0__README.TXT Latest update of this file and all data files: 01/Nov/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 =============================================================================== Bromine Latitudinal Air/Sea Transect II (BLAST II) Cruise data J.M. Lobert, J.H. Butler, S.A. Yvon, L.S. Geller, S.A. Montzka, R.C. Myers, and J.W. Elkins =============================================================================== please acknowledge the source if you use these data! =============================================================================== For more info on this (and other) cruises, please visit our world wide web site at: http://www.cmdl.noaa.gov/noah_home/ocean/ocean.html select BLAST II from the menu. This directory contains the publicly available data from the Oct/Nov 1994 cruise from Bremerhaven, Germany to Punta Arenas, Chile. At this time, the following data 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. bl2_n2o.dat =========== Nitrous Oxide data along with all supporting data that were available. Here is a breakdown of what can be found in this ASCII file: 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 Depth Depth of the ocean in meters. Pressure Atmospheric barometric pressure in hPa=mbar Humidity relative humidity in percent Salinity salinity in per-mille / PSU=practical salinity units PAR Photosynthetically Active Radiation, probably in W/m^2 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) Keep in mind 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 110 values (out of ~ 990 total). The mean time between an air and a water sample (equal to the shift in the dataset) was 21 minutes, which, at a maximum cruising speed of 13 knots, is a maximum of 4.6 nautical miles or much less than 1/10th of a degree of latitude. We think that this error is small and is outweighed by the improved user-friendliness. bl2_n2o.zip =========== The same N2O.DAT file compressed into a ZIP archive for quicker download. bl2_sf6.dat =========== 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 (negative=west) LonEast Longitude in degrees East. 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 Depth Depth of the ocean in meters. Pressure Atmospheric barometric pressure in hPa=mbar Humidity relative humidity in percent Salinity salinity in per-mille / PSU=practical salinity units PAR Photosynthetically Active Radiation, probably in W/m^2 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