Mesospheric Gravity Waves Observed over Ferraz Station and Future Plans

1. 3rd International ANtarctic Gravity Wave Instrument Network (ANGWIN) Science Workshop Mesospheric Gravity Waves Observed over Ferraz Station and Future Plans José V. Bageston; Cristiano M.Wrasse; Cosme Figueiredo; Gabriel A. Giongo ; Hisao Takahashi; Delano Gobbi and Neusa M. P. Leme National Institute for Space Research (INPE), Brazil Cambridge, UK – April, 12 2016

2. Outline • Motivations for gravity wave observations at Commandant Ferraz Station; • MLT Instrumentation at Ferraz; • Gravity Waves observed at Ferraz Station (62.1°S, 58.4°W); • All-Sky airglow observations and its statistics since 2007; • Small scale gravity waves: Examples, Methododology, Wave parameters and propagation directions; • Medium-Scale Gravity Waves: Methodology for keogram analysis, Example for a simulated wave and example for one observed keogram • Future plans for MLT researches at Ferraz and Examples of NLCs in Antarctica • Conclusions and Acknowledges;

3. Motivations • High GWs activity around the Antarctica Peninsula and South America; • A new airglow imager was set at Ferraz station in 2014; • New plans for Noctilucent Clouds observations on the Antarctic Peninsula and new keogram analysis technique;

4. Motivations • Relationship between GWs observed in the Antarctic Peninsula and in the South America and possibility of GWs observation in the summer time by using ground base optical monitoring of noctilucent clouds at distinct sites; Source:https://en.wikipedia.org/wiki/Research_stations_in_Antarctica

5. MLT Instrumentation at Ferraz Station

6. GravityWavesobservedat Ferraz Station • Statistics of observations during the winter time for all observed years • The new airglow imager stopped its operation on June, 2014, due to problems in the voltage transformer near the observation site. • The system restarted on Feb., 2015. • *We need to revise and more events should be found; • ** It was not analyzed yet;

7. Small Scale Gravity Waves (SSGW ) • Examples of mesospheric gravity waves identified in 2007 N N N W W W E E E 3 4 2 1 3 2 1 Jul, 09 23:30 Jul, 09 23:40 Jul, 09 23:50 S S S

8. Small Scale Gravity Waves (SSGW ) • Mesospheric fronts identified in 2011 above Ferraz Station. Vel ~ 89 m/s;  ~ 27 km Per ~ 5 min Vel ~ 60 m/s;  ~ 27 km Per=7.5 min

9. Small Scale Gravity Waves (SSGW ) • Example of one ordinary wave (band type) identified in 2015

10. Observed Wave Parameters for SSGW 2015: 100 events... and we expect to find more events 2010, 2011 223 events

11. Wave Propagation Directions (2010-2011) • The main propagation directions are to northwest and south region, and absence or just a few events that propagate to north or northest;

12. Wave Propagation Directions (2015) • In the last year the main propagation direction was again to northwest (36 events) and south region (35 events) 16 out of 20 faster waves (>60m/s) are propagating to South or to East: Question: Could these waves to be originated by Orographic Effect or Low Pressure Systems ??

13. Methodology for Keogram Analysis: Medium-Scale Waves • Keograms are constructed from a set of airglow images (noramaly a full night) by adding horizontal and vertical slices (1 line or row of pixel – y axis), taken at the ceter of each image, in a time serie (x axis); Wave parameters: Horzintal wavelength = 200 km Observed period = 60 min. Observed speed = 55.6 m/s (200,000/3,600) Propagation direciton = 45°

14. Methodology for Keogram Analysis: Medium-Scale Waves • Keograms can present many forms(inclination) and the combination of zonal and meridional inclinations for each keograma gives the propagation diretion of the horizontal wave structure. Bellow we see the main possible combinations.

