Download presentation
Presentation is loading. Please wait.
Published byPhilip McCarthy Modified over 6 years ago
1
NWAS—NOAA’s flask program for aircraft missions
a.k.a., NOAA’s programmable flask packages (PFPs) Status: * Not yet a funded project for ATom-1 or other ATom deployments * Is currently included in upload planning for ATom-1 in close coordination with PANTHER/UCATS * PFP sampling essentially flight-ready in a configuration similar to that used in HIPPO some changes will be made (e.g., pump, computer control) * Analysis instruments will be by: CCGGG MAGGIC (as in HIPPO) INSTAAR (adding 13CH4 in place of CO2 isotopes in HIPPO) GCMS (which instrument still being considered on basis of gases and precision) Needs: * funding to allow participation in the project— drop-dead date for participation: mid fall, 2015, (know by start of fiscal year) * sampling frequency of flasks is limited by availability of PFPs at NOAA. * as a result, shipping to/from needs to be expedited to minimize time out of service. * rack configuration needs to be finalized with PANTHER and UCATS. S. Montzka C. Sweeney J. Elkins F. Moore NOAA and CIRES Note new addition—regarding INSTAAR contributions, 13CH4 added in place of CO2 isotopes…
2
Three possible configurations.
#1 Preferred and current anticipated. DC-8 layout tight for PANTHER and UCATS #2 PFP’s out of packaging and into low rack. #3 HIPPO configuration use GV full rack and ½ rack side by side. #1 #3 #2
3
#3 HIPPO configuration use GV full rack and ½ rack side by side.
4
NWAS—NOAA’s flask program for aircraft missions
NWAS PFP’s on ATom will: Supply useful and unique science deliverables, Integrated as part of the PANTHER/UCATS combined NOAA-GMD package. Operated, and maintained by PANTHER/UCATS personnel on DC-8. Science deliverables from pfp’s includes: 1) Measurements of: * 13CH4 with sensitivity to assorted chemical processing. * High precision data for CH3CCl3 (MC) sensitive to global OH. * A wide suite of long-lived trace gases, short-lived halogenated gases, hydrocarbons, carbonyl sulfide, ………. 2) As a result of these measurements: A direct link between data from DC-8 instrumentation and: * WMO calibration scales * Global measurements in the NOAA surface networks. thus providing a broader context to ATom results in time and space.
5
NWAS—NOAA’s flask program for aircraft missions
What is NWAS ? Sample collection during flight in glass flasks: * 24 flasks collected per flight (2 × 12 flask packages) * Up to 240 flasks collected per ATom deployment (20 packages-funding dependent) Subsequent flask analysis at NOAA/GMD and CU/INSTAAR for measurements of: * isotopes of CH4 (13CH4) * the main long-lived greenhouse gases (CO2, CH4, N2O, HFCs, SF6, PFCs*) * the main ozone-depleting substances (CFCs, HCFCs, halons, CH3Br, methyl chloroform**, CCl4...) * naturally emitted halogenated gases (CH3Cl, CH2Br2, CHBr3*, CH3I) * other gases of interest (CO, COS, CH2Cl2, CHCl3, C2Cl4, C2H2, C2H6*, C3H8, butanes, pentanes, C6H6*...) * Depending on the GCMS instrument used for analysis ** precision varies by instrument. Fred, John Miller let me know that if we wanted flasks analyzed by MAGGIC, GCMS, and for 13CH4, there would likely NOT be enough air for analyzing the flasks for CO2 isotopes, so I took them off this list…
6
NWAS—NOAA’s flask program for aircraft missions
