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aerocom:optical_properties [2012-03-16 01:57:45] mian.chin@nasa.gov [Questionary on Optical properties] |
aerocom:optical_properties [2022-05-31 09:29:31] (current) |
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- | ===== Questionary on Optical properties ===== | + | ATTENTION - THIS WIKI PAGE IS NO LONGER UPDATED - PLEASE GO TO [[http:// |
+ | |||
+ | ===== Questionary on Optical properties | ||
+ | |||
+ | The Phase III questionnaire is available in the following Google spreadsheet: | ||
+ | |||
+ | https:// | ||
+ | |||
+ | If you have problems accessing this spreadsheet, | ||
+ | |||
+ | ===== Questionary on Optical properties (AeroCom Phase II models)===== | ||
Questions on optical property calculations in AeroCom phase II models with the purpose of a correct interpretation of diagnosed AOD properties in the AeroCom database: | Questions on optical property calculations in AeroCom phase II models with the purpose of a correct interpretation of diagnosed AOD properties in the AeroCom database: | ||
Line 5: | Line 15: | ||
1) Do you assume and how internal mixing when computing optical properties of total | 1) Do you assume and how internal mixing when computing optical properties of total | ||
- | aerosol? Is Size varying? Which mixing assumption? | + | aerosol? Is Size varying? Which mixing assumption? |
- | + | ||
- | External mixing. | + | |
2) Do you differentiate between clear-sky and all-sky relative humidity and | 2) Do you differentiate between clear-sky and all-sky relative humidity and | ||
which one do you use for the AOD calculation, | which one do you use for the AOD calculation, | ||
- | |||
- | No. We use ambient relative humidity. | ||
2b) If you differentiate, | 2b) If you differentiate, | ||
- | 3) Is the reported-to-AeroCom AOD as asked under 2) used directly for the RF calculations? | + | 3) Is the reported-to-AeroCom AOD as asked under 2) used directly for the RF calculations? |
- | + | ||
- | The AOD reported to AeroCom is 550 nm. For RF calculations, | + | |
4) Would you consider the diagnosed AOD provided to the Aerocom database as representative for clear-skies? | 4) Would you consider the diagnosed AOD provided to the Aerocom database as representative for clear-skies? | ||
- | |||
- | Not necessary - but we are doing it anyway. We don't have quantitative numbers to show on monthly averaged basis how much the differences are. | ||
5) If you diagnose a clear-sky | 5) If you diagnose a clear-sky | ||
- | |||
- | N/A | ||
6) Which humidity growth factor and variation do you use ? How does it depend on RH? Do you include sub-grid variability in relative humidity? | 6) Which humidity growth factor and variation do you use ? How does it depend on RH? Do you include sub-grid variability in relative humidity? | ||
- | Based on GADS (aka OPAC). No we don't include sub-grid variability of RH. | + | 7) Do you diagnose the aerosol water mass or aerosol |
- | 7) Do you diagnose the aerosol water mass or aerosol water AOD? How? | + | 8) Is the diagnosed sea salt and sulfate AOD computed at ambient RH? And eventually is that using clear-sky or all-sky |
- | + | ||
- | Yes. Aerosol water = ambient AOD - dry AOD (i.e., no hygroscopic growth). | + | |
- | + | ||
- | 8) Is the diagnosed sea salt and sulfate AOD computed at ambient RH? And eventually is that using clear-sky or all-sky RH? | + | |
- | + | ||
- | Yes they are computed at ambient RH under all sky conditions. | + | |
9) Do you average nighttime and daytime values of AOD into daily averages? | 9) Do you average nighttime and daytime values of AOD into daily averages? | ||
