Warning: XSLTProcessor::transformToXml() [xsltprocessor.transformtoxml]: I/O warning : failed to load external entity "file:////srv/scielo/www/bases/xml/eac/v45n3/1815-5928-eac-45-03-1.xml" in /srv-new/scielo/www/htdocs/class.XSLTransformerPHP5.php on line 36 Estudio preliminar de la refractividad de la troposfera en el mar al norte de Cuba