" ; :date_created = "Wed Sep 16 12:04:57 2020" ; :geographic_region = "Southern Hemisphere" ; :StartYear = "2002" ; :EndYear = "2019" ; :StartDate = "2002-08-01" ; :EndDate = "2019-07-28" ; :Period = "2002-2019" ; :geospatial_lat_min = "-90.0" ; :geospatial_lat_max = "-50.0" ; :geospatial_lon_min = "-180.0" ; :geospatial_lon_max = "180.0" ; :standard_name_vocabulary = "NetCDF Climate and Forecast (CF) Metadata Convention" ; :geospatial_lon_resolution = "variable, depends on ship speed" ; :geospatial_lat_resolution = "variable, depends on ship speed" ; :source = "surface observations" ; :platform = "Various ships, see variables cruise_name or cruise_id" ; :sensor = "Sea-ice observations: Human eye; meteorological observations: standard meteorological instruments aboard the respective ship" ; :comment = "A switch to missing values of -9 (from 0) and -9.9 (from 0.0) for integer and floating point values for cruises starting after ANT-XXXI of the R/V Polarstern in 2016 required to apply this change back to the last entry of the Worby et al. 2008 ASPeCt data set ending in 2005. It is almost impossible to go back to these old ASPeCt observation data and figure whether a \"0\" given there was an observed true zero or a zero given because no observation was possible. Still, ice types denoted as zero are set to -9; sea-ice thickness observations denoted as zero are set to -9. // A manual quality check was made for the total SIC. If a zero is occurring next to at least 70% thick ice at both sides of the cruise track, with one side even showing 90% or more sea ice concentration, if the distance traveled was not exceptionally large and if the ice type does not indicate new or young ice such as frazil/grease/pancake or the like, then this zero is assumed to be set because of a missing observation and is hence set to -9. We note that this setting of cases with zero total SIC to missing value potentially reduces the actually present fraction of open water but the gain of reducing SIC noise in otherwise consolidated ice is anticipated to be larger. // Cases with partial sea ice concentrations set to 0 but with, e.g. information about ridge fraction and thickness, are considered as < 5% sea ice concentration and set to 3%. If setting these values to 3 % (instead of 0%) but the total SIC is 100% requires that one other SIC value needs to be reduced by 3% - typically I use the ice type with the maximum fractional coverage for this, i.e. if total SIC is 100%, primary SIC is 10%, secondary SIC is 90% and tertiary SIC was 0% then the latter two values are changed to 87% and 3%, respectively. If, what happens as well, there is 0% total sea ice concentration and 0% primary SIC but ice type et cet. given then total and primary SIC are set to 3%. In addition: there are cases where two, e.g. secondary and tertiary SIC are given as 0% but ice type and thickness are given; in these case both partial SIC values are set to 2% and the respective remaining partial SIC is set to the original value minus 4%. If total SIC was 0% in this special case then it is set to 4%. // All cruises from 2016 through 2019 as far as they are on IceBox or sent to me by observers. // The Agulhas-II cruise observational data from 2019 come at 5-10 minute temporal resolution. I reduced the sampling to hourly - in accordance with the rest of the data. // The following notions about translations of the ridged ice type and fraction from the ASPeCt codes apply