scholarly journals Middle and High Latitude Whistlers Observed Simultaneously in a Low Latitude Station at Agra.

1997 ◽  
Vol 49 (8) ◽  
pp. 995-1000 ◽  
Author(s):  
Birbal Singh
Keyword(s):  
High Latitude ◽  
Low Latitude ◽  
Latitude Station

scholarly journals Distributions of Arctic and Northwest Atlantic killer whales inferred from oxygen isotopes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cory J. D. Matthews ◽  
Fred J. Longstaffe ◽  
Jack W. Lawson ◽  
Steven H. Ferguson
Keyword(s):  
Oxygen Isotopes ◽  
North Atlantic ◽  
High Latitude ◽  
Newfoundland And Labrador ◽  
Killer Whales ◽  
Low Latitude ◽  
Northwest Atlantic ◽  
Oxygen And Carbon Isotope ◽  
Stable Oxygen ◽  
Morphological Differences

AbstractKiller whales (Orcinus orca) are distributed widely in all oceans, although they are most common in coastal waters of temperate and high-latitude regions. The species’ distribution has not been fully described in the northwest Atlantic (NWA), where killer whales move into seasonally ice-free waters of the eastern Canadian Arctic (ECA) and occur year-round off the coast of Newfoundland and Labrador farther south. We measured stable oxygen and carbon isotope ratios in dentine phosphate (δ18OP) and structural carbonate (δ18OSC, δ13CSC) of whole teeth and annual growth layers from killer whales that stranded in the ECA (n = 11) and NWA (n = 7). Source δ18O of marine water (δ18Omarine) at location of origin was estimated from dentine δ18OPvalues, and then compared with predicted isoscape values to assign individual distributions. Dentine δ18OPvalues were also assessed against those of other known-origin North Atlantic odontocetes for spatial reference. Most ECA and NWA killer whales had mean δ18OPand estimated δ18Omarinevalues consistent with18O-depleted, high-latitude waters north of the Gulf Stream, above which a marked decrease in baseline δ18O values occurs. Several individuals, however, had relatively high values that reflected origins in18O-enriched, low-latitude waters below this boundary. Within-tooth δ18OSCranges on the order of 1–2‰ indicated interannual variation in distribution. Different distributions inferred from oxygen isotopes suggest there is not a single killer whale population distributed across the northwest Atlantic, and corroborate dietary and morphological differences of purported ecotypes in the region.

Total ozone dependence of the difference between the empirically corrected EP-TOMS and high-latitude station datasets

2009 ◽  
Vol 30 (15-16) ◽  
pp. 4283-4294 ◽  
Author(s):  
V. Kravchenko ◽  
A. Evtushevsky ◽  
A. Grytsai ◽  
G. Milinevsky ◽  
J. Shanklin
Keyword(s):  
High Latitude ◽  
Total Ozone ◽  
Latitude Station ◽  
The Difference

Observation of temperatures and emission rates from the OH and O2 nightglow over a southern high latitude station

2006 ◽  
Vol 38 (11) ◽  
pp. 2374-2379 ◽  
Author(s):  
J.-K. Chung ◽  
Y.H. Kim ◽  
Y.-I. Won ◽  
B.K. Moon ◽  
T.H. Oh
Keyword(s):  
High Latitude ◽  
Emission Rates ◽  
Latitude Station ◽  
Southern High Latitude

scholarly journals Simultaneous high- and low-latitude reconnection: ESR and DMSP observations

2002 ◽  
Vol 20 (9) ◽  
pp. 1311-1320 ◽  
Author(s):  
F. Pitout ◽  
P. T. Newell ◽  
S. C. Buchert
Keyword(s):  
High Latitude ◽  
Time Interval ◽  
High Latitudes ◽  
Polar Ionosphere ◽  
Plasma Convection ◽  
Low Latitude ◽  
Svalbard Archipelago ◽  
Cusp Region ◽  
Ionosphere Plasma ◽  
Particle Measurement

Abstract. We present EISCAT Svalbard Radar and DMSP observations of a double cusp during an interval of predominantly northward IMF on 26 November 2000. In the cusp region, the ESR dish, pointing northward, recorded sun-ward ionospheric flow at high latitudes (above 82° GL), indicating reconnection occuring in the magnetospheric lobe. Meanwhile, the same dish also recorded bursts of poleward flow, indicative of bursty reconnection at the subsolar magnetopause. Within this time interval, the DMSP F13 satellite passed in the close vicinity of the Svalbard archipelago. The particle measurement on board exhibited a double cusp structure in which two oppositely oriented ion dispersions are recorded. We interpret this set of data in terms of simultaneous merging at low- and high-latitude magnetopause. We discuss the conditions for which such simultaneous high-latitude and low-latitude reconnection can be anticipated. We also discuss the consequences of the presence of two X-lines in the dayside polar ionosphere.Key words. Magnetospheric physics (solar wind-magnetosphere interactions) – Ionosphere (polar ionosphere; plasma convection)

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