Role of Convection over Asian Role of Convection over Asian Monsoon/Tibetan Region in Hydration Monsoon/Tibetan Region in Hydration

of the Global Stratosphereof the Global Stratosphere

Role of Convection over Asian Role of Convection over Asian Monsoon/Tibetan Region in Hydration Monsoon/Tibetan Region in Hydration

of the Global Stratosphereof the Global Stratosphere

Rong FuRong Fu11

Jonathan WrightJonathan Wright22, and Yuanlong Hu,, and Yuanlong Hu,11

Acknowledgment for Science collaboration: Jonathan H. JiangAcknowledgment for Science collaboration: Jonathan H. Jiang3 3

11School of Earth and Atmospheric Sciences, Georgia Institute of TechnologySchool of Earth and Atmospheric Sciences, Georgia Institute of Technology22 Department of Apply Physics and Mathematics, Columbia University Department of Apply Physics and Mathematics, Columbia University33Jet Propulsion Laboratory, California Institute of TechnologyJet Propulsion Laboratory, California Institute of Technology

Asian Monsoon Year 2008 International WorkshopAsian Monsoon Year 2008 International Workshop

Beijing, China, April 23-25, 2007Beijing, China, April 23-25, 2007

Rong FuRong Fu11

Jonathan WrightJonathan Wright22, and Yuanlong Hu,, and Yuanlong Hu,11

Acknowledgment for Science collaboration: Jonathan H. JiangAcknowledgment for Science collaboration: Jonathan H. Jiang3 3

11School of Earth and Atmospheric Sciences, Georgia Institute of TechnologySchool of Earth and Atmospheric Sciences, Georgia Institute of Technology22 Department of Apply Physics and Mathematics, Columbia University Department of Apply Physics and Mathematics, Columbia University33Jet Propulsion Laboratory, California Institute of TechnologyJet Propulsion Laboratory, California Institute of Technology

Asian Monsoon Year 2008 International WorkshopAsian Monsoon Year 2008 International Workshop

Beijing, China, April 23-25, 2007Beijing, China, April 23-25, 2007

Acknowledgement:

Prof. Wu, Guoxiong

NSFC Oversea Young Scientist Project

NASA Aura Project

Acknowledgement:

Prof. Wu, Guoxiong

NSFC Oversea Young Scientist Project

NASA Aura Project

Asian Monsoon/Tibetan region is a main gateway for near surface air to enter the lower stratosphere

during boreal summer.

Asian Monsoon/Tibetan region is a main gateway for near surface air to enter the lower stratosphere

during boreal summer.

Aura MLS, July 23-29, 2006, Chen 1995; Dunkerton 1995; Rosenlof et al. 1997:

Jackson et al. 1998, Randel et al. 2001; Read et al. 2004

Gettelman et al. 2004

• Stratosphere water vapor may have increased 2 ppmv during the 1954 - 2000 period, or 0.7 ppmv during 1980-1999. (Oltmans and Huffman 1995, Nedoluha et al. 1998, Smith 1999, Rosenlof et al. 2001).

If so, 1 ppmv increase during 1980-2000 can

cause 0.3K/yr cooling in stratosphere and 0.3 Wm-2 increase of surface radiative forcing (e.g., Dvortsov&Solomon 2001; Forster&Shine 2002)

May cause ~ 10% global total ozone decline (Stenke et al. 2005).

• Stratosphere water vapor may have increased 2 ppmv during the 1954 - 2000 period, or 0.7 ppmv during 1980-1999. (Oltmans and Huffman 1995, Nedoluha et al. 1998, Smith 1999, Rosenlof et al. 2001).

If so, 1 ppmv increase during 1980-2000 can

cause 0.3K/yr cooling in stratosphere and 0.3 Wm-2 increase of surface radiative forcing (e.g., Dvortsov&Solomon 2001; Forster&Shine 2002)

May cause ~ 10% global total ozone decline (Stenke et al. 2005).

Importance to Global Climate and Stratospheric Ozone:Importance to Global Climate and Stratospheric Ozone:

Smith 1999

Increase of cross-tropopause transport in the Asian monsoon region may contribute to this trend.

• How is water vapor transported to the lower stratosphere over the Asian monsoon region/Tibetan region?– By monsoon convection or convection

over Tibet?

Dethop et al. 1999: monsoon convection

Dessler and Sherwood 2004: extratropical convection

Gettelman et al. 2004, Fueglistaler et al. 2005: both

Fu et al. 2006: Convection over Tibetan Plateau, PNAS

• How is water vapor transported to the lower stratosphere over the Asian monsoon region/Tibetan region?– By monsoon convection or convection

over Tibet?

Dethop et al. 1999: monsoon convection

Dessler and Sherwood 2004: extratropical convection

Gettelman et al. 2004, Fueglistaler et al. 2005: both

Fu et al. 2006: Convection over Tibetan Plateau, PNAS

• Can the lower stratospheric water vapor in the Asian monsoon/Tibetan region influence the global stratosphere?

• Can the lower stratospheric water vapor in the Asian monsoon/Tibetan region influence the global stratosphere?

Dessler & Sherwood 2004

30N

Data Sets:Data Sets: Aura MLS, water vapor, CO, IWC, (V1.51, Waters

et al. 2005, IEEE). – Water vapor (190 GHz): 215 hPa, 147 hPa, 100

hPa, 68 hPa, ~ 3 km vertical interval, accuracy ~10% at 100 hPa

– CO (240 GHz): accuracy better than 30% at 147 hPa– IWC (118 GHz): 215 hPa, 178 hPa, 147 hPa, 121

hPa, 100 hPa, 83 hPa; Mainly detect cirrus/anvil, insensitive to thin cirrus (Detectable IWC: ≥0.4 mg/m3 at 147 and 100 hPa, 4 mg/m3 at 215 hPa,saturate when IWC>50 mg/m3.)

