ANGWIN Research Activities at Utah State University: Summary and - - PowerPoint PPT Presentation

ANGWIN Research Activities at Utah State University: Summary and Future Plans

Mike J. Taylor, P.-D. Pautet, Y. Zhao, M. Negale,

• V. Chambers, W.R. Pendleton Jr.,

and ANGWIN Colleagues

4th International ANGWIN Workshop, Sao Jose dos Campos, Brazil, 24-26 April, 2018

ANGWIN Instrument Network:2(3) New Stations

Collaborating institutes from: USA, Japan, UK, Australia, Brazil, South Korea…

Goal: To measure and understand large-scale climatology and effects of mesospheric gravity waves over Antarctica

9 Antarctic Sites (2016-to date)

Halley Syowa Davis McMurdo South Pole Rothera Palmer Comandante Ferraz McMurdo Jang Bogo

ANGWIN All-Sky IR Imaging Network

• The ASI network: mainly comprises a set of infrared

(IR) digital imaging systems sited around Antarctica.

• Primary Goal: To obtain unique coordinated 2D

image data of mesospheric gravity wave activity and horizontal propagation parameters.

• InGaAs detector: 70 x stronger OH emission in IR
• Weaker moonlight and auroral emissions in IR

InGaAs camera

IR OH emission spectrum

High Latitude Advanced Mesospheric Temperature Mapper (AMTM) (2011-to date)

• Capability: High-resolution mapping of gravity

wave intensity and temperature field at ~87 km and wave phase relationship.

• Sequentially observes selected emission lines

in the infrared (1.5-1.65μm) OH (3,1) band to derive high-quality temperature maps.

• Temperature precision/pix ~1-2 K in <30 sec.
• High-latitude capability as emission lines avoid

auroral contamination.

ALOMAR (69.3° N, 16.0° E)

South Pole

South Pole (90ºS) AMTM at South Pole

Data since 2011 (3 winters each site) Temperature: ratio of P1(2) and P1(4) lines Aurora + Airglow PFRR

McMurdo Station (78°S)

New AMTM Operational Fall 2017-to date.

Dual AMTM Investigation of Long-Range GW Propagation:McMurdo - South Pole

Collaborative Study with Fe Lidar (X. Chu, USA) at McMurdo

Model WRF temperatures at 40-km (Alexander and Teitelbaum, 2011)

New AMTM and Lidar Measurements at SAAMER, Rio Grande, Argentina (53°S)

Rayleigh lidar (DLR) and AMTM (USU) operational at the SAAMER radar site (red spot), since November 2017. (Courtesy, B. Kaifler, DLR)

Rio Grande, Argentina, First AMTM Data

(November 27-28, 2018) PI: Dominique Pautet

Movie Duration ~5 hours

USU ANGWIN Activities Over Past 2-years

All-Sky OH Imagers:

• Continued winter-time observations of GW from 4 established

stations (McMurdo, South Pole, Davis, and Rothera) 2011 to date.

• IR ASI observations at Halley stopped (2017) due to safety

concerns at base (giant crevasse)

• IR ASI moved to Rothera to complement long-term CCD ASI GW

measurements (2000 -to date)

• New extended-red CCD installed at Palmer 2016 to extend

peninsula GW coverage. Data contamination by station/ship lights.

• AMTM Continued Observations and new instrumentation:
• Continued winter-time observations by original AMTM at South

Pole (2012-to date)

• New AMTM installed at McMurdo (2017) for long-range GW

propagation studies (2017 -to date)

• A third AMTM recently installed at Rio Grande, Argentina (across

Drake Passage) extending latitudinal coverage (Nov.2017-to date)

USU ANGWIN Summary Observations

AMTM Data Examples

Long term temperature evolution of Planetary Waves (see Zhao et al.) Keograms - 1-12hrs waves/tides Temperature/Intensity maps Short-period GWs (see Pautet et al.)

Amundsen-Scott, South Pole Station

Research goal: To quantify the characteristics and variability of mesospheric gravity waves deep within the Anatarctic winter polar vortex AMTM and ASI Observations 2011-to date

Keogram Technique

N S W E Time

24–hr Summary Keogram Showing a Broad Spectrum

• f Waves at South Pole

OH (3,1) rotational temperature OH (3,1) relative band intensity

Non-stop observations from mid-April to end of August > ~3200 hrs (4.5 months), only limited by weather.

