[ppm]CH [ppm] CH 4 4

The efficiency of transport into the stratosphere via the Asian and North

American summer monsoon circulations as derived from the Chemical Lagrangian Model

of the Stratosphere (CLaMS)

Paul Konopka

(with contributions from Xiaolu Yan and Felix Ploeger)

Forschungszentrum J ¨ulich, Germany, p.konopka@fz-juelich.de

http://www.fz-juelich.de/SharedDocs/Personen/IEK/IEK-7/EN/konopka p.html .

Outline of the talk

CLaMS - Lagrangian Chemistry Transport Model driven by meteorological reanalysis (ERA-Interim, NCEP, JRA-55, Merra-2,...) ...more than 100 publications

1. Vertical transport: diabatic heating rates 2. Lagrangian mixing

Transport pathways from the summer monsoons

into the stratosphere

Small-scale structures...

ER-2 flight during SOLVE/THESEO in 2000

Small-scale structures...

ER-2 flight during SOLVE/THESEO in 2000

CLaMS CH4 at θ = 450 K

Small-scale structures...

ER-2 flight during SOLVE/THESEO in 2000

CLaMS CH4 at θ = 450 K

08:00 09:00 10:00 11:00 12:00 13:00 14:00 time [UTC]

0.6 0.8 1.0 1.2 1.4 1.6

CH4 [ppm]

0.6 0.8 1.0 1.2 1.4 1.6

CH4 [ppm]

Exp, ARGUS CLaMS

Small-scale structures...

ER-2 flight during SOLVE/THESEO in 2000

CLaMS CH4 at θ = 450 K

08:00 09:00 10:00 11:00 12:00 13:00 14:00 time [UTC]

0.6 0.8 1.0 1.2 1.4 1.6

CH4 [ppm]

0.6 0.8 1.0 1.2 1.4 1.6

CH4 [ppm]

Exp, ARGUS CLaMS

Konopka et al., 2004, JGR

species lower boundary upper boundary (∼50 km)

CH4 CMDL/AIRS HALOE

Mean Age linear source MIPAS (SF6)

CO2 CMDL Mean Age

CO MOPITT/AIRS Mainz-2D

O3 0 HALOE, θ ≥ 500 K

O3 (tracer) 0 HALOE, θ ≥ 500 K

HCl 0 HALOE, θ ≥ 500 K

H2O ECMWF, ζ ≤ 250 K HALOE

N2O, F11,F12 CMDL 0

HCN MODIS 0

Simplified chemistry

CH4 ⇒ (OH, O(¹D), Cl) ⇒ H2O, CO ⇒ (OH) ⇒ CO2

(hν) ⇒ O3 ⇒ (HO_x) ⇒, N2O, F11, F12 ⇒ (O(¹D), hν) ⇒ HCN ⇒ (OH, O(³D), uptake by the ocean)⇒

Multi-annual CLaMS simulations (1979-today) driven by ERA-Interim, Merra-2, JRA-55, ERA-5,...

- HALOE - Climatology:

Grooss and Russell, ACP, 2005 - CMDL: GLOBALVIEW, 2015 CO2/CH4/CO since 1979/84/91 P. Tans, K. Masarie, P. Novelli - CMDL: CATS (5 stations) N2O, F11, F12 - J. Elkins - MIPAS, SF6-Age

Stiller et al., ACP, 2008 - MOPITT (V3, V4)/AIRS Pommrich at al., GMD, 2014 - HCN

Pommrich at al., GRL, 2010

Lagrangian transport in CLaMS:

(a) diabatic thinking

(b) mixing

diabatic rather than kinematic vert. velocities

kinematic means that vertical velocity w is derived from the mass conservation, i.e.:

∇ · (u, v, w) = 0 ⇒ w = dp

dt = f(u, v)

diabatic means that potential temperature θ defines the vertical coordinate ...and the cross isentropic velocity ^dθ_dt are from the energy budget

(“temperature tendencies” in the reanalyses, Ploeger et al., 2010 for ERA-Interim)

dθ

|{z}dt

vert. velocity

= Qsw

| {z }

shortwave radiation

+ Q_lw

|{z}

longwave radiation

+ Q_lh

|{z}

latent heat

+. . .