Chemical Instrument CO2 MAGGIC CH4 MAGGIC N2O MAGGIC CO MAGGIC SF6 MAGGIC H2 MAGGIC 13CH4 INSTAAR By GCMS (three choices for analyzing ATom flasks; M2 used for HIPPO): Chemical M3 M2 P1* CFCs -11, -12, and -113 Y Y Y -13 N N Y -115 N Y Y -112 Y N ? HCFCs -22, and -142b Y Y Y -141b** N N N -133a, -21 Y N ? HFCs -134a, 152a, 227ea Y Y Y -32, 125, 143a N Y Y --- -365mfc Y Y ? -23, -236fa N N Y Methyl halides CH3Cl, CH3Br, CH3I Y Y Y Chemical M3 M2 P1* Halons H-1301 N Y Y H-1211 and H-2402 Y Y Y Other chlorinated hydrocarbons CH3CCl3***, CCl4, C2Cl2 Y Y Y --- CHCl3, C2Cl4 Y Y Y Other brominated hydrocarbons CHBr3 Y Y N --- CH2Br2 Y Y Y PFCS CF4, C2F6 N N Y Hydrocarbons C2H2 N Y Y C2H6 N N Y --- C3H8 Y Y Y n-butane Y Y Y i-butane Y N Y n-pentane Y Y Y i-pentane Y Y Y n-hexane Y N Y C6H6 Y Y N Carbonyl Sulfide Y Y Y CH3I Y Y Y NF3 N N ? SO2F2 N N ? Notes: Flasks through Maggic and the standarts associated define surface network WMO and connect back to HIPPO. INSTAR to measur delt 13 ( not enough gas to do CO2 isotopes also) GCMS? M3 oldest most connected and has best MC, P1 newest least connected but has more replacent molecules and hydrocarbons. M2 was used in HIPPO Sicence with most trace gas same as discussed in PANTHER UCATS talk, quick look at what Delta 13 C and MC bring to the table. *Instrument still in testing phases, will be operational by ATom-1 **HCFC-141b isn’t well measured because of the Teflon seals in the flasks ***CH3CCl3 is notably better measured on M3 compared to the others
7
Globally averaged atmospheric methane (NOAA GMD)
Increasing concentration, but decreasing growth rate Renewed increase Approxely steady state The Global Monitoring Division, which is part of NOAA’s Earth System Research Laboratory, has been measuring atmospheric methane from the Cooperative Air Sampling Network since Since then, there has been a period of increasing methane concentration but decreasing growth rate; a period approximately at steady state, and since 2007, a renewed increase in concentration. The reasons for this recent increase are not well understood. Sylvia E. Michel … AGU 2014
8
The annual mean of d13CH4 has decreased since 2007 across sites.
latitLaude Here is a plot of annual means of d13CH4 at each site. All of these data come from our lab at INSTAAR. The color represents the latitude of the site, shown here, and the error bars represents the standard deviation for the de-seasonalized data. You can see that annual means decrease at all of the sites. The growth rate seems to stabilize at a few of the high latitude sites in 2012 and 2013, and we’re waiting to see what the 2014 data show. S Sylvia E. Michel … AGU 2014
9
d13CH4 can constrain possible sources of methane
‰ microbes fossil fuels biomass burning Biogenic sources: methanogenic microbes from wetlands, rice paddies, ruminants, landfills, O2-poor reservoirs, manure, etc. Thermogenic sources: natural seeps, mud volcanoes, and exploitation of fossil fuels such as coal, oil, and natural gas Pyrogenic sources: incomplete combustion of biomass, soil carbon, and fuel Sinks influence d13CH4. The OH radical reacts more quickly with 12CH4, leaving the atmosphere enriched in 13CH4. Methane isotopes are useful because of the different isotopic signatures of the different source categories. The isotope delta value of biogenic sources, which include methanogenic microbes from wetlands, rice paddies, ruminants is approximately -50 to -70 ‰ relative to PDB Methane produced during extraction of fossil fuels has a wide range, from about -20 to -60 ‰ And methane produced due to incomplete combustion of biomass is approximately -13 to -25 ‰, depending on the fraction of C3 vs C4 plants. The destruction of methane by the OH radical also has a small fractionation factor, as do destruction of methane in the stratosphere and by methanotrophic soil bacteria, and those are known reasonably well. So although individual sources have large ranges and a lot of geographic variability, their average values are valid on large spatical scales. Sylvia E. Michel … AGU 2014
10
Methyl Chloroform measurements over time
(NOAA’s surface network on GCMS M3) Notes: Exponential decay of trop Methyl Chloride, but normalized north south gradient locks in to a well defined value and fixed temporal structure around 1998? Matched decaying N-S source diff with time ( stratospheric north south assemity in mass flux? Or is the gradient driven by natural assemitrys in OH proccessing between the north and the south?.
