Appendix 2: Mass scattering efficiencies and corresponding Notes notes tables and citation list. 

Table 2. Summary of a literature survey of mass scattering efficiencies using the theoretical method. The 

first column corresponds to the reference number and entry in the associated notes table. Entries correspond 

to the fine mode unless otherwise stated in the column heading, or noted with superscripts.

Theoretical Method Mass Scattering Efficiency (m2 g-1)

*

Note Fine 

Mode 

Coarse 

Mode 

Total 

Mode Sulfate POM Dust Sea Salt 

Location/ 

Study/ 

Characteristic 

Time 

1

1 

 

1.4 ± 

0.7 

Baltimore, MD 

Canadian smoke 

(Supersite) 

Jul 

4,6,10 

2002 

3

2

 

3.8 

2.8† 

Great Smoky 

National Park, 

TN (SEAVS) 

Jul-Aug 

1995 

103  1.07♦

 0.52♦ Sal Island, Cape 

Verde 

Dec 

1991, 

Jan 

1994, 

Dec 

1994- 

Feb 

1995 

17 3.4 0.6 

Big Bend 

National Park, 

TX (BRAVO) 

Jul-Oct 

1999 

19a4  

3 

0.9† 

Santa Maria, 

Azores 

Jun 10, 

1992 

19b4  

28 

2.4† 

Santa Maria, 

Azores 

Jun 13, 

1992 

19c4  

13 

3.3† 

Santa Maria, 

Azores 

Jun 19, 

1992 

19d4  

9.1 

2.5† 

Santa Maria, 

Azores 

Jun 20, 

1992 

19e4  

5.2 

1.6† 

Christmas 

Island 

Aug 3, 

1994 

225  

6.9 

6.0†,♦

5.3 

2.9 0.64‡

 1.3‡

Waliguan 

Mountain, 

Qinghai 

Province, China 

Oct-Nov 

1997, 

Jan 1998 

29a 2.23 

Hopi Point, 

Grand Canyon 

National Park, 

AZ 

Jan-Feb 

1998 

29b 2.59 

Hopi Point, 

Grand Canyon 

National Park, 

AZ 

Jan-Feb 

1998 

29c 4.81 

Hopi Point, 

Grand Canyon 

National Park, 

AZ 

Jan-Feb 

1998 

29d 2.03 Meadview, AZ Summer 

1992 

29e 2.05 Meadview, AZ Summer 

1992 

29f 2.11 Meadview, AZ Summer 

1992 
Note Fine 

Mode 

Coarse 

Mode 

Total 

Mode Sulfate POM Dust Sea Salt 

Location/ 

Study/ 

Characteristic 

Time 

29g 2.63 

Shenandoah 

National Park, 

VA 

Summer 

1990 

29h 3.81 

Shenandoah 

National Park, 

VA 

Summer 

1990 

29i 18.23 

Shenandoah 

National Park, 

VA 

Summer 

1990 

31a 2.4 

Great Smoky 

National Park, 

TN (SEAVS) 

Jul-Aug 

1995 

31b 3.58 

Great Smoky 

National Park, 

TN (SEAVS) 

Jul-Aug 

1995 

31c 9.64 

Great Smoky 

National Park, 

TN (SEAVS) 

Jul-Aug 

1995 

32 3.15 

2.96† 

Big Bend 

National 

Park,TX 

(BRAVO) 

Jul-Oct 

1999 

33 4.21 

Yosemite 

National Park, 

CA (YACS) 

Jul-Sep 

2002 

346 0.48‡ 

Izana, Tenerife, 

Canary Islands Jul 1999 

37 4.3 

Yosemite 

National Park, 

CA (YACS) 

Jul-Sep 

2002 

437 3.6 0.87 

5

♦

2.8♦

3.6†,♦, 

 

Pacific Ocean 

and Cheeka 

Peak, WA (PSI 

and MAGE) 

1991 & 

1992 

458 3.2±0.3 

0.84±0.09, 

1.5±0.2, 

1.12†

 4.1±0.4 Southern Ocean 

Region (ACE1) 

Nov-Dec 

1995 

469  

4

♦

1.7†,♦ 3.3♦

 1.1♦ 1.6♦

Norfolk, VA to 

Cape Town, 

South Africa 

(Aerosols99) 

Jan–Feb 

1999 

4610 4.8±0.5 

3.5±0.7 

4.4±0.9, 

1.83†

6.4±1.1 

7.2±1.8 3.6±0.8 6.0±0.7 

Norfolk, VA to 

Cape Town, 

South Africa 

(Aerosols99) 

Jan–Feb 

1999 

4611 1.02±0.05 1.7±0.4 

1.9 ±0.5‡ 0.60±0.07‡

 1.12±0.16‡

Norfolk, VA to 

Cape Town, 

South Africa 

(Aerosols99) 

Jan–Feb 

1999 

4812  

4.9♦

2.04†,♦

4.1♦

3.6♦ 1.5♦

 1.6♦ Indian Ocean 

(INDOEX) 

Feb-Mar 

1999 

4813 4.5±0.5 

3.9±0.8 

5.0±0.9, 

2.06†

6±1 

5±1 3.4±0.4 5.5±0.3 Indian Ocean (INDOEX) 

Feb-Mar 

1999 

4814 2±1 

3.7±0.6‡

3.9±0.5‡, 

1.6†,‡

4.1±0.9‡

3.6±0.8‡ 0.8±0.3‡

 1.06±0.7‡ Indian Ocean 

(INDOEX) 

Feb-Mar 

1999 
Note Fine 

Mode 

Coarse 

Mode 

Total 

Mode Sulfate POM Dust Sea Salt 

Location/ 

Study/ 

Characteristic 

Time 

4915 4.3±0.6 3.8±0.7 

2.5±0.3†

5.3±0.7 

4.7±0.6 3.4±0.3 5.0±0.5 

Pacific Ocean, 

coastal Asia 

 (ACE-ASIA) 

Spring 

2001 

4916 1.4±0.6 3.2±0.4‡ 2.0±0.3‡

1.8±0.2‡ 0.67±0.16‡

 1.6±0.2‡

Pacific Ocean, 

coastal Asia 

 (ACE-ASIA) 

Spring 

2001 

4917 3±1♦

 3.7±0.6♦ 4.4±0.7♦

3.9±0.6♦ 1.2±0.4♦

 2.8±0.4♦

Pacific Ocean, 

coastal Asia 

 (ACE-ASIA) 

Spring 

2001 

Footnotes for theoretical method table 

*All values reported for a wavelength of 550 nm unless otherwise stated in the Theoretical method note table. Values 

correspond to fine mode unless otherwise noted in the column header or by foot note. Size ranges and relative humidity 

(when reported) are stated in the Theoretical method note table or in the footnotes. Theoretical method includes mixed 

(‘specific’), externally mixed, and mixed/apportioned methods, also found in the Theoretical method note table for each 

entry. 

In the “sulfate” column, italicized values correspond to dry ammonium sulfate. 

In the “POM” column, italicized values are normalized to POM multiplier of Roc = 1.8. 

†

 We converted to dry ammonium sulfate 

‡

 Corresponds to coarse mode (supermicron) 

♦

 Corresponds to total modes (supramicron, fine + coarse) 

1 Average and standard deviation of three time periods (see notes 1a, 1b, and 1c). 

2

 Sulfate is ion, Dp < 3 μm 

3

 Dust and sea salt are for Dp < 8.75. 

4

 Sulfate is ion for 0.18 < Dp < 10 μm 

5

 Sulfate is bisulfate in the accumulation mode. Organic carbon is in the accumulation mode. Dust and sea salt correspond to 

coarse mode. 

6

 Dust is coarse mode. 

7

 Sulfate is ion and sulfate aerosol (nss-SO4+NH4+ H2O), and corrected dry ammonium sulfate aerosol. respectively, for Dp < 

10 um. Mixed fine corresponds to residual mass for Dp < 1 μm and mixed coarse corresponds to residual mass for 1 < Dp < 10 

μm (see notes 43a and 43b). 

8

 Dp < 1 μm. Average and standard deviation of estimates corresponding to air masses for short (< 5 days), long (>= 5 days) 

marine boundary layer residence times, and perturbed air masses. Sulfate is dry (30-45%) ammoniated sulfate mass, sulfate ion 

and corrected dry ammonium sulfate from ion, respectively (see notes 45a-f). 

9

 Sulfate is ion, and corrected dry ammonium sulfate. Dp < 10 μm (see note 46a), RH = 55 %. 

10 Dp < 1.1 μm. Average and standard deviation of values corresponding to North America, Northern Hemisphere marine, 

African dust, African dust/biomass burning, and biomass burning. Sulfate is wet ammoniated sulfate mass (55 % RH), sulfate ion 

and corrected dry ammonium sulfate from ion, respectively, (see notes 46a-k). 

11 1.1 < Dp < 10 μm. Average and standard deviation of values corresponding to North America, Northern Hemisphere marine, 

African dust, African dust/biomass burning, and biomass burning. Sulfate is wet ammoniated sulfate mass (55 % RH), sulfate ion 

and corrected dry ammonium sulfate from ion, respectively (see notes 46l-p). 

12 Dp < 10 μm. Sulfate is ion (see note 48a). 

13 Dp < 1.1 μm. Average and standard deviation of values corresponding to SH Atlantic, SH Indian Ocean, NH Indian Ocean, 

East Indian Subcontinent, Indian Subcontinent, Arabia, Arabian-Indian Subcontinent and Arabian Sea-Coastal India. Sulfate is 

wet ammoniated sulfate mass (55 % RH), sulfate ion and corrected dry ammonium sulfate from ion, respectively (see notes 48aq). 

14 1.1 < Dp < 10 μm. Average and standard deviation of values corresponding to SH Atlantic, SH Indian Ocean, NH Indian 

Ocean, East Indian Subcontinent, Indian Subcontinent, Arabia, Arabian-Indian Subcontinent and Arabian Sea-Coastal India. 

Sulfate is wet ammoniated sulfate mass (55 % RH), sulfate ion and corrected dry ammonium sulfate from ion, respectively (see 

notes 48r-cc). 

15 Dp < 1.1 μm. Average and standard deviation of values corresponding to Polluted-Korea/Japan, Polluted-Japan, 

Volcano+Polluted, dust+Frontal, Dust+Korea, and Dust+Shanghai. Sulfate is sulfate aerosol (nss-SO4+NH4+H2O, RH = 55 %) 

and corrected to dry ammonium sulfate (see notes 49a-f). 
16 1.1 < Dp < 10 μm. Average and standard deviation of values corresponding to Polluted-Korea/Japan, Polluted-Japan, 

Volcano+Polluted, dust+Frontal, Dust+Korea, and Dust+Shanghai. Sulfate is sulfate aerosol (nss-SO4+NH4+H2O, RH = 55 %) 

(see notes 49g-l). 

17 Dp < 10 μm. Average and standard deviation of values corresponding to Polluted-Korea/Japan, Polluted-Japan, 

Volcano+Polluted, dust+Frontal, Dust+Korea, and Dust+Shanghai. Sulfate is sulfate aerosol (nss-SO4+NH4+H2O, RH = 55%) 

(see notes 49m-r). 

Theoretical Method Notes table with further details about measurement methods 

Theoretical Method Notes 

1a Mass derived from size distributions from SMPS and APS (0.00931 < Dp < 20.535 um). Bsp computed with Mie theory at a 

wavelength at 530 nm. RH values not stated. Values are means. Mixed (‘specific’) method. (July 4 0100 LT - July 6 1900 LT 2002, 

Baltimore Supersite. Smoke transport from Canada) 

1b Mass derived from size distributions from SMPS and APS (0.00931 < Dp < 20.535 um). Bsp computed with Mie theory at a 

wavelength at 530 nm. RH values not stated. Values are means. Mixed (‘specific’) method. (July 6 1905 LT - July 10 2200 LT 

2002, Baltimore Supersite. Smoke transport from Canada) 

1c Mass derived from size distributions from SMPS and APS (0.00931 < Dp < 20.535 um). Bsp computed with Mie theory at a 

wavelength at 530 nm. RH values not stated. Values are means. Mixed (‘specific’) method. (July 10 2205 LT - July 13 0055 LT 

2002, Baltimore Supersite. Smoke transport from Canada) 

3

 Bsp computed from ASASP-X OPC dry size distributions. Sulfate acidity varied. The accumulation mode was assumed to be all 

sulfate. Esp computed per mass of sulfate ion. Wavelength not stated. Mixed/apportioned method. (July 15 - August 22 1995, Great 

Smoky Mountains National Park, TN, SEAVS study). 

10 Mass size distributions (0.65 < Dp < 8.75 um). Values are means. Sulfate corresponds to excess sulfate ion. Mineral dust is traced 

by Al. Sea salt derived from sodium based on amounts in sea water. Externally mixed method. Wavelength of 670 nm. (Dec 1991, 

Jan 1994, Dec 1994-Feb 1995, Sal Island, Cape Verde). 

17 Computed using dry accumulation mode and coarse mode volume size distribution with Mie theory. Refractive indices from an 

alignment method. Size dependence of Esp reported. Wavelength of 530 nm. Mixed (‘specific’) method. (July-Oct 1999, Big Bend 

National Park, TX). 

19a MOUDI size distributions at ambient humidity (0.32 < Dp < 10 um, RH = 73 %). Sulfate corresponds to nss-SO4 ion. Externally 

mixed method. (June 10 0800-1900 1992, Santa Maria, Azores archipelago, clean maritime air) 

19b MOUDI size distributions at ambient humidity (0.32 < Dp < 10 um, RH = 95 %). Sulfate corresponds to nss-SO4. Externally 

mixed method. (June 13 2000-0700 1992, Santa Maria, Azores archipelago, drizzle, clean maritime air) 

19c MOUDI size distributions at ambient humidity (0.32 < Dp < 10 um, RH = 81 %). Sulfate corresponds to nss-SO4. Externally 

mixed method. (June 19 2000-0700 1992, Santa Maria, Azores archipelago, continental polluted air) 

19d MOUDI size distributions at ambient humidity (0.32 < Dp < 10 um, RH = 77 %). Sulfate corresponds to nss-SO4. Externally 

mixed method. (June 20 0800-1900 1992, Santa Maria, Azores archipelago, continental polluted air) 

19e MOUDI size distributions at ambient humidity (0.32 < Dp < 10 um, RH = 69 %). Sulfate corresponds to nss-SO4. Externally 

mixed method. (Aug 3 1029-2146 1994, Christmas Island, Republic of Kiribati, low contributions from anthropogenic sources) 

22 MOUDI size distributions (0.056 < Dp < 18 um). Sulfate corresponds to accumulation mode NH4 + SO4 as bisulfate. Water 

soluble OC. Na + Cl (sea salt) associated with coarse mode. Coarse mode dust computed for Ca + CO3. Particle growth by Tang. 