Hybride vertical coordinate ζ coupling the potential temperature θ and the orography-following coordianate σ = _p^p

s

, ps -surface pressure (Mahowald et al., JGR, 2002)

diabatic rather than kinematic vert. velocities

p [hPa]

340 360 380

310

280 100

200

300

500

1013

[K]

0.12

0.25

0.80 0.40

1.00

θ ^=p/p

10 30 50 70

[deg N]

Subtropical Jet σ

diabatic rather than kinematic vert. velocities

p [hPa]

340 360 380

310

280 100

200

300

500

1013

[K]

0.12

0.25

0.80 0.40

1.00

θ ^=p/p

10 30 50 70

[deg N]

Subtropical Jet σ

ζ = θ (pot. Temp.) above 300 hPa

dζ

dt = ^dθ_dt

diabatic rather than kinematic vert. velocities

p [hPa]

340 360 380

310

280 100

200

300

500

1013

[K]

0.12

0.25

0.80 0.40

1.00

θ ^=p/p

10 30 50 70

[deg N]

Subtropical Jet σ

ζ = θ (pot. Temp.) above 300 hPa

dζ

dt = ^dθ_dt

ζ ∼ σ = p/ps, ps - surf. pressure below 300 hPa

dζ

dt = f _dp

dt, ^dθ_dt

Lagrangian mixing =

numerical diffusion versus

atmospheric mixing

Stratospheric stirring

...stratospheric transport is do- minated by horizontal winds.

Due to a strong stable stratifi- cation, the vertical motion is su- pressed.

...stratosphere looks like after mixing few colors with a stirring stick.

Konopka et al., JGR, 2003

Euler versus Lagrange

t=t

t=t

t=t

t=t

1

2

3

4

u

Eulerian grid

...one of the most intriguing features offered by the La- grangian transport is the possibility to to parameterize the “true” physical mixing in terms of the numerical dif- fusion...

Grid adaptation ⇒ mixing

A C B

quasiuniform distribution of air parcels

Delaunay triangulation ⇒ next neighbors

Grid adaptation ⇒ mixing

A C B

quasiuniform distribution of air parcels

Delaunay triangulation ⇒ next neighbors

sheared flow

∆t = 6 − 24 hours

Grid adaptation ⇒ mixing

A C B

quasiuniform distribution of air parcels

Delaunay triangulation ⇒ next neighbors

sheared flow

∆t = 6 − 24 hours

A C B

D

grid adaptation =

regridding of the deformed grid

⇒ new air parcels

⇒ interpolations (num. diffusion)

⇒ mixing

Lyapunov exponent λ

r₀

t=t₀

Consider an air parcel sur- rounded by a small circle of ra- dius r0.

t=t + t r r

+

−

0

After a time ∆t and for sufficiently small values of r0, the circle is deformed into an ellipse with minor and major axes r⁻ and r+

Lyapunov exponent λ

r₀

t=t₀

Consider an air parcel sur- rounded by a small circle of ra- dius r0.

t=t + t r r

+

−

0

After a time ∆t and for sufficiently small values of r0, the circle is deformed into an ellipse with minor and major axes r⁻ and r+

Definition: (Lyapunov exponent)

λ^± = ± 1

∆t ln r^± r0

for sufficiently small ∆t and r0

Incompressible flows ⇒ (r₀² = r⁻r+) ⇒ λ⁻ = λ+

Mixing in the vicinity of the subtropical jet

Hurricane Ivan from space shuttle (NASA)

subtropical jet

over Himalayas

Mixing in the vicinity of the subtropical jet

Hurricane Ivan from space shuttle (NASA)

subtropical jet over Himalayas

strong

deformations ...

