IX. Contributions to terrestrial magnetism.—No. IV

1843 ◽  
Vol 133 ◽  
pp. 113-143 ◽  
Keyword(s):  
Pacific Ocean ◽  
West Coast ◽  
China Seas ◽  
North West ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Times ◽  
The China Seas

In the present number of these Contributions, I resume the consideration of Captain Sir Edward Belcher’s magnetic observations, of which the first portion, viz. that of the stations on the north-west coast of America and adjacent islands, was discussed in No. II. The return to England of Her Majesty’s ship Sulphur by the route of the Pacific Ocean, and her detention for some months in the China Seas, have enabled Sir Edward Belcher to add magnetic determinations at thirty-two stations to those at the twenty-nine stations previously recorded. In the notice of the earlier observations, a provisional coefficient was employed in the formula for the temperature corrections of the results with the intensity needles, as no experiments had then been made for the determination of their individual co­efficients. As soon therefore as Sir Edward Belcher had completed the observation of the times of vibration of those needles at Woolwich, as the concluding station of the series made with them, Lieut. Riddell, R. A. undertook the determination of their several coefficients, which was performed in the manner and with the results described in the subjoined memorandum.

scholarly journals Contributions to terrestrial magnetism

1843 ◽  
Vol 4 ◽  
pp. 465-465 ◽  
Keyword(s):  
Pacific Ocean ◽  
West Coast ◽  
Thin Layers ◽  
China Seas ◽  
Magnetic Intensity ◽  
North West ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The China Seas

In the present number of these contributions, the author resumes the consideration of Captain Sir Edward Belcher’s magnetic observations, of which the first portion, namely, that of the stations on the north-west coast of America and its adjacent islands, vas discussed in No. 2. The return to England of H. M. S. Sulphur by the route of the Pacific Ocean, and her detention for some months m the China Seas, have enabled Sir Edward Belcher to add magnetic determinations at thirty-two stations to those at the twenty-nine stations previously recorded. The author first describes the experiments which he instituted with the different needles employed by Captain Sir Edward Belcher for determining the coefficient to be employed in the formula for the temperature corrections; and takes this opportunity of noticing the singular fact that, in needles made of a particular species of Russian steel, this coefficient is negative; that is, in these needles, an increase of temperature increases the magnetic power. M. Adolphe Erman describes this particular kind of steel as consisting of alternate very thin layers of soft iron and of steel, so that when heated the soft iron layers increase their magnetic intensity and the steel layers diminish theirs.

scholarly journals II. Account of levellings carried across the Isthmus of Panamá, to ascertain the relative height of the Pacific Ocean at Panamá and of the Atlantic at the mouth of the river Chagres; accompanied by geographical and topographical notices of the Isthmus

1830 ◽  
Vol 120 ◽  
pp. 59-68
Keyword(s):  
Pacific Ocean ◽  
North Sea ◽  
Relative Height ◽  
The North ◽  
Isthmus Of Panama ◽  
The Pacific ◽  
The North Sea ◽  
The Pacific Ocean ◽  
Good Mathematician

In November 1827 I received a special commission from General Bolivar to make a survey of the Isthmus of Panamá and Darien, in order to ascertain the best and most eligible line for a communication (whether by road or canal) between the two seas. On my arrival in Panamá in March 1828 I was joined by a brother officer of Engineers, a Swede in the Colombian service, a good mathematician and of habits of great correctness in observation. Upon consulting together, we found that we could combine the particular object of the commission with a second object in which we both felt a deep interest, namely, the determination of the relative height of the ocean on either side of the Isthmus; and that we could best accomplish both, by taking a part of the present line of road between Porto Velo and Panamá, until we should fall in with the river Chagres about twenty miles above Cruces, which village is the usual landing-place for all articles of commerce in their transit from the North Sea to Panamá.

scholarly journals Biogeochemistry of the North Atlantic during oceanic anoxic event 2: role of changes in ocean circulation and phosphorus input

2014 ◽  
Vol 11 (4) ◽  
pp. 977-993 ◽  
Author(s):  
I. Ruvalcaba Baroni ◽  
R. P. M. Topper ◽  
N. A. G. M. van Helmond ◽  
H. Brinkhuis ◽  
C. P. Slomp
Keyword(s):  
Pacific Ocean ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Primary Productivity ◽  
Low Oxygen ◽  
Deep Basin ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The North Atlantic