11
Methyl Chloroform measurements over Latitude and time
(NOAA’s surface network on GCMS M3) Notes: Latitudinal structure locks in at same 1998 time frame and though difficult to see there is evidence of an altitude dependency step function a lat 20 due to both high and low altitude sampling.
12
Science with MC and 13CH4 constrained primarily by surface measurements.
Sparse free trop data for MC and 13CH4 have shown resolvable vertical structure suggesting that: PFP’s on ATom can provide a valuable free trop dataset with vertically resolved seasonal coverage for the trace gasses MC and 13CH4 . They have the potential to substantially advance the field by improving our understanding: * OH distribution and processing of mass flux through that distribution. * How CH4 is processed throughout the troposphere.
13
NWAS—NOAA’s flask program for aircraft missions
Results from HIPPO: Carbon Dioxide in situ vs PFP flasks (H2-H5 only): **Redundant measurements generally improve data quality... **NOAA PFP results allow the data to be more directly comparable to NOAA global network results for the entire suite of measured gases.
14
NWAS—NOAA’s flask program for aircraft missions
Papers published with NOAA flask data collected on HIPPO (model comparisons, satellite validation...): Hossaini, R., et al., The contribution of natural and anthropogenic very short-lived species to stratospheric bromine, Atmos. Chem. Phys., 12, , doi: /acp Hossaini, R., et al., Evaluating global emission inventories of biogenic bromocarbons, Atmos. Chem. Phys., 13, , doi: /acp Kuai, L., et al., Characterization of Aura TES carbonyl sulfide retrievals over ocean, Atmos. Meas. Tech., 7, , doi: /amt Leedham Elvidge, E.C., D. E. Oram, J.C. Laube, A. K. Baker, S. A. Montzka, S. Humphrey, D. A. O’Sullivan, C. A. M. Brenninkmeijer, Increasing concentrations of dichloromethane, CH2Cl2, inferred from CARIBIC air samples collected , Atmos. Chem. Phys., 15, , doi: /acp Park, M., et al., Global variability and trends of CHClF2 (HCFC-22) and CCl3F (CFC-11) estimated from ACE-FTS, HIPPO and WACCM4, in review, 2015. Patra, P.K., et al., Observational evidence for interhemispheric hydroxyl-radical parity, Nature, 513, , doi: /nature13721, 2014. Umezawa, T., et al., Methyl chloride in the upper troposphere observed by the CARIBIC passenger aircraft observatory: large-scale distributions and Asian summer monsoon outflow, J. Geophys. Res., 119, , doi: /2013JD21396, 2014. Waugh, D.W., et al., Tropospheric SF6: Age of air from the northern hemisphere mid-latitude surface, J. Geophys. Res., 118, , doi: /jgrd.50848, 2013. Xiang, B., et al., Global emissions of refrigerants HCFC-22 and HFC-134a: unforeseen seasonal contributions, Proc. Natl. Acad. Sci., 111(49) , doi: /pnas , 2014. END
15
NOAA’s flask program for aircraft missions
Main science deliverables from NWAS: Measurements of 13CH4 1) Measurements from NWAS supplies a direct link for in-situ instruments to WMO calibration scales and ongoing global-scale results. Puts ATom data into a larger context spatially and temporally
16
Redundant data sets: Sample Volume and rate information:
In situ ECD data have even higher data rate of 1 or 2 min ( 2-3 second sample width). (target 0.5% precision) O3 (0.1 Hz) (target 2% +2 ppb precision) H2O (1 Hz) (target 3% + 1 ppb precision) In situ MDS data are similar to flask data except for a higher 3 min. data rate and a sample width of box integration of ~ 150 sec , or about an 80% sample duty cycle. (target 1% precision, ( might do better in ATom) PFP Flask data is altitude targeted (on dives) with ~ seconds of sample width. (24 to 36 flask samples per flight). (target precision 0.05% on up depending on species ) Correlate with Fast Data sets. Integrate over Fast Data sets. Redundant data sets:
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.