Oceanographic Abstracts
555
trophically in the sea, the nutritional mechanism of which will be an interesting theme for a future study of marine diatoms. NETTLETON L. L., L. J. B. LACOSTE and M. GL1CKEN 1962. Quantitative evaluation of precision of airborne gravity meter. J. Geophys. Res., 670 1): 4395-4410. This paper covers a careful quantitative test of the LaCoste and Romberg airborne gravity meter over a triangular test course between Houston, Baton Rouge, Shreveport, and Houston. Each leg of the course was flown twice, the two flights being in opposite directions and on different days. The total length of measured flights was about 1700 miles. ~Ihe gravity meter and its associated instrumentation are basically the same as those used for gravity measurements on surface ships and for the first tests on aircraft (1958 and 1959), but there have been many later improvements in the details of the meter and its associated instrumentation. Also, improvements in methods of processing data were developd during the reduction of the test results. Final evaluation of the measurements made on aircraft is based on comparison with calculated values at 12,000 ft derived from Bouguer data on the ground and absolute values at the airports at the corners of the triangular course. The final results are based on a point-by-point comparison of the observed values with those calculated from the ground data. From the average for all the flights the root mean square deviation between observed and calculated data is 6'6 mgal and the mean deviation with regard to sign is ÷ 1.55 regal. The entire data reduction procedure was carried out independently by the University of Wisconsin after digitizing most of the information and computing the results with an electronic calculator. From their calculations the over-all mean deviation from the digital reduction is 6.0 mgal. without regard to sign and ÷ 1"75 regal with regard to sign. NGUYEN-HAI and NGUYEN-DINH-BA 1961. Quelques observations hydrologiques dans la r6gion Cap St. Jacques-Poulo Condore. Ann. Fac. Sci., Saigon, 1961 : 319-324. Also: Contrib., Inst. Oceanogr. Nahtrang, No. 47. The authors report here results obtained from the data of two hydrologic lines during a national expedition for IGY, in 1958, between St. Jacques Cape and Poulo Condore. NGUYEN-HAI, TRINH THIEN Tu and NGUYEN DINHBA 1960. R6centes variations de temp6rature et de salinit6 ~t INhatrang (avec une Annexe des donn6es des autres points fixes 6tablis dans le pass6). Ann. Fac. Sci., Saigon, 1960: 71-88. Also: Contr. Inst. Oc6anogr., Nhatrang, No. 45. The authors present results of recent routine observations and those of oceanographic stations undertaken in 1957, at Nhatrang. They introduce also in the Note results at other fixed observation-stations for the comparison. NGUYEN-HAI and NGUYEN-Duc-KHANG 1961. Sur les ondes T des s6ismes des Philippines enregistr6es/t Nha-Trang. Ann. Fac. Sci., Saigon, 1961 : 343-368. Also Contrib. Hai-Hoc-Vien Nhatrang, Inst. Oceanogr. Nhatrang, No. 48. According to the authors, T waves recorded at Nhatrang from Philippine Islands earthquakes may present 3 important phases: F and G, Tr, and M. If h is the depth of the earthquake, a and b the land paths of T waves respectively near the epicenter and the station, these phases may be noted as: Ph - - SOFAR - - SVh, for F and G Pa - - SOFAR- - SVh, for Tr and probably S in sediments, for M. SOFAR wave velocity in the China Sea, between the Philippines and Vietnam, were determined as 1.48 ± 0"03 km. NGUYEN-HA1, TRINH-TmEN-Tu and NGUYEN-DINH-BA 1961. Premi6res observations hydrologiques profondes dans la baie de Nha-Trang. Ann. Fac. Sci., Saigon, 1961: 325-342. A]so: Contrib., Inst. Ockanogr. Nhatrang, No. 47. Results obtained from the first study in deep water of the bay are presented in this paper numerically and graphically. Upwelling in the bay is important enough, to note here. OLSON B. E. 1962. Variations in radiant energy and related ocean temperatures. J. Geophys.
Res., 67(12) : 4705-4712.
