{"id":2316,"date":"2019-10-04T17:12:28","date_gmt":"2019-10-04T21:12:28","guid":{"rendered":"https:\/\/www2.whoi.edu\/site\/itp\/?page_id=2316"},"modified":"2021-07-20T13:18:25","modified_gmt":"2021-07-20T17:18:25","slug":"itp49-data-processing","status":"publish","type":"page","link":"https:\/\/www2.whoi.edu\/site\/itp\/data\/completed-missions\/itp49\/itp49-data-processing\/","title":{"rendered":"ITP 049 Data Processing"},"content":{"rendered":"\r\n\t<h1>ITP49 Data Processing<\/h1>\r\n\t<p>The 62 profiles that were transmitted from the ITP were processed according to the procedures described in the\u00a0<a href=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/08\/ITP_Data_Processing_Procedures_35803-1.pdf\">ITP Updated Data Processing Procedures<\/a>.\u00a0 The processing parameters for this ITP are shown in the figures to the right.<\/p>\r\n<p>After collecting two good profiles, CTD data quality dropped starting with profile 3. In addition to profile segments of poor conductivity typically related to cell contamination, conductivity also developed a varying, sometimes large number of very large short-term spikes. The latter was more likely related to instrument problems rather than contaminations. The instrument seemed to recover by profile 20 or so, yielding better salinity estimates for the remainder of the short record.<\/p>\r\n<p>Oxygen was noisy for the first two profiles, but seemed to follow the general profile shape seen in earlier ITP DO profiles collected in this area (e.g., ITP 57 profiles 300 to 350). However, the oxygen calibration factor changed from typical values near unity to a factor around 2.7, and the profile shape changed significantly as well. Starting with profile 3, oxygen data were deleted. Following more deliberations, profiles 1 and 2 were eventually removed as well because of noise.<\/p>\r\n<p>The temperature record included two very unusual profiles (19 and 20) for which deep values were 0.5 to 1 degree colder compared to profiles before and after. Since, however, the pattern was repeated over two profiles, and since shallow values matched earlier and \u00a0later profiles, the data were not edited out. Since this pushed temperature outside the mapped fields typically used at this depth, the conductivity calibration for these two profiles was estimated from earlier\/later profiles. This seemed reasonable as the conductivity calibration time series did not change much in time here.<\/p>\r\n<p>Thermohaline staircases were available to generate initial estimates for CTD lag corrections. They were adjusted manually to reduce profile noise. The conductivity calibration adjustments (variable &#8220;rat&#8221;) were somewhat variable for the early noisy profiles, but still relatively flat and near unity.<\/p>\r\n<p>See the Data Products tab to the left for descriptions of the three levels (I, II, III) of data processing and to access all data.<\/p>\r\n\t\t\t\t<a href=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49loc2_453673.jpg\" target=\"_self\" rel=\"noopener noreferrer\">\r\n\t\t\t\t<img loading=\"lazy\" src=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49loc2_453673.jpg\" alt=\"ITP Surface Buoy Status.\" height=\"1730\" width=\"1000\" title=\"itp49loc2_453673\" \/>\r\n\t\t\t\t<\/a>\r\n\t\tITP Surface Buoy Status.\r\n\t\t\t\t<a href=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49dat1f_453675.jpg\" target=\"_self\" rel=\"noopener noreferrer\">\r\n\t\t\t\t<img loading=\"lazy\" src=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49dat1f_453675.jpg\" alt=\"ITP profiler engineering data.\" height=\"1480\" width=\"1560\" title=\"itp49dat1f_453675\" \/>\r\n\t\t\t\t<\/a>\r\n\t\tITP profiler engineering data.\r\n\t\t\t\t<a href=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49final1_453693.jpg\" target=\"_self\" rel=\"noopener noreferrer\">\r\n\t\t\t\t<img loading=\"lazy\" src=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49final1_453693.jpg\" alt=\"Data\" height=\"2728\" width=\"2074\" title=\"itp49final1_453693\" \/>\r\n\t\t\t\t<\/a>\r\n\t\tTop: number of bad points removed, Middle: variance of verticle difference of temperature and salinity in step region for up-going profiles, Bottom: temperature lag.\r\n\t\t\t\t<a href=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49final2_453695.jpg\" target=\"_self\" rel=\"noopener noreferrer\">\r\n\t\t\t\t<img loading=\"lazy\" src=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49final2_453695.jpg\" alt=\"Data\" height=\"2725\" width=\"2047\" title=\"itp49final2_453695\" \/>\r\n\t\t\t\t<\/a>\r\n\t\tTop: conductivity lag, Middle: conductivity thermal mass amplitude correction, Bottom: conductivity thermal mass lag correction.\r\n\t\t\t\t<a href=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49final3_453697.jpg\" target=\"_self\" rel=\"noopener noreferrer\">\r\n\t\t\t\t<img loading=\"lazy\" src=\"https:\/\/www2.whoi.edu\/site\/itp\/wp-content\/uploads\/sites\/92\/2019\/10\/itp49final3_453697.jpg\" alt=\"Data\" height=\"2720\" width=\"2020\" title=\"itp49final3_453697\" \/>\r\n\t\t\t\t<\/a>\r\n\t\tTop: down pressure deviation correction, Middle: salinity ratio adjustment, Bottom: Number of filtered spikes.\r\n","protected":false},"excerpt":{"rendered":"<p>ITP49 Data Processing The 62 profiles that were transmitted from the ITP were processed according to the procedures described in the\u00a0ITP Updated Data Processing Procedures.\u00a0 The processing parameters for this ITP are shown in the figures to the right. After collecting two good profiles, CTD data quality dropped starting with profile 3. In addition to&hellip;<\/p>\n","protected":false},"author":83,"featured_media":0,"parent":2309,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"tpl-sidebar.php","meta":{"advanced-sidebar-menu\/link-title":"","advanced-sidebar-menu\/exclude-page":false},"_links":{"self":[{"href":"https:\/\/www2.whoi.edu\/site\/itp\/wp-json\/wp\/v2\/pages\/2316"}],"collection":[{"href":"https:\/\/www2.whoi.edu\/site\/itp\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www2.whoi.edu\/site\/itp\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/itp\/wp-json\/wp\/v2\/users\/83"}],"replies":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/itp\/wp-json\/wp\/v2\/comments?post=2316"}],"version-history":[{"count":3,"href":"https:\/\/www2.whoi.edu\/site\/itp\/wp-json\/wp\/v2\/pages\/2316\/revisions"}],"predecessor-version":[{"id":3586,"href":"https:\/\/www2.whoi.edu\/site\/itp\/wp-json\/wp\/v2\/pages\/2316\/revisions\/3586"}],"up":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/itp\/wp-json\/wp\/v2\/pages\/2309"}],"wp:attachment":[{"href":"https:\/\/www2.whoi.edu\/site\/itp\/wp-json\/wp\/v2\/media?parent=2316"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}