Median values. RH not stated. Size dependence of Esp reported. Externally mixed method. (Oct - Nov 1997, Jan 1998,Waliguan 

Mountain, Qinghai Province, China) 

29a DRUM sulfur size distributions for Dp < 2.5 um. Sulfur assumed to be dry ammonium sulfate. Esp computed for ammonium 

sulfate mass. Wavelength not stated. Externally mixed method. Size dependence of Esp observed. (Jan-Feb 1988, Hopi Point, Grand 

Canyon, AZ) 

29b DRUM sulfur size distributions for Dp < 2.5 um. Sulfur assumed to be wet ammonium sulfate. Esp estimated for wet ammonium 

sulfate mass and wet bsp (ammonium sulfate + water) Wavelength not stated. Externally mixed method. Size dependence of Esp 

observed. (Jan-Feb 1988, Hopi Point, Grand Canyon, AZ) 

29c DRUM sulfur size distributions for Dp < 2.5 um. Sulfur assumed to be ammonium sulfate. Enhanced Esp estimated for dry 

ammonium sulfate mass and wet bsp. Wavelength not stated. Externally mixed method. Size dependence of Esp observed. (Jan-Feb 

1988, Hopi Point, Grand Canyon, AZ) 

29d DRUM sulfur size distributions for Dp < 2.5 um. Sulfur assumed to be dry ammonium sulfate. Esp computed for ammonium 

sulfate mass. Wavelength not stated. Externally mixed method. Size dependence of Esp observed. (Summer 1992, Meadview, AZ) 

29e DRUM sulfur size distributions for Dp < 2.5 um. Sulfur assumed to be wet ammonium sulfate. Esp estimated for wet ammonium 

sulfate mass and wet bsp (ammonium sulfate + water) Wavelength not stated. Externally mixed method. Size dependence of Esp 

observed. (Summer 1992, Meadview, AZ) 

29f DRUM sulfur size distributions for Dp < 2.5 um. Sulfur assumed to be ammonium sulfate. Enhanced Esp estimated for dry 

ammonium sulfate mass and wet bsp. Wavelength not stated. Externally mixed method. Size dependence of Esp observed. (Summer 

1992, Meadview, AZ) 
Theoretical Method Notes 

29g

 DRUM sulfur size distributions for Dp < 2.5 um. Sulfur assumed to be dry ammonium sulfate. Esp computed for ammonium 

sulfate mass. Wavelength not stated. Externally mixed method. Size dependence of Esp observed. (Summer 1990, Shenandoah 

National Park, VA) 

29h DRUM sulfur size distributions for Dp < 2.5 um. Sulfur assumed to be wet ammonium sulfate. Esp estimated for wet ammonium 

sulfate mass and wet bsp (ammonium sulfate + water) Wavelength not stated. Externally mixed method. Size dependence of Esp 

observed. (Summer 1990, Shenandoah National Park, VA) 

29i DRUM sulfur size distributions for Dp < 2.5 um. Sulfur assumed to be ammonium sulfate. Enhanced Esp estimated for dry 

ammonium sulfate mass and wet bsp. Wavelength not stated. Externally mixed method. Size dependence of Esp observed. (Summer 

1990, Shenandoah National Park, VA) 

31a Drum size distributions (PM2.5) for dry ammonium sulfate and calculated Bsp. Wavelength not stated. Externally mixed method. 

(July 15 - Aug 25, 1995, Great Smoky National Park, TN) 

31b Drum size distributions (PM2.5) for wet ammonium sulfate and calculated wet Bsp, at ambient humidity. Wavelength not stated. 

Externally mixed method. (July 15 - Aug 25, 1995, Great Smoky National Park, TN). 

31c Drum size distributions (PM2.5) for water enhanced ammonium sulfate at 75% humidity (dry ammonium sulfate mass and wet 

Bsp). Externally mixed method. Wavelength not stated. (July 15 - Aug 25, 1995, Great Smoky National Park, TN) 

32 MOUDI size distributions (0.18 < Dp < 18 um) of dry ammoniated sulfate mass. Exact form of sulfate not specified. Externally 

mixed method. Size dependence of Esp observed. (July-Oct 1999, Big Bend National Park, TX) 

33 DMA dry size distributions of accumulation mode. Mixed (‘specific’) method. (July-Sept 2002, Yosemite National Park, CA) 

34a APS and SMPS size distributions (Dp < 15 um) for dust, assuming Dp < 0.6 is non-dust and the rest is dust. Mixed (‘specific’) 

method. (July 3- 29 1999, Izana, Tenerife, Canary Islands) 

37 DMA and OPC dry aligned size distributions (0.04 < Dp < 2 um) and retrieved refractive indices. Wavelength not stated. Mixed 

(‘specific’) method. (July-Sept 2004, Yosemite National Park, CA) 

43 DMA and APS number distributions, RH = 30 %. Sulfate corresponds to sulfate ion for Dp < 10 um. (April - May 1991, Cheeka 

Peak, WA). Mixed fine corresponds to residual mass (Dp < 1 um). Total corresponds to super micron (1 < Dp < 10 um) residual 

mass. Mixed/apportioned method. (1991 & 1992, PSI and MAGE samples). 

43b DMA and APS number distribution, RH = 30 %. Sulfate corresponds to sulfate aerosol. Mixed/apportioned method (Feb-March 

1992, PSI and MAGE samples, Pacific Ocean from 33 N to 12 S along 140 W) 

45a Size distribution and mass data for Dp < 1 um. RH varies between 30-45 %. Sulfate corresponds to (nss-SO4+NH4+H20). Mixed 

Fine corresponds to Dp < 1 um and (sea salt + nss-so4).Sea salt corresponds to Dp < 1 um and Na+K+Mg+Ca+Cl+ss-SO4). 

Mixed/apportioned method (Nov-Dec 1995, 41 deg south to 54 south, 135 east to 160 east, for Marine air, short (<5 days) marine 

boundary layer residence time) 

45b Size distribution and mass data for Dp < 1 um. RH varies between 30-45 %. Sulfate corresponds to (nss-SO4+NH4+H20). Mixed 

fine corresponds to Dp < 1 um and (sea salt + nss-so4). Sea salt corresponds to Dp < 1 um and (Na+K+Mg+Ca+Cl+ss-SO4). 

Mixed/apportioned method (Nov-Dec 1995, 41 deg south to 54 south, 135 east to 160 east, for Marine air, long (>= 5days) marine 

boundary layer residence time ) 

45c Size distribution and mass data for Dp < 1 um. RH varies between 30-45 %. Sulfate corresponds to (nss-SO4+NH4+H20). Mixed 

fine corresponds to Dp < 1 um and (sea salt + nss-so4). Sea salt corresponds to Dp < 1 um and (Na+K+Mg+Ca+Cl+ss-SO4). 

Mixed/apportioned method (Nov-Dec 1995, 41 deg south to 54 south, 135 east to 160 east, for Perturbed marine air) 

45d Size distribution and mass data for Dp < 1 um. RH varies between 30-45 %. Sulfate corresponds to nss-SO4 ion. 

Mixed/apportioned method (Nov-Dec 1995, 41 deg south to 54 south, 135 east to 160 east, for Marine air, short (<5 days) marine 

boundary layer residence time) 

45e Size distribution and mass data for Dp < 1 um. RH varies between 30-45 %. Sulfate corresponds to nss-SO4 ion. 

Mixed/apportioned method (Nov-Dec 1995,41 deg south to 54 south, 135 east to 160 east, for Marine air, long (>= 5days) marine 

boundary layer residence time) 

45f Size distribution and mass data for Dp < 1 um. RH varies between 30-45 %. Sulfate corresponds to nss-SO4 ion. 

Mixed/apportioned method. (Nov-Dec 1995,41 deg south to 54 south, 135 east to 160 east, for Perturbed marine,) 

46a Size distributions for Dp < 10 um, RH = 55 %. Sea salt, nss-SO4 ion, dust/trace elements, POM = 1.6* OC for North American 

air masses and POM = 2.1*OC for all other air masses. Reported means for North America, NH marine, dust, dust/biomass burning, 

biomass burning. Mixed/apportioned method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46b Size distributions for Dp < 1.1 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion, with Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to dust or trace elements. POM = 1.6* OC for 

North American air masses and POM = 2.1*OC for all other air masses. Fine mixed aerosol for Dp < 1.1 um. Mean for North 

America. Mixed/apportioned method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46c Size distributions for Dp < 1.1 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion, with Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to dust or trace elements. POM = 1.6* OC for 

North American air masses and POM = 2.1*OC for all other air masses. Fine mixed aerosol for Dp < 1.1 um. Mean for Northern 

Hemisphere marine. Mixed/apportioned method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 
Theoretical Method Notes 

46d Size distributions for Dp < 1.1 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion, with Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to dust or trace elements. POM = 1.6* OC for 

North American air masses and POM = 2.1*OC for all other air masses. Fine mixed aerosol for Dp < 1.1 um. Mean for African dust. 

Mixed/apportioned method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46f Size distributions for Dp < 1.1 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion, with Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to dust or trace elements. POM = 1.6* OC for 

North American air masses and POM = 2.1*OC for all other air masses. Fine mixed aerosol for Dp < 1.1 um. Mean for biomass 

burning. Mixed/apportioned method (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46g Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (includes Bsp due to nss-SO4 ion, 

NH4, and water, and sulfate mass due to nss-SO4, NH4 and water. Mean for North America. Mixed/apportioned method. (Jan 14 -

Feb 8 1999, Norfolk, VA to Cape Town, South Africa)

46h Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (includes Bsp due to nss-SO4 ion, 

NH4, and water, and sulfate mass due to nss-SO4, NH4 and water. Mean for Northern Hemisphere marine. Mixed/apportioned 

method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46i Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (includes Bsp due to nss-SO4 ion, 

NH4, and water, and sulfate mass due to nss-SO4, NH4 and water. Mean for African dust. Mixed/apportioned method. (Jan 14 -Feb 

8 1999, Norfolk, VA to Cape Town, South Africa) 

46j Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (includes Bsp due to nss-SO4 ion, 

NH4, and water, and sulfate mass due to nss-SO4, NH4 and water. Mean for African dust/biomass burning. Mixed/apportioned 

method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46k Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (includes Bsp due to nss-SO4 ion, 

NH4, and water, and sulfate mass due to nss-SO4, NH4 and water. Mean for biomass burning. Mixed/apportioned method. (Jan 14 -

Feb 8 1999, Norfolk, VA to Cape Town, South Africa)

46l Size distributions for 1.1 < Dp < 10 um and RH = 55%. Sea salt includes NO3 and water. Dust refers to dust or trace elements. 

POM = 1.6* OC for North American air masses and POM = 2.1*OC for all other air masses. Mixed coarse aerosol for 1.1 < Dp < 10 

um. Mean for North America. Mixed/apportioned method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46m Size distributions for 1.1 < Dp < 10 um and RH = 55%. Sea salt includes NO3 and water. Dust refers to dust or trace elements. 

POM = 1.6* OC for North American air masses and POM = 2.1*OC for all other air masses. Mixed coarse aerosol for 1.1 < Dp < 10 

um. Mean for Northern Hemisphere marine. Mixed/apportioned method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South 

Africa) 

46n Size distributions for 1.1 < Dp < 10 um and RH = 55%. Sea salt includes NO3 and water. Dust refers to dust or trace elements. 

POM = 1.6* OC for North American air masses and POM = 2.1*OC for all other air masses. Mixed coarse aerosol for 1.1 < Dp < 10 

um. Mean for African dust. Mixed/apportioned method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46o Size distributions for 1.1 < Dp < 10 um and RH = 55%. Sea salt includes NO3 and water. Dust refers to dust or trace elements. 

POM = 1.6* OC for North American air masses and POM = 2.1*OC for all other air masses. Mixed coarse aerosol for 1.1 < Dp < 10 

um. Mean for African dust/biomass burning. Mixed/apportioned method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South 

Africa) 

46p Size distributions for 1.1 < Dp < 10 um and RH = 55%. Sea salt includes NO3 and water. Dust refers to dust or trace elements. 

POM = 1.6* OC for North American air masses and POM = 2.1*OC for all other air masses. Mixed coarse aerosol for 1.1 < Dp < 10 

um. Mean for biomass burning. Mixed/apportioned method. (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

48a Size distributions for Dp < 10 um and RH = 55 %. Sea salt, nss-SO4 ion, inorganic oxidized material (dust), POM =1.6*OC. 

Mean for entire experiment. Mixed/apportioned method. (Feb-March 1999, Arabian Sea, Bay of Bengal, Indian Ocean, north and 

south of the ITCZ) 

48b Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion. Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to inorganic oxidized material plus residual. POM 

= 1.6*OC. Fine mixed aerosol corresponds to Dp < 1.1 um. Mean for SH Atlantic. Mixed/apportioned method. (Feb-March 1999) 

48c Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion. Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to inorganic oxidized material plus residual. POM 

= 1.6*OC. Fine mixed aerosol corresponds to Dp < 1.1 um. Mean for SH Indian Ocean. Mixed/apportioned method. (Feb-March 

1999) 

48d Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion. Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to inorganic oxidized material plus residual. POM 

= 1.6*OC. Fine mixed aerosol corresponds to Dp < 1.1 um. Mean for NH Indian Ocean. Mixed/apportioned method. (Feb-March 

1999) 

48e Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion. Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to inorganic oxidized material plus residual. POM 

= 1.6*OC. Fine mixed aerosol corresponds to Dp < 1.1 um. Mean for East Indian Subcontinent. Mixed/apportioned method. (FebMarch 1999) 
Theoretical Method Notes 

48f Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion. Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to inorganic oxidized material plus residual. POM 

= 1.6*OC. Fine mixed aerosol corresponds to Dp < 1.1 um. Mean for Indian Subcontinent. Mixed/apportioned method. (Feb-March 

1999) 

48h Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion. Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to inorganic oxidized material plus residual. POM 

= 1.6*OC. Fine mixed aerosol corresponds to Dp < 1.1 um. Mean for Arabia-Indian subcontinent. Mixed/apportioned method. (FebMarch 1999) 

48i Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion. Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion. Dust refers to inorganic oxidized material plus residual. POM 

= 1.6*OC. Fine mixed aerosol corresponds to Dp < 1.1 um. Mean for Arabian sea, coastal India. Mixed/apportioned method. (FebMarch 1999) 

48j Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, and 

water, and sulfate mass due to nss-SO4, NH4 and water). Mean for SH Atlantic. Mixed/apportioned method. (Feb-March 1999) 

48k Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, and 

water, and sulfate mass due to nss-SO4, NH4 and water). Mean for SH Indian Ocean. Mixed/apportioned method. (Feb-March 

1999) 

48l Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, and 

water, and sulfate mass due to nss-SO4, NH4 and water). Mean for NH Indian Ocean. Mixed/apportioned method. (Feb-March 

1999) 

48m Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, and 

water, and sulfate mass due to nss-SO4, NH4 and water). Mean for East Indian subcontinent. Mixed/apportioned method. (FebMarch 1999) 

48n Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, and 

water, and sulfate mass due to nss-SO4, NH4 and water). Mean for Indian subcontinent Mixed/apportioned method. (Feb-March 

1999) 

48o Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, and 

water, and sulfate mass due to nss-SO4, NH4 and water). Mean for Arabia Mixed/apportioned method. (Feb-March 1999) 

48p Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, and 

water, and sulfate mass due to nss-SO4, NH4 and water). Mean for Arabia-Indian subcontinent Mixed/apportioned method. (FebMarch 1999) 

48q Size distributions for Dp < 1.1 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, and 

water, and sulfate mass due to nss-SO4, NH4 and water). Mean for Arabian Sea, coastal India Mixed/apportioned method. (FebMarch 1999) 

48r Size distributions for 1.1 < Dp < 10 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion (Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion). Dust refers to inorganic oxidized material plus residual. 