Abstract. The geological record provides evidence for the periodic occurrence of water column anoxia and formation of organic-rich deposits in the North Atlantic Ocean during the mid-Cretaceous (hereafter called the proto-North Atlantic). Both changes in primary productivity and oceanic circulation likely played a role in the development of the low-oxygen conditions. Several studies suggest that an increased input of phosphorus from land initiated oceanic anoxic events (OAEs). Other proposed mechanisms invoke a vigorous upwelling system and an ocean circulation pattern that acted as a trap for nutrients from the Pacific Ocean. Here, we use a detailed biogeochemical box model for the proto-North Atlantic to analyse under what conditions anoxia could have developed during OAE2 (94 Ma). The model explicitly describes the coupled water, carbon, oxygen and phosphorus cycles for the deep basin and continental shelves. In our simulations, we assume the vigorous water circulation from a recent regional ocean model study. Our model results for pre-OAE2 and OAE2 conditions are compared to sediment records of organic carbon and proxies for photic zone euxinia and bottom water redox conditions (e.g. isorenieratane, carbon/phosphorus ratios). Our results show that a strongly elevated input of phosphorus from rivers and the Pacific Ocean relative to pre-OAE2 conditions is a requirement for the widespread development of low oxygen in the proto-North Atlantic during OAE2. Moreover, anoxia in the proto-North Atlantic is shown to be greatly influenced by the oxygen concentration of Pacific bottom waters. In our model, primary productivity increased significantly upon the transition from pre-OAE2 to OAE2 conditions. Our model captures the regional trends in anoxia as deduced from observations, with euxinia spreading to the northern and eastern shelves but with the most intense euxinia occurring along the southern coast. However, anoxia in the central deep basin is difficult to achieve in the model. This suggests that the ocean circulation used in the model may be too vigorous and/or that anoxia in the proto-North Atlantic was less widespread than previously thought.

IV.—Geological Notes on the Peninsula of Nicoya, Costa Rica

1912 ◽  
Vol 9 (6) ◽  
pp. 258-265 ◽  
Author(s):  
James Romanes
Keyword(s):  
Costa Rica ◽  
Pacific Ocean ◽  
The South ◽  
North West ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Gulf Of Nicoya

During a visit to Costa llica in the year 1910 I was able to spend about ten days in the comparatively little-known peninsula of Nicoya. The trend of the peninsula is north-west to south-east, and it is separated from the mainland by the Gulf of Nicoya, a shallow arm of the Pacific Ocean, which opens to the sea on the south-east.

scholarly journals A global climatology of tropospheric and stratospheric ozone derived from Aura OMI and MLS measurements

2011 ◽  
Vol 11 (17) ◽  
pp. 9237-9251 ◽  
Author(s):  
J. R. Ziemke ◽  
S. Chandra ◽  
G. J. Labow ◽  
P. K. Bhartia ◽  
L. Froidevaux ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Northern Hemisphere ◽  
Tropospheric Ozone ◽  
Stratospheric Ozone ◽  
Ozone Monitoring Instrument ◽  
Asian Continent ◽  
Nasa Goddard Space ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean

Abstract. A global climatology of tropospheric and stratospheric column ozone is derived by combining six years of Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) ozone measurements for the period October 2004 through December 2010. The OMI/MLS tropospheric ozone climatology exhibits large temporal and spatial variability which includes ozone accumulation zones in the tropical south Atlantic year-round and in the subtropical Mediterranean/Asia region in summer months. High levels of tropospheric ozone in the Northern Hemisphere also persist in mid-latitudes over the eastern part of the North American continent extending across the Atlantic Ocean and the eastern part of the Asian continent extending across the Pacific Ocean. For stratospheric ozone climatology from MLS, largest column abundance is in the Northern Hemisphere in the latitude range 70° N–80° N in February–April and in the Southern Hemisphere around 40° S–50° S during August–October. Largest stratospheric ozone lies in the Northern Hemisphere and extends from the eastern Asian continent eastward across the Pacific Ocean and North America. With the advent of many newly developing 3-D chemistry and transport models it is advantageous to have such a dataset for evaluating the performance of the models in relation to dynamical and photochemical processes controlling the ozone distributions in the troposphere and stratosphere. The OMI/MLS gridded ozone climatology data are made available to the science community via the NASA Goddard Space Flight Center ozone and air quality website http://ozoneaq.gsfc.nasa.gov/.

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