over King Sejong Station, Antarctic Peninsula Hosik Kam 1 , Yong Ha - - PowerPoint PPT Presentation

Propagation analysis of mesospheric gravity waves

• n OH and OI-557.7 nm airglow layers
• ver King Sejong Station, Antarctic Peninsula
• 2018. 4. 24.

Instituto Nacional de Pesquisas Espaciais, INPE, São José dos Campos, SP, Brasil.

Hosik Kam1, Yong Ha Kim1, Takuji Nakamura2,3, Masaki Tsutsumi2,3, Yoshihiro Tomikawa2,3 , Masaru Kogure3,2, Septi Perwitasari2, Jeong-Han Kim4

1 Department of Astronomy, Space, and Geology, Chungnam National University, Daejeon, South Korea 2 National Institute of Polar Research, Tachikawa, Japan 3 Department of Polar Science, SOKENDAI (The Graduate University for Advanced Studies), Tachikawa, Japan 4 Division of Polar Climate Sciences, Korea Polar Research Institute, Incheon, South Korea

Contacts: Hosik Kam: kamhosik@cnu.ac.kr

King Sejong Station (KSS)

Geographical Location: 62°S, 58°W All-Sky Meteor Radar SATI GPS/TEC monitor All-sky camera FPI

New observatory (Feb 2017)

Observation

 has been operating since May 2008.  multi-wavelength filter wheel to capture airglow at different altitudes.

Constituent of Airglow Central Wavelength (nm) Exposure Time (sec) Altitude (km)

OH Meinel 720.0 – 820.0 20 87 OI 5577 557.7 150 96 OI 6300 630.0 150 250

All-Sky Camera

Images of Wave feature observed by KSS ASC on 29 April, 2012

All-Sky Meteor Radar

 has been operating since March 2007.  12 kW Transmit power / 33 MHz frequency  Daily detection of 12000 – 40000 meteors  Horizontal Wind profiles in 80 – 100 km were derived

Sky map of 34884 meteors detected by KSS MR on 8 April, 2016



Duration of KSS ASC observation: March ~ October, 2008~

ASC Observation

Observed days

2008 92 2009 33 2010 146 2011 171 2012 216 2013 195 2014 210 2015 197 2016 187 2017 X 2018 Observing Total 1,455 +

 Criteria for clear condition image sequence

① Duration time of clear condition: Over 1 hour ② Valid region of clear condition: Over 100 pix x 100 pix (~100 km x 100 km)

 Total windows of image sequence for analysis in 2013

Observed days Clear nights Windows 195 29 31

ASC Data Analysis

Utilizing Matsuda_fft program from NIPR

• Horizontal phase speed PSD distribution

Raw OH ~ 87 km Raw OI-557.7 ~ 96km

Simultaneous analysis for OH & OI-5577 observed on same time & same spatial grid

• f 31 - image sequence windows

𝐽′/𝐽0(=𝜍′/𝜍0)

Input data:

𝐽′ 𝐽0 = 𝐽−𝐽 𝐽

𝐽 : Temporal mean of image sequence

Power Spectrum Density of I’/I0 (logarithmic scale)

M-transform [Matsuda et al., 2014] 3D-FFT Horizontal wavelength range: 5-100 km

Results_ Seasonal variation of total PSD

 Characteristics of seasonal variation of wave activity ( 𝑸𝑻𝑬) over KSS

• 1. Seasonal variation with strong wave activities during winter time.
• 2. Larger wave activities at KSS than Syowa & Davis station
• 3. Larger wave activities on OH layer(*) than those of OI-557.7 layer (*)

OH PSD OI-557.7 PSD

𝑄𝑇𝐸 in each PSD distribution  Proxy of Wave activity

𝑄𝑇𝐸 variation over Syowa & Davis station (Contributed from Masaru Kogure (NIPR)) 𝑄𝑇𝐸 variation over KSS

Results_ 1. Strong activities during winter

OH PSD OI-557.7 PSD

𝑄𝑇𝐸 in each PSD distribution  Proxy of Wave activity

𝑄𝑇𝐸 variation over Syowa & Davis station (Contributed from Masaru Kogure (NIPR)) 𝑄𝑇𝐸 variation over KSS

• From ASC airglow raw images (OH) over KSS,

ASC images in winter show non-monochromatic waves rather than fall and spring, relatively.

2013.6.11 2013.3.7

• Also shown in Syowa & Davis station.
• As various studies, strong activities in winter time

at Antarctica.

