scholarly journals Solar cycle 22 control on daily geomagnetic variation at Terra Nova Bay (Antarctica)

1998 ◽  
Vol 41 (5-6) ◽  
Author(s):  
L. Cafarella ◽  
A. Meloni ◽  
P. Palangio
Keyword(s):  
Solar Cycle ◽  
Time Variation ◽  
Daily Variation ◽  
Current System ◽  
Geomagnetic Variation ◽  
Field Variation ◽  
Terra Nova Bay ◽  
Polar Latitude ◽  
Observatory Data ◽  
Terra Nova

Nine summer geomagnetic observatory data (1986-1995) from Terra Nova Bay Base, Antarctica (Lat.74.690S, Long. 164.120E, 80.040S magnetic latitude) are used to investigate the behaviour of the daily variation of the geomagnetic field at polar latitude. The instrumentation includes a proton precession magnetometer for total intensity |F| digital recordings; DI magnetometers for absolute measuring of the angular elements D and I and a three axis flux-gate system for acquiring H,D Z time variation data. We find that the magnetic time variation amplitude follows the solar cycle evolution and that the ratio between minimum solar median and maximum solar median is between 2-3 for intensive elements (H and Z) and 1.7 for declination(D). The solar cycle effect on geomagnetic daily variation elements amplitude in Antarctica, in comparison with previous studies, is then probably larger than expected. As a consequence, the electric current system that causes the daily magnetic field variation reveals a quite large solar cycle effect at Terra Nova Bay.

Solar quiet daily (Sq) geomagnetic variation during minimum of solar cycle 23/24

2020 ◽  
Author(s):  
Anatoly Soloviev ◽  
Artem Smirnov
Keyword(s):  
Solar Activity ◽  
Current System ◽  
Geomagnetic Variation ◽  
Solar Cycles ◽  
Middle Latitudes ◽  
Observatory Data ◽  
Summer Hemisphere ◽  
Orthogonal Components ◽  
E Region ◽  
Good Agreement

<p class="Textbody"><span lang="EN-US">The most regular of all daily geomagnetic field variations is the so-called solar quiet, or Sq, variation. It is attributed to the two current vortices flowing in the E-region of the dayside ionosphere. We present an investigation of the time-dependent parameters of Sq variation for the historical minimum of solar activity in 2008. We apply "Measure of Anomalousness" algorithm to detection of magnetically quiet days. The global maps of seasonal Sq amplitudes of the three orthogonal components are derived using 75 INTERMAGNET and 46 SuperMAG stations at low and middle latitudes. The global Sq amplitudes are compared to the previous Coupled Magnetosphere-Ionosphere-Thermosphere (CMIT) model simulations and show good agreement. Significant variability was found in Sq(X) and Sq(Y) based on the solar activity and latitude, while almost no difference is observed in Sq(Z) for across all latitudes and seasons. We analyze equivalent Sq current system using observatory data from the Australian mainland and narrow European-African latitudinal segment. Sq current system also strongly depends on solar activity, as current vortices are strongest in the local summer-hemisphere and disintegrate during local winter. The dynamics of Sq variation along the solar cycles 23 and 24 is also discussed and compared to Swarm-based spherical harmonic Sq model.</span></p>

Particulate organic matter release below melting sea ice (Terra Nova Bay, Ross Sea, Antarctica): Possible relationships with zooplankton

2021 ◽  
pp. 103510
Author(s):  
Alessandro Cau ◽  
Claudia Ennas ◽  
Davide Moccia ◽  
Olga Mangoni ◽  
Francesco Bolinesi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sea Ice ◽  
Particulate Organic Matter ◽  
Ross Sea ◽  
Terra Nova Bay ◽  
Terra Nova

scholarly journals A comparison between polynya area and associated ice production with mooring-based measurements of temperature, salinity and currents in the southwestern Ross Sea, Antarctica

2011 ◽  
Vol 52 (57) ◽  
pp. 291-300 ◽  
Author(s):  
Stefan Kern ◽  
Stefano Aliani
Keyword(s):  
Ross Sea ◽  
Time Lag ◽  
Ice Formation ◽  
Terra Nova Bay ◽  
In Situ Observations ◽  
Satellite Microwave ◽  
Terra Nova ◽  
Ice Production ◽  
The Impact