Mixing in the vicinity of the subtropical jet

Hurricane Ivan from space shuttle (NASA)

subtropical jet over Himalayas

... and mixing !

Pan et al., 2006, JGR

λ

- “critical Lagran-

-gian deformation”

Transport pathways from the summer monsoons into the

stratosphere

ASM ⇒ stratosphere: Why we should care?

HCN averaged between 0 and 100⁰E

Randel et al., Science, 2010 (cf. Park at al., JGR, 2013)

...monsoon circulation pro- vides an effective pathway for pollution from Asia, and In- donesia to enter the global stratosphere...

...mainly CO, HCN, SO2 and aerosols but also CO2 and H2O

ASM ⇒ stratosphere: Why we should care?

HCN averaged between 0 and 100⁰E

Randel et al., Science, 2010 (cf. Park at al., JGR, 2013)

...monsoon circulation pro- vides an effective pathway for pollution from Asia, and In- donesia to enter the global stratosphere...

...mainly CO, HCN, SO2 and aerosols but also CO2 and H2O

Questions:

How much of the polluted air goes into the deep stratosphere (tropical pipe) and how much goes into the

extra-tropical NH lower stratosphere?

Can we quantify these 2 pathways of

transport?

Method

CLaMS driven by horizontal winds and total diabatic heating rates from ERA-Interim (Dee et al., 2011)

resolution (100km - horizontal, 400m - vertical)

monsoon tracer: air mass origin fraction (Orbe et al. 2013)

every day between July and August of the years 2010-2013 in the anticyclone core between 370 and 380 K (source region)

edge of the anticyclone core defined by the maximum of the PV gradient (“Nash criterion for vortex edge”, Ploeger et al., 2015)

Method

(a)

0 50 100 150

Longitude 0

10 20 30 40 50 60 70

Latitude

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 PVU

3.57×10⁵

3.58×10⁵

3.59×10⁵

3.60×10⁵ 3.60

×10

5

3.61

×10

5

3.61×10⁵ 3.62

×10₅

0 50 100 150

Longitude 0

10 20 30 40 50 60 70

Latitude

4 4

4 4

Time-averaged PV field at 380 K. Air parcels between 370 and 380 K and within the PV-barrier are set to 1 (from 1.07 until 31.08)

Method

0 2 4 6 8 10

PDF [%]

320 340 360 380 400 420 440

Pot. temperature [K]

f(trop<380K)=32.7%

PDF of tropopause potential temperature inside the mon- soon anticyclone from all days during July-August 2010-2013

Method

0 2 4 6 8 10

PDF [%]

320 340 360 380 400 420 440

Pot. temperature [K]

f(trop<380K)=32.7%

PDF of tropopause potential temperature inside the mon- soon anticyclone from all days during July-August 2010-2013

Source region between 370 and 380 K:

tropopause is mainly above (more than 75% cases) convective outflow is mainly below

CLaMS versus HCN: seasonal evolution

(a)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

Monsoon air fraction (JAS) Monsoon air fraction (JAS)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

0.05 0.08 0.14 0.25 0.42 0.71 1.20 2.04 3.47 5.89 10.00 [%]

120

160 160

200 200

200

210

210 210

220 230

250

270

Air mass origin fraction from CLaMS and HCN from ACE-FTS (black con- tours, hatched HCN > 215 pptv.)

CLaMS versus HCN: seasonal evolution

(b)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

Monsoon air fraction (OND) Monsoon air fraction (OND)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

0.05 0.08 0.14 0.25 0.42 0.71 1.20 2.04 3.47 5.89 10.00 [%]

160

200 200

200

210 210

210

220 220

220

230 230

250 270

Air mass origin fraction from CLaMS and HCN from ACE-FTS (black con- tours, hatched HCN > 215 pptv.)

CLaMS versus HCN: seasonal evolution

(c)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

Monsoon air fraction (JFM) Monsoon air fraction (JFM)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

0.05 0.08 0.14 0.25 0.42 0.71 1.20 2.04 3.47 5.89 10.00 [%]

160

200 200

200

210 210

210

220 220

Air mass origin fraction from CLaMS and HCN from ACE-FTS (black con- tours, hatched HCN > 215 pptv.)