to Antarctic data starting with the WWOS cruise in 2006 and are further amended in 2016 / 2017 as indicated further below. ASPeCt Code of ice topography: 100: Fraction of deformed ice and average ridge height both set to 0 if cells are empty; Otherwise, if the fraction cell contains a 0 then fraction of deformed ice is set to 0.05 and average ridge height is set to 0.1 m. Starting with Antarctic 2017 for a 100 the ridged ice fraction is 0.05 and the ridge height is 20% of the SIT for SIT < 0.2m, otherwise 0.1 m; ASPeCt code of ice topography: 200 (rafted pancake ice): Fraction of deformed ice: 0.5, average ridge height: 0.05 m --> changed to one half of the SIT starting with PIPERS cruise in 2017 for ANTARCTIC; ASPeCt code of ice topography: 300 (compressed pancake): Fraction of deformed ice: 0.5; if the ice type is NOT pancake, however, then the fraction is set to 0.25 as it is then compressed, frozen together pancakes which possibly (this is an assumption) have a larger floe size. In these cased 0.5 is only kept if the floe size type is 500 or less in the ASPeCt code. Average ridge height: 0.02 m --> changed to one half of the SIT starting with PIPERS cruise in 2017 for ANTARCTIC; ASPeCt code of ice topography: 400 (rafted nilas): Unless there is a number given for the fraction: Fraction of deformed ice: 0.1; average ridge height: 0.01 m --> change to one half of SIT starting with PIPERS cruise in 2017 for Antarctic; all the above said (for ice topography 100 through 400) is obsolete if the ice type is 10, 11 or 12; then ridged ice fraction and ridge height are both set to 0.0; ASPeCt code of ice topography: 500 to 800 (without any notion about deformation): Fraction of deformed ice: 0.05; average ridge height: 0.1 m // Please see the ASPeCt code, e.g. under http://www.aspect.aq for further information." ; :references = "1) ASPeCt data (2002 until 2005) Worby, A. P., C. A. Geiger, M. J. Paget, M. L. van Woert, S. F. Ackley, and T. L. DeLiberty, 2008, Thickness distribution of Antarctic sea ice. J. Geophys. Res., 113, C05S92, doi:10.1029/2007JC004254.; 2) GLOBEC 2002: Perovich, D. K., B. C. Elder, K. J. Claffey, S. Stammerjohn, R. Smith, S. F. Ackley, H. R. Krouse, and A. J. Gow, 2004, Winter sea-ice properties in Marguerite Bay, Antarctica, Deep Sea Res., Part II, 51, 20232039. This data is part of the original ASPeCt data set (Worby et al., 2008, see above).; 3) ARISE 2003: Massom, R. A., and 17 others, 2006, ARISE (Antarctic Remote Ice Sensing Experiment) in the East 2003: Validation of satellite derived sea ice data products, Ann. Glaciol., 44, 288296, doi:10.3189/172756406781811268. This data is part of the original ASPeCt data set (Worby et al., 2008, see above).; 4) ISPOL 2004/05: Hellmer, H. H., M. Schröder, C. Haas., G. S. Dieckmann, and M. Spindler, 2008, The ISPOL drift experiment, Deep Sea Res., Part II, 55, 913-917, doi:10.1016/j.dsr2.2008.01.001. This data is part of the original ASPeCt data set (Worby et al., 2008, see above).; 5) Maudness 2005: McPhee, M., Nathaniel B. Palmer cruise NBP0506, cruise DOI: 10.7284/905512. http://www.marine-geo.org/tools/entry/NBP0506. This data is part of the original ASPeCt data set (Worby et al., 2008, see above).; 6) WWOS 2006: Lemke, P., 2009, The Expedition ANTARCTIC XXIII/7 of the Research Vessel Polarstern in 2006, vol. 586, Bremerhaven, Germany, Alfred Wegener Inst. Polar Marine Res., 2009, ser. Reports on Polar and Marine Research.; 7) ODEN2006: