TY - JOUR T1 - Wind-induced drift of objects at sea: The leeway field method A1 - Breivik,Oyvind A1 - Allen,Arthur A. A1 - Maisondieu,Christophe A1 - Roth,Jens Christian AD - Norwegian Meteorol Inst, NO-5007 Bergen, Norway. AD - US Coast Guard, Office of Search and Rescue, CT, USA AD - IFREMER, France AD - Royal Norwegian Navy, Norway UR - https://doi.org/10.1016/j.apor.2011.01.005 DO - 10.1016/j.apor.2011.01.005 KW - Search and rescue KW - SAR KW - Leeway KW - Trajectory modelling KW - Surface currents KW - Drifting objects KW - Drifters KW - Ocean modeling N2 - A method for conducting leeway field experiments to establish the drift properties of small objects (0.1-25 m) is described. The objective is to define a standardized and unambiguous procedure for condensing the drift properties down to a set of coefficients that may be incorporated into existing stochastic trajectory forecast models for drifting objects of concern to search and rescue operations and other activities involving vessels lost at sea such as containers with hazardous material. An operational definition of the slip or wind and wave-induced motion of a drifting object relative to the ambient current is proposed. This definition taken together with a strict adherence to a 10 m wind speed allows us to refer unambiguously to the leeway of a drifting object. We recommend that all objects if possible be studied using what we term the direct method, where the object's leeway is studied directly using an attached current meter. We establish a minimum set of parameters that should be estimated for a drifting object for it to be included in the operational forecast models used for prediction of search areas for drifting objects. We divide drifting objects into four categories, depending on their size. For the smaller objects (less than 0.5 m), an indirect method of measuring the object's motion relative to the ambient current must be used. For larger objects, direct measurement of the motion through the near-surface water masses is strongly recommended. Larger objects are categorized according to the ability to attach current meters and wind monitoring systems to them. The leeway field method proposed here is illustrated with results from field work where three objects were studied in their distress configuration; a 1:3.3 sized model of a 40-foot Shipping container, a World War II mine and a 220 I (55-gallon) oil drum. (C) 2011 Elsevier Ltd. All rights reserved. Y1 - 2011/04 PB - Elsevier Sci Ltd JF - Applied Ocean Research SN - 0141-1187 VL - 33 IS - 2 SP - 100 EP - 109 ID - 14814 ER -