Refractivity in the Arctic Regions

• Main Author: Stahlhut, Keir D.
• Other Authors: NAVAL POSTGRADUATE SCHOOL MONTEREY CA
• Format: Text
• Language: English
• Published: 2006
• Subjects: Atmospheric Physics; Electricity and Magnetism; *DUCTS; *ELECTROMAGNETISM; *ARCTIC REGIONS; FREQUENCY; LOW TEMPERATURE; ATMOSPHERIC REFRACTION; GRADIENTS; HUMIDITY; SURFACE TEMPERATURE; TEMPERATURE GRADIENTS; VERTICAL ORIENTATION; DUCTING; REFRACTIVITY; Arctic
• Online Access: http://www.dtic.mil/docs/citations/ADA457168; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA457168

The purpose of this study is to quantify patterns or trends of electromagnetic ducting conditions in the Arctic. On average, ducts occurred 5% of the time in the summer months, and 2-3% in the spring, fall, and winter months. This is considered a low approximation due to the vertical resolution of the sounding data. For some local regions, ducts occurred up to 20% of the time, especially in summer months. In general, local areas near coast lines or near the pole over ice/ocean had higher frequency of ducts than local areas over land mass. For summer and fall months, humidity gradients contributed most to the formation of a duct, while temperature gradients contributed to a lesser degree. For spring months, temperature gradients contributed most to the formation of the duct, while humidity gradients contributed to a lesser degree. For winter months, due to the extremely cold surface temperatures and low available humidity, temperature gradients were the dominant contribution to duct formation, and humidity gradients worked against duct formation. The original document contains color images.