Electrical conductivity of the Great Lakes

Abstract

A cri tical exa mination has bcen made of the electrical co ndu ct ivity valu es assigned, for radio propagation purposes, to t he waters of the Great Lakes. Discrepa ncies between co nd uctivity values meas ured in t he laboratory and t hose deduce d from fi eld s t re ngt h m easurements are shown to have been t he res ul t of both expenmental error and the use of faul ty standard t heoretical fi eld stre ngth cmves. The latter source of errol' is the res ult of e rror in thc standard curves t hemselves and lll t he usc of a d lelectn c con s tant of 15 for over-water propagation. Condu ctivi ty valu es derived frOl.n laboratory m easuremen ts of wate r sa mples are sign ifi ca ntl y d ifferent from those published In co nd uc!,lvlty maps. Lal:ge seasonal var iations in conductivity, appr oac hi ng a factor of two 11l some cases, a rc a slg nlfi -cant compli cating fac tor.