POM = 1.6*OC. Mixed coarse aerosol corresponds to 1.1 < Dp < 10 um. Mean for SH Atlantic Mixed/apportioned method. (FebMarch 1999) 

48s Size distributions for 1.1 < Dp < 10 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion (Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion). Dust refers to inorganic oxidized material plus residual. 

POM = 1.6*OC. Mixed coarse aerosol corresponds to 1.1 < Dp < 10 um. Mean for SH Indian Ocean Mixed/apportioned method. 

(Feb-March 1999) 

48t Size distributions for 1.1 < Dp < 10 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion (Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion). Dust refers to inorganic oxidized material plus residual. 

POM = 1.6*OC. Mixed coarse aerosol corresponds to 1.1 < Dp < 10 um. Mean for NH Indian Ocean Mixed/apportioned method. 

(Feb-March 1999) 

48u Size distributions for 1.1 < Dp < 10 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion (Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion). Dust refers to inorganic oxidized material plus residual. 

POM = 1.6*OC. Mixed coarse aerosol corresponds to 1.1 < Dp < 10 um. Mean for East Indian Subcontinent Mixed/apportioned 

method. (Feb-March 1999) 

48v Size distributions for 1.1 < Dp < 10 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion (Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion). Dust refers to inorganic oxidized material plus residual. 

POM = 1.6*OC. Mixed coarse aerosol corresponds to 1.1 < Dp < 10 um. Mean for Indian Subcontinent Mixed/apportioned method. 

(Feb-March 1999) 

48w Size distributions for 1.1 < Dp < 10 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion (Bsp 

due to nss-SO4, NH4 and water, and sulfate mass due to nss-SO4 ion). Dust refers to inorganic oxidized material plus residual. 

POM = 1.6*OC. Mixed coarse aerosol corresponds to 1.1 < Dp < 10 um. Mean for Arabia Mixed/apportioned method. (Feb-March 

1999) 
Theoretical Method Notes 

48x Size distributions for 1.1 < Dp < 10 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion (Bsp 

due to nss- SO4, NH4 and water, and sulfate mass due to nss-SO4 ion). Dust refers to inorganic oxidized material plus residual. 

POM = 1.6*OC. Esp for BC and nss K includes associated SO4 and NO3. Mixed coarse aerosol corresponds to 1.1 < Dp < 10. 

Mean for Arabia-Indian subcontinent Mixed/apportioned method. (Feb-March 1999) 

48y Size distributions for 1.1 < Dp < 10 um, RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 ion (Bsp 

due to nss- SO4, NH4 and water, and sulfate mass due to nss-SO4 ion). Dust refers to inorganic oxidized material plus residual. 

POM = 1.6*OC. Esp for BC and nss K includes associated SO4 and NO3. Mixed coarse aerosol corresponds to 1.1 < Dp < 10. 

Mean for Arabian sea, coastal India Mixed/apportioned method. (Feb-March 1999) 

48z Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, 

and water, and sulfate mass due to nss-SO4, NH4 and water) Mean for East Indian subcontinent. Mixed/apportioned method. (FebMarch 1999) 

48aa Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, 

and water, and sulfate mass due to nss-SO4, NH4 and water). Mean for Indian subcontinent Mixed/apportioned method. (Feb-March 

1999) 

48bb Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, 

and water, and sulfate mass due to nss-SO4, NH4 and water) Mean for Arabia Mixed/apportioned method. (Feb-March 1999) 

48cc Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sulfate corresponds to nss-SO4 aerosol (Bsp due to nss-SO4 ion, NH4, 

and water, and sulfate mass due to nss-SO4, NH4 and water). Mean for Arabia-Indian subcontinent Mixed/apportioned method. 

(Feb-March 1999) 

49a Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol 

(Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized 

material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and 

NO3. Mixed fine aerosol for Dp < 1.1 um. Mean for Polluted-Korea/Japan. Mixed/apportioned method. (mid-March to mid-April 

2001) 

49b Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol 

(Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized 

material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere.Esp for EC and nss K, includes associated SO4 and 

NO3. Mixed fine aerosol for Dp < 1.1 um. Mean for Polluted-Japan. Mixed/apportioned method. (mid-March to mid-April 2001) 

49c Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol 

(Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized 

material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere.Esp for EC and nss K, includes associated SO4 and 

NO3. Mixed fine aerosol for Dp < 1.1 um. Mean for Volcano+Polluted. Mixed/apportioned method. (mid-March to mid-April 2001) 

49d Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol 

(Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized 

material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and 

NO3. Mixed fine aerosol for Dp < 1.1 um. Mean for dust + Frontal. Mixed/apportioned method. (mid-March to mid-April 2001) 

49e Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol 

(Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized 

material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and 

NO3. Mixed fine aerosol for Dp < 1.1 um. Mean for Dust + Korea .Mixed/apportioned method. (mid-March to mid-April 2001) 

49f Size distributions for Dp < 1.1 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol (Bsp 

due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized material. 

POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and NO3. Mixed 

fine aerosol for Dp < 1.1 um. Mean for Dust + Shanghai. Mixed/apportioned method. (mid-March to mid-April 2001) 

49g Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 

aerosol (Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic 

oxidized material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 

and NO3. Mixed coarse aerosol for 1.1 < Dp < 10 um. Mean for Polluted-Korea/Japan Mixed/apportioned method. (mid-March to 

mid-April 2001) 

49h Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 

aerosol (Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic 

oxidized material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 

and NO3. Mixed coarse aerosol for 1.1 < Dp < 10 um. Mean for Polluted-Japan Mixed/apportioned method. (mid-March to midApril 2001) 
Theoretical Method Notes 

49i Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol 

(Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized 

material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and 

NO3. Mixed coarse aerosol for 1.1 < Dp < 10 um. Mean for Volcano+Polluted Mixed/apportioned method. (mid-March to midApril 2001) 

49j Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol 

(Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized 

material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and 

NO3. Mixed coarse aerosol for 1.1 < Dp < 10 um. Mean for dust + Frontal.Mixed/apportioned method. (mid-March to mid-April 

2001) 

49k Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 

aerosol (Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic 

oxidized material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 

and NO3. Mixed coarse aerosol for 1.1 < Dp < 10 um. Mean for Dust + Korea. Mixed/apportioned method. (mid-March to midApril 2001) 

49l Size distributions for 1.1 < Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol 

(Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized 

material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and 

NO3. Mixed coarse aerosol for 1.1 < Dp < 10 um. Mean for Dust + Shanghai Mixed/apportioned method. (mid-March to mid-April 

2001) 

49m Size distributions for Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol 

(Bsp due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized 

material. POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and 

NO3. Mixed total aerosol for Dp < 10 um. Mean for Polluted-Korea/Japan. Mixed/apportioned method. (mid-March to mid-April 

2001) 

49n Size distributions for Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol (Bsp 

due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized material. 

POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and NO3. Mixed 

total aerosol for Dp < 10 um. Mean for Polluted-Japan. Mixed/apportioned method. (mid-March to mid-April 2001) 

49o Size distributions for Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol (Bsp 

due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized material. 

POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and NO3. Mixed 

total aerosol for Dp < 10 um. Mean for Volcano+Polluted. Mixed/apportioned method. (mid-March to mid-April 2001) 

49p Size distributions for Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol (Bsp 

due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized material. 

POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and NO3. Mixed 

total aerosol for Dp < 10 um. Mean for dust + Frontal. Mixed/apportioned method. (mid-March to mid-April 2001) 

49q Size distributions for Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol (Bsp 

due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized material. 

POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and NO3. Mixed 

total aerosol for Dp < 10 um. Mean for Dust + Korea. Mixed/apportioned method. (mid-March to mid-April 2001) 

49r Size distributions for Dp < 10 um and RH = 55 %. Sea salt includes NO3 and water. Sulfate corresponds to nss-SO4 aerosol (Bsp 

due to nss-SO4 ion, NH4, and water, and sulfate mass due to nss-SO4, NH4 and water). Dust refers to inorganic oxidized material. 

POM = 2.1*OC in marine regions and POM = 1.6*OC elsewhere. Esp for EC and nss K, includes associated SO4 and NO3. Mixed 

total aerosol for Dp < 10 um. Mean for Dust + Shanghai. Mixed/apportioned method. (mid-March to mid-April 2001) 
Table 3 Summary of a literature survey of mass scattering efficiencies using the measurement method. The 

first column corresponds to the reference number and entry in the associated notes table. 

Measurement Method Mass Scattering Efficiencies (m2 g-1)* 

Note Fine Mode Coarse 

Mode Total Sulfate Total Dust** 

Location/ 

Characteristics/ 

Study 

Time 

1

1

 1.2±0.9 Baltimore MD 

Canadian Smoke Jul 4,6,10 2002 

2

2 1.84±0.18 

Yulin China 

Polluted periods 

(ACE-Asia) 

Apr 2002 

2

3 1.03±0.13 

Yulin China 

Dust periods 

(ACE-Asia) 

Apr 2002 

6

4 3.0±0.6 2.3 Beijing China Jun 1999 

7

5 3.9±0.5 Atlanta GA 

(Supersite) Jul–Sep 1999 

8a 1.65 Brisbane Australia Apr-Jun 1999 

9a 7.6 Fort Meade MD 

(MARCH-Atlantic study) Jul 1999 

116 2.1±0.2 Phoenix AZ Winter 1989-

1990 

117 1.720±0.014 Meadview AZ 

(MOHAVE study) Summer 1992 

118 1.89±0.04 Buffalo Pass CO 

(Mt. Zirkel Visibility Study) 

Summer/Fall 

1995 

119 2.2±0.4 Brighton CO 

(NFRAQS Study) Winter 1997 

1110 2.0±0.5 Welby CO 

(NFRAQS Study) Winter 1997 

1111 3.45±0.07 Bakersfield CA 

(IMS95 Study) Winter 1995 

1112 5.1±0.4 Mexico City Mexico Winter 1997 

1213 3.7, 4.1, 5.2 Maldives (INDOEX) 

(bsp < 25 Mm-1) Feb–Mar 1999 

1214 3.4, 2.2, 3.9, 

4.7 

Maldives (INDOEX) 

(25 < bsp < 55 Mm-1) Feb–Mar 1999 

1215 3.5, 2.9, 4.1, 

4.4 

Maldives (INDOEX) 

(bsp > 55 Mm-1) Feb–Mar 1999 

1216 3.5, 3.1, 3.8, 

4.5 

Maldives 

Bay of Bengal trajectory 

(INDOEX study) 

Feb–Mar 1999 

1217 2.7, 3.9, 4.3 Maldives Arabian trajectory 

(INDOEX study) Feb–Mar 1999 

18a18  

2.02 

(1.47) 

Big Bend National Park, TX 

(BRAVO study) Jul-Oct 1999 

21a 4.1 Bondville IL Jan-Dec 1995 

23a 0.77 Barbados Apr-May 1994 

27a 4.19 Mt. Rainier National Park WA 

(PREVENT study) Summer 1990 

27b 4.26 

North Cascades National Park 

WA 

(PREVENT study) 

Summer 1990 

 
Note Fine Mode Coarse 

Mode Total Sulfate Dust 

Location/ 

Characteristics/ 

Study 

Time 

34a19 3.70±0.14 0.52 Tenerife Canary Islands Jul 1995 

35a20 3.7* Dallas Fort-Worth TX 

(DFWWHP study) Feb 23, 1995 

35b21 3.1* Dallas Fort-Worth TX 

(DFWWHP study) Feb 25, 1995 

35c22 3.8* Dallas Fort-Worth TX 

(DFWWHP study) Dec 30, 1995 

42a 6 New England and Mid-Atlantic 

Smoke aerosol Jul 2002 

47h 2.5 Barrow AK 1997-2000 

50a 3.67 San Joaquin Valley CA 

(IMS95 Study) 

Dec 1995–Jan 

1996 

54a23 1.91 Buffalo Pass CO 

(Mt. Zirkel Visibility Study) 

Aug, Sep, Oct 

1995 

56a23 2.37 0.27 Spirit Mountain NV 

(SCENES program) Apr-Sep 1989 

56c24 2.53 0.28 Meadview AZ 

(SCENES program) Apr-Sep 1989 

56d24 2.5 0.54 Meadview AZ 

(SCENES program) Apr-Sep 1989, 

56e 2.4 0.52 Spirit Mountain NV 

(SCENES program) Apr-Sept1989 

57a 4 Linan China Nov 1999 

Footnotes for Measurement Method 

* All values reported for a wavelength of 550 nm unless otherwise stated in the note table. Size ranges, relative humidity (when 

reported) and instruments are stated in the Measurement note table. Value in parentheses corresponds to efficiencies converted to 

dry ammonium sulfate. 

** Dust values correspond to total size distribution. 

1 Average and standard deviation of three time periods (see notes 1a, 1b, and 1c). Mass derived from size distribution volume 

concentration and density. 

2

 Average and standard deviation of three polluted periods (see notes 2a, 2b, and 2c) 

3

 Average and standard deviation of three dust periods (see notes 2d, 2e, and 2f in note table) 

4

 Average and standard deviation of PM1.8 from MOUDI and PM2.5 from filter mass (see notes 6a and 6c) 

5

 Average and standard deviation of PM2.5 TEOM, PM2.5 filter and PM1.8 MOUDI estimates (see notes 7a, 7b and 7c) 

6

 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11a and 11b). 

7

 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11c and 11d). 

8

 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11e and 11f). 

9

 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11g and 11h). 

10 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11i and 11j). 

11 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11k and 11l). 

12 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11m and 11n). 

13 Values correspond to estimates from gravimetric mass from Caltech and R/V Ronald Brown and the sum of chemically 

analyzed mass from R/V Ronald Brown, respectively (see notes 12a, 12b and 12c). 

14 Values correspond to estimates from gravimetric mass from Caltech, sum of chemically analyzed mass from U. of Miami, 

gravimetric mass from R/V Ronald Brown and the sum of chemically analyzed mass from R/V Ronald Brown, respectively (see 

notes 12d, 12e, 12f and 12g). 

15 Values correspond to estimates from gravimetric mass from Caltech, sum of chemically analyzed mass from U. of Miami, 

gravimetric mass from R/V Ronald Brown and the sum of chemically analyzed mass from R/V Ronald Brown, respectively (see 

notes 12h, 12i, 12j and 12k). 

