Satellite monitoring of dust storms over southwest Asia

Dr. Alireza Rashki

Ferdowsi university of Mashhad, Mashhad, Iran

a.rashki@um.ac.ir

• According to the International Standardization Organization (ISO 4225 - ISO, 1994), Dust are small solid particles, below 75 μm in diameter, are suspended in the atmosphere.

• They mostly originating from the arid lands and desert regions.

• Dust cycle is an integral part of the Earth system

• Desert dust in recent years has grown increasingly and has important role in climate change of the world (Park and Jung, 2008).

•dust has direct effects on air pollution, disruption of Transportation

Systems, prevalence of respiratory disease (Samet et al., 2000Goudie , 2014

Dust sources regions

4

• (1) Great Basin, (2) Sonoran, (3) Chihuahua, (4) Peruvian, (5) Atacama, (6)Monte, (7) Patagonia, (8) Sahara, (9) Somali-Chabli, (10) Namib, (11) Kalahari,(12) Karroo, (13) Arabian, (14) Rub al Khali, (15) Turkestan, (16) Iranian, (17)Thar, (18) Taklimakan, (19) Gobi, (20) Great Sandy, (21) Simpson, (22) Gibson,(23) Great Victoria and (24) Sturt

Every year about 2,000 tons

Study area

• Remote sensing techniques are very effective in identifying and monitoring of dust emission (Badok et al.2009) and can specify and classify their scope and their affected areas.

• UV Aerosol Index (AI)

• It is an index that detects the presence of uv-absorbing aerosols such as dust

• AI = 100 [ log10 (I360/I331)measured - log10 (I360/I331)calculated]

• Aerosol Optical Depth (AOD)

• Aerosol Optical Depth" is the degree to which aerosols prevent the transmission of light by absorption or scattering of light.

Satellite data used in this study

Spectral band

Spectral resolution

PeriodSourceVariable Name

UV1.25° × 1°01/1979- 05/1993TOMS Nimbus-7UV Aerosol Index (TOMSN7L3 v008)

UV1.25° × 1°07/1996- 12/2005Earth ProbeUV Aerosol Index (TOMSEPL3 v008)

UV0.25° × 0.25°01/2005- 10/2014OMIUV Aerosol Index (OMTO3G.003)

555 nm0.5° × 0.5°03/2000- 11/2013MISR TerraAerosol Optical Depth (MIL3MAE v4)

550 nm1° × 1°07/2002- 09/2014Aqua-MODISAerosol Optical Depth (Deep Blue, Land-only) (MYD08_M3 v6)

550 nm1° × 1°03/2000- 12/2007Terra-MODISAerosol Optical Depth (Deep Blue, Land-only) (MOD08_M3 v6)

downloadable on relevant sites such as GIOVANII

Monthly-mean spatial

distribution of the

Earth-Probe TOMS

AI values over South

west Asia (2001–2005)

Monthly-mean

spatial distribution

of the Aura-OMI

AI values over

South west Asia

during 2006–2012

12/7/2017 9

“Wind 120 days” or “Lavar”

RegCM4 simulations of air temperature at near-ground level (945 hPa) during JJA 1990

12/7/2017 11

RegCM4 simulations of wind velocity

Distribution of frequency of annual dust storms over SW Asia.

12/7/2017 12

81 dust storms days per year over

Sistan. The most active dust source in

SW Asia (Middleton, 1986)

The Hamoun lakes

Hamoun lakes complex:

-largest fresh water ecosystem of

the Iranian Plateau

- one of the first wetlands in the

Ramsar Convention. Landsat MSS false color composite (bands 4, 2, and 1) images of the

Hamoun lakes (1976-1987). Landsat 7 ETM+ false color composite (bands 4,

3, and 2) for 1998-2003. 12/7/2017 13

14

Sistan

Hamoun dried bed

12 July 2004

WHO report of

2015, 3000 cities in

103 countries.

12/7/2017 15

Case dust storms over SistanSeptember 13, 2003

June 14, 2003

12/7/2017 16

Sistan dust activity (HYSPLIT model)5-day forward air-

mass trajectories

originated from the

Sistan/Hamoun

basin on the dust-

storm days for the

June–September

months during the

period 2001–2012.

12/7/2017 17

Density plot of the

5-day forward air-

mass trajectories

The exceptional case of June 2008

Aqua MODIS true color images over Arabian Sea on days during the second half of

June 2008.

12/7/2017 19

• AOD (10km) (2000-2014)

1

2

Time series of AOD and AI (monthly mean values) from multiple satellite sensors over Sistan region (30-31º N, 61-62º E). The lower panel emphasizes the 2000s.

1979 1982 1985 1988 1991 1994 1997 2000 2003 2006 2009 20120.0

0.5

1.0

1.5

2.0

2.5

3.0

Nimbus 7(1979-1993)

EP (1996-2001)

OMI (2005-2011)

MISR (2000-2011)

MODIS Aqua (2002-2011)

MODIS Terra (2000-2007)

Year

AI

0.0

0.2

0.4

0.6

0.8

1.0

AO

D

1.2

1.6

2.0

2.4

2.8

Nimbus 7

EP

OMI

MODIS Aqua

MODIS Terra

MISR

A I

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.2

1.6

2.0

2.4

2.8

Spring

Summer

Autumn

Winter

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.2

1.6

2.0

2.4

2.8

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1980 1985 1990 1995 2000 2005 20100.8

1.2

1.6

2.0

2.4

2.8

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

A O

D

Annual mean variation of AOD and AI for different satellite sensors and time periods over Sistan region (30-31º N, 61-62º E).

Jan Feb Mar Apr May Jan July Aug Sep Oct Nov Dec

0.8

1.2

1.6

2.0

2.4

2.8 Nimbus 7(1979-1993)

OMI(2005-2011)

EP( 1996-2001)

MISR(2000-2010)

MODIS Aqua (2002-2011)

MODIS Terra (2000-2007)

Month

AI

0.0

0.2

0.4

0.6

0.8

1.0

AO

D

AOD from SARA algorithm(High resolution 500*500 m)

• ρAER(λ,θs,θv,Φ) = ρTOA(λ,θs,θv,Φ) - ρRAY(λ,θs,θv,Φ) -(T(θs)T(θv) ρs(λ,θs,θv,Φ) / 1- ρs(λ,θs,θv,Φ)S(λ))

• Band 4 (MOD02)

• AOD deep blue 10km (MOD04)

• Surface reflectance Band 4 (MOD09)

• Solar zenith

• Sensor zenith

• Digital elevation model(DEM)

• Pressure from sea level

• …

From MODIS

AOD (SARA) index (500*500m resolution)

13 July 2016

IranAfghanistan

Hamoun lakes

Sistan

Wind

conclusion

• Satellite images are useful tools for detecting dust

• Sistan region and Thar desert are two major resources of dust emission in South West Asia

• In the Sistan region detected several hot spots increasing dust in atmosphere.

• Seasonal lakes are major sources of dust emissions in the Sistan region

• High resolution dust Index specified dynamics of dust emissions