- | Yes. | + | 10) What is the single-scattering albedo of your BC, POM, DUST? Does it vary as a function of size, RH? How roughly? Which range? |
- | + | ||
- | 10) What is the single-scattering albedo of your BC, POM, DUST? Does it vary as a function of size, RH? How roughly? Which range? | + | |
- | + | ||
- | At 550 nm: | + | |
- | SSA for BC: 0.2080, 0.2086, 0.2139, 0.2481, 0.3227, 0.3830, 0.4594, 0.5359 at 0, 50, 70, 80, 90, 95, 98, 99% RH. | + | |
- | + | ||
- | SSA for POM: 0.9618, 0.9773, 0.9819, 0.9851, 0.9897, 0.9932, 0.9960, 0.9972 at 0, 50, 70, 80, 90, 95, 98, 99% RH. | + | |
- | + | ||
- | SSA for dust: 0.9675, 0.9652, 0.9507, 0.9196, 0.8717, 0.8107, 0.7314, 0.6601 for dust effective radius of 0.14, 0.24, 0.45, 0.80, 1.4, 2.4, 4.5, 8.0 um. No hygroscopic growth is considered. | + | |
11) What is the absorption coefficient of BC? How is it calculated? | 11) What is the absorption coefficient of BC? How is it calculated? | ||
- | |||
- | I assume you mean "mass absorption efficiency" | ||
- | |||
- | At 550 nm: | ||
- | MAE for BC: 7.3529, 7.4091, 0.4491, 8.5266, 8.0192, 9.7856, 10.190, 10.521 m2/g at 0, 50, 70, 80, 90, 95, 98, 99% RH. | ||
- | |||
- | They are calculated from the Mie code with refractive indices (BC/water volume weighted), size distributions, | ||
- | |||
12) Please provide the refractive index at 0.55 microns for each aerosol species? And eventually further information on the hygroscopicity for each species. | 12) Please provide the refractive index at 0.55 microns for each aerosol species? And eventually further information on the hygroscopicity for each species. | ||
- | BC: 1.75 - 0.44i | ||
- | POM: 1.53-0.006i | ||
- | SO4: 1.43-10^(-8)i | ||
- | Dust: 1.53-0.0055i | ||
- | Seasalt: 1.50-10^(-8)i | ||
- | (see Table 2 in Chin et al., Ann. Geophys., 2009) | ||
===== MODELS ===== | ===== MODELS ===== | ||
Line 313: | Line 284: | ||
Please refer to Table 4 of [[http:// | Please refer to Table 4 of [[http:// | ||
+ | |||
+ | |||
==== GMI.A2.* and GMI-MERRA.A2.* ==== | ==== GMI.A2.* and GMI-MERRA.A2.* ==== | ||
+ | 1) Do you assume and how internal mixing when computing optical properties of total | ||
+ | aerosol? Is Size varying? Which mixing assumption? | ||
- | ==== GISS-modelE.A2.* ==== | + | External mixing. |
+ | |||
+ | 2) Do you differentiate between clear-sky and all-sky relative humidity and | ||
+ | which one do you use for the AOD calculation, | ||
+ | |||
+ | No. We use ambient relative humidity. | ||
+ | |||
+ | 2b) If you differentiate, | ||
+ | |||
+ | 3) Is the reported-to-AeroCom AOD as asked under 2) used directly for the RF calculations? | ||
+ | |||
+ | The AOD reported to AeroCom is 550 nm. For RF calculations, | ||
+ | |||
+ | 4) Would you consider the diagnosed AOD provided to the Aerocom database as representative for clear-skies? | ||
+ | |||
+ | Not necessary - but we are doing it anyway. We don't have quantitative numbers to show on monthly averaged basis how much the differences are. | ||
+ | |||
+ | 5) If you diagnose a clear-sky | ||
+ | |||
+ | N/A | ||
+ | |||
+ | 6) Which humidity growth factor and variation do you use ? How does it depend on RH? Do you include sub-grid variability in relative humidity? | ||
+ | |||
+ | Based on Tang and Munkelwitz (1996) water activity formula determined at the HeHe laser wavelength of 0.633 microns for ammonium nitrate and ammonium sulfate. All others based on GADS (aka OPAC). No we don't include sub-grid variability of RH. | ||
+ | |||
+ | 7) Do you diagnose the aerosol water mass or aerosol water AOD? How? | ||
+ | |||
+ | Not for AeroCom II aerosol direct radiative forcing activity (not required). Yes for AeroCom HTAP activity. Aerosol water = ambient AOD - dry AOD (i.e., no hygroscopic growth). | ||