16 Values correspond to estimates from gravimetric mass from Caltech, sum of chemically analyzed mass from U. of Miami, 

gravimetric mass from R/V Ronald Brown and the sum of chemically analyzed mass from R/V Ronald Brown, respectively (see 

notes 12l, 12m, 12n and 12o). 
17 Values correspond to estimates from sum of chemically analyzed mass from U. of Miami, gravimetric mass from R/V Ronald 

Brown and the sum of chemically analyzed mass from R/V Ronald Brown, respectively (see notes 12p, 12q, and 12r). 

18 Converting this value to ammonium sulfate mass would be 1.47 m2

 g-1

19 Average and standard deviation of values from a dusty and non-dusty period (see notes 34b and 34c). 

20 Ratio of bsp and dry+water mass at RH = 73%. 

21 Ratio of bsp and dry+water mass at RH = 44%. 

22 Ratio of bsp and dry+water mass at RH=71%. 

23 Computed by using mass and bsp values reported in the manuscript 

24 As reported in the manuscript. 

Measurement Method Notes table with further details about measurement methods 

Measurement Method Notes 

1a Mass derived from size distributions from SMPS and APS (0.00931 < Dp < 20.535 μm). Bsp measured with Radiance Research 

M903 integrating nephelometer at a wavelength at 530 nm. RH values not stated. Values are means. (July 4 0100 LT - July 6 1900 

LT 2002, Baltimore Supersite. Smoke transport from Canada)

1b Mass derived from size distributions from SMPS and APS (0.00931 < Dp < 20.535 μm). Bsp measured with Radiance Research 

M903 integrating nephelometer at a wavelength at 530 nm. RH values not stated. Values are means. July 6 1905 LT - July 10 2200 

LT 2002, Baltimore Supersite. Smoke transport from Canada)

1c Mass derived from size distributions from SMPS and APS (0.00931 < Dp < 20.535 μm). Bsp measured with Radiance Research 

M903 integrating nephelometer at a wavelength at 530 nm. RH values not stated. Values are means. (July 10 2205 LT - July 13 

0055 LT 2002, Baltimore Supersite. Smoke transport from Canada)

2a Esp derived from slope of TEOM PM9 mass and corrected Bsp measured with a TSI 3563 nephelometer at a wavelength of 450 

nm. RH values not stated. (April, 2002, Zhenbeitai, Yulin, China, polluted period 3, local origin)

2b Esp derived from slope of TEOM PM9 mass and corrected Bsp measured with a TSI 3563 nephelometer at a wavelength of 450 

nm. RH values not stated. (April, 2002, Zhenbeitai, Yulin, China polluted period 4, local origin,)

2c Esp derived from slope of TEOM PM9 mass and corrected Bsp measured with a TSI 3563 nephelometer at a wavelength of 450 

nm. RH values not stated. (April, 2002, Zhenbeitai, Yulin, China, polluted period 5, local origin)

2d Esp derived from slope of TEOM PM9 mass and corrected Bsp measured with a TSI 3563 nephelometer at a wavelength of 450 

nm. RH values not stated. (April, 2002, Zhenbeitai, Yulin, China, dust period 3, local origin)

2e Esp derived from slope of TEOM PM9 mass and corrected Bsp measured with a TSI 3563 nephelometer at a wavelength of 450 

nm. RH values not stated. (April, 2002, Zhenbeitai, Yulin, China, dust period 4, transported + local origin)

2f Esp derived from slope of TEOM PM9 mass and corrected Bsp measured with a TSI 3563 nephelometer at a wavelength of 450 

nm. RH values not stated. (April, 2002, Zhenbeitai, Yulin, China, dust period 5, local origin)

6a Mixed fine corresponds to mass from MOUDI size distributions up to PM1.8 and Bsp measured with a Radiance Research 

nephelometer at a wavelength at 530 nm and RH < 40 %. (Jun 11 - Jun 15, 1999, Peking University, Beijing, China)

6b Mass from TEOM PM10 and Bsp measured with a Radiance Research nephelometer at a wavelength at 530 nm and RH < 40 %. 

(Jun 10 22:00 -June 16 11:00 1999, Peking University, Beijing, China)

6c Mass from PM2.5 filter and Bsp measured with a Radiance Research nephelometer at a wavelength at 530 nm and RH < 40 %. 

(Jun 10 22:00 -June 16 11:00 1999, Peking University, Beijing, China )

7a TEOM PM2.5 mass and Bsp measured with a Radiance Research M903 nephelometer at a wavelength of 530 nm. Average RH 

value of 48 %. (July 30 - Sept 3 1999, Atlanta, GA)

7b PM2.5 filter mass and Bsp measured with a Radiance Research M903 nephelometer at a wavelength of 530 nm (July 30 - Sept 3 

1999, Atlanta) 

7c MOUDI mass (includes sum of all stages and after-filter, 0.056 < Dp < 1.78 μm). Eap based on measured EC size distribution and 

measured Bap with a PSAP at a wavelength of 550 nm. (July 30 - Sept 3 1999, Atlanta, GA) 

7d R&P 5400 EC data and Bap measured with a PSAP at a wavelength of 550 nm. (July 30 - Sept 3 1999, Atlanta, GA) 

8a PM2.5 Esp mass and dry Bsp from a nephelometer at a wavelength of 530 nm for all PM2.5 aerosols. (April-June 1999, Eagle 

Farm, Brisbane, Australia)

9a PM2.5 mass and Bsp from a Belfort Model 6620 forward scatter visibility meter at a wavelength of 515 nm for hydrated aerosol. 

Ambient water mass estimated through ISORROPIA. (July 1999, 2000, Fort Meade, MD)

11a PM2.5 mass and Bsp from MRI model 1550 nephelometer at a wavelength of 450 nm. Unweighted regression. (Winter 1989-

1990, Phoenix, AZ, 6 hour sampling durations)

11b PM2.5 mass and Bsp from MRI model 1550 nephelometer at a wavelength of 450 nm. Effective-variance-weighted regression. 

(winter 1989-1990, Phoenix, AZ, 6 hour sampling durations)

11c PM2.5 mass and Bsp from MRI model 1560 nephelometer at a wavelength at 525 nm and RH < 60 %. Unweighted regression. 

(Summer 1992, Meadview, AZ, 12 hour samples)

11d PM2.5 mass and Bsp from MRI model 1560 nephelometer at a wavelength at 525 nm and RH < 60 %. Effective variance 

weighted regression. (Summer 1992, Meadview, AZ, 12 hour samples)
11e PM2.5 mass and Bsp from TSI nephelometer at RH < 60 %. Unweighted regression. (Summer/fall 1995, Buffalo pass, CO, 6 

hour samples)

Measurement Method Notes

11f PM2.5 mass and Bsp from TSI nephelometer at RH < 60 %. Effective variance weighted regression. (Summer/fall 1995, Buffalo 

pass, CO, 6 hour samples)

11g PM2.5 mass and Bsp from ambient-temperature Optec NGN-2 nephelometer. Unweighted regression. (Winter 1997, Brighton, 

CO,12 hour sampling durations)

11h PM2.5 mass and Bsp from ambient-temperature Optec NGN-2 nephelometer. Effective variance weighted regression.(Winter 

1997, Brighton, CO,12 hour sampling durations)

11i PM2.5 mass and Bsp from ambient-temperature Optec NGN-2 nephelometer. Unweighted regression of PM2.5 and Bsp. (Winter 

1997, Welby, CO, 12 hour sampling durations)

11j PM2.5 mass and Bsp from ambient-temperature Optec NGN-2 nephelometer. Effective variance weighted regression. (Winter 

1997, Welby, CO, 12 hour sampling durations)

11k PM2.5 mass and Bsp from ambient-temperature Optec NGN-2 nephelometer. Unweighted regression. (Winter 1995, Bakersfield, 

CA, 3 hour samples)

11l PM2.5 mass and Bsp from ambient-temperature Optec NGN-2 nephelometer. Effective variance weighted regression. (Winter 

1995, Bakersfield, CA,3 hour samples)

11m PM2.5 mass and Bsp from ambient-temperature Optec NGN-2 nephelometer. Unweighted regression. (Winter 1997, Mexico 

City, Mexico, urban site, 6 hour samples)

11n PM2.5 mass and Bsp from ambient-temperature Optec NGN-2 nephelometer. Effective variance weighted regression (Winter 

1997, Mexico City, Mexico, urban site, 6 hour samples)

12a Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Caltech data. Ratio 

of Bsp and gravimetric mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, for low Bsp regime (Bsp < 25 

Mm-1))

12b Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Ratio of Bsp and gravimetric mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, for low Bsp regime 

(Bsp < 25 Mm-1)) 

12c Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Ratio of Bsp and the sum of chemically analyzed mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, 

for low Bsp regime (Bsp < 25 Mm-1)) 

12d Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Caltech data.Esp is 

ratio of Bsp and gravimetric mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, medium Bsp regime (25 < 

Bsp < 55 Mm-1))

12e Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. U. Miami data. Esp 

is ratio of Bsp and sum of chemically analzyed mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, 

medium Bsp regime (25 < Bsp < 55 Mm-1)) 

12f Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Esp is ratio of Bsp and gravimetric mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, medium Bsp 

regime (25 < Bsp < 55 Mm-1)) 

12g Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Esp is ratio of Bsp and sum of chemically analyzed mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, 

Maldives, medium Bsp regime (25 < Bsp < 55 Mm-1))

12h Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Caltech data. Esp 

is ratio of Bsp and gravimetric mass.(Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, high Bsp regime (Bsp > 

55 Mm-1))

12i Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. U. Miami data. Esp 

is ratio of Bsp and sum of chemically analzyed mass.(Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, high 

Bsp regime (Bsp > 55 Mm-1))

12j Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Esp is ratio of Bsp and gravimetric mass.(Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, high Bsp 

regime (Bsp > 55 Mm-1)) 

12k Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Esp is ratio of Bsp and chemically analyzed mass.(Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, high 

Bsp regime (Bsp > 55 Mm-1)) 

12l Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Caltech data. Esp is 

ratio of Bsp and gravimetric mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, Bay of Bengal Trajectory) 

12m Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. U. of Miami data. 

Esp is ratio of Bsp and sum of chemically analyzed mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, 

Bay of Bengal Trajectory) 
12n Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Esp is ratio of Bsp and gravimetric mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, Bay of Bengal 

Trajectory) 

Measurement Method Notes

12o Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Esp is ratio of Bsp and sum of chemically analyzed mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, 

Maldives, Bay of Bengal Trajectory) 

12p

 Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. U. of Miami data. 

Esp is the ratio of Bsp and sum of chemically analyzed mass. (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, 

Arabian Sea Trajectory) 

12q Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Esp is the ratio of Bsp and gravimetric mass.(Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, Maldives, Arabian 

Sea Trajectory) 

12r Bsp is measured with a TSI 3563 nephelometer at RH = 33 % and Dp < 1 μm. Bap is measured with a PSAP. Ronald Brown R/V 

data. Esp is the ratio of Bsp and sum of chemically analyzed mass (Feb 11 - March 25, 1999, Kashidhoo Climate Observatory, 

Maldives, Arabian Sea Trajectory) 

18a Computed from SO4 measurements and bsp measurements with a NGN-2 Optec nephelometer at a wavelength at 530 nm, for 

RH < 90 %. Corresponds to RH = 0% from curve fit to Esp as a function of RH, for NH4/SO4 molar ratio of 1.56 and mass as 

sulfate ion. (July-Oct 1999, Big Bend National Park, TX)

21a Gravimetric mass for Dp < 1 μm and RH < 40 %, and from bsp measured with an integrating nephelometer (Jan-Dec 1995, 

Bondville, IL)

23a Bsp measured with Radiance Research M903 nephelometer at a wavelength of 530 nm, RH < 40% and Dp < 10 μm, corrected for 

truncation. (April 4 - May 3, 1994, Barbados)

27a PM2.5 mass and Bsp measured with integrating nephelometers run at near ambient conditions. Esp computed JLH. Wavelength 

not stated. Eap is the ratio of Babs by LIPM and LAC mass. (summer 1990, Tahoma Woods, Mount Rainier National Park, WA)

27b PM2.5 mass and Bsp measured with integrating nephelometers run at near ambient conditions. Esp computed JLH. Wavelength 

not stated. Eap is the ratio of Babs by LIPM and LAC mass. (summer 1990, Marblemount, North Cascades National Park, WA)

34a Computed Esp total mass and total Bsp during non-dusty period and assumed the relationship held during dusty period. 

Subtracted non-dust scattering from total Bsp during dusty period to get dust scattering. Bsp from a TSI 3563 nephelometer, 

corrected for truncation. (July 3 - 29 1995, Izana, Tenerife, Canary Islands)

34b Measured SO4 data as ammonium sulfate and Bsp from TSI 3563 nephelometer during non-dusty periods. Bsp attributed to 

sulfate was determined by subtracting off dust-related Bsp and assuming everything else is sulfate. RH not stated. (July 3 - 29 1999, 

Izana, Tenerife, Canary Islands)

34c Measured SO4 data as ammonium sulfate and Bsp from TSI 3563 nephelometer during dusty periods. Bsp attributed to sulfate 

was determined by subtracting off dust-related Bsp and assuming everything else is sulfate. RH not stated. (July 3 - 29 1999, Izana, 

Tenerife, Canary Islands)

35a Mass is estimated from dry size distributions with water from SCAPE. Bsp from ambient RH Optec NGN-2 nephelometer. RH = 

73 %. Wavelength not stated (Feb 23 10:00-11:00 1995, Dallas-Fort Worth. Estimated for 1 hour of data)

35b Mass is estimated from dry size distributions with water from SCAPE. Bsp from Optec NGN-2 nephelometer. RH = 44 %. 

Wavelength not stated (Feb 25 10:00-11:00 1995, Dallas-Fort Worth. Estimated for 1 hour of data.)

35c Mass is estimated from dry size distributions with water from SCAPE. Bsp from Optec NGN-2 nephelometer. RH = 71 %. 

Wavelength not stated.(Dec 30 10:00-11:00 1994, Dallas-Fort Worth. Estimated for 1 hour of data.)

