NOAA/ESRL Greenhouse Gas and Ozone Measurements from Aircraft in Alaska

Transcription

1 NOAA/ESRL Greenhouse Gas and Ozone Measurements from Aircraft in Alaska A. Karion C. Sweeney, S. Wolter, T. Newberger, L. Patrick, H. Chen, S. Oltmans, B. Miller, S. Montzka, P. Tans GMD Annual Conference 18 May 2011

2 Outline Motivation Instrumentation and data quality Factors influencing seasonal variability - Boundary layer processes - Stratospheric exchange - Transport from low latitudes

3 Alaska Coast Guard (ACG) Aircraft Site U.S. Coast Guard conducts regular flights across Alaska for Arctic Domain Awareness (ADA); for search and rescue operations as sea ice melts. NOAA/USCG collaboration flights of opportunity Test bed for instrumentation for commercial aircraft Unprecedented scientific opportunity monitoring Arctic response to warming and sea ice melting establish baseline and monitor inter-annual variability stratospheric/tropospheric exchange

4 Alaska Coast Guard (ACG) Aircraft Site Inlet plate replaces existing window Temperature, RH, and Pressure 3 calibration gases (CO/CO 2 /CH 4 ) control box / datalogger 2 flask packs Picarro CRDS ozone Flask compressor - continuous CO 2 /CH 4 /CO, O 3, T, RH, P - 24 Flasks (PFP) with > 50 species *Thanks to Duane Kitzis, Pat Lang, Paul Novelli for tanks and flask analysis.

5 Flask Comparisons (2010 season) mean = ppm 1-σ = 0.41 ppm mean = -0.2 ppb 1-σ = 3.8 ppb CO 2 CH 4 Flask CRDS (ppm) Flask CRDS (ppb) N=205 N=203 *only 2 flights with CO so far: -3 ppb ± 4 ppb

6 Barrow Barrow Kivalina Kivalina Galena Fairbanks (PFA) Galena Fairbanks (PFA) Anchorage Month Anchorage Month Kodiak Kodiak Kivalina Barrow Galena Fairbanks (PFA) Bi-weekly 8-hour flights on C-130 March November 16 flights per season Kodiak large spatial extent (> 3000 km & 3 profiles per flight) 2011 much of the sampling occurs at high altitude (~8000 m)

7 Dip into BL for profile over Kivalina CH 4 CO 2 4 April 2011

8 Dip into BL for profile over Kivalina CH 4 CO 2 stratospheric influence High CO band CO Ozone 4 April 2011

9 2011 ACG flights: high CO layers 1.1 ppb/ppb 39 ppb/ppm CH 4 (ppb) 0.3 ppb/ppb CO (ppb) Prudhoe Bay 12 ppb/ppm CO (ppb) CO 2 (ppm) High-altitude pollution band (~7.8 km) Similar bands of high-altitude CO observed in recent campaigns (ARCTAS [Singh et al. 2010, Warneke et al. 2009], and HIPPO [Wofsy et al. 2011])

10 2011 ACG flights: Winter m = 12.2±0.02 R 2 =0.92 Prudhoe Bay Stratospheric influence

11 2011 ACG flights: Winter m = 12.2±0.02 R 2 =0.92 AGASP III (1992) Prudhoe Bay Stratospheric influence *Conway et al., 1993

12 Seasonal Cycle in CO 2 and CH 4 summer winter

13 Seasonal Cycle in CO 2 and CH 4 Strat/trop BL processes? Photosynthesis/respiration summer winter Low altitude High altitude CH 4 by month BL processes?

14 Altitude (in-)dependence of Seasonal Cycle (CH 4 ) Much of the variability is transported from lower latitudes Kivalina, AK (ACG) JFM AMJ JAS OND Poker Flat, AK JFM AMJ JAS OND New Hampshire Small gradient despite surface influence of interior Alaska JFM AMJ JAS OND (MLO Seasonal Cycle AND Trend subtracted)

15 Summary Regular flights on a C-130 collect continuous data autonomously Test bed for future measurements on commercial or cargo aircraft Reveal interesting science regular flights throughout the season over multiple years Variability in CO 2 and CH 4 largely transported from lower latitudes Addition of continuous CO valuable for pinpointing high-altitude pollution

16 Spring April 30 May March 30 April 27 May 7 May 25 July Summer June June 22 Aug 9 Aug 19 July 20

17 Fall 2009 Oct 13 Oct Sep 23 Sep 28 Oct 12 Oct 26 Nov 10 Nov 23 Winter Nov 23

18 2010 Seasonal Cycle: Kivalina summer ~ 8-10 ppm winter summer ~ 8 ppm winter ~ 18 ppm CO 2 and CH 4 over Kivalina CO 2 altitude profile over Kivalina

19 2011 flights: high CO layers High-altitude pollution band (4/4/2011 data shown) ARCTAS campaign observed similar plumes (Warneke 2009; Singh 2010) attributed to biomass burning in Asia in Singh et al report 0.25 ppb CH 4 / ppb CO and 65 ppb CO/ ppm CO 2 in aged BB / urban plumes at 6.9 km over Alaska. Pollution bands also observed on HIPPO-2 (Nov 2009) at 6-8 km over Arctic (Wofsy et al, 2011), with CO up to 250 ppb.

20 2011 flights: Stratospheric Influence 4/4/2011 and 4/21/2011 4/4/2011 only O 3 CH 4 Ozone profiles over Kivalina on two different days show significant stratospheric influence.

21 2009 Season Flight Paths 4/30 5/12 6/23 7/28 10/13 10/27 11/10 11/23

22 2010 Season Flight Paths 3/30 4/27 5/07 5/25 6/22 8/09 8/19 9/23 9/28 10/12 10/26

23 Flask Analysis (both seasons)

24 ACG Flasks

25 Comparison to other datasets: CO 2 /CH 4 A-Gasp Missions (March & April) subtract MLO trend include flights from Poker Flat, AK and ACG March/April only Flask data only

26 Comparison to other datasets: CO 2 /CO subtract MLO trend include flights from A-Gasp III, Poker Flat, AK and ACG March/April only enhancement ratios typical of urban air