+ | |||
+ | 8) Is the diagnosed sea salt and sulfate AOD computed at ambient RH? And eventually is that using clear-sky or all-sky RH? | ||
+ | |||
+ | Yes they are computed at ambient RH under all sky conditions. | ||
+ | 9) Do you average nighttime and daytime values of AOD into daily averages? | ||
+ | |||
+ | Yes. | ||
+ | |||
+ | 10) What is the single-scattering albedo of your BC, POM, DUST? Does it vary as a function of size, RH? How roughly? Which range? | ||
+ | |||
+ | At 550 nm: | ||
+ | SSA for BC: 0.2080, 0.2086, 0.2139, 0.2481, 0.3227, 0.3830, 0.4594, 0.5359 at 0, 50, 70, 80, 90, 95, 98, 99% RH. | ||
+ | |||
+ | SSA for POM: 0.9618, 0.9773, 0.9819, 0.9851, 0.9897, 0.9932, 0.9960, 0.9972 at 0, 50, 70, 80, 90, 95, 98, 99% RH. | ||
+ | |||
+ | SSA for dust: 0.9916, 0.9909, 0.9864, 0.9767, 0.9604, 0.9353, 0.8933, 0.8399 for dust effective radius of 0.14, 0.24, 0.45, 0.80, 1.4, 2.4, 4.5, 8.0 um. No hygroscopic growth is considered. | ||
+ | |||
+ | 11) What is the absorption coefficient of BC? How is it calculated? | ||
+ | |||
+ | I assume you mean "mass absorption efficiency" | ||
+ | |||
+ | At 550 nm: | ||
+ | MAE for BC: 7.3529, 7.4091, 0.4491, 8.5266, 8.0192, 9.7856, 10.190, 10.521 m2/g at 0, 50, 70, 80, 90, 95, 98, 99% RH. | ||
+ | |||
+ | They are calculated from the Mie code with refractive indices (BC/water volume weighted), size distributions, | ||
+ | |||
+ | |||
+ | 12) Please provide the refractive index at 0.55 microns for each aerosol species? And eventually further information on the hygroscopicity for each species. | ||
+ | |||
+ | BC: 1.75 - 0.44i; | ||
+ | POM: | ||
+ | (NH4)2SO4: 1.53-10^(-7)i; | ||
+ | NH4NO3: | ||
+ | Dust: 1.53-0.0055i; | ||
+ | Seasalt: | ||
+ | |||
+ | The refractive indices of ammonium sulfate and ammonium nitrate are calculated using lacis-refrac.rhwmri.f provided by Andrew Lacis [ftp:// | ||
+ | |||
+ | ==== GISS-modelE.A2.* ==== | ||
+ | 1) Do you assume and how internal mixing when computing optical properties of total aerosol? Is Size varying? Which mixing assumption? | ||
+ | |||
+ | Aerosol are externally mixed, size distributions are prescribed | ||
+ | |||
+ | 2) Do you differentiate between clear-sky and all-sky relative humidity and which one do you use for the AOD calculation, | ||
+ | |||
+ | We do not differentiate between clear sky and all sky humidity, but we provide both, clear and all sky AOD for AeroCOm. | ||
+ | |||
+ | 3) Is the reported-to-AeroCom AOD as asked under 2) used directly for the RF calculations? | ||
+ | |||
+ | Yes | ||
+ | |||
+ | 4) Would you consider the diagnosed AOD provided to the Aerocom database as representative for clear-skies? | ||
+ | |||
+ | We provided both clear and all sky. | ||
+ | |||
+ | 5) If you diagnose a clear-sky AOD ⇒ How do you compute it? What are the assumptions on RH? Any threshold of RH you use? Cloud fraction weighting to derive a monthly average Clear-sky AOD? | ||
+ | |||
+ | Clear sky is defined when the Monte Carlo sampling of cloud fraction sees zero cloud fraction in the column. | ||
+ | |||
+ | 6) Which humidity growth factor and variation do you use? How does it depend on RH? | ||
+ | |||
+ | Sea salt, nitrate and sulfate get humidified following Lacis and Oinas 1991 and depends on ambient RH | ||
+ | |||
+ | Do you include sub-grid variability in relative humidity? | ||
+ | |||
+ | No | ||
+ | |||
+ | We use different parameterizations for sulfate and sea salt. | ||
+ | |||
+ | Yes | ||
+ | |||
+ | 7) Do you diagnose the aerosol water mass or aerosol water AOD? How? | ||
+ | |||
+ | No | ||
+ | |||
+ | 8) Is the diagnosed sea salt and sulfate AOD computed at ambient RH? And eventually is that using clear-sky or all-sky RH? | ||