42a Fine mass and ambient Bsp measured with an Optec NGN3 nephelometer. POM = 1.8*OC. Stated as smoke scattering to mass 

ratio. (July 2002, New England and Mid-Atlantic States, smoke conditions)

47h RH < 40 %, TSI 3563 nephelometer, Dp < 1 um; absorption by PSAP, Dp < 1 um,using multiple linear regression, corresponding 

to total submicron aerosol, (All year 1997 - 2000, Barrow,AK)

50a Heated Belfort-MRI 1550B nephelometer at a wavelength of 475 nm and PM2.5 mass regression for RH < 60 %, (Dec 9 1995 - 

Jan 6 1996, Bakersfield Van Horn School, San Joaquin Valley, CA)

54a Linear regression of PM2.5 mass and Bsp with TSI 3563 nephelometer at a RH of 31 %. (Aug 3 - Sept 2, 1995 and Sept 15 - Oct 

15 1995, Buffalo Pass, Mt Zirkel Wilderness Area, CO, average morning (0600-1200 MST) and afternoon (1200-1800 MST))

56a PM2.5 gravimetric mass and Bsp measured with a MRI 1597 integrating nephelometer at a wavelength of 525 nm. Eap is for a 

ratio of Babs from LIPM and PM2.5 aerosol. Coarse Esp is for 2.5 < Dp < 15 μm gravimetric mass. Ratio computed by JLH. (AprilSept 1989, Spirit Mountain, Nevada)

56b Eap for coarse (2.5 < Dp < 15 μm) gravimetric mass and Babs from LIPM. Ratio computed by JLH. (April-Sept 1989, Spirit 

Mountain, Nevada 

56c PM2.5 gravimetric mass and Bsp measured with a MRI 1597 integrating nephelometer at a wavelength of 525 nm. Coarse mode 

corresponds to 2.5 < Dp < 15 μm gravimetric mass. Ratio computed by JLH. (April-Sept 1989, Meadview, AZ)

56d Mean PM2.5 dust + haze mass and Bsp measured with a MRI 1597 integrating nephelometer at a wavelength of 525 nm. Coarse 

mode corresponds to 2.5 < Dp < 15 μm. (April-Sept 1989, Meadview, AZ)
56e Mean PM2.5 dust + haze mass and Bsp measured with a MRI 1597 integrating nephelometer at a wavelength of 525 nm. Coarse 

mode corresponds to 2.5 < Dp < 15 μm (April-Sept 1989, Spirit Mountain, NV)

57a PM2.5 mass and Bsp measured with Radiance Research nephelometer at 530 nm for RH < 40 %. Bap measured with a PSAP at 

565 nm. (Oct 28-Nov 20 1999, Linan, China)
Table 4. Summary of a literature survey of mass scattering efficiencies using the multi-linear 

regression (MLR) method. The first column corresponds to the reference number and entry in 

the associated notes table. Entries correspond to the fine mode unless otherwise stated in the 

column heading, or noted with superscripts. 

Multi-Linear Regression Method Mass Scattering Efficiency (m2 g-1)* 

Notes Fine 

Mode 

Coarse 

Mode Sulfate POM Nitrate Dust Sea Salt Location/ Study Time 

4

1 5.8 0.5 5.6 

4.1† 0.71♦

Sde Boker 

Israel 

(ARACHNE 

study) 

Dec 

1995–

Oct 

1997 

8

2 

 10.9 2.73 Brisbane 

Australia 

Apr-Jun 

1999 

113 2.5±0.6 0.62±0.16 Tucson AZ 

Winter 

1989-

1990 

114 1.5±0.4 0.8±0.3 

Welby CO 

(NFRAQS 

study) 

Summer 

1996 

115 3.0±0.2 0.275±0.007 

Welby CO 

(NFRAQS 

study) 

Winter 

1996 

146 0.07 2.08 1.05 

0.82 1.77 2.06 

Canyonlands 

National Park 

UT 

1990-

1991 

157 0.9, 3.11 3.44 Salt Lake 

City UT 

Jan-Feb 

2001 

168 3 7.4 

3.4† 

Sde Boker 

Israel 

(ARACHNE 

study) 

Jun-Jul 

1996 

20 3.669 0.121 

Sde Boker 

Israel 

(ARACHNE 

study) 

Feb-Mar 

1997 

219 

4.57 

4.0† 4.11 Bondville IL Jan-Dec 

1995 

2510  3.2±0.3 3.10±0.10 

2.07 ± 0.07 3.47±0.12 0.7±0.6 

Meadview 

AZ 

(MOHAVE 

study) 

Summer 

1992 

2511  2.6±0.3 2.28±1.11 

1.5±0.7 6.0 ± 1.7 5±2 

Meadview 

AZ 

(MOHAVE 

study 

Winter 

1992 

2512  8±3 2.6±0.9 

1.7±0.6 2.4 ± 0.9 4±3 Phoenix AZ 

Winter 

1989-

1990 

2513  

7.3±0.3 

3.05†

12±8 

8±5 1.8±0.9 Uniontown PA 

Summer 

1990 

26 5.2 0.34 Sde Boker 

Israel 

1995–

Feb 

1997 

30 2.2 1.8 

1.4 2.2 0.79 

Grand 

Canyon 

National Park 

AZ 

Jul-Aug 

1998 
Notes Fine 

Mode 

Coarse 

Mode Sulfate POM Nitrate Dust Sea Salt Location/ Study Time 

36 6.3 

4.6† 2.9‡

Tenerife 

Canary 

Islands 

Jul 1995 

39 8.3 

6.0† 

Rural Great 

Hungarian 

Plain 

Oct 

1994–

Mar 

1995 

4314 4.3 0.6 3.6 

2.6†,♦ 

Pacific Ocean 

and Cheeka 

Peak WA 

(PSI91 and 

MAGE92 

Studies) 

1991 & 

1992 

4415  

4.5 ± 0.9 

3.2†,♦ 

4.95 ± 

0.07, 

0.90 ± 

0.3‡

Central 

Pacific Ocean 

(RITS 93 and 

RITS 94) 

1993 & 

1994 

4616  

5.7 

2.4†,♦ 2.7♦

0.9♦ 2.2♦

Norfolk VA 

to Cape 

Town, South 

Africa, 

(Aerosols99) 

Jan-Feb 

1999 

4717 0.82 5.3 

3.9† 2.2 Barrow, AK 1997-2000 

4818  

2 

0.83†,♦

1.6 

1.4♦ 0.51♦

 1.7♦ Indian Ocean 

(INDOEX) 

Feb-Mar 

1999 

5019 3.00±0.14 3.9±0.3 

1.5† 

San Joaquin 

Valley CA 

(IMS95) 

Dec 

1995–

Jan 1996 

5120  5.2±0.3 1.9±0.4 

1.8±0.4 

Cranmore 

Mountain NH 

Apr–

May, 

2000 

52 6.54 3.36 

2.61 

Southern 

New 

Hampshire 

Jul 

2000- 

Sep 

2001 

5422  

5.3±0.3 

3.3†

0.9±0.3 

0.7±0.2 6.2±0.4 

Mt Zirkel 

Wilderness 

Area, CO 

(MZVS 

study) 

Aug-Oct 

1995 

56a23 2.4 1.7 2.6, 

0.45‡

Meadview 

AZ 

Apr-Sep 

1998 

56b23 2.2 1.9 3.1, 

0.34‡

Spirit 

Mountain NV 

Apr-Sep 

1998 

Footnotes for multi-linear regression method table 

All values reported for a wavelength of 550 nm unless otherwise stated in the note table. Values correspond to fine mode 

unless otherwise noted in the column header or by foot note. Size ranges and relative humidity (when reported) are stated in 

the MLR note table or in the footnotes. MLR method includes internally mixed and externally mixed methods, also found in 

the MLR note table for each entry. 

In the “sulfate” column, values corresponding to dry ammonium sulfate are italicized. 

In the “POM” column, values we normalized to POM multiplier of 1.8 are italicized 

†

 We converted to dry ammonium sulfate 
‡

 Corresponds to coarse mode (supermicron) 

♦

 Corresponds to total modes (supramicron, fine + coarse) 

1

 Two separate MLR runs were performed, one with fine mass (Dp < 2 μm) and coarse mass (2-10 μm). The second was with 

total dust (Dp < 10 μm) and fine sulfate ion (Dp < 2 μm). 

2

 Sulfate is PM2.5 ammonium sulfate, soil is PM2.5. 

3

 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11a and 11b). Coarse refers 

to PM10 – PM2.5. 

4

 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11c and 11d). Coarse refers 

to PM10 – PM2.5. 

5

 Average and standard deviation of unweighted and effective-variance weighted estimates (see notes 11e and 11f). Coarse refers 

to PM10 – PM2.5. 

6

 Reporting annual values only. Dust corresponds to PM2.5 mode. 

7

 Organic carbon values are for non-volatile organics and semi-volatile organics, respectively (see notes 15a and 15b). 

8

 Fine mixed refers to fine mass – nss-SO4 ion. Sulfate is sulfate ion 

9

 Organic carbon value refers to carbon-containing aerosols 

10 Average and standard deviation of effective variance weighting with and without intercepts, and no weighting (see notes 25a, 

25b, and 25c) for PM2.5. 

11 Average and standard deviation of effective variance weighting with and without intercepts, no weighting, and average 

absolute difference < 20 % effective variance weighting (see notes 25d, 25e, 25f, and 25g) for PM2.5. 

12 Average and standard deviation of effective variance weighting with and without intercepts, no weighting, and average 

absolute difference < 20 % effective variance weighting (see notes 25h, 25i, 25j, and 25k) for PM2.5. 

13 Average and standard deviation of effective variance weighting with and without intercepts, and no weighting (see notes 25l, 

25m, and 25n) for PM2.5. 

14 Sulfate corresponds to sulfate ion for Dp < 10 μm. Fine mixed is residual mass for Dp < 1 μm and coarse mixed is for residual 

mass for 1 < Dp < 10 μm. 

15 Average and standard deviation for RITS93 and RITS94 (see notes 44a and 44c). Sulfate is nss-SO4 ion for Dp < 10 μm. Sea 

salt is listed for Dp < 1 μm and 1 < Dp < 10 μm, respectively. 

16 Sulfate ion, all values are for Dp < 10 μm. 

17 Sulfate ion and sea salt for Dp < 1 μm 

18 Sulfate ion and other values for Dp < 10 μm 

19 Fine sulfate corresponds to ammonium salts (SO4+NO3+NH4). Mixed fine is everything besides salts. Average and standard 

deviation for OC back up filter added back and subtracted, respectively (see notes 50a and 50b) 

20 Sulfate is ammonium sulfate. Average and standard deviation of N/NE and W/SW air masses (notes 51a and 51b) 

21 Sulfate is ammonium sulfate 

22 Sulfate is ammonium sulfate and nitrate is ammonium nitrate. Average and standard deviation for uncorrected OC, OC 

corrected for positive organic artifact, and corrected for negative organic artifact, respectively. (OC numbers are for uncorrected 

and negative artifact correction only). See notes 54a, 54b and 54c. 

23 Mixed fine is PM2.5 haze. Mixed coarse is 2.5 < Dp < 15 μm haze. Dust is for fine and coarse mode, respectively. 

Multi-Linear Regression Method Notes table with further details about measurement methods 

Multi Linear Regression (MLR) Method Notes 

4

 Mass from SFU samplers and total Bsp measured with a TSI 3563 nephelometer, corrected for non-Lambertian and truncation 

errors. Average instrument RH was 38 %. MLR performed twice: once with fine particle mass (Dp < 2 μm) and coarse particle mass 

(2 < Dp < 10 μm). The second MLR was performed with dust (Dp < 10 μm) and sulfur converted to sulfate ion (Dp < 2 μm). 

Internal and external mixture methods. (Dec 1995 - Oct 1997, Sde Boker, Negev desert, Israel)

8

 PM2.5 Esp mass and dry Bsp from a nephelometer at a wavelength of 530 nm for all PM2.5 aerosols, PM2.5 soil, and PM2.5 

ammonium sulfate. External mixture method. (April-June 1999, Eagle Farm, Brisbane, Australia) 

11a PM2.5 mass and Bsp from MRI model 1592 nephelometer at a wavelength at 530 nm. Coarse mode is PM10 – PM2.5. Internal 

mixture method. Unweighted regression. (Winter 1989-1990, Tucson, AZ,6 hour sampling durations)

11b PM2.5 mass and Bsp from MRI model 1592 nephelometer at a wavelength at 530 nm. Effective variance weighted regression. 

Coarse mode is PM10 – PM2.5. Internal mixture method. (Winter 1989-1990, Tucson, AZ, 6 hour sampling durations)

11c PM2.5 mass and Bsp from an ambient-temperature Optec NGN-2 nephelometer. Coarse mode is PM10 – PM2.5. Unweighted 

regression. Internal mixture method. (Summer 1996, Welby, CO,12 hour sampling durations)

11d PM2.5 mass and Bsp from an ambient-temperature Optec NGN-2 nephelometer. Coarse mode is PM10 – PM2.5. Effective 

variance weighted regression. Internal mixture method. (Summer 1996, Welby, CO,12 hour sampling durations)

11e PM2.5 mass and Bsp from an ambient-temperature Optec NGN-2 nephelometer. Coarse mode is PM10 – PM2.5. Unweighted 

regression. Internal mixture method. (Welby, CO, winter 1996,12 hour sampling durations)
Multi Linear Regression (MLR) Method Notes

11f PM2.5 mass and Bsp from an ambient-temperature Optec NGN-2 nephelometer. Coarse mode is PM10 – PM2.5. Effective 

variance weighted regression. Internal mixture method. (Welby, CO, winter 1996,12 hour sampling durations)

14 Bext with Optec LPV-2 transmissometer. MLR with bext and organic material from BOSS, sulfate as ammonium sulfate, nitrate 

as ammonium nitrate, corrected for RH using Tang’s curves, Dust as fine crustal material, assuming crustal is Fe and Si. Externally 

mixed method. (1990-1991, Canyonlands National Park, UT)

15a Bsp measured with OPTEC NGN-2 integrating nephelometer at a wavelength of 530 nm. Nitrate as ammonium nitrate. Organic 

carbon for non-volatile organic material, using a 1.64 multiplier. Externally mixed method. (Jan 30 - Feb 4 2001, Salt Lake City, 

UT)

15b Bsp measured with OPTEC NGN-2 integrating nephelometer at a wavelength of 530 nm. Organic carbon as semi-volatile 

organic material. Externally mixed method. (Jan 30 - Feb 4 2001, Salt Lake City, UT)

16 Bsp by TSI 3563 nephelometer for RH < 50 %. Mixed fine mass is residual fine mass (PMfine - nss-SO4). Sulfate as nss-SO4. 

Internally mixed method. (June 20 - July 10 1996, Sde Boker, Negev Desert, Israel)

20 Fine mass (Dp < 2 μm) and Bsp from TSI 3563 integrating nephelometer at 50 % RH. Coarse mode is 2 < Dp < 10 μm. Internally 

mixed method (Feb 18 - March 15 1997, Sde Boker, Negev Desert, Israel)

21 Mass for Dp < 1 μm and RH < 40 % and Bsp from a MRI 1560 integrating nephelometer. Sulfate corresponds to ammonium 

bisulfate. Mixed fine mass corresponds to residual mass for Dp < 1 μm (portion of gravimetric mass not identified by IC). (Jan-Dec 

1995, Bondville, IL)

25a Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

Effective variance weighting, no intercept. Externally mixed method. Wavelength not stated. RH = 26.1 %. (summer 1992, 

Meadview, AZ)

25b Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

Effective variance weighting, with intercept. Externally mixed method. Wavelength not stated. RH = 26.1 %. (Summer 1992, 

Meadview, AZ)

25c Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

No weighting. Wavelength not stated. Externally mixed method. RH = 26.1 %. (Summer 1992, Meadview, AZ)

25d Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

Effective variance weighting, no intercept. Externally mixed method. Wavelength not stated. RH = 45.1 %. (Winter 1992, 

Meadview, AZ)

25e Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

Effective variance weighting, with intercept. Externally mixed method. Wavelength not stated. RH = 45.1 %. (Winter 1992, 

Meadview, AZ)

25f Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

No weighting. Wavelength not stated. Externally mixed method. RH = 45.1 %. (winter 1992, Meadview, AZ)

25g Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

Absolute average difference < 20 % effective variance weighting. Externally mixed method. RH = 45.1 %. Wavelength not stated. 

