{"id":222,"date":"2023-08-29T15:56:09","date_gmt":"2023-08-29T19:56:09","guid":{"rendered":"https:\/\/www2.whoi.edu\/staff\/kbrink\/?page_id=222"},"modified":"2023-09-06T12:23:01","modified_gmt":"2023-09-06T16:23:01","slug":"exercise","status":"publish","type":"page","link":"https:\/\/www2.whoi.edu\/staff\/kbrink\/exercise\/","title":{"rendered":"Exercise and Data"},"content":{"rendered":"\n\n\t

Exercise and Data<\/h1>\n

A.7. Data Analysis: Tides and Winds<\/h2>\n

The data files below contain hourly data (sf_23m_hr_hw.dat) and low-pass filtered data (tides removed: sf_23m_hw.dat). The current meter data are for the period 1998-1999 at the Georges Bank “Southern Flank” location on map A.1. Wind stress (txhw, tyhw) is from the same location and is in dyne\/cm2. Sea level (zhw) is from Boston and is in cm. (Boston is just off the map to the west.) Currents (uhw, vhw, uuhw, vvhw) are in cm\/s. All the vectors are in (east, north) coordinates. Time (thr, thw) is in 1995 days.<\/p>\n

    \n
  1. Make a sensible coordinate rotation for the vector time series. Explain your choice, preferably in terms of the statistics of the flow field.<\/li>\n
  2. Using least-squares fits, find the amplitudes of the M2 and K1 tides for both u and v.<\/li>\n
  3. Using correlations (or some other statistical tool) and the low-pass-filtered data, explore the relations between currents, winds, and sea level. Explain what you find in physical terms.<\/li>\n<\/ol>\n\t\t\t\t\n\t\t\t\t\"Figure\"\n\t\t\t\t<\/a>\n\t

    The data necessary for this exercise are available in the zip files to be downloaded here. Each zip file includes an ascii flat file as follows:<\/p>\n

    Hourly data file<\/strong>: sf_23m_hr_hw.dat<\/a><\/h3>\n\n\n\n\n\t\n\n\t\n\t\n\t
    Column<\/th>Variable<\/th>Units<\/th>Description<\/th>\n<\/tr>\n<\/thead>\n
    1<\/td>thr<\/td>1995 days<\/td>Time (hourly)<\/td>\n<\/tr>\n
    2<\/td>uhr<\/td>cm\/s<\/td>Eastward current<\/td>\n<\/tr>\n
    3<\/td>vhr<\/td>cm\/s<\/td>Northward current<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n

    Smoothed data file: <\/strong>sf_23m_hw.dat<\/a><\/h3>\n

    (tides and other higher frequency motions removed)<\/p>\n\n\n\n\n\t\n\n\t\n\t\n\t\n\t\n\t\n\t
    Column<\/th>Variable<\/th>Units<\/th>Description<\/th>\n<\/tr>\n<\/thead>\n
    1<\/td>thw<\/td>1995 days<\/td>time (4 times per day)<\/td>\n<\/tr>\n
    2<\/td>txhw<\/td>dyne\/cm2<\/td>Eastward wind stress<\/td>\n<\/tr>\n
    3<\/td>tyhw<\/td>dyne\/cm2<\/td>Northward wind stress<\/td>\n<\/tr>\n
    4<\/td>uhw<\/td>cm\/s<\/td>Eastward current<\/td>\n<\/tr>\n
    5<\/td>vhw<\/td>cm\/s<\/td>Northward current<\/td>\n<\/tr>\n
    6<\/td>zhw<\/td>cm<\/td>Barometrically adjusted Boston sea level<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n","protected":false},"excerpt":{"rendered":"

    Exercise and Data A.7. Data Analysis: Tides and Winds The data files below contain hourly data (sf_23m_hr_hw.dat) and low-pass filtered data (tides removed: sf_23m_hw.dat). The current meter data are for the period 1998-1999 at the Georges Bank “Southern Flank” location on map A.1. Wind stress (txhw, tyhw) is from the same location and is in…<\/p>\n","protected":false},"author":11,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/www2.whoi.edu\/staff\/kbrink\/wp-json\/wp\/v2\/pages\/222"}],"collection":[{"href":"https:\/\/www2.whoi.edu\/staff\/kbrink\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www2.whoi.edu\/staff\/kbrink\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/staff\/kbrink\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/staff\/kbrink\/wp-json\/wp\/v2\/comments?post=222"}],"version-history":[{"count":4,"href":"https:\/\/www2.whoi.edu\/staff\/kbrink\/wp-json\/wp\/v2\/pages\/222\/revisions"}],"predecessor-version":[{"id":301,"href":"https:\/\/www2.whoi.edu\/staff\/kbrink\/wp-json\/wp\/v2\/pages\/222\/revisions\/301"}],"wp:attachment":[{"href":"https:\/\/www2.whoi.edu\/staff\/kbrink\/wp-json\/wp\/v2\/media?parent=222"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}