(Yoshiki and Sato [2000], Venkat Ratnam et al. [2004], Whiteway et al. [1997], Baumgaertner and McDonald [2007], Jiang et al. [2005]…)

Results_ 1. Strong activities during winter

OH PSD OI-557.7 PSD

𝑄𝑇𝐸 in each PSD distribution  Proxy of Wave activity

𝑄𝑇𝐸 variation over Syowa & Davis station (Contributed from Masaru Kogure (NIPR)) 𝑄𝑇𝐸 variation over KSS

• From PSD analysis from ASC images over KSS,

As a result, expanded or homogeneous distribution from non-monochromatic waves in winter images  Might be Secondary GWs or breaking GWs

2013.6.11 2013.3.7

• Also shown in Syowa & Davis station.
• As various studies, strong activities in winter time

at Antarctica.

(Yoshiki and Sato [2000], Venkat Ratnam et al. [2004], Whiteway et al. [1997], Baumgaertner and McDonald [2007], Jiang et al. [2005]…)

Results_ 1. Strong activities during winter

 Tendency of non-monochromatic waves on ASC images during winter.  Expanded or homogeneous features in PSD distribution during winter time contributed to enhance the wave activities ( 𝑄𝑇𝐸).  If these features were induced by secondary GWs, the strong activities during winter in seasonal variation of 𝑄𝑇𝐸 indicated that the secondary GWs were captured on ASC over Antarctic peninsula winter MLT region.  Around 60S at winter, secondary GWs are generated in the stratosphere and lower mesosphere (Becker at al. [2017]).

2013.3.13 2013.4.17 2013.5.15 2013.6.11 2013.7.10 2013.8.8 2013.9.6 2013.10.5

OH PSD distribution near monthly 15th

Results_ 2. Stronger wave activities over KSS than Syowa & Davis station

𝑄𝑇𝐸 variation over Syowa & Davis station (Contributed from Masaru Kogure (NIPR)) 𝑄𝑇𝐸 variation over KSS

Six major SH GW hot spots [Becker et al. (2017)]

Sub-tropical Andes / Antarctic Peninsula / Southern Andes / Tasmania / Ross ice Shelf / Southern edge of Africa

• KSS Magnitude range of 𝑄𝑇𝐸: 10-4 to 10-2
• Syowa Magnitude range of 𝑄𝑇𝐸: 10-4 to 10-3
• Davis Magnitude range of 𝑄𝑇𝐸: 10-5 to 10-3
• Antarctic Peninsula is widely known as GW hot spot.
• As various studies, strong wave activities over

Antarctic Peninsula.

(Baumgaertner and McDonald [2007]; Alexander et al. [2007]; Hertzog et al. [2008]; Plougonven et al. [2008]…)

Results_ 3. Stronger OH PSD than OI-557.7 PSD

𝑄𝑇𝐸 variation over KSS (top) and Difference 𝑄𝑇𝐸 between OH PSD and OI-557.7 PSD (bottom)

OH PSD OI-557.7 PSD

Difference PSD between OH PSD and OI-557.7 PSD (OH PSD minus OI-557.7 PSD)

Generally, 𝑄𝑇𝐸 of OH has a larger power than 𝑄𝑇𝐸 of OI-557.7.

 If GWs have upward propagation from OH airglow layer (~87 km) to OI-557.7 nm airglow layer (~96 km), it means that the PSD of the waves are weakened.  In other word, the 𝑄𝑇𝐸 of waves loses the power when waves propagate through MLT region.

logarithmic scale nonlogarithmic scale

OH PSD OI-557.7 PSD

Blocking diagram from 86 km to 96 km with 2 km of height bin from KSS MR winds with 15 min of time resolution which is corresponding to clear image sequence window time.

2013.4.12

Difference PSD between OH PSD and OI-557.7 PSD (OH PSD minus OI-557.7 PSD)

Critical level filtering case

Results_ 3. Stronger OH PSD than OI-557.7 PSD

Blocking diagram 𝑑ℎ = 𝑑ℎ − (𝑣𝑑𝑝𝑡𝜄 + 𝑤𝑡𝑗𝑜𝜄) 𝑣: zonal wind 𝑤: meridional wind 𝜄: propagation direction (0°~360°)

logarithmic scale nonlogarithmic scale

Critical level filtering  Inference from Blocking Diagram using horizontal winds

OH PSD OI-557.7 PSD

Difference PSD (OH PSD – OI PSD) 2013.3.24

Main difference PSD  Northwest with 10-20m/s  88-96 km of blocking diagram

Blocking diagram from KSS MR

Critical level filtering case

Results_ 3. Stronger OH PSD than OI-557.7 PSD

logarithmic scale nonlogarithmic scale

OH PSD OI-557.7 PSD

Difference PSD (OH PSD – OI PSD) 2013.4.17

Blocking diagram from KSS MR

Main difference region of PSD  Northwest with 10-20m/s  88-96 km of blocking diagram

