Aerosol particles

and mountain regions

Alpine Summer School 25 June 2013

Angela Marinoni

Mountains are barometers of climate change. As

the world heats up, mountain glaciers — the

source of water for many of the world’s river

systems and people — are melting at

unprecedented rates, while rare plants and animals

struggle to survive over ever diminishing areas.

Mountain people, already among the

world’s most disadvantaged, face

greater hardships.

Understanding how climate

change affects mountains,

and learning how to manage

and mitigate any negative

effects, is vital for all of us,

wherever we live. FAO focus on mountains

by J Ross and T Hofer

The mountain regions has gained growing attention due to its

significant role in global atmospheric circulation and its sensitivity

for providing a first indication of climate changes, and thus is vital

for a better understanding of global climate and environmental

changes and their impacts and interactions to human activities.

MOUNTAINS: BAROMETERS OF CLIMATE CHANGE

BC deposition on snow/ice surfaces

Deposition of black carbon is a major driver of glacial retreat in the Hindu-Kush-

Himalaya-Tibetan region (ABC Regional assessment, 2008).

Ramanathan and Carmichael report that the impact of BC on melting snow and

glaciers may equal the impact of increased atmospheric CO2.

Flanner et al (2007) estimated that BC-induced reduction of snow albedo is a major

forcing term (about 20 W m-2) in the

Tibetan side of the Himalayas.

Starting from BC concentrations at NCO-P

in pre-monsoon season we estimate:

26-68 µg Kg-1 BC snow concentration

2 – 5.2 % snow albedo reduction

70 – 204 mm (we) runoff increase from

a typical Tibetan glacier equal to

24 % of the seasonal runoff

[Yasunari et al., ACP, 2010]

What is black carbon?

Black carbon is a particulate aerosol resulting from the incomplete combustion of

fossil fuels, biomass and biofuels. It is emitted from both anthropogenic and natural

sources. It consists of pure carbon in several linked forms.

Aerosols in the atmosphere

scatter and/or absorb

sunlight, cooling or warming

the atmosphere accordingly.

Radiative Forcing (W/m2) 1750-2005

Courtesy of Dennis Clare

BC is the most efficient aerosol in warming the atmosphere

How changed BC emissions?

Source: Bond et al, 2007

Source: Ramanathan et al, 2008

In Asia (China, India) coal and biomass burning emit the majority of black

carbon, with diesel vehicles contributing in a smaller proportion, while in USA

and Europe diesel vehicles and use of fossil fuels are the most important source

of black carbon.

Estimated vertical temperature profile for

the period 1950-2002 due to greenhouse

gases and sulphate aerosols (CO2+SO4

curve) and that due to the addition of ABCs to

CO2+SO4 (ABC+CO2+SO4)

(Source: Ramanathan and others 2007).

BC can reduce the radiation at surface

The aerosols in ABCs reduce the amount of

solar radiation reaching the surface and such

reduction can decrease crop productivity

Global Atmospheric

Watch

It is a program of the World Meteorological Organization Mondiale for evaluating the “health conditions” of the atmosphere with the aim to support correct environmental interventions.

http://gaw.kishou.go.jp/

High

altitude

stations

The Global Atmosphere Watch (GAW) programme take place in 1989 with the aims: to monitor background conditions of the atmosphere, to evaluate pollution transport, to study pollutants trend, to study climate environemnt interactions

Stratospheric intrusions,

free troposphere transports

Long-range

transport

Local and regional

scales Emissions

(ABC)

Free Troposphere

Planetary

Boundary Layer

Mountain ridges can represent a source of particles in the free troposphere

Mt. Everest “NCO-Pyramid”

27.9N, 86.7E; 5079 m asl

Mt. Cimone “O. Vittori” Station

44.1N, 10.4E; 2165 m asl

4/2009

Surface Ozone

GreenHouse Gaese (CO2, CH4, N2O, SF6)

Black Carbon

Aerosol size distribution (10nm to 20µm)

Aerosol Mass (PM10)

Halocarbons (CFC, HFC, HCFC,...)