+ | |||
+ | Yes we use ambient all sky RH. | ||
+ | |||
+ | 9) Do you average nighttime and daytime values of AOD into daily averages? | ||
+ | |||
+ | Yes | ||
+ | |||
+ | 10) What is the single-scattering albedo of your BC, POM, DUST? Does it vary as a function of size, RH? How roughly? Which range? | ||
+ | |||
+ | 11) What is the absorption coefficient of BC? How is it calculated? | ||
+ | |||
+ | BC absorption is calculated based on BC mass, an BC enhancement factor of 1.5 is applied to take into account BC enhancement effect due to internal mixing. | ||
+ | |||
+ | 12) Please provide the refractive index at 0.55 microns for each aerosol species? And eventually further information on the hygroscopicity for each species. | ||
+ | |||
+ | The following refractive indices at 550nm are used in this study: Sulfate (1.528-1.e-7i), | ||
+ | |||
==== GISS-MATRIX.A2.* ==== | ==== GISS-MATRIX.A2.* ==== | ||
- | + | 1) Do you assume and how internal mixing when computing optical properties of total aerosol? Is Size varying? Which mixing assumption? | |
+ | |||
+ | Mixing state is taken into consideration. Particles including BC have core shell structure; other particles use volume mixing approach. The size is prognostic and the mixing state assumption follows the population definitions in Bauer et al 2008 ACP | ||
+ | |||
+ | 2) Do you differentiate between clear-sky and all-sky relative humidity and which one do you use for the AOD calculation, | ||
+ | |||
+ | We do not differentiate between clear sky and all sky humidity, but we provide both, clear and all sky AOD for AeroCOm. | ||
+ | |||
+ | 3) Is the reported-to-AeroCom AOD as asked under 2) used directly for the RF calculations? | ||
+ | |||
+ | Yes | ||
+ | |||
+ | 4) Would you consider the diagnosed AOD provided to the Aerocom database as representative for clear-skies? | ||
+ | |||
+ | We provided both clear and all sky. | ||
+ | |||
+ | 5) If you diagnose a clear-sky AOD ⇒ How do you compute it? What are the assumptions on RH? Any threshold of RH you use? Cloud fraction weighting to derive a monthly average Clear-sky AOD? | ||
+ | |||
+ | Clear sky is defined when the Monte Carlo sampling of cloud fraction sees zero cloud fraction in the column. | ||
+ | |||
+ | 6) Which humidity growth factor and variation do you use ? How does it depend on RH? Do you include sub-grid variability in relative humidity? | ||
+ | |||
+ | We calculate the uptake of water following the thermodynamical model EQSAM and for Sea salt using the Lewis parameterization (Lewis and Schwartz 2004) | ||
+ | |||
+ | 7) Do you diagnose the aerosol water mass or aerosol water AOD? How? | ||
+ | |||
+ | No, aerosol water is one component that determines the mixing state of aerosols. Aerosol water is tracked for each aerosol population. | ||
+ | |||
+ | 8) Is the diagnosed sea salt and sulfate AOD computed at ambient RH? And eventually is that using clear-sky or all-sky RH? | ||
+ | |||
+ | Yes we use ambient all sky RH. | ||
+ | |||
+ | 9) Do you average nighttime and daytime values of AOD into daily averages? | ||
+ | |||
+ | Yes | ||
+ | |||
+ | 10) What is the single-scattering albedo of your BC, POM, DUST? Does it vary as a function of size, RH? How roughly? Which range? | ||
+ | |||
+ | 11) What is the absorption coefficient of BC? How is it calculated? | ||
+ | |||
+ | BC absorption is calculated depending on aerosol mixing state – see question 1) | ||
+ | |||
+ | 12) Please provide the refractive index at 0.55 microns for each aerosol species? And eventually further information on the hygroscopicity for each species. | ||
+ | |||
+ | The following refractive indices at 550nm are used: Sulfate (1.528-1.e-7i), | ||
