pathway from the boundary layer to the utls · pathway from the boundary layer to the utls ... asma...
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Pathway from the boundary layer to the UTLS over the Asian summer monsoon region
Jianchun Bian LAGEO
Institute of Atmospheric Physics Chinese Academy of Sciences
Outline 1. TP → ASM (E to W)
2. O3 → H2O, cirrus & aerosol
3. Dynamics → microphysics, chemistry & radiation
4. Extra-tropical TL → TTL
5. Sat. & simulation → in situ obs.
6. Summary
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1. From Tibetan Plateau to the ASM
Zhou et al., 1995
! Guess: BL pollutants converge to TP, and then are transported to UTLS by ASM updraft, which is induced by the huge elevated heat source (Yeh et al., 1957; Flohn, 1957).
! Mechanisms: dynamics, chemistry
! TP has been a long-lasting topic for atmospheric research (Yeh, 1949, 1950; Yin, 1949; Bolin,
1950).
! TOMS measurements show a summertime total ozone valley over TP (Zhou et al., 1995)
30 40 50 60 70 80 90 100 110 120Longtitude (E)
260
265
270
275
280
285JJA
OM
I tot
al o
zone
(DU
) 450
600
750
900
1050
Terra
in in
pre
ssur
e (h
Pa)
30 N
285 DU
0 1000 2000 3000 4000 5000
50 60 70 80 90 100 110
Total ozone anomaly (DU) in JJA (2005-2009)
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30
35
40
In view of Asia region, ozone valley is a phenomenon of terrain: Good agreement between total O3 and terrain!
Ozone Terrain
! Total ozone decreases 4-4.5 DU per 100 hPa elevation change
! TP terrain causes a reduction of ~20 DU total ozone.
Bian et al., AAS, 2010
0 40 80 120 160SAGE II ozone partial pressure (nb)
1
10
100
1000
Pres
sure
(hPa
)
(45E-75E)
(75E-105E)
Non-ASM
TP & IP share the same ozone profile, but have lower ozone in UTLS relative to non-ASM region.
Blue – Tibet P.
Red – Iran P.
Green – non-ASM
Lower O3 in UTLS
Bian et al., AAS, 2010
0 40 80 120 160SAGE II ozone partial pressure (nb)
1
10
100
1000
Pres
sure
(hPa
)(45E-75E)
(75E-105E)
Non-ASM
Non-ASM: 300 DU
TP: 267DU
ASM UTLS 20DU
Terrain 20DU
267DU = 300 DU + 7 DU – 20 DU – 20 DU TP Non-ASM Higher trop. Lower_UTLS Terrain –20% +60% +60%
Budget
Bian et al., AAS, 2010
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1. From Tibetan Plateau to the ASM
! Focus shifts from the TP to the whole ASM region.
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2. From O3 to H2O, cirrus, and aerosol
H2O
Cirrus
H2O
Bian et al., Chinese JAS, 2011
! Maximum H2O within anticyclone (Rosenlof et al., 1997)
! Maximum cirrus & enhanced aerosol (Vernier et al., 2011)
! H2O, cirrus & aerosol are critical for chemistry, radiation
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CALIPSO SR @532nm, 15–17 km
Asian tropopause aerosol layer (ATAL)
ATAL
15–45oN average
ATAL
Anticyclone Anticyclone
Vernier et al, GRL, 2011
! ATAL impacts also on microphysics.
Lelieveld et al., ACP, 2007
Upward flux
Impact on global climate
! Simulations: the upward water mass flux associated with ASM accounts for 75% of global flux during boreal summertime (Gettelman et al., 2004)
~ 17 km
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3. From dynamics to microphysics, chemistry & radiation
! Dynamics: 2 key processes
1. Deep convection (Randel et al., JGR, 2006; Fu et al., GRL, 2007):
convective transport + emission source = pathway → destination (Yan et al., AAS, 2015)
2. Anticyclone trapping effect (Li et al., GRL, 2005; Park et al, JGR, 2007): bi-mode (Yan et al, AOSL, 2011)
3. Many issues to be investigated: main outflow level, wet scavenge, …
! Microphysics, chemistry, radiation:
1. formation of cirrus & aerosol
2. super-saturation
3. inhomogeneous/homogeneous nucleation & chemistry
Tracing CO-maxima within ASM anticyclone by WRF-Chem
! CO emission： Global Fire+ Asia Anthropogenic
! Period：20060501-20060701； no chemistry
! Wind：FNL（1°× 1°）； chemical initial & boundary condition：MOZART4
Indian C.
E. China
Yan et al., 2015, AAS
I－O =30ppb I－O =20ppb
I－O =13ppb I－O =2ppb
Simulation and contribution of different emission
Yan et al., 2015, AAS
Pathway of emission from Indian continent
Yan et al., 2015, AAS
Pathway of emission from Eastern China
Yan et al., 2015, AAS
IM: 50-67.5E
TM: 80-92.5E
Center no. in the longitude during 2005-2009 summer
! ASMA center has bi-peak distribution zonally (Zhang et al, 2002)
Effect of the bimodality of ASM anticyclone
Iran mode Tibet mode
Yan et al., 2011, AOSL
Composite analysis Iran mode
Tibet mode
Water vapor distribution for different mode
Yan et al., 2011, AOSL
IM
TM
Climate ave.
