scholarly journals The Comprehensive Study of Low Thermospheric Sodium Layers during the 24th Solar Cycle

Atmosphere ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 284
Author(s):  
Yuchang Xun ◽  
Guotao Yang ◽  
Jihong Wang ◽  
Lifang Du ◽  
Zelong Wang ◽  
...  
Keyword(s):  
Sodium Atom ◽  
Local Times ◽  
Annual Variations ◽  
Sporadic E Layer ◽  
Sporadic E ◽  
Variation Trends ◽  
Lidar Observations ◽  
Atom Layer ◽  
Comprehensive Study

The low thermospheric sodium layer (LTSL) is the separate sodium atom layer above 105 km. Based on 11,607 h of lidar observations from Yanqing (40.5° N, 116.0° E) from 2010 to 2016, we found 38 LTSLs wherein the peak densities were more than five percent above those of the main sodium layers. This work presents the peak altitudes, peak local times and peak densities of the LTSLs as well as the long-term characteristics of the seasonal and inter-annual variations of LTSLs. We analyzed the correlation between the LTSL and sporadic E layer (Es). The seasonal variation trends of the occurrences of LTSL and Es are similar, and the results showed that 95% of the LTSLs were accompanied by Es. We also found that 69% of the LTSL cases exhibited apparent downward phase progressions, while the descending rates of the LTSLs are consistent with the phase speeds of the tide.

LONG TERM CHANGES IN THE SPORADIC E-LAYER PHENOMENA OVER FORTALEZA, BRAZIL

2018 ◽  
Vol 11 (3) ◽  
Author(s):  
M. A. Abdu ◽  
I. S. Batista ◽  
P. Muralikrishna ◽  
J.H.A Sobral
Keyword(s):  
Long Term Changes ◽  
Sporadic E Layer ◽  
Sporadic E

Para solicitação de resumo, entrar em contato com editor-chefe ([email protected]). 

scholarly journals Equatorial E Region Electric Fields and Sporadic E Layer Responses to the Recovery Phase of the November 2004 Geomagnetic Storm

2017 ◽  
Vol 122 (12) ◽  
pp. 12,517-12,533 ◽  
Author(s):  
J. Moro ◽  
L. C. A. Resende ◽  
C. M. Denardini ◽  
J. Xu ◽  
I. S. Batista ◽  
...  
Keyword(s):  
Geomagnetic Storm ◽  
Electric Fields ◽  
Recovery Phase ◽  
E Region ◽  
Sporadic E Layer ◽  
Sporadic E

scholarly journals Interannual variability of larval fish assemblages associated with water masses in winter in the Taiwan Strait during 2007–2013

2021 ◽  
Author(s):  
Yu-Kai Chen ◽  
Chia-Yi Pan ◽  
Yi-Chen Wang ◽  
Hsiu-Ju Tseng ◽  
Bo-Kun Su ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Larval Fish ◽  
Taiwan Strait ◽  
Assemblage Structure ◽  
Sea Surface ◽  
Coastal Current ◽  
Annual Variations ◽  
Frontal Zones ◽  
The Taiwan Strait

AbstractIn this study, the interannual variations of ichthyoplankton assemblages in the Taiwan Strait (TS) during the winters of 2007–2013 were determined. The cold China Coastal Current (CCC) and Mixed China Coastal Water (MCCW) intruded into the TS and impinged with the warm Kuroshio Branch Current (KBC) with annual variations. Consequently, the ichthyoplankton community in the TS was mainly structured into two assemblages characterized by differing environmental conditions. The composition of the warm KBC assemblage was relatively stable and was characterized by Diaphus B and Bregmaceros spp. By contrast, the cold MCCW assemblage demonstrated considerable variations over the years, with demersal Gobiidae and Scorpaenidae families considered the most representative. In addition, Benthosema pterotum and Trichiurus spp. were common in both KBC and MCCW assemblages. The distribution of the KBC assemblage demonstrated sharp boundaries in the frontal zones, whereas changes in the assemblage structure between the frontal zones were gradual for the MCCW assemblage, particularly when demersal taxa were dominant. Sea surface temperature and salinity were most strongly associated with variability in the assemblage structure during the study period. Thus, this paper provides a better understanding of long-term larval fish dynamics during winter in the TS.