CLaMS versus HCN: seasonal evolution

( d)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

Monsoon air fraction (AMJ) Monsoon air fraction (AMJ)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

0.05 0.08 0.14 0.25 0.42 0.71 1.20 2.04 3.47 5.89 10.00 [%]

160

200 200

200

210 210

220230

250270

Air mass origin fraction from CLaMS and HCN from ACE-FTS (black con- tours, hatched HCN > 215 pptv.)

CLaMS versus HCN: seasonal evolution

( d)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

Monsoon air fraction (AMJ) Monsoon air fraction (AMJ)

−

50 0 50

Latitude [deg]

300 350 400 450 500 550 600 650

Pot. temperature [K]

0.05 0.08 0.14 0.25 0.42 0.71 1.20 2.04 3.47 5.89 10.00 [%]

160

200 200

200

210 210

220230

250270

Air mass origin fraction from CLaMS and HCN from ACE-FTS (black con- tours, hatched HCN > 215 pptv.)

Time evolution

Jul 1 Oct 1 Jan 1

0.00 0.05 0.10 0.15

Monsoon air fraction [%]

NH (380K) tropics (460K) tropics (400K) SH (380K)

Apr 1

Air mass origin fraction in 4 selected destination regions. Shading shows the variability.

Time evolution

Jul 1 Oct 1 Jan 1

0.00 0.05 0.10 0.15

Monsoon air fraction [%]

NH (380K) tropics (460K) tropics (400K) SH (380K)

Apr 1

Air mass origin fraction in 4 selected destination regions. Shading shows the variability.

Strongest contribution in the NH extra-tropical lowermost stratosphere (∼ 15%)

Transport into the tropical pipe less than (∼ 5%)

Conclusions:

Vertical transport across the tropopause (chimney) consistent with Garny and Randel, 2016, but much more isentropic transport into the NH extra-tropical lowermost stratosphere (15%) than into the tropical pipe (5%)

This strong isentropic transport (blower) consistent with Orbe et al., 2015 and Pan et al., 2016. However, it occurs mainly above the tropopause

ACP, accepted

What is new?

3×2 source regions:

ASM - Asian summer monsoon

NASM - North American summer monsoon

Tropics (15S-15N)

Questions:

ASM versus NASM

ASM and NASM compared with the tropics ERA-Interim versus MERRA-2 winds

Pathways of transport (CLaMS-ERA-I)

ASM

350 400 450 500 550 600 650

Pot. temperature [K]

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

Column [m]

350 400 450 500 550 600 650

Pot. temperature [K]

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

Column [m]

NASM

350 400 450 500 550 600 650

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

350 400 450 500 550 600 650

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

0.50 0.67 0.91 1.23 1.66 2.24 3.02 4.07 5.49 7.41 10.00 [%]

SC TC Total

350-360K370-380K

(a) (b)

(c) (d)

Air mass origin frac- tion during the following April-June (8-10 months after release)

NASM is always weaker than ASM!

Pathways of transport (CLaMS-ERA-I)

ASM

350 400 450 500 550 600 650

Pot. temperature [K]

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

Column [m]

350 400 450 500 550 600 650

Pot. temperature [K]

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

Column [m]

NASM

350 400 450 500 550 600 650

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

350 400 450 500 550 600 650

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

0.50 0.67 0.91 1.23 1.66 2.24 3.02 4.07 5.49 7.41 10.00 [%]

SC TC Total

350-360K370-380K

(a) (b)

(c) (d)

Air mass origin frac- tion during the following April-June (8-10 months after release)

NASM is always weaker than ASM!

tracers released close to the tropopause (370-380K) are primarily transported into the Northern Hemisphere

tracers released clearly below the tropopause (350-360K) are trans- ported to the tropical pipe, and even to the Southern Hemisphere.

