United States Department of Commerce National Oceanic and Atmospheric Administration Environmental Research Laboratories Global Monitoring Division Aerosols group ------------------------------ This area is a public access point to selected data obtained from GMD aerosol sampling stations. ------------------------------ This document gives a general overview of the directory layout in this area, and the process for retrieving these data. Please familiarize yourself with the documentation files before using these data, so as to avoid misinterpretation. We also strongly recommend contacting a NOAA/GMD Aerosol group scientist to discuss your interpretation of the data. See email address provided below. -----------------------------ACCESS POINTS--------------------------------- FTP: ftp://aftp.cmdl.noaa.gov/aerosol WWW: http://www.esrl.noaa.gov/gmd/aero/ Data formats: DESCRIBED BELOW Questions/comments: E-mail: mailto:betsy.andrews@noaa.gov ---------------------------------NOTICE------------------------------------ When using these data in a publication or presentation, you should acknowledge the National Oceanic and Atmospheric Administration (NOAA), Global Monitoring Division (GMD), Aerosols Group. The NOAA/GMD scientists would appreciate being notified of any studies involving the data. We would also like to receive drafts of presentations andi publications to ensure that the quality and limitations of the NOAA/GMD data are accurately represented. Feedback from users may also help us to improve the quality of the data and the location of the sampling sites. Comments regarding the README files and the data files are encouraged. Please send comments to the e-mail address given above. ---------------------------------WARNING----------------------------------- Users should read and understand all "README" and other documentation files before using these data, to avoid misinterpretation of the measurements. NOAA/GMD has attempted to provide the most precise measurements possible. We reserve the right to modify these files when necessary. --------------------------------------------------------------------------- ----------------------Directory layout for this area:---------------------- doc/ - Documentation of the aerosol system, data corrections and analysis. PLEASE FAMILIARIZE YOURSELF WITH THESE DOCUMENTS! articles/ - articles describing data corrections and measured and calculated parameters overview/ - overview description of basic GMD aerosol system drawings/stations/ - drawings of various parts of the sampling system drawings/stn/ - flow diagrams for individual stations There are 8 station directories with sub-directories for each year of data collected. aao/ - Airborne Aerosol Observatory (aerosol profiles over Bondville, Illinois, USA* bnd/ - Bondville, Illinois, USA brw/ - Barrow, Alaska, USA mlo/ - Mauna Loa Observatory, Hawaii, USA smo/ - American Samoa spo/ - South Pole Observatory sum/ - Summit, Greenland thd/ - Trinidad Head Observatory, California, USA wsa/ - Sable Island, Nova Scotia, Canada ------------------------Data file formats:--------------------------------- There are two formats of data files provided for each station and year. (1) NCDC netcdf format This file contains the hourly-averaged data for the given year for *all* of the basic parameters measured at that station (i.e., number concentration, sub10um and/or sub1um light scattering and/or light absorption). It will not include ancillary measurements that may be made at the stations (e.g., CCN, f(RH), met data). The file makes extensive use of NetCDF4 groups and hierarchy, so they must be imported with software that supports both. For example, when using XArray in Python, you must make use of the 'group=' keyword argument for dataset construction. File naming convention for netcdf format files: AEROSOL_HOUR_{STN}_{start_time}_{end_time}_{gen_time}.nc where: {STN}=three letter abbrevation for station, e.g., Barrow=BRW {start_time} is the start time of the measurements in the file in YYYYMMDDTHHmmSSZ format {end_time} is the end time of the measurements in the file in YYYYMMDDTHHmmSSZ format {gen_time} is the time the file was generated in YYYYMMDDTHHmmSSZ format (2) NASA-AMES format with the expanded EBAS specified header These are human-readable ascii files. There is one hourly-averaged file for each basic parameter measured at that station. The EBAS format for the different measurements (light absorption, light scattering and particle number concentration is described here: http://www.gaw-wdca.org/Submit-Data/Regular-Annual-Data-Reporting/Integrating-Nephelometer-regular http://www.gaw-wdca.org/Submit-Data/Regular-Annual-Data-Reporting/Filter-Absorption-Photometer-regular http://www.gaw-wdca.org/Submit-Data/Regular-Annual-Data-Reporting/Condensation-Particle-Counter-regular File naming convention for NASA-AMES format files: {EBAS_stn_code}.{start_time}.{gen_time}.{variable}.aerosol.1y.1h.lev2.nas.gz where: {EBAS_stn_code} is the EBAS station code, e.g., Barrow=US0008R {start_time} is the start time of the measurements in the file in YYYYMMDDHHmmSS format {gen_time} is the time the file was generated in YYYYMMDDTHHmmSSZ format (3) *AAO files have the format described here: https://www.esrl.noaa.gov/gmd/aero/data/datafmt.html#hgeS contact Dr. Betsy Andrews for more details ------------------------Data description:---------------------------------- Data are hourly-averaged with the timestamp representing the start of each hourly averaging time. Timestamp is UTC. Data are reported at STP (T_std=0 C) and have been corrected for known non-idealities. Data have undergone QA/QC and points considered invalid or contaminated by the station mentor are not included in the hourly-averaged values. Instrument descriptions and sampling conditions are included in the file header information. Questions/comments: E-mail: mailto: betsy.andrews@noaa.gov ------------------------Retrieval of datafiles:---------------------------- To transfer these files do the following steps from the ftp prompt: 1. ftp> bin ! set transfer mode to binary 2. ftp> cd (directory) ! change to directory 3. ftp> recv (filename).zip ! receive the file 4. ftp> bye ! leave ftp 5. $ unzip (filename).zip ! unzip your local copy, if necessary -----------------------------References:----------------------------------- These are journal articles and reports by NOAA/GMD authors describing aerosol measurements at the various NOAA surface stations. We keep an updated list of aerosol group publications from 2010-present here: ftp://aftp.cmdl.noaa.gov/aerosol/doc/newsletter/publications.html Andrews, E., Ogren, J.A., Bonasoni, P., Marinoni, A., Cuevas, E., Rodriguez, S., Sun, J.Y., Jaffe, D.A., Fischer, E.V., Baltensperger, U., Weingartner, E., Collaud Coen, M., Sharma, S., Macdonald, A.M., Leaitch, W.R., Lin, N.-H., Laj, P., Arsov, T., Kalapov, I., Jefferson, A., Sheridan, P.J., Climatology of aerosol radiative properties in the free troposphere, Atmospheric Research, 102, 365-393, 2011. Andrews, E., Sheridan, P.J., Fiebig, M., McComiske, M., Ogren, J. A., Arnott, P., Covert, D., Elleman, R., Gasparini, R., Collin, D., Jonsson, H., Schmid, B., Wang., J., Comparison of methods for deriving arosol asymmetry parameter, J. Geophys. Res., Vol. 111, No. D5, D05S04,10.129/2004JD005734 2006. Bodhaine, B. A., and M. E. Murphy, Calibration of n automatic condensation nuclei counter at the South Pole, J. Aerosol Sc., 11, 305-312, 1980. Bodhaine, B. A., The GMCC four-wavelength nephelomter, In Light Absorption by Aerosol Particles, H. E. Gerber and E. E. Hidman (Eds.), Spectrum, Hampton, VA, 149-168, 1982. Bodhaine, B. A., Aerosol measurements