October 19-22, 2009 The Extra-Tropical UTLS: Observations, Concepts and Future Directions
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Transcript of October 19-22, 2009 The Extra-Tropical UTLS: Observations, Concepts and Future Directions
Seasonal distribution and transport of CO2 in the tropopause region based on
frequent observations in the CONTRAIL project
Yousuke Sawa (Meteorological Research Institute)
Toshinobu Machida (National Institute for Environmental Studies)
Hidekazu Matsueda (Meteorological Research Institute)
1. CONTRAIL (Comprehensive Observation Network for Trace
gases by AIrLiner) from 2005 ・ Instruments description ・ flight area/data
2 . Observed CO2 in the tropopause region
・ Time series of CO2
・ Distributions of CO2
3 . Conclusions ・ Transport pathways of CO2
to the lower stratosphere
October 19-22, 2009The Extra-Tropical UTLS: Observations, Concepts and Future
DirectionsCommunity workshop at NCAR, Boulder, USA
CO2 as a transport tracer
• CO2 is very stable in the atmosphere
• CO2 has (relatively) well-known seasonal cycles depending on the latitudes
• CO2 can be used as a transport tracer
355360365370375380385
CO
2 (p
pm)
30N-25N
355360365370375380385
CO
2 (p
pm)
20N-15N
355360365370375380385
CO
2 (p
pm)
10N-5N
355360365370375380385
CO
2 (p
pm)
EQ-5S
355360365370375380385
CO
2 (p
pm)
10S-15S
355360365370375380385
CO
2 (p
pm)
20S-25S
1993 1995 1997 1999 2001 2003 2005 2007
CO2 ( 9-12km )
(between Australia and Japan)
Matsueda et al., 2002, 2008
New instruments: development for CONTRAIL
Vertical Distribution
Vertical Distribution
Latitudinal/Longitudinal Distribution
• Ascending/descending: 10 sec average (~80m vertical)• Cruising altitudes:1 min average (~15 km horizontal)• Detailed structures
Functions:• in-situ CO2 measurement• 1-2 month continuous observation• real time control by aviation information (ARINC)• Onboard calibrations high accuracy 0.2 ppmMachida et al., 2008
Continuous CO2 Measurement Equipment (CME)
Wide range,High frequency
CONTRAIL CO2 Data set
2005 Nov. – 2009 Mar.(3212 legs)CO2 1-min data: ~1 million dataAltitude: 8-12 km
Main routes for analysis
between North America and Japan
Num
ber
of d
ata
(/da
y)
Between Europe and Japan• 680 legs• almost every day from November 2006 to Mar. 2008.
Examples of observed CO2
Meteorological Re-analysis Data (JCDAS)
2006122100UT
330K
CO2 were well corresponded to the PVs
December, 2006
Significant variationsTropospheric or stratospheric ?
Equator
North Pole
EquivalentLatitude
Analytical Methods
ΔΘ : differences in potential temperature
Lower stratosphere
Upper troposphere
Vertical coordinate:
=0K (Tropopause =2 PVU)
=20K
=10K
=-10K
=-20K
Latitudinal coordinate:
Hoor et al., 2004 Hegglin et al., 2006
Reanalysis dataJMA Climate Data Assimilation System (JCDAS)Same system as JRA-25 (Onogi et al., 2007) T106, L40, 6hr
Vertical profiles of CO2
by reference to
Above tropopause, the CO2 shows different vertical gradients above and below of about 25K.
CO2 (ppm) CO2 (ppm)
25K
0K
(from flights between Europe and Japan)
Oct. Dec.
Mar. May
Aug. Sep.
Time series of CO2 for each binbetween Japan and Europe
between Japan and North America
Upper troposphere:a strong seasonal cycle maximum in spring minimum in summer
Lower stratosphere:a gradual decrease in winter and spring followed by a rapid increase in summer
Seasonal cycle of CO2 in LSMax.: SeptemberMin.: April
Amplitude: 1.2 ppm (=20-30K)1.8 ppm (=30-40K)
2.2 ppm (=40-50K)
July 2007
ΔΘ=0
Oct. 2006 Mar. 2007
→ Equivalent Latitude
ΔΘ=0
Pot
entia
l Tem
pera
ture Descent of
low CO2
Seasonal changes of CO2 distributions
Aug 2007
ΔΘ=0
Sep. 2007
ΔΘ=0
Rapid meridional transport of high CO2
form lower latitudes
Summer : CO2//Θ, CO2//ΔΘ
Winter : CO2//Θ, CO2//ΔΘ
uniformly distributed
~constant
CO2(ppm)
CO2 distributions in summer 2008
CO2 distributions in summer 2007 between Japan
and North America
between Japan and Europe
Longitudinal difference ?
10W-50E (W)
50-110E (C)
110-150E (E)
Jul. 2007 340<<360K
ECW
May Jun. Jul. Aug. Sep.
2007 Jan 2007 Mar
2007 Jul 2007 Aug 2007 Sep
Equivalent latitude→
Pot
entia
l tem
pera
ture
CONTRAIL-Transport model intercomparison
Niwa et al.CO2 by NICAM-gl6 (Niwa@CCSR/Tokyo Univ.)
the courtesy of Niwa(CCSR/Tokyo Univ.), Patra(JAMSTEC)
Conclusions :Transport pathways of CO2 to the lower stratosphere
• Frequent CO2 observations were made in the tropopause region by using JAL airliners.
• Rapid CO2 increases were found in the summer in the lower stratosphere, followed by gradual decreases from winter to spring.
• CO2 distributions in - coordinates suggest the existence of a rapid meridional transport on potential temperature surfaces in summer, and a subsidence of air from higher altitudes in winter to spring.
• More JAL observations could provide new evidences about the meridional transport pathways, such as relationships to the monsoon circulation.
How to access CONTRAIL CO2 data-> Contact us!
CME data• request -> PIs• PIs -> data protocol -> data user• data user -> agreement, description of the study, members -> PIs• PIs -> CO2 data set -> data users• Short annual report -> PIs
• contact the PIs to discuss the results as well as co-authorship and collaboration before presentation or publication
ASE CO2 data are submitted to• WDCGG (WMO world data center for greenhouse gases)• globalview CO2 (processed by Dr. Masarie @ NOAA/GMD)
Related projects:• CONTRAIL TMI (Transport model intercomparison) among CCSR/Tokyo Univ., MRI/JMA, JAMSTEC, NIES• GOSAT validation• many Carbon cycle model studies,…
747-Classic1993 ~ 2005 for ASE
747-4002005 ~ for ASE and CME
777-2002006 ~ for CME
Thank you
References• Machida et al. (2008): Worldwide measurements of
atmospheric CO2 and other trace gas species using commercial airlines, J. Atmos. Oceanic. Technol. 25(10), 1744-1754, DOI: 10.1175/2008JTECHA1082.1.
• Matsueda et al.(2008): Evaluation of atmospheric CO2 measurements from new flask air sampling of JAL airliner observation, Pap. Meteorol. Geophys. 59, 1-17.
• Sawa, Y., T. Machida, H. Matsueda (2008): Seasonal variations of CO2 near the tropopause observed by commercial aircraft, J. Geophys. Res., 113, D23301, doi:10.1029/2008JD010568.
We would like to acknowledge many engineers of the Japan Airlines, JAL Foundation and JAMCO Tokyo for supporting our CONTRAIL project. The CONTRAIL project is financially supported by the Research Fund by Global Environmental Research Coordination System of the Ministry of the Environment in Japan.
Acknowledgements