Measurements from the U.S.S. Rehoboth taken while anchored at about 34°N, 62°W, for twelve days in June 1953 are used to compute reflectivities of the water surface for different sun altitudes and sky conditions. These are compared with similar measurements made by Anderson over Lake Hefner and with published values of the albedo for diffuse radiation. Measurements over the ocean gave a reflectivity of about 7 per cent for diffuse radiation, which compares favorably with the refiectivity recomputed by Burr from Schmidt's work. An upper limit of about 10 per cent is suggested for sea level variations in solar radiation caused by local changes in the amount of precipitable water vapor in the atmosphere within a 24-hr period. Diurnal variations in radiant energy are reflected in corn-
556
Oceanographic Abstracts
parable variations in water temperature if the radiant heat is logarithmically distributed with depth. Below the mixed layer diurnal variations in temperature are obscured by the more pronounced variations caused by motion of the water. PANDOLFO J. 1962. Polarization of sunlight reflected from the sea surface. J. Geophys. Res., 67(11): 4303-4308. The observation of purple-blue solar glitter points when the sea surface is viewed through polarizing glasses can be explained on the following basis. Reflection of sunlight at angles of incidence close to the Brewster angle for the long and medium wavelengths of the visible spectrum produces a reflected beam with a component wave vibrating parallel to the plane of incidence and deficient in red, green, and yellow light. Since this component of the reflected beam is the one transmitted by polarizing glasses, the glitter points appear to be purple-blue. Other colorimetric properties of the parallel reflected component predicted by this explanation are consistent with the observations. The explanation may be used to obtain extreme values of sea surface slope at the time of the observation, and the extreme values obtained are consistent with previous estimates of extreme sea surface slopes. It is suggested that the type of observations described might be useful in the measurement of sea surface slope distributions over small areas. PAPENFUSS G. F. 1962. Problems in the taxonomy and geographic distribution of Antarctic marine algae (Abstr. Symp. Ant. Biol.) Polar Rec. 11(72): 320. Also SCAR Bull. # 1 2 . Many Antarctic marine algae have a geographic range which extends into the sub-Antarctic. It seems advisable, therefore, as far as the algae are concerned, to regard the Antarctic and sub-Antarctic as forming a single biogeographic province. A total of some 400 species, representative of more than 150 genera, have been reported from the following localities: Palmer Peninsula (Graham Land), Enderby Land, Commonwealth Bay (George V Land), the Terre Ad61ie coast, Victoria Land, Fuegia, Falkland Islands, South Georgia, South Orkneys, South Shetlands, Prince Edward Islands, Iles Crozet, Iles Kerguelen, Heard Island, Macquarie Island, Auckland Islands, and Campbell Island. Large gaps exist in our knowledge of the morphology and taxonomy of Antarctic algae, and, at present, little can be concluded about the identity and distribution of many of the forms. A fairly large number have been referred to species erected on material from other parts of the world, including the northern hemisphere. These identifications require confirmation. More than thirty genera have been established on material from Antarctica. Several of these genera, including some of the largest of Antarctic algae, cannot be assigned to known families (or orders), nor are they sufficiently understood to justify the creation of new families. Examples illustrating the current confusion will be discussed. The greatest advance in knowledge not only of Antarctic algae but of phycology in general would accrue from: (l) detailed study of properly prepared new material obtained preferably in the areas at which previous collections were made; (2) comparison of these specimens with the types of the species to which they are presumed to belong; and (3) a restudy of all the published material from Antarctica. PIKE G. C. 1962. Migration and feeding of the gray whale (Eschrichtius gibbosus). J. Fish. Res. Bd. Canad., 19(5): 815-838. Observations of gray whales from the coasts of British Columbia, Washington, and Alaska are compared with published accounts in order to re-assess knowledge of migration and feeding of the American herd. Source of material is mainly from lighthouses and lightships. The American herd of gray whales retains close contact with the shore during migration south of Alaska. Off Washington and British Columbia the northward migration begins in February, ends in May, and is at a peak during the first two weeks in April; the southward migration occurs in December and January, and is at a peak in late December. Northward migrants stop occasionally to rest or feed; southward migrants are travelling faster and appear not to stop to rest or feed during December and January. Gray whales seen off British Columbia, sometimes in inside protected waters, from June through October, probably remain in this area throughout the summer and fall months. Available evidence suggests that gray whales retain contact with the coast while circumscribing the Gulf of Alaska, enter the Bering Sea through eastern passages of the Aleutian chain, and approach St. Lawrence Island by way of the shallow eastern part of the Bering Sea. Arriving off the coast of St. Lawrence Island in May and June the herd splits with some parts dispersing along the Koryak coast and some parts continuing northward as the ice retreats through Bering Strait. Gray whales feed in the waters of the Chukchi Sea along the Siberian and Alaskan coasts in July, August and September. Advance of the ice through Bering Strait in October initiates the southern migration for most of the herd. In summering areas, in northern latitudes, gray whales feed in shallow waters on benthic and near-benthic organisms, mostly.amphipods. There is no evidence to indicate that gray whales utilize ocean currents or follow the same routes as other baleen whales in their migrations. Visual contact with coastal landmarks appear to aid gray whales in successfully accomplishing the 5000-mile migration between summer feeding grounds in the Bering and Chukchi Seas and winter breeding grounds in Mexico. Reconstruction of the migration from all available data shows that most of the American herd breeds and calves in January and February, migrates northward in March, April and May, feeds from June through~October, and migrates southward in November and December.