Sporadic E layer formation time

1968 ◽  
Vol 11 (9) ◽  
pp. 756-759
Author(s):  
Yu. A. Ignat'ev
Keyword(s):  
Formation Time ◽  
Layer Formation ◽  
Sporadic E Layer ◽  
Sporadic E

scholarly journals INCREASE OF THE THERMOCLINE LAYER DUE TO TSUNAMI 2004 IN NANGRO ACEH DARUSSALAM WATERS

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Hadikusumah Hadikusumah ◽  
J. D. Lekalete
Keyword(s):  
Indian Ocean ◽  
Light Transmission ◽  
Mixed Layer Depth ◽  
Heat Content ◽  
Annual Variations ◽  
The Indian Ocean ◽  
Local Water ◽  
Straits Of Malacca ◽  
Tsunami Energy

Research of physical oceanographic conditions post-tsunami was carried out and subsequently compared with the pre-tsunami 1998. Measurement of suhu, salinity and light transmission was conducted by CTDSBE911pls Model. Results showed that the flow in the Straits of Malacca flowed into the northwest and turned back into the Strait of Bengal and the next rotation into the flow of waters along the west coast of Nangro Aceh Darusalam (NAD). The mainstream off coast NAD in the Indian Ocean flowed to the northwest. Upper thermocline layer (17 m to 50 m) moved upward in 2005 and 2006 compared with previous data 1998 (90 m to 125 m). The moving upward thermocline in 2006 was allegedly due to the influence of Indian Ocean Dipole (IOD) positive. This requires further verification through long-term data collection to determine the monthly and annual variations, which will be compared with previous research. Light transmission (Tx) in 2005 from the surface to near the bottom (water column) was found lower than the year 1998 and 2006. This result was allegedly caused by resuspension from the seabed by energy turbulent produced by the tsunami. Heat content between 5 to 65 m depth in 2005 was higher than in 1998 and 2006. The higher heat content during the year of 2005 (post tsunami) was caused by friction due to the influence of tsunami energy, which predominantly found in the mixed layer depth. Type of water masses in the study area was a mixing between the local water mass, Malacca Strait Water (MSA), Bay of Bengal Water (BBW) under the influence of Arab Waters (AW), and the Indian Deep Water (IDW).Keywords: current, thermocline, heat content, watermass type, and Nangro Aceh Darusalam

scholarly journals Energetics and structure of the lower E region associated with sporadic E layer

2008 ◽  
Vol 26 (9) ◽  
pp. 2929-2936 ◽  
Author(s):  
K.-I. Oyama ◽  
K. Hibino ◽  
T. Abe ◽  
R. Pfaff ◽  
T. Yokoyama ◽  
...  
Keyword(s):  
Electric Field ◽  
Field Data ◽  
Magnetic Line ◽  
Height Range ◽  
Sounding Rockets ◽  
Main Structure ◽  
Irregular Structures ◽  
E Region ◽  
Sporadic E Layer ◽  
Sporadic E

Abstract. The electron temperature (Te), electron density (Ne), and two components of the electric field were measured from the height of 90 km to 150 km by one of the sounding rockets launched during the SEEK-2 campaign. The rocket went through sporadic E layer (Es) at the height of 102 km–109 km during ascent and 99 km–108 km during decent, respectively. The energy density of thermal electrons calculated from Ne and Te shows the broad maximum in the height range of 100–110 km, and it decreases towards the lower and higher altitudes, which implies that a heat source exists in the height region of 100 km–110 km. A 3-D picture of Es, that was drawn by using Te, Ne, and the electric field data, corresponded to the computer simulation; the main structure of Es is projected to a higher altitude along the magnetic line of force, thus producing irregular structures of Te, Ne and electric field in higher altitude.

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