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

Transcription

1 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, April, 2018

2 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

3 9 Antarctic Sites (2016-to date) omandante Ferraz Palmer Halley Rothera Syowa South Pole McMurdo Jang Bogo Davis McMurdo

4 ANGWIN All-Sky IR Imaging Network InGaAs camera IR OH emission spectrum 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

5 High Latitude Advanced Mesospheric Temperature Mapper (AMTM) (2011-to date) AMTM at South Pole 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 ( μm) OH (3,1) South band Poleto 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 (90ºS) PFRR Aurora + Airglow Data since 2011 (3 winters each site) Temperature: ratio of P 1 (2) and P 1 (4) lines

6 New AMTM Operational Fall 2017-to date. McMurdo Station (78 S)

7 Dual AMTM Investigation of Long-Range GW Propagation:McMurdo - South Pole Collaborative Study with Fe Lidar (X. Chu, USA) at McMurdo

8 New AMTM and Lidar Measurements at SAAMER, Rio Grande, Argentina (53 S) Model WRF temperatures at 40-km (Alexander and Teitelbaum, 2011) Rayleigh lidar (DLR) and AMTM (USU) operational at the SAAMER radar site (red spot), since November (Courtesy, B. Kaifler, DLR)

9 Rio Grande, Argentina, First AMTM Data (November 27-28, 2018) PI: Dominique Pautet Movie Duration ~5 hours

10 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)

11 USU ANGWIN Summary Observations

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

13 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

14 Keogram Technique N S E W Time

15 24 hr Summary Keogram Showing a Broad Spectrum of Waves at South Pole July 01, 2012 OH (3,1) rotational temperature South Pole OH (3,1) relative band intensity Front Non-stop observations from mid-april to end of August > ~3200 hrs (4.5 months), only limited by weather.

16 Bores The River Severn bore, UK Morning Glory over Australia (Dewan and Picard, 2001) 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.

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

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

19 Winter Season OH Rotational Temperatures at South Pole Similar winter averages Strong variability during the winter and year-to-year

20 GW and PW Spectra, South Pole, 2012 Normalized Power Gravity Waves 2012 Normailzed Power day Planetary Waves 45 day 5 day 28 day 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

21 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)

22 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)

23 Combined Ground-based and Satellite Measurements Temperature (K) OH (3,1) Rothera AMTM Date (Y. Zhao) 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 days. Temperature (K) Band pass filter: days days Rothera 0-10 Southpole SOFIE_Rothera Date Altitude (km) Temperature (K) Date Figures show 3-D structure of the Rossby wave observed by SOFIE and MLS during 2014.

24 Short Period GW Investigation Using All-Sky IR Imaging Network InGaAs camera IR OH emission spectrum 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

25 Wave Propagation Around Antarctica Rothera Syowa Davis events 80 events 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 events Plots of wave phase speed vs. direction for each event

26 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, Note the different levels of wave power and differing directionalities. Day-to-day variability at a given site can be quantified during season.

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

28 Halley Station 4100 Images June 16, 2012 ~ 680 Minutes

29 Halley Station 5400 Images July 19, 2012 ~ 720 Minutes

30 Halley Station 4300 Images August 15, 2012 ~ 715 Minutes

31 Investigating the Climatology of Mesospheric and Thermospheric Gravity Waves at High Northern Latitudes Dr. Michael R. Negale Complementary studies to ANGWIN GW observations.

32 High Latitude MLT and Thermosphere ALOMAR PFRR PFRR ASI Jan 2011 Apr 2013 PFRR PFISR Aug 2010 Apr 2013 ALOMAR AMTM Oct 2011 Mar 2012

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

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

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

36 18 May 2011 PFISR MSTIDs Electron density profiles from the zenith pointing beam. Low passed filtered electron densities. Relative electron density perturbations

37 Results for a Single MSTID 18 May 2011 Altitude averaged values: Period: 58 min. Horizontal Wavelength: 400 km Horizontal Phase Speed: 115 m/s * Note the increase in horizontal wavelength with altitude, consistent with Vadas [2007] theoretical study.

38 652 Events Whole Year PFISR MSTID Results Thermosphere Mesosphere Mean: 41 min 446 km 187 m/s ASI AMTM 12 min 13 min 29 km 44 m/s 21 km 35 m/s

39 Ishida et al. [2008] PFISR/SuperDARN MSTID Azimuth Comparison for Fall/Winter Frissell et al. [2016] Ishida et al. [2008] (Dec 2003 Feb 2013): 125 EVENTs PFISR: 262 EVENTs PFISR: 130 EVENTs Frissel et al. [2016] (Nov 2012 Apr 2015): 304 EVENTs

40 PFISR MSTID Full Seasonal Propagations Summer (May - Aug) Fall (Sep Oct) Winter (Nov - Feb) Spring (Mar - Apr) New Northern Hemisphere Spring/Summer Time Results

41 PFISR MSTID Full Seasonal Propagations Summer (May - Aug) Fall (Sep Oct) Winter (Nov - Feb) Spring (Mar - Apr) New NH spring/summer time results: Establishes a full seasonal GW propagation cycle for high latitude MSTIDs.

42 Summary 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.

43 The Atmospheric Waves Experiment (AWE) A NASA Heliophysics Explorers Mission of Opportunity Phase A Study Science Team Mike J Taylor 1, J M Forbes 2, D C Fritts 3, S D Eckermann 4, H-L Liu 5, J B Snively 6, and D Janches AWE Mission To investigate & quantify the impacts of small-scale GWs (λ h ~ km) that produce the greatest ITM effects.