(Winter 1992, Meadview, AZ)

25h Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

Effective variance weighting, no intercept. Wavelength not stated. Externally mixed method. RH = 31.8 %. (Winter 1989-1990, 

Phoenix, AZ)

25i Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

Effective variance weighting, with intercept. Wavelength not stated. Externally mixed method. RH = 31.8 %. (Winter 1989-1990, 

Phoenix, AZ)

25j Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

No weighting. Wavelength not stated. Externally mixed method. RH = 31.8 %. (Winter 1989-1990, Phoenix, AZ)

25k Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium sulfate. POM = 1.2*OC. Dust as residual mass. 

Absolute average difference < 20 % effective variance weighting. Wavelength not stated. Externally mixed method. RH = 31.8 %. 

(Winter 1989-1990, Phoenix, AZ)

25l Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium bisulfate. POM = 1.2*OC. Dust as residual mass. 

Effective variance weighting, no intercept. Wavelength not stated. Externally mixed method. RH = 66.7 %. (Summer 1990, 

Uniontown, PA)

25m Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium bisulfate. POM = 1.2*OC. Dust as residual 

mass. Effective variance weighting, with intercept. Wavelength not stated. Externally mixed method. RH = 66.7 %. (Summer 1990, 

Uniontown, PA)

25n Bsp estimated with ELSIE. Nitrate as ammonium nitrate. Sulfate as ammonium bisulfate. POM = 1.2*OC. Dust as residual mass. 

No weighting. Wavelength not stated. Externally mixed method. RH = 66.7 %. (Summer 1990, Uniontown, PA)

26 Bsp measured with a TSI 3563 integrating nephelometer and mass for fine mode (Dp < 2 μm) for coarse mode (2< Dp < 10 μm). 

RH not stated. Internally mixed method. (1995-mid Feb 1997,Sde Boker, Negev Desert, Israel)

30 Dry ammonium sulfate mass and Bsp for dry from Radiance Research M903 nephelometer at a wavelength of 530 nm. POM = 

1.4*OC. Nitrate is ammonium nitrate. Soil is PM2.5. Externally mixed method. (July-Aug 1998, Grand Canyon National Park, AZ)
Multi Linear Regression (MLR) Method Notes

36 Bsp from Radiance research nephelometer at a wavelength of 530 nm. Sulfate corresponds to nss-sulfate for average RH = 45 % 

and Dp < 1 μm. Sea salt corresponds to sodium ion for average RH = 45 % and 1 < Dp < 10 μm. Externally mixed method. (July 

1995, Tenerife)

39 Bsp with MRI 1550 nephelometer for Dp < 1 μm and RH = 30 %. Sulfate as ion. Externally mixed method. (Oct 1994 - March 

1995, rural Great Hungarian Plain)

43 Bsp measured with an integrating nephelometer at RH = 30 % and Dp < 10 μm. Sulfate corresponds to sulfate ion. Mixed fine 

corresponds to submicron residual mass. Mixed coarse corresponds to supermicron residual mass. Internally mixed method. (1991 & 

1992, Pacific Ocean from 33 N to 12 S along 140 W, Cheeka Peak, WA, for PSI and MAGE samples)

44a Bsp was calculated from DMA and APS size distribution measurements at RH = 30 %. Sulfate corresponds to sulfate ion. Sea 

salt is submicron. Externally mixed method. (March-May 1993, 70 deg south to 55 north along 140 W, RITS 93)

44b Bsp was calculated from DMA and APS size distribution measurements at RH = 30 %. Sea salt is supermicron. Externally mixed 

method. (March-May 1993, 70 deg south to 55 north along 140 W, RITS 93)

44c Bsp was calculated from DMA and APS size distribution measurements at RH = 30 %. Sulfate corresponds to sulfate ion. Sea 

salt is submicron. Externally mixed method. (Nov 1993 - Jan 1994, 70 deg south to 55 north along 140 W, RITS 94)

44d Bsp was calculated from DMA and APS size distribution measurements at RH = 30 %. Sea salt is supermicron. Externally mixed 

method (Nov 1993 - Jan 1994, 70 deg south to 55 north along 140 W, RITS 94)

46a Bsp measured with a TSI 3563 integrating nephelometer at RH = 55 % and for Dp < 10 μm. Sulfate corresponds to nss-SO4 ion. 

POM = 1.6*OC for North American air masses and 2.1*OC for all other air masses. Externally mixed method. Mean values for 

North America, NH marine, dust, dust/biomass burning, biomass burning. (Jan 14-Feb 8, 1999, Norfolk, VA to Cape Town, South 

Africa)

47d Bsp measured with a TSI 3563 nephelometer for Dp < 1 μm and RH < 40 %. Sulfate corresponds to SO4 ion. Mixed fine aerosol 

corresponds to residual mass. Externally mixed method. (All year 1997 - 2000, Barrow,AK)

48a Bsp measured with TSI 3563 integrating nephelometer at RH = 55 % for Dp < 10 μm. Sulfate corresponds to nss-SO4 ion. POM 

= 1.6*OC. Dust refers to inorganic oxidized material. Mean for the entire experiment. Externally mixed method. (Feb-Mar 1999, 

Arabian Sea, Bay of Bengal, Indian Ocean -north and south of the ITCZ)

50a Heated Belfort-MRI 1550B nephelometer at a wavelength of 475 nm and RH < 60 %. Mixed fine aerosol corresponds to salts 

(SO4+NH4+NO3). OC back up filter added. Internally mixed method. (Dec 9 1995 - Jan 6 1996, Bakersfield Van Horn School, San 

Joaquin Valley, CA)

50b Heated Belfort-MRI 1550B nephelometer at a wavelength of 475 nm and RH < 60 %. Mixed fine corresponds to all other species 

besides salts. OC back up filter was added back. Internally mixed method. (Dec 9 1995 - Jan 6 1996, Bakersfield Van Horn School, 

San Joaquin Valley, CA)

50c Heated Belfort-MRI 1550B nephelometer at a wavelength of 475 nm and RH < 60 %. Mixed fine aerosol corresponds to salts 

(SO4+NH4+NO3). OC back up filter was subtracted. Internally mixed method. (Dec 9 1995 - Jan 6 1996, Bakersfield Van Horn 

School, San Joaquin Valley, CA)

50d Heated Belfort-MRI 1550B nephelometer at a wavelength of 475 nm and RH < 60 %. Mixed fine aerosol corresponds to all other 

species besides salts. OC back up filter was subtracted. Internally mixed method. (Dec 9 1995 - Jan 6 1996, Bakersfield Van Horn 

School, San Joaquin Valley, CA)

51a Bsp measured with Radiance Research M903 nephelometer at 530 nm at ambient RH (< 50 % typically). Sulfate corresponds to 

ammonium sulfate. POM = 1.7*OC. OC from TOT. Externally mixed method. (April 18 - May 13, 2000, Cranmore Mountain, New 

Hampshire, for north/northeast air masses,)

51b Bsp measured with Radiance Research M903 nephelometer at 530 nm at ambient RH (<50 % typically). Sulfate corresponds to 

ammonium sulfate. POM = 1.7*OC. OC from TOT. Externally mixed method. (April 18 - May 13, 2000, Cranmore Mountain, New 

Hampshire, for west/southwest air masses)

52 Bsp from Radiance Research M903 nephelometer at a wavelength of 530 nm. Sulfate corresponds to ammonium sulfate. POM 

=1.4*OC from TOT method. Values correspond to all measurements. Externally mixed method. (July 2000-Sept 2001, rural site in 

southern New Hampshire)

54a PM2.5 mass and Bsp with TSI 3563 nephelometer for RH < 52 %. Sulfate corresponds to ammonium sulfate. POM = 1.4*OC). 

Nitrate corresponds to ammonium nitrate. Uncorrected OC. Externally mixed method. (Aug 3 - Sept 2, 1995 and Sept 15 - Oct 15 

1995, Buffalo Pass, Mt Zirkel Wilderness Area, CO)

54b PM2.5 mass and Bsp with TSI 3563 nephelometer for RH < 52 %. Sulfate corresponds to ammonium sulfate. POM = 1.4*OC). 

Nitrate corresponds to ammonium nitrate. OC corrected for positive organic artifact. Externally mixed method. (Aug 3 - Sept 2, 

1995 and Sept 15 - Oct 15 1995, Buffalo Pass, Mt Zirkel Wilderness Area, CO)

54c PM2.5 mass and Bsp with TSI 3563 nephelometer for RH < 52 %. Sulfate corresponds to ammonium sulfate. POM = 1.4*OC). 

Nitrate corresponds to ammonium nitrate. OC corrected for negative organic artifact. Externally mixed method. (Aug 3 - Sept 2, 

1995 and Sept 15 - Oct 15 1995, Buffalo Pass, Mt Zirkel Wilderness Area, CO)

56a PM2.5 mass and Bsp measured with a MRI 1597 integrating nephelometers at wavelength of 525nm. Mixed fine corresponds to 

haze. Dust corresponds to PM2.5. Coarse mode aerosol corresponds to 2.5 < Dp < 15 μm, both for haze and dust. Internally mixed 

method. (April-Sept 1998, Meadview, AZ)
Multi Linear Regression (MLR) Method Notes

56b PM2.5 mass and Bsp measured with a MRI 1597 integrating nephelometers at wavelength of 525nm. Mixed fine corresponds to 

haze. Dust corresponds to PM2.5. Coarse mode aerosol corresponds to 2.5 < Dp < 15 μm, both for haze and dust. Internally mixed 

method. (April-Sept 1998, Spirit Mountain, NV)
Table 5. Summary of a literature survey of mass scattering efficiencies using the partial 

scattering method. The first column corresponds to the reference number and entry in the 

associated notes table. Entries correspond to the fine mode. 

Partial Scattering Method Mass Scattering Efficiency (m2 g-1)

* 

Notes Fine 

Mode Sulfate POM Nitrate Dust Location (Study) Time 

25a1 3.5 4.8 

3.2 3.8 2.4 Meadview AZ (MOHAVE) 

Summer 

1992, 

25b2 2.7 3.6 

2.4 3.3 2.3 Meadview AZ 

(MOHAVE) 

Summer 

1992, 

25c1 4

5 

3.3 4.1 2.1 Meadview AZ (MOHAVE) 

Winter 

1992, 

25d2 3.1 4 

2.7 3.7 2.4 Meadview AZ 

(MOHAVE) 

Winter 

1992, 

25e1 2.7 3.6 

2.4 3.8 2 Phoenix AZ Winter 1989-1990 

25f2 2.2 3 

2 3.1 2.1 Phoenix AZ Winter 

1989-1990, 

25g1 6.9 

2.9†

8.5 

5.7 1.8 4.3 Uniontown PA Summer 1990 

25h2 7 

2.9†

8.8 

5.9 3.7 4.2 Uniontown PA Summer 

1990 

41a3 1.23 3.81 

2.5 Bondville IL May-Dec 1994 

41b4 5.78 6.9 

4.6 Bondville IL May-Dec 1994 

53a5 4.5 7.1 

3.4†

5.6 

3.11 6.6 Denver CO Jan 5 1998 

53b6 2.3 2.1 4.0 

2.2 2.3 Denver CO Jan 13 1998 

54a7 2.47 3.61 

2.8 2.63 1.76 

Mt Zirkel Wilderness Area 

CO 

(MZVS) 

Aug, Sep 

Oct 1995 

58a 16 

2.7†

6.7 

5.2 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Jan 18, 

1990 

58b 6.3 

3.2†

5.3 

4.12 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Jan 20, 

1990 

58c 4.6 4.5 

3.5 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Jan 21, 

1990 

58d 3.4 5.7 

4.4 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Jan 22, 

1990 

58e 5.6 

2.4†

6.3 

4.9 

Hopi Point, Grand Canyon 

National Park AZ) 

(NGSVS) 

Jan 30, 

1990 

58f 3.5 

2.0†

8.1 

6.3 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Feb 12, 

1990 

58g 8 

2.7†

5.6 

4.9 

Hopi Point, Grand Canyon 

National Park, AZ 

(NGSVS) 

Feb 13, 

1990 

58h 15.4 

2.2†

6.7 

5.2 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Feb 19, 

1990 
Notes Fine 

Mode Sulfate POM Nitrate Dust Location (Study) Time 

58i 5.6 

3.2†

5.6 

4.4 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Feb 28, 

1990 

58j 3 

1.9†

7 

5.4 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Mar 1, 

1990 

58k 5.4 

2.6†

4.2 

3.3 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Mar 2, 

1990 

58l 5.4 

2.7†

5.1 

4.0 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Mar 3, 

1990 

58m 5.2 

1.93†

1.3 

1.01 

Hopi Point, Grand Canyon 

National Park AZ 

(NGSVS) 

Mar 4, 

1990 

Footnotes for partial scattering method table 

*All values for a wavelength of 550 nm unless otherwise stated in the Notes table. Values in parentheses are reported 

as dry ammonium sulfate efficiencies in the literature. See notes table for the original form of sulfate and the relative 

humidity of the measurements. 

In the “sulfate” column, values corresponding to dry ammonium sulfate are italicized. 

In the “POM” column, values we normalized to POM multiplier of 1.8 are italicized 

Estimates in bold correspond to constant-size scenario. 

†

 We converted to dry ammonium sulfate 

1

 Core/shell scenario with constant particle number. Values correspond to PM2.5. 

2

 Homogeneous composition with constant particle size. Values correspond to PM2.5. 

3

 Corresponds to PM2.5 aerosols at low RH (30-63 %), core/shell scenario used. 

4

 Corresponds to PM2.5 aerosols high RH (> 75 %), core/shell scenario used. 

5

 Corresponds to RH = 74 %. Interactive efficiency (conserves particle number). 

6

 Corresponds to RH = 38 %. Interactive efficiency (conserves particle number). 

7

 Constanct composition as a function of size assumed 

Partial Scattering Method Notes table with further details about measurement methods 

Partial Method Notes 

25a Esp estimated with ELSIE and MOUDI size distributions, assuming core/shell scenario with constant particle number. Sulfate 

corresponds to ammonium sulfate. Nitrate corresponds to ammonium nitrate. POM =1.2*OC. Dust corresponds to residual mass. 

Dust is 20 % soluble and OC is 60 % soluble. RH = 26.1 %. Wavelength ~ 530 nm. Results correspond to PM2.5 (Summer 1992, 

Meadview, AZ)

25b Esp estimated with ELSIE and MOUDI size distributions, assuming homogeneous composition and constant particle size. Sulfate 

corresponds to ammonium sulfate. Nitrate corresponds to ammonium nitrate. POM =1.2*OC. Dust corresponds to residual mass. 

Dust is 20 % soluble and OC is 60 % soluble. RH = 26.1 %. Wavelength ~ 530 nm. Results correspond to PM2.5 (Summer 1992, 

Meadview, AZ)

25c Esp estimated with ELSIE and MOUDI size distributions, assuming core/shell scenario with constant particle number. Sulfate 

corresponds to ammonium sulfate. Nitrate corresponds to ammonium nitrate. POM =1.2*OC. Dust corresponds to residual mass. 