at four background sites, J. Geophys. Res., 88, 10753-10768, 1983. Bodhaine, B. A., and J. J. DeLuisi, An aerosol climatology of Samoa, J. Atmos. Chem., 3, 107-122, 1985. Bodhaine, B. A., J. J. DeLuisi, J. M. Harris, P. Humere, and S. Bauman, Aerosol measurements at the South Pole, Tellus, 38, 223235, 1986. Bodhaine, B. A., The Barrow aerosol record, 1976-184, In Arctic Air Pollution, B. Stonehouse (Ed.), Cambridge, 159-173, 1986. Bodhaine, B. A., Barrow surface aerosol: 1976-1986 Atmos. Environ., 23, 2357-2369, 1989. Bodhaine, B. A., and M. K. Shanahan, Condensation nucleus and aerosol scattering extinction measurements at the South Pole Obseratory: 1979-1988, NOAA Data Rep. ERL CMDL-1, Climate Monitoring and Diagnosics Laboratory, Boulder, Colorado, 148 pp., 1990. Bodhaine, B. A., N. C. Ahlquist, and R. C. Schnell Three-wavelength nephelometer suitable for aircraft measurement of backgroundaerosol scattering coefficient, Atmos. Environ., 25A, 2267-2276, 1991. Bodhaine, B. A., and J. M. Harris, Aerosol measureents at the South Pole during 1987, NOAA Data Rep. ERL CMDL-9, Climate Monitoing and Diagnostics Laboratory, Boulder, CO, 120 pp., 1992. Delene, D.J. and J. A. Ogren, Variability of aerosl optical properties at four North American surface monitoring sites, J. Atms. Sci., 59, 1135-1150, 2002. Fiebig, M., and J. A. Ogren, Retrieval and climatology of the aerosol asymmetry parameter in the NOAA aerosol monitoring network, J. Geophys. Res., 111, D21204, doi:10.1029/2005JD006545, 2006. Murphy, M. E., and B. A. Bodhaine, The Barrow, Alaka automatic condensation nuclei counter and four wavelength nephelometer Instrument details and four years of observations, NOAA Tech. Memo, ERL ARL-90, Air Resources Laboratories, Silver Spring, MD, 101 pp., 1980. Massey, D. M., T. K. Quakenbush, and B. A. Bodhaine, Condensation nuclei and aerosol scattering extinction measurements at Muna Loa Observatory: 1974-1985, NOAA Data Rep., ERL ARL-14, Air Resources Labortory, Silver Spring, MD, 174 pp., 1987. Quakenbush, T. K., and B. A. Bodhaine, Surface aersols at the Barrow GMCC Observatory: Data from 1976 through 1985, NOAAData Rep., ERL ARL-10, Air Resources Laboratory, Silver Spring, MD, 23 pp., 1986. Quinn, P.K., Miller, T.L., Bates, T.S., Ogren, J.A, Andrews, E., Shaw, G.E., A Three-Year Record of Simultaneously Measured erosol Chemical and Optical Properties at Barrow, Alaska, J. Geophys. es. 107, 4130-4145, 2002. Quinn, P., Andrews, E., Christensen, J., Dutton, E, Shaw, G., Arctic Haze (chapter 4), AMAP Assessment Report Acidifying pollutants, Actic haze, and acidification in the Arctic, 2005 Sharma, S., Andrews, E., Barrie, L.A. and Ogren, JA., Variations and sources of the equivalent black carbon in the high Arctc revealed by long term observations at Alert and Barrow: 1989-2003, J. Geophys. Res 111 (D14): Art. No. D14208, 2006. Sheridan, P.J., Delene, D.J. and Ogren, J.A., For years of continuous surface aerosol measurements from the Department of Enegy's Atmospheric Radiation Measurement Program Southern Great Plains Cloudand Radiation Testbed site, J. Geophys. Res., 106, 20735-20747, 2001. Spracklen, D. V., Carslaw, K. S., Merikanto, J., Mnn, G. W., Pickering, S., Ogren, J. A., Andrews, E., Baltensperger, U., Wingartner, E., Boy, M., Kulmala, M., Laakso, L., Lihavainen, H., Kivekäs, N., Mhalopoulos, N., Kouvarakis, G., Jennings, S. G., Birmili, W., Wiedensohler, A.,Weller, R., Laj, P., Sellegri, K., Bonn, B., and Krejci, R.: Explaining global surace aerosol number concentrations in terms of primary emissions and particle formtion, Atmos. Chem. Phys., 4775-4793, 2010. --------------------------------------------------------------------------- Questions / Comments / Suggestions e-mail : betsy.andrews@noaa.gov ---------------------------------------------------------------------------