AbstractWintertime (April–September) area estimates of the Terra Nova Bay polynya (TNBP), Antarctica, based on satellite microwave radiometry are compared with in situ observations of water salinity, temperature and currents at a mooring in Terra Nova Bay in 1996 and 1997. In 1996, polynya area anomalies and associated anomalies in polynya ice production are significantly correlated with salinity anomalies at the mooring. Salinity anomalies lag area and/or ice production anomalies by about 3 days. Up to 50% of the variability in the salinity at the mooring position can be explained by area and/or ice production anomalies in the TNBP for April–September 1996. This value increases to about 70% when considering shorter periods like April–June or May–July, but reduces to 30% later, for example July–September, together with a slight increase in time lag. In 1997, correlations are smaller, less significant and occur at a different time lag. Analysis of ocean currents at the mooring suggests that in 1996 conditions were more favourable than in 1997 for observing the impact of descending plumes of salt-enriched water formed in the polynya during ice formation on the water masses at the mooring depth.

scholarly journals Diesel oil and PCB-degrading psychrotrophic bacteria isolated from Antarctic seawaters (Terra Nova Bay, Ross Sea)

2004 ◽  
Vol 23 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Maria De Domenico ◽  
Angelina Lo Giudice ◽  
Luigi Michaud ◽  
Marcello Saitta ◽  
Vivia Bruni
Keyword(s):  
Ross Sea ◽  
Diesel Oil ◽  
Psychrotrophic Bacteria ◽  
Terra Nova Bay ◽  
Terra Nova

Particulate matter composition and bacterial distribution in Terra Nova Bay (Antarctica) during summer 1989–1990

Polar Biology ◽  
1995 ◽  
Vol 15 (6) ◽  
pp. 393-400 ◽  
Author(s):  
M. Fabiano ◽  
R. Danovaro ◽  
E. Crisafi ◽  
R. La Ferla ◽  
P. Povero ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Terra Nova Bay ◽  
Terra Nova

scholarly journals Summer Epiphytic Diatoms from Terra Nova Bay and Cape Evans (Ross Sea, Antarctica) - A Synthesis and Final Conclusions

PLoS ONE ◽  
2016 ◽  
Vol 11 (4) ◽  
pp. e0153254 ◽  
Author(s):  
Roksana Majewska ◽  
Peter Convey ◽  
Mario De Stefano
Keyword(s):  
Ross Sea ◽  
Epiphytic Diatoms ◽  
Terra Nova Bay ◽  
Terra Nova

Significance of selected halocarbons monitoring in air samples collected in the Terra Nova Bay region (northern Victoria Land, Antarctica)

1999 ◽  
Vol 11 (2) ◽  
pp. 261-264 ◽  
Author(s):  
Filippo Mangani ◽  
Michela Maione ◽  
Luciano Lattanzi
Keyword(s):  
Ross Sea ◽  
Atmospheric Concentration ◽  
Air Samples ◽  
Terra Nova Bay ◽  
Victoria Land ◽  
Rate Of Increase ◽  
Terra Nova ◽  
Concentration Levels

CCl3F (or CFC-11) and CCl2F2 (or CFC-12) were determined in air samples collected, during subsequent summer Antarctic campaigns, in different sampling sites in the Ross Sea Region. The samples were analysed by GC-ECD after enrichment. Data obtained since 1988–89 were plotted to observe the trend of CFCs atmospheric concentration levels. A decrease in the rate of increase of CFC-12 concentration was observed, whilst the concentration of CFC-11 was actually seen to be decreasing.

scholarly journals Morning quiet-time ionospheric current reversal at mid to high latitudes

2005 ◽  
Vol 23 (2) ◽  
pp. 385-391 ◽  
Author(s):  
R. Stening ◽  
T. Reztsova ◽  
D. Ivers ◽  
J. Turner ◽  
D. Winch
Keyword(s):  
Magnetic Field ◽  
Daily Variation ◽  
Current System ◽  
Early Morning ◽  
High Latitudes ◽  
Quiet Time ◽  
Ionospheric Current ◽  
Set Up ◽  
Current Reversal ◽  
Local Noon

Abstract. The records of an array of magnetometers set up across the Australian mainland are examined. In addition to a well-defined current whorl corresponding to the ionospheric Sq current system, another system of eastward flowing currents is often found in the early morning. The system is most easily identified at observatories poleward of the focus of the Sq system, where a morning reversal from eastward to westward currents can be seen. The time of the reversal is usually later, sometimes up to 12h local noon, in June (Southern Winter) than in other seasons. There is some evidence of a similar current system at other longitudes and in the Northern Hemisphere. An important outcome of the study is that it enables identification of which features of a daily variation of the northward magnetic field ΔX relate to an Sq current whorl and which must be attributed to some other current system.

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