...and from CLaMS-Merra-2

ASM

350 400 450 500 550 600 650

Pot. temperature [K]

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

Column [m]

350 400 450 500 550 600 650

Pot. temperature [K]

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

Column [m]

NASM

350 400 450 500 550 600 650

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

350 400 450 500 550 600 650

160 200 200

200

210 210

220 230

250270

−60 −40 −20 0 20 40 60

Latitude [deg]

1 4 10 50 200

0.50 0.67 0.91 1.23 1.66 2.24 3.02 4.07 5.49 7.41 10.00 [%]

SC TC Total

350-360K370-380K

(a) (b)

(c) (d)

Air mass origin frac- tion during the following April-June (8-10 months after release)

NASM is always weaker than ASM!

tracers released close to the tropopause (370-380K) are primarily transported into the Northern Hemisphere

tracers released clearly below the tropopause (350-360K) are trans- ported to the tropical pipe, and even to the Southern Hemisphere.

Horizontal taperecorder

Top: source region clearly below the tropopause (350-360K) Bottom: source region close to the tropopause (370-380K)

Two pathways into the tropical pipe

Monsoon pathway: ascent into the stratosphere inside the anticyclone followed by quasi-horizontal transport (420K) to the tropical lower stratosphere

Tropical pathway: quasi-horizontal transport to the tropics (360K) below the tropopause followed by ascent to the stratosphere via tropical upwelling

More than half of mass released between 350-360 K follows the tropical pathway!

Implications for H ₂ O taperecorder

Contribution to the wet phase of the H2O taperecorder:

Top: mainly through the tropical pathway Bottom: through the monsoon pathway

H ₂ O-tracer correlations in the tropical pipe

Two contributions to the wet phase of the H2O taperecorder:

Tropical pathway (magenta): drier, more young air Monsoon pathway (cyan): moister, older air

Conclusions:

Monsoon tracers released close to the tropopause (370-380K) are primarily transported into the Northern Hemisphere

Monsoon tracers released clearly below the tropopause (350-360K) are more transported to the tropical pipe, and even to the Southern Hemisphere.

ASM always weaker then NASM

Two pathways of transport from the ASM and NASM into the tropical pipe:

1. Monsoon pathway: confinement by the anticyclone (slower, moister) 2. Tropical pathway: Hadley cell + tropical upwelling (faster, drier)

Transport efficiency

Transport efficiency = AOF × m_dest/msource

“normalized air origin fraction”

important when different source regions have to be compared to each other (like monsoon regions versus tropics)

Transport efficiency greatest from the ASM and tropical sources close to the tropopause (370-380K)!

Transport efficiency

Transport efficiency = AOF × m_dest/msource

“normalized air origin fraction”

important when different source regions have to be compared to each other (like monsoon regions versus tropics)

Transport efficiency greatest from the ASM and tropical sources close to the tropopause (370-380K)!

Vertical view

(a) (b)

0 2 0 4 0 6 0 8 0

3 0 0

3 5 0

4 0 0

4 5 0

5 0 0

Pot.temperature[K]

−

−

0 2 0 4 0 6 0 8 0

3 0 0

3 5 0

4 0 0

4 5 0

5 0 0

Pot.temperature[K] 0 2 0 4 0 6 0 8 0

3 0 0

3 5 0

4 0 0

4 5 0

5 0 0

−

−

0 2 0 4 0 6 0

3 0 0

3 5 0

4 0 0

4 5 0

5 0 0

) d)

3 0 0

3 5 0

4 0 0

4 5 0

5 0 0

Pot.temperature[K]

−

−

3 0 0

3 5 0

4 0 0

4 5 0

5 0 0

Pot.temperature[K] 3 0 0

3 5 0

4 0 0

4 5 0

5 0 0

−

−

3 0 0

3 5 0

4 0 0

4 5 0

5 0 0

. . . . . . . . . . . AM-frac

[%]

Latitude section of monsoon air mass fraction, 40-100⁰E.

Tropopause-based coordinates.