Dust is 20 % soluble and OC is 60 % soluble. RH = 45.1%. Wavelength ~ 530 nm. Results correspond to PM2.5 (Winter 1992, 

Meadview, AZ)
Partial Method Notes

25d Esp estimated with ELSIE and MOUDI size distributions, assuming homogeneous composition and constant particle size. Sulfate 

corresponds to ammonium sulfate. Nitrate corresponds to ammonium nitrate. POM =1.2*OC. Dust corresponds to residual mass. 

Dust is 20 % soluble and OC is 60 % soluble. RH = 45.1 %. Wavelength ~ 530 nm. Results correspond to PM2.5 (Winter 1992, 

Meadview, AZ)

25e Esp estimated with ELSIE and MOUDI size distributions, assuming core/shell scenario with constant particle number. Sulfate 

corresponds to ammonium sulfate. Nitrate corresponds to ammonium nitrate. POM =1.2*OC. Dust corresponds to residual mass. 

Dust is 20 % soluble and OC is 60 % soluble. RH = 31.8 %. Wavelength ~ 530 nm. Results correspond to PM2.5 (Winter 1989-

1990, Phoenix, AZ)

25f Esp estimated with ELSIE and MOUDI size distributions, assuming homogeneous composition and constant particle size. Sulfate 

corresponds to ammonium sulfate. Nitrate corresponds to ammonium nitrate. POM =1.2*OC. Dust corresponds to residual mass. 

Dust is 20 % soluble and OC is 60 % soluble. RH = 31.8 %. Wavelength ~ 530 nm. Results correspond to PM2.5 (Winter 1989-

1990, Phoenix, AZ)

25g Esp estimated with ELSIE and MOUDI size distributions,assuming core/shell with constant particle number. Sulfate corresponds 

to ammonium bisulfate. Nitrate corresponds to ammonium nitrate. POM =1.2*OC. Dust corresponds to residual mass. Dust is 20 % 

soluble and OC is 60 % soluble. RH = 66.7 %. Wavelength ~ 530 nm. Results correspond to PM2.5 (Summer 1990, Uniontown, 

PA)

25h Esp estimated with ELSIE and MOUDI size distributions, assuming homogeneous composition and constant particle size. Sulfate 

corresponds to ammonium bisulfate. Nitrate corresponds to ammonium nitrate. POM =1.2*OC. Dust corresponds to residual mass. 

Dust is 20 % soluble and OC is 60 % soluble. RH = 66.7 %. Wavelength ~ 530 nm. Results correspond to PM2.5 (Summer 1990, 

Uniontown, PA)

41a MOUDI size distributions, computed for PM2.5 ammonium sulfate for low RH (30- 63 %), POM (=1.2*OC) assuming OC is 60 

% soluble using ELSIE. Core/shell scenario assumed. (May-Dec 1994, Bondville, IL) 

41b MOUDI size distributions, computed for PM2.5 ammonium sulfate for high RH (RH > 75 %), POM (=1.2*OC) assuming OC 60 

% is soluble using ELSIE. Core/shell scenario assumed. (May-Dec 1994, Bondville, IL)

53a MOUDI size distribution (0.03 < Dp < 3.16 um) and ELSIE calculations. Water soluble organic mass taken to be 25% of total 

carbon. Sulfate corresponds to ammonium sulfate mass. Nitrate form not stated. POM multiplier not stated. RH = 74 %. Wavelength 

not stated. Interactive efficiency. (Jan 5 1988, Denver, CO, northeasterly flow)

53b MOUDI size distribution (0.03 < Dp < 3.16 um) and ELSIE calculations. Water soluble organic mass taken to be 25% of total 

carbon. Sulfate corresponds to ammonium sulfate mass. Nitrate form not stated. POM multiplier not stated. RH = 38 %. Wavelength 

not stated. Interactive efficiency. (Jan 13 1988, Denver, CO, stagnant air mass)

54a Results from ELSIE for ammonium sulfate or bisulfate, ammonium nitrate, POM (=1.4*OC) and dust. Size distributions inverted 

from Bsp measurements from a TSI nephelometer. Constant composition as a function of size. (Aug 3 - Sept 2, 1995 and Sept 15 - 

Oct 15 1995, Buffalo Pass, Mt Zirkel Wilderness Area, CO)

58a Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions at RH = 92.2 %, and at a wavelength of 525 nm. NGS study. (Jan 18, 1990, Hopi 

Point, Grand Canyon National Park, AZ)

58b Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions at RH = 63.3 %, and at a wavelength of 525 nm. NGS study. (Jan 20, 1990, Hopi 

Point, Grand Canyon National Park, AZ)

58c Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions at RH = 44.8 %, and at a wavelength of 525 nm. NGS study. (Jan 21, 1990, Hopi 

Point, Grand Canyon National Park, AZ)

58d Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions at RH = 32.9 %, and at a wavelength of 525 nm. NGS study. (Jan 22, 1990, Hopi 

Point, Grand Canyon National Park, AZ).

58e Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions at RH = 72.2 %, and at a wavelength of 525 nm. NGS study. (Jan 30, 1990, Hopi 

Point, Grand Canyon National Park, AZ)

58f Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions at RH = 53.6 % and at a wavelength of 525 nm. NGS study. (Feb 12, 1990, Hopi 

Point, Grand Canyon National Park, AZ)

58g Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions at RH = 81.8 %, and at a wavelength of 525 nm. NGS study. (Feb 13, 1990, Hopi 

Point, Grand Canyon National Park, AZ),

58h Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions at RH = 92.6 %, and at a wavelength of 525 nm. NGS study. (Feb 19, 1990, Hopi 

Point, Grand Canyon National Park, AZ)
Partial Method Notes

58i Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions, RH = 55.2 %, and at a wavelength of 525 nm. NGS study. (Feb 28, 1990, Hopi 

Point, Grand Canyon National Park, AZ)

58j Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions, RH = 48.0 %, and at a wavelength of 525 nm. NGS study. (Mar 1, 1990, Hopi 

Point, Grand Canyon National Park, AZ)

58k, Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions, RH = 67.9 %, and at a wavelength of 525 nm. NGS study. (Mar 2, 1990, Hopi 

Point, Grand Canyon National Park, AZ)

58l Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions, RH = 63.5 %, and at a wavelength of 525 nm. NGS study. (Mar 3, 1990, Hopi 

Point, Grand Canyon National Park, AZ)

58m Esp calculated for ammonium sulfates and water (per gram of ammonium sulfate), carbonaceous aerosol (POM =1.4*OC) using 

composite model and MOUDI size distributions, RH = 76.5 %, and at a wavelength of 525 nm. NGS study. (Mar 4, 1990, Hopi 

Point, Grand Canyon National Park, AZ)
Table 7. Summary of mass absorption and scattering efficiencies (αap) of light absorbing carbon 

(LAC) and other species. The first column corresponds to the reference number and entry in the 

associated notes table. The method table refers to the type of method used to compute αap (see 

footnotes). 

Mass Absorption Efficiency and LAC Scattering Efficiency (m2 g-1)

*

Note Method αsp

(LAC) 

Specific 

αap (fine 

mode) 

Specific αap

(coarse 

mode) 

αap 

(LAC) 

αap

(Soil) 

αap

(POM) Location/Study Time 

5 M-1 

8.1 

(13) 

Big Bend National 

Park TX 

(BRAVO) 

Sep-Oct 

1999 

7

1 M-1 18.3, 9.3, 5.3 Atlanta GA 

(Supersite) 

Jul-Sep 

1999 

8

2 MLR1&2 3.89 1.52 0.22 9.08 (10.5),

0.32 0.17 1.11 Brisbane Australia Apr-Jun 1999 

123 M-1 20, 12 

Maldives 

(INDOEX) (bsp < 

25 Mm-1) 

Feb–

Mar 

1999 

124 M-1 13, 17 

Maldives 

(INDOEX) (25 < 

bsp < 55 Mm-1

Feb–

Mar 

1999 

125 M-1 14, 10 

Maldives 

(INDOEX) (bsp > 

55 Mm-1) 

Feb–

Mar 

1999 

126 M-1 16, 12 

Maldives Bay of 

Bengal trajectory 

(INDOEX study) 

Feb–

Mar 

1999 

127 M-1 16 

Maldives Arabian 

trajectory 

(INDOEX study) 

Feb–

Mar 

1999 

13a T-2 7.3 Bondville IL Jun-Sep 

1997 

13b T-2 6 Bondville IL Jun-Sep 

1997 

13c T-2 3.6 Bondville IL Jun-Sep 

1997 

13d T-2 5.1 Bondville IL Jun-Sep 

1997 

13e T-2 4.7 Bondville IL Jun-Sep 

1997 

13f T-2 1.7 Bondville IL Jun-Sep 

1997 

16 MLR1&2 8.9 

Sde Boker Israel 

(ARACHNE 

study) 

Jun-Jul 

1996 

198 T-2 6.5 ± 0.2 Santa Maria 

Azores 

Jun 

1992 

24a9 M-1 12 (19.2) Grenoble France 

24b9 M-1 12 (19.2) Paris France 

24c9 M-1 20 (32) 

Savannah areas, 

Ivory Coast and 

Congo 

24d9 M-1 18 (28.8) Western 

Mediterranean 

 
Note Method αsp

(LAC) 

Specific 

αap (fine 

mode) 

Specific αap

(coarse 

mode) 

αap 

(LAC) 

αap

(Soil) 

αap

(POM) Location/Study Time 

24e9 M-1 5 (8) 

Remote Areas 

northern tropical 

Pacific, Mace 

Head, Ireland; 

Greenland 

27a M-1 14.22 (16.4) Mount Rainier 

National Park WA 

Summer 

1990 

27b M-1 16.9 (19.5) North Cascades 

National Park WA 

Summer 

1990 

28a10 MLR1&2 12.5 (14.4) 1.8 3.3 Meadview AZ Summer 

1992 

28b11 MLR1&2 11.7 (13.5) 3.7 7.9 Meadview AZ Summer 

1992 

38 T-1 0.37 12.9 (12.4) Yosemite National 

Park (YACS) 

Jul-Sep 

2002 

40a12 M-1 3.58 (4.5) Brighton, CO 

(NFRAQS) Jan 1997

40b13 M-1 8±4 

(10 ± 5) 

Brighton CO 

(NFRAQS) 

Dec 

1996, 

Jan 1997

46a MLR-2 3.6 

Norfolk VA to 

Cape Town South 

Africa, 

(Aerosols99) 

Jan-Feb 

1999 

46b T-3 3.3 

Norfolk VA to 

Cape Town South 

Africa, 

(Aerosols99) 

Jan-Feb 

1999 

4614 T-3 4.0±1.4 

Norfolk VA to 

Cape Town, South 

Africa 

(Aerosols99) 

Jan-Feb 

1999 

48a MLR-2 8.5 Indian Ocean 

(INDOEX) 

Feb-Mar 

1999 

48b T-3 8.8 Indian Ocean 

(INDOEX) 

Feb-Mar 

1999 

4815 T-3 4.4±1.7 Indian Ocean 

(INDOEX) 

Feb-Mar 

1999 

4916 T-3 3.88±0.8 

Pacific Ocean, 

coastal Asia 

(ACE-ASIA) 

Spring 

2001 

4917 T-3 0.61±0.14‡ 

Pacific Ocean, 

coastal Asia 

(ACE-ASIA) 

Spring 

2001 

4918 T-3 2.6±0.4♦

 

Pacific Ocean, 

coastal Asia 

(ACE-ASIA) 

Spring 

2001 

5119 MLR-2 10.2±0.8 Cranmore 

Mountain NH 

Apr–

May, 

2000 

52 MLR-2 12.85 Southern New 

Hampshire 

Jul 

2000- 

Sep 

2001 

5320 P 1.5±0.9 10.3 Denver CO Jan 1988
Note Method αsp

(LAC) 

Specific 

αap (fine 

mode) 

Specific αap

(coarse 

mode) 

αap 

(LAC) 

αap

(Soil) 

αap

(POM) Location/Study Time 

5621 M-1 0.37 0.082 Spirit Mountain 

NV 

Apr-Sep 

1989, 

57 M-1 8.6 (8.8) Linan China Oct-Nov 

1999 

Footnotes for absorption efficiency table 

Values reported for a wavelength of 550 nm, unless stated in the notes table. Italicized efficiencies in parentheses 

correspond to estimates corrected to 550 nm assuming a λ

-1 relationship. Size range and relative humidity (when reported) 

and instruments are stated in the Measurement note table or below 

Methods: 

M-1 refers to measurement method where bsp and mass are both measured 

M-2 refers to measurement method where bsp is measured and mass derived from volume distributions 

T-1 refers to theoretically calculated bsp and specific mass derived from number or volume size distributions 

T-2 refers to theoretically calculated bsp and mass size distributions per species 

T-3 refers to theoretically calculated bsp and mass is apportioned to a species from number or volume size distribution 

measurements 

MLR-1 refers to multi-linear regression assuming an internally mixed aerosol model 

MLR-2 refers to a multi-linear regression assuming an externally mixed aerosol model 

P refers to partial scattering method 

‡

 Corresponds to coarse mode (supermicron) 

♦

 Corresponds to total modes (supramicron, fine + coarse) 

1

 Three values listed correspond to estimates from PM2.5 filter mass, summed MOUDI mass and R&P mass, respectively (see 

notes 7a, 7b, and 7c). 

2

 Eap for EC is for PM2.5 and coarse (PM10 – PM2.5), respectively. Soil and OC are also coarse. 