July 01, 2012 South Pole

Front

Bores

The River Severn bore, UK “Morning Glory” over Australia

http://www.dropbears.com/brough/index.html http://www.severn-bore.co.uk/

• Bores are guided/ducted waves.
• Characterized by an extensive sharp

leading “front” (step).

• Undular Bore: trailing waves are

phase-locked and propagate along the stable layer.

• Wave crests are added with time as

the front dissipates energy.

(Dewan and Picard, 2001)

Characteristics of a “Frontal/Bore” Event

May19-20, 2012

Over 80 strong frontal events

• bserved from South Pole during the

past 5 winter seasons.

N S E W

Event characteristics: Horizontal wavelength = 39.0 km, Horizontal phase speed = 79 m/s, Observed period 8.3 min Direction of motion 279.5° Note the growth in the trailing wave crests with time

(Pautet et al., 2017)

Temperature Movie Showing Growth of Trailing Waves (May 19/20 2012)

Winter Season OH Rotational Temperatures

at South Pole 2011-2015

Similar winter averages Strong variability during the winter and year-to-year

GW and PW Spectra, South Pole, 2012

20 40 60 5000 10000

Normailzed Power Period (day) 2012 18 day

28 day 45 day

• Broad range of gravity waves (GW), no significant tides
• Rich spectrum of planetary waves (PW) (e.g. Sivjee and

Walterscheid, 2002)

• For 2012: 5, 18, 28, 45 days
• Significant year to year variability

5 day

6 12 18 24 200 400 600

Normalized Power Period (hour) 2012

Gravity Waves Planetary Waves

Remarkable ~28-Day Planetary Wave During Winter 2014 at South Pole

(Courtesy Y. Zhao, USU)

Lomb-Scargle Analysis

28.7-day

• ~4.5 cycles
• bserved
• Amplitude ~12K.

Comparison of Davis and South Pole OH Temperature Data 2014

Davis (69S, 78 E)

• Spectral analysis of Davis OH Spectrometer temperature

data shows no significant 28 day PW (Y.Zhao, D. Murphy)

Combined Ground-based and Satellite Measurements

60 120 180 240 300 160 180 200 220 240 260

Temperature (K) Date

OH (3,1) Rothera AMTM 2014 90 180 270 360 20 40 60 80 100

Date Altitude (km)

• 5.000
• 3.000
• 1.000

1.000 3.000 5.000

Temperature (K)

Figures show 3-D structure of the Rossby wave observed by SOFIE and MLS during 2014. South Pole and Rothera data together with SOFIE/AIM and MLS/Aura satellite data identify this as a Rossby wave (1,4) mode (Madden, 2007; Sassi et al., 2012) with theoretical period of 28.08 days.

Band pass filter: 24-30 days

60 120 180 240 300 360

• 20
• 10

10 20

Temperature (K) Date

Rothera Southpole SOFIE_Rothera

days

(Y. Zhao)

Short Period GW Investigation Using All-Sky IR Imaging Network

• The ASI network: mainly comprises a set of infrared

(IR) digital imaging systems sited around Antarctica.

• Primary Goal: To obtain unique coordinated 2D

image data of mesospheric gravity wave activity and horizontal propagation parameters.

• InGaAs detector: 70 x stronger OH emission in IR
• Weaker moonlight and auroral emissions in IR

InGaAs camera

IR OH emission spectrum

Wave Propagation Around Antarctica

• These 3 sites at similar latitudes (67-69°S) all

exhibited similar winter seasonal wave dynamics.

• Many low speed (<40 m/s) westward waves
• Eastward events exhibited much higher (>70 m/s) phase speeds.
• Consistent with critical level filtering by wintertime eastward

stratospheric winds blocking low velocity eastwards waves.

50 100 150 30 60 90 120 150 180 210 240 270 300 330 50 100 150 50 100 150 30 60 90 120 150 180 210 240 270 300 330 50 100 150 50 100 150 30 60 90 120 150 180 210 240 270 300 330 50 100 150

Rothera Syowa

183 events 209 events 80 events

2012 2011 2012

Davis

Plots of wave phase speed vs. direction for each event

New Velocity Analysis Method

(Matsuda et al., JGR, 2014)

• A new spectral analysis method for quantifying

the horizontal gravity wave phase velocity distribution.