! IM：
Higher trop. tracers over IP,
lower strat. tracers over IP,
Opposite over the TP
H2O(ppmv) CO(ppbv) O3(ppbv)
Composition distribution for different mode
Yan et al., 2011, AOSL
! Although ASM anticyclone locates at sub-tropics (ExTL), it has
TTL mixing structure (Pan et al., JGR, 2014). However, somewhat
different from TTL, such as TIL, higher top boundary level.
! Unknowns: 1. Top & bottom boundary
2. Physical & chemical processes related to cirrus, dehydration,
aerosol, and so on; micro-scale waves related to in situ formation of
cirrus
3. How to get into tropical pipe or stratosphere from ASM
anticyclone ?
……
4. From extra-tropical transition layer to TTL
Boulder 40N
Pan et al., 2014, JGR
Gettelman et al., 2011, RG
Tropics 10N
KM 25N
! ATAL formation mechanisms: 1. Anthropogenic SO2 emissions (Neely III et al, JGR, 2014) 2. Carbonaceous and sulfate materials (Vernier et al, JGR, 2015) 3. Ammonium nitrate (NH4NO3) (Liao et al, communication) …… True evidence ?
5. From sat. & simulation to in situ measurement
Vernier et al., 2015, JGR
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! Above and many other related studies have used satellite data and models.
! Satellite product lacks of validation over this region, and the vertical resolution is low so many finer structures can’t be seen.
! We are trying to conduct coincident in situ measurements of water vapor, ozone and particle in the UTLS within the ASM anticyclone.
! These observations will be significant for quantifying the moisture transport associated with the ASM, for identifying the transport pathway, and for understanding microphysical process in the ASM-TL. —— Scientific goals
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Sounding Water vapor, Ozone and Particle (SWOP)
campaign at Lhasa and Kunming during the Asian summer monsoon
Thanks to Hongbin Chen, Daren Lu, Yuejian Xuan, Jinqiang Zhang, Zhixuan Bai (IAP/CAS) …
Holger Vömel (GRUAN, DWD), Frank Wienhold (ETH), Dale Hurst, Samuel Oltmans, Emrys Hall, Allen Jordan (NOAA)
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Campaign Locations
" ASM anticyclone spans subtropical Asian continent between 20–40N, higher tropopause
" KM (25.0N, 102.6E) within southeast edge of anticyclone, influenced by the air mass from outside
" LH (29.6N, 91.1E) @ anticyclone center and consistently within anticyclone limit
Bian et al. GRL, 2012
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" Compact Optical Backscatter Aerosol Detector (ETH) " NOAA Frost Point Hygrometer (NOAA GMD) " Cryogenic Frost Point Hygrometer (Vömel-DMT) " Electrochemical Concentration Cell Ozonesonde (DMT) " Radiosonde: P, T, U, winds (u,v) (InterMet)
Balloon-borne sondes
• CFH & FPH measure the water vapor concentration and RHi by detecting the frost point of the air-mass.
• COBALD detects cloud particle and aerosol by emitting light at two wavelengths (455nm, 870nm), and receiving the back-scattered signal.
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LS KM
2010 Aug 22-28 12 CFH/ECC 3 Cobald 2013 Aug 3-26 22 CFH/ECC 18 Cobald
Six IOPs during 2009-2014
2009, Aug 7-13 11 CFH/ECC 2011, Sep 12-15 4 CFH/ECC 2012, Aug 11-Sep 6 21 CFH/FPH 38 ECC , 12 Cobald 2014, Aug 13-22 10 CFH/ECC/Cobald
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Balloon-borne Sondes & Timing
" Once or twice daily
" Kunming:
– Aug 7-13, 2009, CFH/ECC/RS80 (11 sets)
– Sep 12-15, 2011, CFH/ECC/iMet (4 sets)
– Aug 11-Sep 6, 2012, CFH (6), FPH (15), COBALD (12), ECC (38)
– Aug 13-22, 2014, CFH (10), COBALD (10), ECC(10)
" Lhasa: – Aug 22-28, 2010, CFH/ECC/iMet (9 sets), CFH/COBALD/ECC/iMet (3 sets)
– Aug 3-26, 2013, CFH/ECC/iMet (6 sets), CFH/COBALD/ECC/Imet (18 sets)
" Ozone: ECC ozonesonde (99)
" Water vapor: CFH-RS80 (11), CFH-iMet (54), FPH-iMet (15)
" Cloud and aerosol: COBALD (43)
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First in situ measurement of UTLS H2O and O3 during ASM
H2O O3 RHi - Supersaturation
Kunming
Lhasa
Bian et al, JGR, 2012
RHi distribution changes with temperature
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Aerosol and cirrus
0 2 4 6 8 10Water vapor mixing ratio (ppmv)
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16
18
20
22
Altit
ude
(km
)
1 2 3 4BSR
0 20 40 60 80 100RHi (%)
H2O mixing ratioRHiBSR_RedBSR_Blue
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Asian tropopause aerosol layer is indeed observed by in situ measurements !
Vernier et al, JGR, 2015
True evidence ? To be confirmed
Russian M-55 Geophysica
To be confirmed by StratoClim aircraft campaign
Rex et al, ACAM, 2013
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Summary: # knowns << # unknowns Park et al, JGR, 2009
So, we come here to find the true evidence !
Thank you very much