EAC 24, Hall, October 1967
Page 21
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Transcription
western high had built up. By the 19th the gradient system was bringing in increased low cloudiness and winds. A thick fog bank in the forenoon of the 17th necessitated securing observations for two hours. Cold fog and mist patches were encountered irregularly during most of the survey, notably on the 22nd. Weather moderated on the 23rd as we moved westwardly into the amicably strengthening high. The high weakened on the 24th as a deepening low in the Gulf of Alaska began to send weather down the coast. The cloud deck deepened and northerly winds built up continually, reach- ing 25-30+ Kts. by the 26th. In general the moderate to strong winds and seas made for less than average observing conditions, but for the most part I feel the biasing effect probably amounts to less than 10-15 percent reduction in observabil- ity over the last five surveys. Nocturnal conditions were very poor. A full moon on the 17th-18th continued to shine through broken skies for five nights. An eclipse and concurrent nocturnal observations began at 0125 on the 18th. During the hour preceding the total phase of the eclipse no birds were recorded. A single unidentified bird was logged just about at the beginning of the dark phase. No further birds were recorded during an hour of eclipsed darkness. Deep cloud layers the night of 24-25 October blotted out an already waning moon and eight birds were logged during two hours of watch. No other attempts were made to hold night watches. Broad slick areas were found, as in previous surveys, around 35° N, 123° W. A wide variety of surface and subsurface life was evi- dent from the skiff on that day. Aside from this fairly "cluttered" area in the northeast little else was noted in the rest of the Grid. A few floating logs and various pieces of debris were noted in the western cen- tral areas. BT data and previous observations indicate that this area (roughly, sections "U & X") is a relatively stagnant region, often barren of birds and usually with a good deal of flotsam; logs, planking, etc. Collections Two Mourning Doves and one Meadowlark were collected in the Grid, and one Meadowlark was collected outside the Grid. One serum sample was obtained from the Meadowlark outside the Grid, but none were obtained in the Grid. No mammal or other collections were obtained. Eastern Grid Survey #15 Over 900 miles and 99.2 hours of diurnal observations, 187 birds of 24 species were recorded. An additional nine birds of at least three species were recorded over 40 miles of nocturnal watch. Fourteen sight- ings of marine mammals were made.