3

 Values correspond to Caltech data and R/V Ronald Brown data (see notes 12a and 12b) 

4

 Values correspond to Caltech data and R/V Ronald Brown data (see notes 12c and 12d) 

5

 Values correspond to Caltech data and R/V Ronald Brown data (see notes 12e and 12f) 

6

 Values correspond to Caltech data and R/V Ronald Brown data (see notes 12g and 12h) 

7

 Values correspond to R/V Ronald Brown data (see notes 12i) 

8

 Average and standard deviation of two polluted air mass events at RH values of 81 % and 77 % (see notes 19a and 19b) 

9

 Time periods not given in manuscript 

10 PM2.5 O4 and OP fractions for organic carbon and E1 and E2 fractions for EC. Regression performed with intercept (see notes 

28a and 28b) 

11 PM2.5 O4 and OP fractions for organic carbon and E1 and E2 fractions for EC. Regression performed without intercept (see 

notes 28c and 28d) 

12 Comparison of photoacoustic and TOR EC data (see note 40a) 

13 Comparison of aethalometer and photoacoustic data. Average and standard deviation of days in Dec 1996 and Jan 1997 (see 

notes 40b and40c) 

14 For Dp < 10 μm. Average and standard deviation of values for North America, NH marine, African dust, African dust/biomass 

burning and biomass burning (see notes 46c-g) 

15 For Dp < 1.1 μm. Average and standard deviation of SH Atlantic, SH Indian Ocean, NH Indian Ocean, East Indian 

Subcontinent, Indian Subcontinent, Arabia, Arabia-Indian subcontinent, Arabian sea-coastal India (see notes 48c-j) 

16 For Dp < 1.1 μm. Average and standard deviation of polluted-Korea/Japan, polluted-Japan, volcano-polluted, dust+frontal, 

dust+Korea, dust+Shanghai (see notes 49a-f) 

17 For 1.1 < Dp < 10 μm. Average and standard deviation of polluted-Korea/Japan, polluted-Japan, volcano-polluted, 

dust+frontal, dust+Korea, dust+Shanghai (see notes 49g-l) 

18 For Dp < 10 μm. Average and standard deviation of polluted-Korea/Japan, polluted-Japan, volcano-polluted, dust+frontal, 

dust+Korea, dust+Shanghai (see notes 49m-r) 

19 Average and standard deviation of two air masses (see notes 51a and 51b) 

20 Average and standard deviation of two time periods and RH (74 % and 38 %). 

21 Computed from data in manuscript 
Absorption Efficiency Method Notes table with further details about measurement methods 

Mass Absorption Efficiency Notes 

5

 Comparison between aethalometer and photoacoustic technique at a wavelength of 880 nm. (Sept 17- Oct 17, 1999, Big Bend 

National Park, TX) 

7a TEOM PM2.5 mass and Bap measured with a PSAP at a wavelength of 550 nm. Average RH value of 48 %. (July 30 - Sept 3 

1999, Atlanta, GA) 

7b PM2.5 filter mass and Bap measured with a PSAP at a wavelength of 550 nm. Average RH value of 48 %. (July 30 - Sept 3 1999, 

Atlanta) 

7c MOUDI mass (includes sum of all stages and after-filter, 0.056 < Dp < 1.78 um). Bap measured with a PSAP at a wavelength of 

550 nm. Average RH value of 48 %. (July 30 - Sept 3 1999, Atlanta, GA) 

8

 PM2.5 EC and dry Bsp from a nephelometer at a wavelength of 530 nm. PM2.5 mass and Babs measured by integrating plate laser 

absorption at a wavelength of 633 nm. Eap for soil, organic carbon are coarse (PM10 –PM2.5). Eap for EC for PM2.5 and PM10, 

respectively. Soil form not stated. OC multiplier not stated.(April-June 1999, Eagle Farm, Brisbane, Australia) 

12a Bap is measured with a PSAP at RH = 33 % and Dp < 1 um. Caltech data. (Feb 11 - March 25, 1999, Kashidhoo Climate 

Observatory, Maldives, for low Bsp regime (Bsp < 25 Mm-1))

12b Bap is measured with a PSAP at RH = 33 % and Dp < 1 um. Ronald Brown R/V data. (Feb 11 - March 25, 1999, Kashidhoo 

Climate Observatory, Maldives, for low Bsp regime (Bsp < 25 Mm-1)) 

12c Bap is measured with a PSAP at RH = 33 % and Dp < 1 um. Caltech data. (Feb 11 - March 25, 1999, Kashidhoo Climate 

Observatory, Maldives, medium Bsp regime (25 < Bsp < 55 Mm-1))

12d Bap is measured with a PSAP at RH = 33 % and Dp < 1 um. Ronald Brown R/V data. (Feb 11 - March 25, 1999, Kashidhoo 

Climate Observatory, Maldives, medium Bsp regime (25 < Bsp < 55 Mm-1)) 

12e Bap is measured with a PSAP at RH = 33 % and Dp < 1 um. Caltech data. (Feb 11 - March 25, 1999, Kashidhoo Climate 

Observatory, Maldives, high Bsp regime (Bsp > 55 Mm-1))

12f Bap is measured with a PSAP RH = 33 % and Dp < 1 um. Ronald Brown R/V data. Feb 11 - March 25, 1999, Kashidhoo Climate 

Observatory, Maldives, high Bsp regime (Bsp > 55 Mm-1)) 

12g Bap is measured with a PSAP at RH = 33 % and Dp < 1 um. Caltech data. (Feb 11 - March 25, 1999, Kashidhoo Climate 

Observatory, Maldives, Bay of Bengal Trajectory) 

12h Bap is measured with a PSAP at RH = 33 % and Dp < 1 um. Ronald Brown R/V data. (Feb 11 - March 25, 1999, Kashidhoo 

Climate Observatory, Maldives, Bay of Bengal Trajectory) 

12i Bap is measured with a PSAP at RH = 33 % and Dp < 1 um. Ronald Brown R/V data. (Feb 11 - March 25, 1999, Kashidhoo 

Climate Observatory, Maldives, Arabian Sea Trajectory) 

13a MOUDI size distributions, Eap corresponds to Dp = 0.09 um and density of 1.9. Babs measured by transmission of light with 

spectrophotometer, (June -Sept, 1997, Bondville, IL) 

13b MOUDI size distributions, Eap corresponds to Dp = 0.16 um and density of 1.9. Babs measured by transmission of light with 

spectrophotometer, (June - Sept 1997, Bondville, IL).

13c MOUDI size distributions, Eap corresponds to Dp = 0.30 um and density of 1.9. Babs measured by transmission of light with 

spectrophotometer, (June - Sept 1997, Bondville, IL).

13d MOUDI size distributions, Eap corresponds to Dp = 0.55 um and density of 1.9. Babs measured by transmission of light with 

spectrophotometer, (June - Sept 1997, Bondville, IL).

13e MOUDI size distributions, Eap corresponds to Dp = 1.0 um and density of 1.9. Babs measured by transmission of light with 

spectrophotometer, (June - Sept 1997, Bondville, IL).

13f MOUDI size distributions, Eap corresponds to Dp = 2.7 um and density of 1.9. Babs measured by transmission of light with 

spectrophotometer, (June - Sept 1997, Bondville, IL).

16 Bap by AE-9 aethalometer, corrected to 550 assuming 1/lambda. RH < 50 %. (June 20 - July 10 1996, Sde Boker, Negev Desert, 

Israel) 

19a MOUDI size distributions at ambient humidity (0.32 < Dp < 10 um, RH = 81 %). Soot size distributions assumed to match nssSO4. (June 19 2000-0700 1992, Santa Maria, Azores archipelago, continental polluted air) 

19b MOUDI size distributions at ambient humidity (0.32 < Dp < 10 um, RH = 77 %). Soot size distributions assumed to match nssSO4. (June 20 0800-1900 1992, Santa Maria, Azores archipelago, continental polluted air) 

24a McGee Scientific Aethalometer and thermally analyzed black carbon concentrations at a wavelength of 880 nm. (Grenoble, 

France)

24b McGee Scientific Aethalometer and thermally analyzed black carbon concentrations at a wavelength of 880 nm (Paris, France)

24c McGee Scientific Aethalometer and thermally analyzed black carbon concentrations at a wavelength of 880 nm (Savannah areas, 

Ivory Coast and Congo)

Mass Absorption Efficiency Notes
24d McGee Scientific Aethalometer and thermally analyzed black carbon concentrations at a wavelength of 880 nm (Western 

Mediterranean)

24e McGee Scientific Aethalometer and thermally analyzed black carbon concentrations at a wavelength of 880 nm (Remote Areas 

(northern tropical Pacific, Mace Head, Ireland; Greenland)

27a PM2.5 Babs by LIPM and LAC mass. (summer 1990, Tahoma Woods, Mount Rainier National Park, WA)

27b PM2.5 Babs by LIPM and LAC mass. (summer 1990, Marblemount, North Cascades National Park, WA)

28a PM2.5 Babs by LIPM. Mass corresponds to the O4+OP fractions of OC by TOR. Regression intercept of 3.1. Wavelength not 

stated. (Summer 1992, Meadview, Grand Canyon National Park, AZ) 

28b PM2.5 Babs by LIPM. Mass corresponds to the E1+E2 fractions of EC by TOR. Regression intercept of 3.1. Wavelength not 

stated. (Summer 1992, Meadview, Grand Canyon National Park, AZ)

28c PM2.5 Babs by LIPM. Mass corresponds to the O4+OP fractions of OC by TOR. Regression with no intercept. Wavelength not 

stated. (Summer 1992, Meadview, Grand Canyon National Park, AZ)

28d PM2.5 Babs by LIPM. Mass corresponds to the E1+E2 fractions of EC by TOR. Regression with no intercept. Wavelength not 

stated. (Summer 1992, Meadview, Grand Canyon National Park, AZ)

38 DMA and OPC dry aligned size distributions (0.04 < Dp < 2 um) and retrieved refractive indices at a wavelength of 530 nm. Eap 

corresponds to integrated accumulation mode mass and to PM2.5 EC mass (July-Sept, 2002, Yosemite National Park, CA) 

40a Regression of TOR EC vs photoacoustic Babs at a wavelength of 685 nm. (Jan 3 and 6-9, 1997, Brighton, CO) 

40b Regression of BC from Magee Scientific AE-10IM aethalometer BC and photoacoustic Babs at a wavelength of 685 nm (avg 

Dec 17&18 1996, Brighton, CO)

40c Regression of BC from Magee Scientific AE-10IM aethalometer BC and photoacoustic Babs at a wavelength of 685 nm (avg Jan 

3 and 6-9 1997, Brighton, CO)

46a Bap measured with PSAP at RH = 55 % and for Dp < 10 um. Mean values for North America, NH marine, dust, dust/biomass 

burning, biomass burning. (Jan 14-Feb 8, 1999, Norfolk, VA to Cape Town, South Africa) 

46b Size distributions for Dp < 10 um, RH = 55 %. Esp for BC. Reported means for North America, NH marine, dust, dust/biomass 

burning, biomass burning, (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa)

46c Size distributions for Dp < 1.1 um, RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for North America (Jan 

14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46d Size distributions for Dp < 1.1 um, RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for Northern Hemisphere 

marine, (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46e Size distributions for Dp < 1.1 um, RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for African dust, (Jan 14 

-Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46f Size distributions for Dp < 1.1 um, RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for African dust/biomass 

burning, (Jan 14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

46g Size distributions for Dp < 1.1 um, RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for biomass burning, (Jan 

14 -Feb 8 1999, Norfolk, VA to Cape Town, South Africa) 

48a Bap measured with PSAP for Dp < 1um at RH = 55 %. Mean for the entire experiment; (Feb-Mar 1999, Arabian Sea, Bay of 

Bengal, Indian Ocean -north and south of the ITCZ) 

48b Size distributions for for Dp < 10 um and RH = 55 %. Mean for entire experiment. (Feb-March 1999, Arabian Sea, Bay of 

Bengal, Indian Ocean, north and south of the ITCZ) 

48c Size distributions for Dp < 1.1 um and RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for SH Atlantic (FebMarch 1999) 

48d Size distributions for Dp < 1.1 um and RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for SH Indian Ocean 

(Feb-March 1999) 

48e Size distributions for Dp < 1.1 um and RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for NH Indian Ocean, 

(Feb-March 1999) 

48f Size distributions for Dp < 1.1 um and RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for East Indian 

Subcontinent (Feb-March 1999) 

48g Size distributions for Dp < 1.1 um and RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for Indian 

Subcontinent, (Feb-March 1999) 

48h Size distributions for Dp < 1.1 um and RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for Arabia, (FebMarch 1999) 

48i Size distributions for Dp < 1.1 um and RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for Arabia-Indian 

subcontinent, (Feb-March 1999) 

48j Size distributions for Dp < 1.1 um and RH = 55 %. BC includes nss-K and associated SO4 and NO3. Mean for Arabian sea, 

coastal India, (Feb-March 1999) 

49a Size distributions for Dp < 1.1 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for PollutedKorea/Japan (mid-March to mid-April 2001) 

Mass Absorption Efficiency Notes
49b Size distributions for Dp < 1.1 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Polluted-Japan 

(mid-March to mid-April 2001) 

49c Size distributions for Dp < 1.1 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Volcano+Polluted 

(mid-March to mid-April 2001) 

49d Size distributions for Dp < 1.1 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for dust + Frontal 

(mid-March to mid-April 2001) 

49e Size distributions for Dp < 1.1 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Dust + Korea 

(mid-March to mid-April 2001) 

49f Size distributions for Dp < 1.1 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Dust + Shanghai 

(mid-March to mid-April 2001) 

49g Size distributions for 1.1 < Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for PollutedKorea/Japan, (mid-March to mid-April 2001) 

49h Size distributions for 1.1 < Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for PollutedJapan, (mid-March to mid-April 2001) 

49i Size distributions for 1.1 < Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for 

Volcano+Polluted, (mid-March to mid-April 2001) 

49j Size distributions for 1.1 < Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for dust + 

Frontal (mid-March to mid-April 2001) 

49k Size distributions for 1.1 < Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Dust + 

Korea (mid-March to mid-April 2001)

49l Size distributions for 1.1 < Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Dust + 

Shanghai (mid-March to mid-April 2001) 

49m Size distributions for Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for PollutedKorea/Japan (mid-March to mid-April 2001) 

49n Size distributions for Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Polluted-Japan 

(mid-March to mid-April 2001) 

49o Size distributions for Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Volcano+Polluted 

(mid-March to mid-April 2001) 

49p Size distributions for Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for dust + Frontal 

(mid-March to mid-April 2001) 

49q Size distributions for Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Dust + Korea 

(mid-March to mid-April 2001) 

49r Size distributions for Dp < 10 um and RH = 55 %. EC includes nss-K and associated SO4 and NO3. Mean for Dust + Shanghai 

(mid-March to mid-April 2001) 

51a Bap measured with PSAP at 565nm (corrected to 550 nm) at ambient RH (< 50 % typically. EC from TOT. (April 18 - May 13, 

2000, Cranmore Mountain, New Hampshire, for north/northeast air masses)

51b Bap measured with PSAP at 565nm (corrected to 550 nm) at ambient RH (< 50 % typically. EC from TOT. (April 18 - May 13, 

2000, Cranmore Mountain, New Hampshire, for west/southwest air masses)

52 Bsp from Radiance Research M903 nephelometer at a wavelength of 530 nm. Bap with PSAP at 550 nm. Sulfate corresponds to 

ammonium sulfate. POM =1.4*OC from TOT method. Values correspond to all measurements. (July 2000-Sept 2001, rural site in 

southern New Hampshire)

53a MOUDI size distribution (0.03 < Dp < 3.16 um) and ELSIE calculations. RH = 74 %. Wavelength not stated. Interactive 

efficiency. (Jan 5 1998, Denver, CO, northeasterly flow)

53b MOUDI size distribution (0.03 < Dp < 3.16 um) and ELSIE calculations. RH = 38 %. Wavelength not stated. Interactive 

efficiency. (Jan 13 1998, Denver, CO, stagnant air mass)

56 Eap is for a ratio of Babs from LIPM and PM2.5 aerosol. Coarse Eap is for 2.5 < Dp < 15 um gravimetric mass. Ratio computed 

from data in manuscript. (April-Sept 1989, Spirit Mountain, Nevada)

57 PM2.5 mass and Bap measured with a PSAP at 565 nm for RH < 40 %. (Oct 28-Nov 20 1999, Linan, China)
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