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 4 th 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 Comandante Ferraz Palmer Rothera Syowa South Pole Davis McMurdo Jang Bogo McMurdo

ANGWIN All-Sky IR Imaging Network InGaAs camera • The ASI network: mainly comprises a set of infrared IR OH (IR) digital imaging systems sited around Antarctica. emission spectrum • 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

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 (1.5-1.65 μ m) OH (3,1) band to South Pole derive high-quality temperature maps. • Temperature precision/pix ~1-2 K in <30 sec. • High-latitude capability as emission lines avoid auroral contamination. AMTM at South Pole PFRR Aurora + Airglow ALOMAR (69.3° N, 16.0° E) South Pole (90ºS) Data since 2011 (3 winters each site) Temperature: ratio of P 1 (2) and P 1 (4) lines

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

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. Model WRF temperatures at 40-km (Courtesy, B. Kaifler, DLR) (Alexander and Teitelbaum, 2011)

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

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

Keogram Technique N S E W Time

24 – hr Summary Keogram Showing a Broad Spectrum of Waves at South Pole July 01, 2012 South Pole OH (3,1) rotational temperature Front 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.

Bores (Dewan and Picard, 2001) http://www.severn-bore.co.uk/ The River Severn bore, UK • Bores are guided/ducted waves. http://www.dropbears.com/brough/index.html • 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 “Morning Glory” over Australia the front dissipates energy.

Characteristics of a “Frontal/Bore” Event May19-20, 2012 N Over 80 strong frontal events observed from South Pole during the past 5 winter seasons . S (Pautet et al., 2017) E Note the growth in the trailing wave crests with time W Event characteristics: Horizontal wavelength = 39.0 km, Horizontal phase speed = 79 m/s, Observed period 8.3 min Direction of motion 279.5°

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 Gravity Waves Planetary Waves 600 10000 2012 18 day 2012 Normailzed Power Normalized Power 400 45 day 5000 5 day 28 day 200 0 0 0 6 12 18 24 0 20 40 60 Period (hour) Period (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

Remarkable ~28-Day Planetary Wave During Winter 2014 at South Pole • ~4.5 cycles observed • Amplitude ~12K. Lomb-Scargle Analysis 28.7-day (Courtesy Y. Zhao, USU)

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 2014 Band pass filter: 24-30 days 260 20 days Rothera (Y. Zhao ) 240 Southpole Temperature (K) SOFIE_Rothera 10 Temperature (K) 220 0 200 180 -10 OH (3,1) Rothera 160 AMTM -20 0 60 120 180 240 300 360 60 120 180 240 300 Date Date 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. 100 -5.000 80 -3.000 Altitude (km) Temperature (K) -1.000 60 1.000 40 3.000 20 5.000 90 180 270 360 Date Figures show 3-D structure of the Rossby wave observed by SOFIE and MLS during 2014 .

Short Period GW Investigation Using All-Sky IR Imaging Network InGaAs camera • The ASI network: mainly comprises a set of infrared IR OH (IR) digital imaging systems sited around Antarctica. emission spectrum • 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

Wave Propagation Around Antarctica Rothera Syowa Davis 2012 2012 2011 0 0 0 150 150 150 330 30 330 30 330 30 100 100 100 300 60 300 60 300 60 50 50 50 0 0 270 90 0 0 270 90 0 0 270 90 50 50 50 240 120 240 120 240 120 100 100 100 210 150 210 150 210 150 150 150 150 80 events 183 events 209 events 180 180 180 Plots of wave phase speed vs. direction for each event • 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.

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 2012 : Large Short-Term Variability Halley Station ● 5650 Images ● May 11, 2012 ● ~ 940 Minutes (Courtesy: V. Chambers)

Halley Station June 16, 2012 4100 Images ~ 680 Minutes

Halley Station July 19, 2012 5400 Images ~ 720 Minutes

Halley Station August 15, 2012 4300 Images ~ 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 PFRR PFRR ASI Jan 2011 – Apr 2013 ALOMAR AMTM Oct 2011 – Mar 2012 PFRR PFISR Aug 2010 – Apr 2013

MLT GW Results PFRR ASI, Three Winters, 289 Events Mean: 44 ± 1 m/s 29 ± 1 km 12 ± 1 min ALOMAR AMTM, One Winter, 310 Events Mean: 13 ± 1 min 35 ± 1 m/s 21 ± 1 km

MLT GW Phase Velocities Similar characteristics over large longitude range. PFRR ASI ALOMAR AMTM

ALOMAR: Effects of Wind Blocking on Observed GWs Blocked Region at MLT