Critical level filtering case

Results_ 3. Stronger OH PSD than OI-557.7 PSD

logarithmic scale nonlogarithmic scale

OH PSD OI-557.7 PSD

Difference PSD (OH PSD – OI PSD) 2013.5.15

Blocking diagram from KSS MR

Main difference region of PSD  1) Northeast with 10-50m/s & 2) Southeast with 20-40m/s  1) 88-90km of blocking diagram & 2) 94-96km of blocking diagram

Critical level filtering case

Results_ 3. Stronger OH PSD than OI-557.7 PSD

logarithmic scale nonlogarithmic scale

Critical level filtering case

OH PSD OI-557.7 PSD

Difference PSD (OH PSD – OI PSD) 2013.10.5

Blocking diagram from KSS MR

Main difference region of PSD  Southwest with 30-50m/s  90-96 km of blocking diagram

Results_ 3. Stronger OH PSD than OI-557.7 PSD

logarithmic scale nonlogarithmic scale

Results_ 3. Stronger OH PSD than OI-557.7 PSD

𝑄𝑇𝐸 variation over KSS (top) and Difference 𝑄𝑇𝐸 between OH PSD and OI-557.7 PSD (bottom)

OH PSD OI-557.7 PSD

Difference PSD between OH PSD and OI-557.7 PSD (OH PSD minus OI-557.7 PSD)

Total clear windows: 31 Number of larger 𝑄𝑇𝐸 of OH than 𝑄𝑇𝐸 of OI-557.7: 27 Number of Difference PSD similar with wind blocking diagram: 16  About half of event windows show attenuated power of waves in OI-557.7 nm images probably due to wind filtering when waves propagated through MLT region.

logarithmic scale nonlogarithmic scale

Summary

 Criteria for clear condition image sequence

① Duration time of clear condition: Over 1 hour ② Valid region of clear condition: Over 100 pix x 100 pix (~100 km x 100 km)  Simultaneous analysis for OH & OI-5577 observed on same time & same spatial grid of 31 image sequence windows.

 Analysis the OH & OI-555.7nm airglow ASC image (2013 data) observed at King Sejong Staion (62°S, 58°W) utilizing Matsuda-FFT program.

 Characteristics of seasonal variation of 𝑸𝑻𝑬 over King Sejong Station

• 1. Seasonal variation with strong wave activities during winter time.

 Tendency of non-monochromatic waves on ASC images during winter.  Expanded feature in PSD distribution might be due to secondary GWs.  Probability of secondary GWs observed on ASC images.  Secondary GWs probably contribute to increase power in 𝑄𝑇𝐸 during winter.

• 2. Larger wave activities at KSS than Syowa & Davis station.

 Antarctic Peninsula is well known as one of the GW hot spots.

• 3. Larger wave activities on OH layer than those of OI-557.7 layer

 In general, 𝑄𝑇𝐸 of OH > 𝑄𝑇𝐸 of OI-557.7.  Inference for critical filtering from blocking diagram using horizontal wind from KSS meteor radar.  Found the events which show difference PSD distribution between OH and OI-557.7 similar with the wind blocking diagram.  About half of events show attenuated power of waves in OI-557.7 nm images probably due to wind filtering when waves propagated through MLT region.

 The result is ‘Preliminary work’: Future works  Analysis the 2014-2016 for climatology.

Thank You For Listening!!

Contacts: Hosik Kam: kamhosik@cnu.ac.kr

Propagation analysis of mesospheric gravity waves on OH and OI-557.7 nm airglow layers

• ver King Sejong Station, Antarctic Peninsula

Hosik Kam1, Yong Ha Kim1, Takuji Nakamura2,3, Masaki Tsutsumi2,3, Yoshihiro Tomikawa2,3 , Masaru Kogure3,2, Septi Perwitasari2, Jeong-Han Kim4

1 Department of Astronomy, Space, and Geology, Chungnam National University, Daejeon, South Korea 2 National Institute of Polar Research, Tachikawa, Japan 3 Department of Polar Science, SOKENDAI (The Graduate University for Advanced Studies), Tachikawa, Japan 4 Division of Polar Climate Sciences, Korea Polar Research Institute, Incheon, South Korea

Results_ PSD of OH images

March April May June July August September October

Results_ case of 𝑄𝑇𝐸 of OH < 𝑄𝑇𝐸 of OI-557.7

OH PSD OI-557.7 PSD

Difference PSD (OH PSD – OI PSD) 2013.3.7