Natural Radioactivity (Be7, Pb210, Rn222)

Meteorological Parameters

Aerosol Chemistry

Aerobiology (pollen and spores)

Measurements performed at Mt. Cimone Station

Lat. N 27°57' Lon. E 86°48'

Altitude: 5079 m asl

Khumbu Valley (Nepal),

at 5079 m a.s.l.

not far from the Italian Pyramid Observatory

Atmospheric

Brown Clouds

Himalaya

(Nepal) April

2009

Po Valley

(Italy)

Summer

2006

Atmospheric background conditions and tropospheric composition

can profitably be studied by means of continuous monitoring activities at High Mountain Stations

that provide unique opportunities to detect and analyses global change processes

Mt.Cimone NCO-P

Black Carbon

0

100

200

300

400

500

600

700

800

900

1000

0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 0:00

UTC + 4:45

ng

m-3

PRE-MONSOON

MONSOON

POST-MONSOON

DRY

black carbon diurnal variations

[Marinoni et al., 2010]

00 06 12 18

Vy

(m/s

)

-2

-1

0

1

2

3

4Monsoon

Pre-monsoon

Post-monsoon

Dry season

[Bonasoni et al., 2010]

High pollution can reach the high Himalayan region,

in particular during pre-monsoon season carrying high

concentrations of atmospheric pollutants

Photo: Khumbu Valley, April 2009

4/2009

NCO-P: Wildfires in South Asia (April 2009)

NCO-P, Khumbu Valley, April 27 2009

Forest Fire Hot Spots April 24-25, 2009

Fire had spread to at least

four high altitude protected

areas, including Annapurna,

Kanchanjunga, Langtang and

Makalu Barun national parks

for an unusually long period,

(Department of National Parks

and Wildlife Conservation) 358 fire Incidents in

Nepal on April 25

NCO-P: fires in South Asia (April 2010)

ACUTE POLLUTION EPISODE OF APRIL

2010

L evog luc os an

0

400

800

1200

22/03/10 23/03/10 24/03/10 25/03/10 26/03/10 27/03/10 28/03/10 29/03/10 30/03/10 31/03/10 01/04/10 02/04/10 03/04/10 04/04/10 05/04/10 06/04/10 07/04/10 08/04/10 09/04/10 10/04/10

ng

m

-3

ng

m-3

AP

RIL,

7 2

01

0

NC

O-P

web

cam

im

ag

es

10:46 NST

16:46 NST

Nucleation Event : 24 February 2006 •Locally >5000 part. cm-3

•Linked to windslope

•Takes place after

decrease on

condensational sink

•Not seen in Mass (BC or

PM)

•Peak of nanoparticles

takes place before

accumulation mode - 4h

delay-

• Not always « banana »

shaped: spatial

extention of nucleation

event.

4 h

DIam

ete

r (

nm

)

Local time (UTC + 4:45)

Dry season 25-50%RH

Monsoon 84-98%RH

Post-Monsoon 25-45%RH

Pre-Monsoon 45-85%RH

• High CN conc. locally (over 5000 # cm-3)

• Ultrafine particles

appear with frequency 0.5 (up to 0.8 in July)

• Nucleation event

control the free tropospheric background?

Which are the precursor?

Daily variability of particle size distribution

[Sellegri et al., ACP, 2010]

[Venzac et al., PNAS, 2009]

Evidence of high pollution event in the Himalaya during summer monsoon break 2006.

Surface ozone, black carbon

Nepal Climate Observatory – Pyramid, 12 – 22 June 2006

Long-range transport of dust and pollution during Monsoon break

0

2

4

6

8

10

12

7 8

night

10 11

afternoon

18 19

afternoon

22 23

night

25 26

afternoon

Days of June

mg

m-3

crustal matter

Inorganic Cations

Cl

organic anions

SO4

NO3

NH4

WSOM

WINSOM

NAINITAL

Coarse, fine particles

NCO-P

Coarse, fine particles

chemical composition PM10

Northern - Southern Himalaya stations: DAILY RAINFALL June-July 2006

0

5

10

15

20

25

30

35

01/0

6/20

06

05/0

6/20

06

09/0

6/20

06

13/0

6/20

06

17/0

6/20

06

21/0

6/20

06

25/0

6/20

06

29/0

6/20

06

03/0

7/20

06

07/0

7/20

06

11/0

7/20

06

15/0

7/20

06

19/0

7/20

06

23/0

7/20

06

27/0

7/20

06

31/0

7/20

06

mm

Xigaze Tingri Lhasa NCO-P