Aqua MODIS cloud (MYD08_D3), aerosol (MYD08), 1º´1º, reff, Pcld, fcld, tcld, aerosol optical depth (AOD).

• TRMM Precipitation radar (PR, 2A25): along-track reflectivity of precipitation sized hydrometeors.

The Goddard Fast Trajectory model: (Schoeberl and Sparling, 1995) driven by (UKMO) reanalysis data: updated daily at 12 UTC, 2.5º´3.75º lat/lon grid.

Aura MLS, water vapor, CO, IWC, (V1.51, Waters et al. 2005, IEEE).

– Water vapor (190 GHz): 215 hPa, 147 hPa, 100 hPa, 68 hPa, ~ 3 km vertical interval, accuracy ~10% at 100 hPa

– CO (240 GHz): accuracy better than 30% at 147 hPa– IWC (118 GHz): 215 hPa, 178 hPa, 147 hPa, 121

hPa, 100 hPa, 83 hPa; Mainly detect cirrus/anvil, insensitive to thin cirrus (Detectable IWC: ≥0.4 mg/m3 at 147 and 100 hPa, 4 mg/m3 at 215 hPa,saturate when IWC>50 mg/m3.)

Aqua MODIS cloud (MYD08_D3), aerosol (MYD08), 1º´1º, reff, Pcld, fcld, tcld, aerosol optical depth (AOD).

• TRMM Precipitation radar (PR, 2A25): along-track reflectivity of precipitation sized hydrometeors.

The Goddard Fast Trajectory model: (Schoeberl and Sparling, 1995) driven by (UKMO) reanalysis data: updated daily at 12 UTC, 2.5º´3.75º lat/lon grid. For the periods of Aug - Sept. 15 2004,

July 15 - Sept. 15 2005

Where does water vapor enter the lower stratosphere?Where does water vapor enter the lower stratosphere?

High water vapor (> 5 ppmv) at 100 hP detected by MLS during Aug. 2004 and 2005.

Air rich in water vapor also appear to enters the lower stratosphere primarily over the TP and its south slope.

Water vapor at 100 hPa: Probability of Convective Source for high water vapor at the tropopause:

TRMM PR>18dBz above 10 km

Goddard fast trajectory model forced by UKMO winds for upto 5 days.

MLS high H2O

Fu et al. 2006, PNAS

Aural MLS, Aug-Sept 04,05

TP

MON TP SLP MON

380K 203K

+7K

199K

+2K

197K

360K 212K

+12K

208K

8 K

200K

TP

monsoon

TRMM PR

Aura MLS clear-sky temperatures:

TP

monsoon

Aura MLSWhy Tibet?

• Why is the troposphere-to-stratosphere water vapor transport is so strong over the Tibetan Plateau?

• Convection penetrates deeper,•Warmer and less saturated tropopause

layer

• Why is the troposphere-to-stratosphere water vapor transport is so strong over the Tibetan Plateau?

• Convection penetrates deeper,•Warmer and less saturated tropopause

layer

•Can the lower stratospheric water vapor in the Asian monsoon/Tibetan region influence the global stratosphere?

•Can the lower stratospheric water vapor in the Asian monsoon/Tibetan region influence the global stratosphere?

Water vapor enters the tropical stratosphere controls water vapor in the global stratosphere:

Water vapor enters the tropical stratosphere controls water vapor in the global stratosphere:

Holton et al. 1995Source: Pan et al. 2006, UCAR TIIMES

?

Mote et al. 1995, 1996: The “tape recorder”

The “tropical pipe”

Where is the main source for the seasonal moistening of

the tropical stratosphere? Where is the main source for the seasonal moistening of

the tropical stratosphere?

At 68 mb, MLS H2O >3.6 ppmv, Oct-Dec, 12˚S-12˚N.

40 days ago

80 days ago 120 days ago, July-Sept.

Mostly from the Asian monsoon region!

How does LS water vapor over Asian monsoon/Tibetan

region enter the “tropical pipe”? How does LS water vapor over Asian monsoon/Tibetan

region enter the “tropical pipe”?

Forward trajectory analysis begin with Aura MLS high water vapor samples (> 5 ppmv) at 100 hPa over the Asian monsoon/Tibetan region (> 2000 samples).

~70hPa

~80hPa

MLS “tape record” 5S-5N

~70hPa

Conclusions:Conclusions: Convective transport over the

Tibetan Plateau provides a main pathway for water vapor and CO to enter the lower stratosphere in the Asian monsoon region.

The summer moistening of the global tropical stratosphere is mainly contributed by moist air from the Asian Monsoon/Tibetan region.

Other tracers can be transported by the same processes.

Convective transport over the Tibetan Plateau provides a main pathway for water vapor and CO to enter the lower stratosphere in the Asian monsoon region.

The summer moistening of the global tropical stratosphere is mainly contributed by moist air from the Asian Monsoon/Tibetan region.

Other tracers can be transported by the same processes.

Monsoon region: 10˚-25˚N

743

Where is the main source region? Indian subcontinent or Tibetan Plateau?

Tibetan Plateau: 27˚-35˚N

739

What is the role of convection over the Tibetan Plateau?What is the role of convection over the Tibetan Plateau?

Sept. 2005

ISCCP convective clustersTRMM PR rainrate (mm/h), JJA, 1998-2000 Convection over Tibet

penetrates higher than that over Asian monsoon region.

Convection over Tibet penetrates higher than that over Asian monsoon region.

Fu et al. 2006,GRLA

ltit

ud

e,

km

5 km above sea-level

In situ radar, Uyeda et al. 2001