Ozsoy-Cicek, B., H. Xie, S. F. Ackley and K. Ye, 2009, Antarctic summer sea ice concentration and extent: comparison of ODEN 2006 ship observations, satellite passive microwave and NIC sea ice charts, The Cryosphere, 3(1), 19, doi:10.5194/tc-3-1-2009; 8) SIMBA2007: Lewis, M. J., J. L. Tison, B. Weissling, B. Delille, S. F. Ackley, F. Brabant, and H. Xie, 2011, Sea ice and snow cover characteristics during the winterspring transition in the Bellingshausen Sea: an overview of SIMBA 2007, Deep Sea Res., Part II, 58(9-10), 1019-1038, doi:10.1016/j.dsr2.2010.10.027; 9) SIPEX2007: Worby, A. P., A. Steer, J. L. Lieser, P. Heil, D. Yi, T. Markus, I. Allison, R. A. Massom, N. Galin, and J. Zwally, 2011, Regional-scale sea-ice and snow thickness distributions from in situ and satellite measurements over East Antarctica during SIPEX 2007, Deep Sea Res., Part II, 58(9-10), 11251136, doi:10.1016/j.dsr2.2010.12.001; 10) McMurdo re-supply: Sea-ice observations during ODEN cruise 2007/08; Stephen F. Ackley, UTSA, personal communication, 2010.; 11) McMurdo re-supply: Sea-ice observations during ODEN cruise 2008/09; Sea-ice observations contact point: P. Yager; Stephen F. Ackley, UTSA, personal communication, 2010. Tekeli, A. E., S. Kern, S. F. Ackley, B. Ozsoy-Cicek, and H. Xie, 2011, Summer Antarctic sea ice as seen by ASAR and AMSR-E and observed during two IPY field cruises: a case study. Ann. Glaciol., 52(57), 327-336, doi:10.3189/172756411795931697; 12) McMurdo re-supply: Sea-ice observations during N.B. Palmer cruise in 2009: Jacobs, S., Nathaniel B. Palmer cruise NBP0901, cruise DOI: 10.7284/905547, http://www.marine-geo.org/tools/entry/NBP0901; Sea-ice observations contact point: S. Stammerjohn; Stephen F. Ackley, UTSA, personal communication, 2010. Tekeli, A. E., S. Kern, S. F. Ackley, B. Ozsoy-Cicek, and H. Xie, 2011, Summer Antarctic sea ice as seen by ASAR and AMSR-E and observed during two IPY field cruises: a case study. Ann. Glaciol., 52(57), 327-336, doi:10.3189/172756411795931697; 13) ICEBELL: Williams, G., T. Maksym, J. Wilkinson, C. Kunz, C. Murphy, P. Kimball and H. Singh, 2015, Thick and deformed Antarctic sea ice mapped with autonomous underwater vehicles, Nature Geoscience, 8, 6167, doi:10.1038/NGEO2299, Stephen F. Ackley, UTSA, personal communication, 2012.; 14) Heil, P., Worby, A.P., Steer, A., Massom, R., Lieser, J. (2014, updated 2018) ASPeCt bridge-based sea-ice observations - 2007 to 2013, Australian Antarctic Data Centre - CAASM Metadata: https://data.aad.gov.au/metadata/records/ASPECT_2007_2013, https://data.aad.gov.au/eds/3876/download; obtained via J. L. Lieser and P. Heil, ACE-CRC, 2016, personal communication, before the release at this site.; 15) SIPEX 2012: Heil, P., S. Stammerjohn, P. Reid, R. A. Massom, and J. K. Hutchings, 2016, SIPEX 2012: Extreme sea ice and atmospheric conditions off East Antarctica, Deep Sea Res., Part II, 131, 7-21, doi.10.1016/j.dsr2.2016.06.015; 16) AWECS: Lemke, P., 2014, The Expedition of the Research Vessel Polarstern to the Antarctic in 2013 (ANT-XXIX/6 - AWECS). Berichte zur Polar- und Meeresforschung, Reports on Polar and Marine Research, 679, 154 pp, https://doi.org/10.2312/BzPM_0679_2014; 17) Meyer, B., and L. Auerswald, 2014, The Expedition of the Research Vessel Polarstern to the Antarctic in 2013 (ANT-XXIX/7). Berichte zur Polar- und Meeresforschung, Reports on Polar and Marine Research, 674, 130 pp, https://doi.org/10.2312/BzPM_0674_2014; 18) Knust, R., and