• Very good comparison of 2011 season integrated

wave power spectrum with individually measured wave events from Syowa.

• Results from 4 ANGWIN sites for selected days in April-May, 2013.

Note the different levels of wave power and differing directionalities.

• Day-to-day variability at a given site can be quantified during season.

Halley Station ● 5650 Images ● May 11, 2012 ● ~ 940 Minutes

Halley 2012 : Large Short-Term Variability

(Courtesy: V. Chambers)

Halley Station 4100 Images June 16, 2012 ~ 680 Minutes

Halley Station 5400 Images July 19, 2012 ~ 720 Minutes

Halley Station 4300 Images August 15, 2012 ~ 715 Minutes

Investigating the Climatology of Mesospheric and Thermospheric Gravity Waves at High Northern Latitudes

• Dr. Michael R. Negale

Complementary studies to ANGWIN GW observations.

High Latitude MLT and Thermosphere

ALOMAR AMTM Oct 2011 – Mar 2012 PFRR PFISR Aug 2010 – Apr 2013 PFRR ASI Jan 2011 – Apr 2013 PFRR ALOMAR

MLT GW Results

ALOMAR AMTM, One Winter, 310 Events

Mean: 29 ± 1 km 44 ± 1 m/s 12 ± 1 min Mean: 21 ± 1 km 35 ± 1 m/s 13 ± 1 min

PFRR ASI, Three Winters, 289 Events

ALOMAR AMTM PFRR ASI

MLT GW Phase Velocities

Similar characteristics over large longitude range.

ALOMAR: Effects of Wind Blocking on Observed GWs

Blocked Region at MLT

Relative electron density perturbations Low passed filtered electron densities. Electron density profiles from the zenith pointing beam.

18 May 2011

PFISR MSTIDs

Altitude averaged values:

• Period: 58 min.
• Horizontal Wavelength: 400 km
• Horizontal Phase Speed: 115 m/s

18 May 2011

* Note the increase in horizontal wavelength with altitude, consistent with Vadas [2007] theoretical study.

Results for a Single MSTID

652 Events 187 m/s Mean: 41 min Thermosphere Mesosphere

Whole Year PFISR MSTID Results

21 km 35 m/s 13 min AMTM 29 km 44 m/s 12 min ASI 446 km

Ishida et al. [2008] (Dec 2003 – Feb 2013): 125 EVENTs PFISR: 130 EVENTs

Ishida et al. [2008]

Frissel et al. [2016] (Nov 2012 – Apr 2015): 304 EVENTs PFISR: 262 EVENTs

Frissell et al. [2016]

PFISR/SuperDARN MSTID Azimuth Comparison for Fall/Winter

Fall (Sep – Oct) Winter (Nov - Feb)

PFISR MSTID Full Seasonal Propagations

Summer (May - Aug) Spring (Mar - Apr)

New Northern Hemisphere Spring/Summer Time Results

Fall (Sep – Oct) Winter (Nov - Feb)

PFISR MSTID Full Seasonal Propagations

Summer (May - Aug) Spring (Mar - Apr)

New NH spring/summer time results: Establishes a full seasonal GW propagation cycle for high latitude MSTIDs.

• New longitudinal GW studies revealed similar mesospheric

GW characteristics.

• Dominant propagation direction towards NW and a

secondary peak to the NE.

• Low phase speed events to the west and high phase

speed events to the east, consistent with wind blocking.

• Novel coincident thermospheric/mesospheric GW study

using combined radar and optical measurements.

• Established first full season thermospheric GW

characteristics at high latitudes.

• GW azimuths in mesosphere/thermosphere showed

consistent seasonal changes mainly driven by critical level wind blocking.

Summary

Mike J Taylor1, J M Forbes2, D C Fritts3, S D Eckermann4, H-L Liu5, J B Snively6, and D Janches7

Science Team

1 2 4 3 5 6 7

AWE Mission To investigate & quantify the impacts of small-scale GWs (λh~30- 300 km) that produce the greatest ITM effects.

The Atmospheric Waves Experiment (AWE)

A NASA Heliophysics Explorers Mission of Opportunity “Phase A” Study