0__README.TXT Latest update of this file and all data files: 30/Oct/96 =============================================================================== National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostics Laboratory Nitrous Oxide and Halocarbons Division James H. Butler 325 Broadway R/E/CG1 Boulder, CO 80303 USA Tel +1 303 497 6898 Fax +1 303 497 6290 email jbutler@cmdl.noaa.gov (internet) =============================================================================== Bromine Latitudinal Air/Sea Transect 1994 (BLAST 94 or BLAST I) Cruise data J.M. Lobert, J.H. Butler, S.A. Montzka, L.S. Geller, R.C. Myers, and J.W. Elkins =============================================================================== please acknowledge the source if you use these data! =============================================================================== For more information on this cruise, see our world wide web page: http://www.cmdl.noaa.gov/noah_home/ocean/ocean.html =============================================================================== This directory contains the publicly available data from this cruise, which took place between Seattle, WA to Punta Arenas, Chile. At this time, the following files are available. 0__README.TXT this file that you are currently reading. ============== 0_CruiseInfo.TXT A textfile with some generell cruise info, goals, etc, ================ basically an excerpt from our WWW homepage. CRUISE1.WK1 =========== A Lotus 1-2-3 spreadsheet file with generell data like position, meteorological data, for each of the GC/MS injections taken during the cruise, a total of 546 injections, 276 air and 271 surface water measurements. Each one of those lines has a corresponding injection of ambient air or equilibrated surface water air. Each row is denoted "AR" or "EQ" for Air or Equilibrator, respectively. The next spreadsheets will contain the respective data for methyl bromide on the same row basis as this file, i.e. similar rows correspond to each other. The following data are in this file: GAS: labels: AR for air injection, EQ for Equilibrator (surface water) Date: The decimal date of the injection in spreadsheet format, the day after 01-01-1900 DOY: The decimal Julian Day of the year 1992 Latitude: in degrees north (negative = south) Longtitude: in degrees West (negative). Longtitude: in degrees East (positive) makes for better charting. SST: Sea surface temperature, in degrees Celsius. THEQ: Temperature of the Equilibrator water. Warming: THEQ - SST, the warming of the surface water on its way from the ocean to the equilibrator, in degrees Celsius. H2Ovapor: water vapor pressure, in hPa (mbar). AirTemp: air temperature, in degrees Celsius. Humidity: relative humidity, in percent. Pressure: ambient atmospheric pressure, in hPa (mbar). WndSpdRel: Wind speed relative to the ship, in meters per second WndSpdTru: True wind speed, in meters per second. WndDirRel: Wind direction relative to the ship, in degrees. Ship course=0. WndDirTru: True wind direction, in degrees. North = 0 = 360 Salinity: in practical salinity units (PSU). Zones: Zones that identify the coastal, open ocean, upwelling regions defined in our Science paper. Indicated is the beginning of the zone. Latitude: latitude for those zones. >>>>>>>>>> Download this file in BINARY format !! <<<<<<<<<<<<< CRUISE1.TXT =========== This file is plain ASCII and contains the same data as the above. All numbers were saved with as many decimals as they have in the spreadsheet. This does NOT mean, that we can caluclate the mixing ratio of methyl bromide to its 8th digit.... The first line contains the above column headers, followed by the numbers in line two. Note that the last two columns contain only 7 entries each! CH3BR.WK1 ========= A Lotus 1-2-3 spreadsheet file with methyl bromide data. All data in this file line up with data in file CRUISE1.WK1. The following data are in this specific file: GAS: type of injection AR for Air, EQ for Equilibrator (surface water) Latitude: in degrees north Mole Fraction Air: of methyl bromide in ambient air, in ppt Mole Fraction water: of methyl bromide in the surface water, in ppt Partial Pressure Air: of methyl bromide in ambient air, in pico-bar Partial Pressure water: of methyl bromide in surface water, in pico-bar. Partial pressures are mole fractions that were corrected for water vapor pressure. Saturation anomaly: fraction, multiply with 100 to get percent. Net Saturation anomaly: fraction, multiply with 100 to get percent. The net saturation anomaly is the saturation anomaly of methyl bromide corrected for physical effects with the saturation anomaly of CFC-11. >>>>>>>>>> Download this file in BINARY format !! <<<<<<<<<<<<< CH3BR.DAT ========= This file is plain ASCII and contains the same data as the above. If you have access to a spreadsheet, download