scholarly journals Predictability Associated with High-Latitude Retrograde Waves in the 1979-80 Winter Season

Author(s):  
Huei-Ping HUANG ◽  
Girish Nigamanth RAGHUNATHAN
Keyword(s):  
2011 ◽  
Vol 24 (22) ◽  
pp. 5799-5811 ◽  
Author(s):  
Kathryn L. Verlinden ◽  
David W. J. Thompson ◽  
Graeme L. Stephens

Abstract The authors exploit three years of data from the CloudSat and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellites to document for the first time the seasonally varying vertical structure of cloudiness throughout Antarctica and the high-latitude Southern Ocean. The results provide a baseline reference of Southern Hemisphere high-latitude cloudiness for future observational and modeling studies, and they highlight several previously undocumented aspects and key features of Antarctic cloudiness. The key features of high-latitude Southern Hemisphere cloudiness documented here include 1) a pronounced seasonal cycle in cloudiness over the high-latitude Southern Hemisphere, with higher cloud incidences generally found during the winter season over both the Southern Ocean and Antarctica; 2) two distinct maxima in vertical profiles of cloud incidence over the Southern Ocean, one centered near the surface and another centered in the upper troposphere; 3) a nearly discontinuous drop-off in cloudiness near 8 km over much of the continent that peaks during autumn, winter, and spring; 4) large east–west gradients in upper-level cloudiness in the vicinity of the Antarctic Peninsula that peak during the austral spring season; and 5) evidence that cloudiness in the polar stratosphere is marked not by a secondary maximum at stratospheric levels but by a nearly monotonic decrease with height from the tropopause. Key results are interpreted in the context of the seasonally varying profiles of vertical motion and static stability and compared with results of previous studies.


2013 ◽  
Vol 15 (2) ◽  
pp. 43-44 ◽  
Author(s):  
Go SUZUKI ◽  
Kousuke YATSUYA ◽  
Soyoka MUKO
Keyword(s):  

2020 ◽  
Vol 66 (1) ◽  
pp. 56-65
Author(s):  
L. V. Egorova

The problem of diagnosing and predicting the characteristics of the polar ionosphere can be investigated by studying the effect of magnetospheric disturbances on the high-latitude ionosphere. Our task is to investigate the dependence of the variations in the electron concentration F of the ionosphere region at the subauroral stations of vertical sounding (VS) Sodankyla, Lovozero and Gorkovskaya on variations in the geomagnetic field. The data of AE and PC of geomagnetic indices were used during substorms in the winter of 2011–2012. For analysis, the epoch overlapping method was used. As a result, it was shown that the perturbation in the electromagnetic field is accompanied by a subsequent amplification of variations during the critical frequencies fоF2, and hence the electron concentration, auroral and subauroral ionosphere.We conclude that the geomagnetic indices AE and PC can serve as predictors of disturbances during the ionospheric parameter fоF2 of the high-latitude ionosphere in the winter season.An increase in the amplitude level of AE from 100 to 350 nT (and PC > 2) during the night hours of the winter season precedes an increase in the critical frequencies of the ionosphere F2 layer by an average of 30% of the median. An increase in the amplitude level of AE from 180 to 520 nT (and PC> 2) in the winter season in the afternoon precedes the positive or negative deviation of the critical frequencies of the ionosphere F2 layer from the median by a mean of 10%. The response of the high-latitude ionosphere of the F2 layer to variations in the AE and PC indices appears in the first hour after the maximum during geomagnetic indices, the delay of the maximum deviation from the median 1 hour at night and 3 hours in the afternoon at Lovozero station, at Sodankyla and Gorkovskaya is about 3 hours at night and weakly expressed during the day.I declare I have no competing interests.


Author(s):  
Kevin Knuuti ◽  
Karen Knuuti
Keyword(s):  

2019 ◽  
Vol 25 (1) ◽  
Author(s):  
ADITYA NARAYAN

The present investigation deals with the prevalence of infection of cestode, Pseudoinverta oraiensis19 parasitizing Clarias batrachus from Bundelkhand Region (U.P.) India. The studies were recorded from different sampling stations of Bundelkhand region of Uttar Pradesh. For this study 360 fresh water fish, Clarias batrachus were examined. The incidence of infection, monsoon season (17.50%) followed by winter season (20.00%) whereas high in summer season (30.00%).


2017 ◽  
Vol 23 (2) ◽  
Author(s):  
S. D. CHATE ◽  
R. J. CHAVAN

The present study deals with the ant community variation in and around Aurangabad city. During the study total 16 species of ants belonging to twelve genera and four subfamilies were reported in eight habitat from urban and periurban regions. Abundance of ants was more in peri-urban region as compared to urban region. Subfamily myrmicinae was more dominant as compared to other subfamilies. Seasonal abundance of ants was seen to be more in winter season and less in rainy season.


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