15. Methodology for Keogram Analysis: Medium-Scale Waves • By using FFT analysis, in a similar way (but distinct set of eqs.) to the analysis of individual all-sky images it’s possible to reach a set of wave parameters for the MSGW 1D FFT Averaged Spectrum Time (UT) Simulated wave parameters: Horiz Wavelength = 200 km Period = 60 min. Speed = 55.6 m/s (200,000/3,600) Phi = 45°

16. Methodology for Keogram Analysis: Medium-Scale Waves • Application of the metodology to analize keograms to one case of observed data obtained from airglow observations at Ferraz Station on Jul., 18 2015.

17. Methodology for Keogram Analysis: Medium-Scale Waves • Details of the analysis and results Period = (33.95-33.45) hs Period = (0.5*60 ) = 30 min

18. The Future Plans for the MLT Researches in Ferraz • Rewirethe meteor radar will be challenge (depends mainly on monetary funds and window for technicians go to Ferraz); • Improvements in the internet bandwidth at Ferraz (depends upon the Brazilian Antarctic Program/Navy); • We have plan to continue to observe NLC at Ferraz; • The all-sky airglow observations will be mantained at Ferraz; • Until now we don’t have mesospheric winds observations from the local meteor radar. So, we will cooperate with another stations in order to obtain mesospheric winds (e.g., the King Sejong Station - a Korean Station located at King George Island, Rothera and TDF); • Continue the analysis of our observed gravity waves: search for medium-scale waves apply ray-tracing to previous observed waves;

19. Examples of NLCs in Antarctica • Images from the AIM satellite and from the ground at Ferraz Station Feb.,10 2008 Photos by Gabriel Dechiche (USP) Jan., 24 2009 http://simonejeepeira.blogspot.com.br/2009_03_01_archive.html http://lasp.colorado.edu/aim/browse-images.php Interesting video: https://www.youtube.com/watch?v=GHpxD807kM4

20. Examples of NLCs in Antarctica • Images from the AIM satellite and from the ground at Ferraz Station 06/02/2016 02:30 LT 06/02/2016 02:00 LT 02:15 LT 06/02/2016

21. Project of the new Brazilian Station Artistic picture of the new Ferraz Station Future permanent station Current facilities Source: Estúdio 41 (http://www.estudio41.com.br/?conteudo=projeto&id=54)

22. Conclusions • Recently (2014 and 2015) we have been observed only mesospheric gravity waves at Ferraz Station and currently we are analyzing the airglow data along the NLCs images taken with a standard photographical camera; • Also, in the past we observed gravity waves, mesospheric winds and temperatures at the Brazillian Antarctic Station. However, two of these experiments were stoped in 2012 due to the fire in our station. Unfortunatly, we could not fix them yet in order to give continued in the data serie; • It was characterized gravity wave parameters for aproximatly 500 wave events in 4 years with full winter period of observations, comprising a total 290 nights; • We started investigations of medium-scale gravity waves with airglow images (keograms) by using data of 2007, 2010 and 2011. Also, we intent to apply the same methodology to the data from 2015 ahead; • The reconstruction of the Brazilian Antarctic station will be started effectively in the next summer (Nov. 2016 to March 2017), with plan to be finished by early 2018;

23. Acknowledgments • ANGWIN Local Organizing Committee for supporting me partially in order to attend this fruitful scientific event and have the opportunity to visit BAS on Apr. 15; • CNPq for the financial support to develop the project for NLCs Observations at Ferraz Station (Grant461531/2014-3); • Brazilian Antarctic Program (PROANTAR, MMA, CNPq Grant n° 52.0186/06-0); • INCT-APA (CNPq Grant 574018/2008-5 and FAPERJ Grant E-16/170.023/2008); • EMBRACE/CEA for their support by borrowing one of their new airglow imager to be installed at our Brazilian Antarctic Station in 2014 which continues working until now. E-mail contact:bageston@gmail.com jose.bageston@inpe.br THANK YOU FOR THE ATTENTION