the spreadsheet file for less pain. Due to empty cells in this text-file (each line is for either air OR water, never for both), the missing data were filled with the string "NAN", a string that is used in some software programs to indicate "not-a-number". If you wish to load this file into other programs, simply load it into a text-editor first, replace "NAN" with a "0" or any other descriptive number, and save it. N2O.DAT ======= This is an ASCII file with data from our online ECD system that we operated during this cruise. The file contains columns of data with the first row being the title of the column. !! Missing numbers (in the general data) are replaced with the number 9999, please replace the number 9999 with whatever string or number your application can handle. We choose this number, because none of the data are anywhere near this value and some applications cannot handle strings properly or ignore them, ultimately shifting parts of columns. !! For this dataset, we decided to have a more user-friendly format. Fact is that both air and water samples were analyzed at different times (alternating with calibration gases), hence analysis times do not line up for both air and water. Instead of providing the user with two different sets of columns for air and water, in this dataset we shifted the air results to the next earlier water sample. We shifted only the entire dataset, not individual rows. Wherever there was either an air or water sample missing, we deleted that particular row and removed it from the dataset, which reduced the dataset by about 64 values (out of ~ 660 total). The mean time between an air and a water sample (equal to the shift in the dataset) was 23 minutes, which, at a maximum cruising speed of 16 knots, is a maximum of 5.3 nautical miles or less than 1/10th of a degree of latitude. We think that this error is small and is outweighed by the improved user-friendliness. Here are the titles of the data columns and the units that go along with it: Date123 The date in spreadsheet format, 34361 is January 27th, 1994. DOY The decimal Julian Day of Year 1994 Year decimal year of 1994 (=DOY/365+1994) Lat Latitude in degrees, negative is south of the equator Lon Longitude in degrees West WndSpdTru True wind speed in m/s (not corrected for height: 29.9 m) WndSpdRel True wind direction in degrees WndDirTru Wind speed relative to the ship in m/s (not corrected for height: 29.9 m) WndDirRel Wind direction relative to the ship's motion in degrees COG course over ground in degrees SOG speed over ground in m/s Pressure Atmospheric barometric pressure in hPa=mbar Humidity relative humidity in percent Salinity salinity in per-mille / PSU=practical salinity units Warming warming in degrees Celsius between the water intake and the equilibrator = difference between SST and SST_EQ AirTemp Air temperature in degrees Celsius SST Sea surface temperature in degrees Celsius SST_EQ Temperature inside the equilibrator in degree Celsius. H2Ovapor Water vapor for the given temperature and pressure (hPa) H2Ocorrect correction applied to the mixing ratio to calculate partial pressure, which is needed to calculate the saturation anomalies. MFAir Dry Mole Fraction of N2O in the air in ppb or nanomole per mole PPair Partial Pressure of N2O in air in nano-atm MFwater Dry Mole Fraction of N2O in equilibrated air in ppb or nanomole per mole PPwater Partial Pressure of N2O in equilibrated air in nano-atm SA Saturation anomaly; SA = (PPwater-PPair) / PPair (multiply by 100 to get percent) N2O.ZIP ======= The same N2O.DAT file compressed into a ZIP archive for quicker download. SF6.DAT ======= Data for sulfur hexafluoride in the atmosphere during our BLAST II cruise. Missing data were replaced with the number "9999". Here are the column headers: Date123 JulianTime Year Lat Lon WndSpdTru WndSpdRel WndDirTru WndDirRel COG SOG Gyro Pressure Humidity Salinity AirTemp SST MixRatSF6 Date123 The date in spreadsheet format, 34361 is January 27th, 1994. DOY The decimal Julian Day of Year 1994 Year decimal year of 1994 (=DOY/365+1994) Lat Latitude in degrees, negative is south of the equator Lon Longitude in degrees West WndSpdTru True wind speed in m/s (not corrected for height: 29.9 m) WndSpdRel True wind direction in degrees WndDirTru Wind speed relative to the ship in m/s (not corrected for height: 29.9 m) WndDirRel Wind direction relative to the ship's motion in degrees COG Course over ground (°) SOG Speed over ground (m/s) GYRO The ship's heading in degrees. Pressure Atmospheric barometric pressure in hPa=mbar Humidity relative humidity in percent Salinity salinity in per-mille / PSU=practical salinity units AirTemp Air temperature in degrees Celsius SST Sea surface temperature in degrees Celsius MF_SF6 Dry Mole Fraction of SF6 in the air in ppt or picomole per mole JML