M. Schröder, 2014, The Expedition PS82 (ANT-XXIX/9) of the Research Vessel POLARSTERN to the southern Weddell Sea in 2013/2014. Berichte zur Polar- und Meeresforschung, Reports on Polar and Marine Research, 680, 155 pp, https://doi.org/10.2312/BzPM_0680_2014; 19) Boebel, O., 2015, The Expedition PS89 (ANT-XXX/2) of the Research Vessel POLARSTERN to the Weddell Sea in 2014/2015. Berichte zur Polar- und Meeresforschung, Reports on Polar and Marine Research, 689, 151 pp, https://doi.org/10.2312/BzPM_0689_2015; 20) Schröder, M., 2016, The Expedition PS96 (ANT-XXXI/2, FROSN) of the Research Vessel POLARSTERN to the southern Weddell Sea in 2015/2016. Berichte zur Polar- und Meeresforschung, Reports on Polar and Marine Research, 700, 142 pp, https://doi.org/10.2312/BzPM_0700_2016; 21) Lieser, J. L., et al., Sea-ice observations during the spring 2016 Aurora Australis support cruise, 2016-11-04 00:00:00 UTC to 2016-11-24 00:00:00 UTC, 2016, personal communication, Jan Lieser, Nov. 23, 2016.; 22) de Jong, Ehlke; Vichi, Marcello; Saunders, Clinton F W; Kotilainen, Mikko J; Luyt, Hermann; Peel, Stephen P M; Swart, Daniël J (2018): Sea ice conditions within the Antarctic Marginal Ice Zone in summer 2016, onboard the SA Agulhas II. University of Cape Town, PANGAEA, https://doi.org/10.1594/PANGAEA.885208, last accessed August 18, 2020.; 23) Ackley, S. F., et al., Sea-ice observations during the PIPERS cruise into the Ross Sea, Antarctica from aboard USAP Nathaniel B. Palmer cruise 17-04, 2017-04-19 00:00:00 UTC to 2017-06-06 00:00:00 UTC, https://data.aad.gov.au/aspect/cruises/USAP NBP 17-04 (PIPERS).aspect, last accessed August 18, 2020.; 24) de Jong, Ehlke; Vichi, Marcello; Mehlmann, Carolin Birgitta; Eayrs, Clare; De Kock, Wade; Moldenhauer, Marcel; Audh, Riesna Reuben (2018): Sea Ice conditions within the Antarctic Marginal Ice Zone in winter 2017, onboard the SA Agulhas II. University of Cape Town, PANGAEA, https://doi.org/10.1594/PANGAEA.885211, last accessed August 18, 2020.; 25) Santini, Marcelo, Rosa, Eliana, Jianiovan, Henrique, Moura, Fuelvio, Vera, Thiago, Breno, Carla, Sea-ice observations from aboard NPo Almirante Maximiano during cruise SA OPERANTAAR XXXVII, 2018-11-21 00:00:00 UTC to 2018-11-22 00:00:00 UTC, 2018, https://data.aad.gov.au/aspect/cruises/SA OPERANTAAR XXXVII.aspect, last accessed August 18 2020.; 26) de Jong, Ehlke; et al.: Sea ice conditions within the Antarctic Marginal Ice Zone in winter 2019, onboard the SA Agulhas II 2019-07-26 00:00:00 UTC to 2019-07-29 00:00:00 UTC, 2019 University of Cape Town, originally with 5 to 10 minute sampling, only the hourly values taken here, personal communication, Ehlke de Jong, Feb. 4 2020." ; :citation = "Kern, Stefan (2020). ESA-CCI_Phase2-Plus__Standardized_Manual_Visual_Ship-Based_SeaIceObservations_v02 covering the period May 2002 through December 2019. World Data Center for Climate (WDCC), Deutsches Klimarechenzentrum, Hamburg, Germany, https://cera-www.dkrz.de/WDCC/ui/cerasearch/ , and Integrated Climate Data Center (ICDC) at CEN, University of Hamburg, Hamburg, Germany, https://icdc.cen.uni-hamburg.de" ; :history = "Wed Sep 16 12:06:45 2020: ncap2 -s number_of_observations=int(number_of_observations) ASPeCt-ASSIST__standardized__ShipBasedSeaIceObservations__SH__UHAM-ICDC_v2.0_fv0.01_short.nc ASPeCt-ASSIST__standardized__ShipBasedSeaIceObservations__SH__UHAM-ICDC_v2.0_fv0.01.nc" ; :NCO = "\"4.5.2\"" ; :nco_openmp_thread_number = 1 ; }