Investigating Mesospheric Wave Activities at High Latitude Stations - - PowerPoint PPT Presentation

Investigating Mesospheric Wave Activities at High Latitude Stations and South Pole

Yucheng Zhao, M. J. Taylor, P.-D. Pautet,

• D. Soward, W. R. Pendleton Jr.

CASS, Utah State University, USA

4th ANGWIN, INPE Brazil, April 24-26, 2018

High-Latitude Research Using an Advanced Mesospheric Temperature Mapper (AMTM)

• The AMTM sequentially observes selected

emission lines in the OH (3,1) band to derive high-quality temperature maps @ ~85 km.

• Temperature precision/pix ~2 K in 30 sec.
• High-latitude capability as emission lines avoid

auroral contamination.

• 2 AMTM operational since 2011: ALOMAR,

Northern Norway (69.3°N), and at South Pole (90°S) Antarctica.

• 3rd AMTM installed at McMurdo station (78°S)

2017.

• Oct 2017, one of the AMTMs was relocated

from ALOMAR to Poker Flat Research Range (65°N) AMTM at South Pole

AMTM Temperature Map

• Zenith temperature (20x20 central pixels)

Daily Temperature Measurements

>2,500 data pts/24 hours

temperature

High latitude Sites: South and North

South Pole (90ºS)

McMurdo (78°S) Poker Flat (65°N)

Sites and Data

ALOMAR South Pole McMurdo PFRR

Latitude

69.3° N 90° S 78° S 65° N

Season starting date

Oct 1 April 19 March 21

• Nov. 1

(2017)

Season ending date

April 15 August 31 September 30 April

Season duration

6.5 Months 4.5 months >6 months ~6 months

Daily data duration

longest ~16-17 hours Mostly 24 hours Some 24 hours ~16 hours

Winter Season Daily Mean Temperatures

180 190 200 210 220 230 240

Temperature (K)

ALOMAR 2012-13

Oct Nov Dec Jan Feb Mar Apr

180 190 200 210 220 230 240 Apr May Jun Jul Aug

Temperature (K) South Pole 2012

60 120 180 240 300 180 190 200 210 220 230 240

Temperature (K) Date McMurdo 2017

170 180 190 200 210 220 230 240

Temperature (K)

Nov Dec Jan Feb Mar

Poker Flat 2017-18

211.0 ±12 K 212.7 ± 10 K 214.3 ± 10 K 205.5 ± 8 K

Kaoru Sato: 2nd Information related to ICSOM-3 and request of data

The Major Sudden Stratospheric Warming (SSW): 12 February 2018

Planetary Wave Activities

• Rich spectrum from both sites
• Planetary waves with different periods were observed

5 day 18 day 45 day 28day

10 20 30 40 50 60 70 80 1000 2000 3000 4000

40 days Normalized Power Period (day) 14 days

ALOMAR South Pole

Planetary Wave Activities

10 20 30 40 50 60 1000 2000 3000 4000 5000 6000

Normalized Power Period (day) McMurdo, 2017

10 20 30 40 50 1000 2000 3000 4000 5000

Normalized Power Period (day)

Poker Flat, 2017-18

Mesospheric Planetary Waves Observed at South Pole

2012

160 170 180 190 200 210 220 230

Temperature (K)

Oct Dec Jan Mar

Planetary Wave Activities at ALOMAR (a year later)

90 120 150 180 210 240 180 200 220 240

Date Temperature (K)

ALOMAR 2015-2016 South Pole 2014

Similar wave was observed during the 2015-16 winter season at ALOMAR. Period~ 23 days

The PW Mike and Dominique Mentioned:

McMurdo 2017: the return of the 28 day Rossby wave?

Gravity Wave/Tide Spectrum

• ALOMAR:
• Strong semidiurnal tides
• Gravity waves 3-10 hours
• South pole:
• No/very weak tides
• Strong gravity wave activities with periods 4-10 hours

6 12 18 24 200 400 600

Normalized Power Period (hour) 2012

6 12 18 24 500 1000 1500

Normalized Power period (hr) ALOMAR 2012-2013

South Pole

GW/Tidal spectrum at PFRR and McMurdo

6 12 18 24 500 1000 1500 2000

Normalized Power Period (hour)

Poker Flat, 2017-18

6 12 18 24 200 400 600 800 1000

Normalized Power Period (hour) McMurdo 2017

• Similar GW spectrum
• Clear tidal signature at Poker Flat

The Mid-Latitude GW Activities (Chile, 30ºS)

Gravity wave energy peaked in the middle of each winter season.

Daily Temperature Variance (GW activities)

120 150 180 210 240 10 20 30 40 50

Temperature Variance (K2) Date

10 20 30 40 50 60 70

Mar Apr Feb Jan Dec Nov

Temperature Variance (K2)

Oct

ALOMAR South Pole

The variance from both sites are of similar values ALOMAR: wave energy decreased South Pole: wave energy increased Yoshiki and Sato (2000): gravity wave energy peaked in spring in the stratosphere (SH)

300 330 360 390 420 450 10 20 30 40 50

Temperature Variance (K2)

Date Poker Flat 2017-18

120 180 240 10 20 30 40 50 60

Temperature Variance (K2) Date

McMurdo 2017

Daily Temperature Variance (GW activities)

Multi-Year: South Pole vs. ALOMAR

120 150 180 210 240 10 20 30 40

Temperature Variance (K2) Date

2011 2012 2013 2014

10 20 30 40

Temperature Variance (K2)

2013-14 2014-15 2012-13 Oct Dec Feb Apr

ALOMAR

South Pole

Summary

• Winter time mesospheric temperature data from four unique sites,

ALOMAR, PFRR, McMurdo and South Pole stations, showed similarities and differences during winter seasons.

• Similar winter time mean temperature for all stations but clear decrease

through the winter for 3 stations other than PFRR which showed SSW signature in Feb.

• Different planetary waves were observed from all sites and year-to-year

variability in planetary wave activities for South Pole and ALOMAR.

• Short-period gravity wave spectrum are similar. However, strong semi-

diurnal tides were observed at 3 high latitude stations, while no/weak tidal signatures at South Pole during winter season.

• During the winter season, gravity wave energy increased at South Pole.
• The other three high latitude stations, wave energy peaked in the middle
• f the winter season except for 2012-13 season at ALOMAR where the

wave energy decreased through the winter.

• Questions:

What contribute to the change of the GW energy variation during the winter season? Lower atmospheric sources, filtering conditions?