SS is the 2 digit seconds. 4.0 Science Parameter Information Each file contains header information followed by the data in ASCII format. The parameters contained within the file are: parameter units ----------------- ------- time minutes time seconds acceleration rate meters per second height(MSL) meters pressure hectoPascal temperature degree Celsius relative humidity percentage dewpoint degree Celsius Instrumentation: Vaisala RS-80 Radiosonde processed by Vaisala PP15 Sounding Processor 5.0 Description of Sample Read Software These data are in ASCII format and no read software is provided. 7.0 Sample Data File Start Up Date 25 JUL 01 10:47 UTC System test passed -No errors found Sounding program RV 8.29 Station :COV Location : 36.91 N 75.71 W 23 m RS-number: 116362403 Ground check : Ref RS Corr Pressure : 1014.5 1015.0 -0.5 Temperature : 25.4 25.3 0.1 Humidity : 2 0 2 Started at: 25 JUL 01 11:06 UTC Time AscRate Hgt/MSL Pressure Temp RH Dewp min s m/s m hPa degC % degC 0 0 0.0 23 1013.0 24.5 93 23.3 0 5 1.9 32 1011.9 24.6 93 23.4 0 10 1.9 42 1010.8 24.6 92 23.2 0 15 2.5 57 1009.0 24.6 92 23.3 0 20 2.5 72 1007.3 24.6 91 23.0 0 25 2.8 89 1005.3 24.5 91 23.0 0 30 2.8 107 1003.4 24.4 91 22.8 0 35 3.5 126 1001.2 24.3 91 22.8 0 40 3.5 146 999.0 24.2 91 22.6 0 45 3.7 164 996.9 24.1 92 22.8 0 50 3.7 182 994.8 23.9 92 22.5 0 55 3.7 200 992.8 23.8 92 22.5 1 0 3.7 219 990.7 23.7 92 22.3 1 5 3.6 237 988.7 23.6 92 22.3 1 10 3.6 255 986.6 23.4 92 22.0 1 15 3.7 274 984.5 23.3 92 22.0 1 20 3.7 293 982.3 23.2 92 21.8 1 25 3.7 311 980.3 23.1 92 21.8 ... (continued)