==== BCC_AGCM2.0.1_CAM.A2.* ==== | ==== BCC_AGCM2.0.1_CAM.A2.* ==== | ||
+ | 1) Do you assume and how internal mixing when computing optical properties of total aerosol? Is Size varying? Which mixing assumption? | ||
+ | Reply: No, all species of aerosols are external mixture. The size spectrum of each aerosol is divided into 12 bins with radii. | ||
+ | |||
+ | 2) Do you differentiate between clear-sky and all-sky relative humidity and which one do you use for the AOD calculation, | ||
+ | Reply: No, we don’t differentiate between clear-sky and all-sky relative humidity. We use all-sky relative humidity for the AOD calculation. | ||
+ | |||
+ | 3) Is the reported-to-AeroCom AOD as asked under 2) used directly for the RF calculations? | ||
+ | Reply: Yes, all-sky AOD is used in the RF calculations. | ||
+ | |||
+ | 4) Would you consider the diagnosed AOD provided to the Aerocom database as representative for clear-skies? | ||
+ | Reply: Yes. | ||
+ | |||
+ | 5) If you diagnose a clear-sky AOD => How do you compute it? What are the assumptions on RH? Any threshold of RH you use? Cloud fraction weighting to derive a monthly average Clear-sky AOD? | ||
+ | Reply: Cloud fraction weighting is used to derive a clear-sky AOD ((1-CLDTOT)*OD550AER), | ||
+ | |||
+ | 6) Which humidity growth factor and variation do you use? How does it depend on RH? Do you include sub-grid variability in relative humidity? | ||
+ | Reply: Kohler theory is used to calculate the humidity growth. We don't include sub-grid variability in relative humidity. | ||
+ | |||
+ | |||
+ | 7) Do you diagnose the aerosol water mass or aerosol water AOD? How? | ||
+ | Reply: No. | ||
+ | |||
+ | 8) Is the diagnosed sea salt and sulfate AOD computed at ambient RH? And eventually is that using clear-sky or all-sky RH? | ||
+ | Reply: Yes. The all-sky RH is used. | ||
+ | |||
+ | 9) Do you average nighttime and daytime values of AOD into daily averages? | ||
+ | Reply: Yes. | ||
+ | |||
+ | 10) What is the single-scattering albedo of your BC, POM, DUST? Does it vary as a function of size, RH? How roughly? Which range? | ||
+ | Reply: The single-scattering albedo is calculated from Mie theory. At 550 nm, the single-scattering albedos are 0.00118 - 0.575 for BC, 0.0233 - 0.999 for POM, and 0.0355 - 0.975 for dust. They vary with particle size and RH. | ||
+ | |||
+ | 11) What is the absorption coefficient of BC? How is it calculated? | ||
+ | Reply: The absorption coefficient of BC is 5.11, 5.30, 6.18, 9.34, 10.7, 6.11, 2.72, 1.26, 0.600, 0.289, 0.141, and 0.0695 m2/g in 12 bins at 550 nm. It's calculated using Mie-theory. | ||
+ | |||
+ | 12) Please provide the refractive index at 0.55 microns for each aerosol species? And eventually further information on the hygroscopicity for each species. | ||
+ | Reply: Refractive index at 0.55 micron is (1.75, 0.44), (1.53, 0.0059), (1.53, 0.008), (1.43, 1.e-8), (1.5, 9.7e-9) for BC, POM, dust, sulfate, and sea salt, respectively. Kohler theory is used to calculate the aerosol hygroscopicity. | ||
+ | |||
==== CAM4-Oslo-Vcmip5.A2.* ==== | ==== CAM4-Oslo-Vcmip5.A2.* ==== | ||
Line 423: | Line 600: | ||
==== GOCART-v4Ed.A2.* ==== | ==== GOCART-v4Ed.A2.* ==== | ||
+ | 1) Do you assume and how internal mixing when computing optical properties of total | ||
+ | aerosol? Is Size varying? Which mixing assumption? | ||
+ | |||
+ | External mixing. | ||
+ | |||
+ | 2) Do you differentiate between clear-sky and all-sky relative humidity and | ||
+ | which one do you use for the AOD calculation, | ||
+ | |||
+ | No. We use ambient relative humidity. | ||
+ | |||
+ | 2b) If you differentiate, | ||
+ | |||
+ | 3) Is the reported-to-AeroCom AOD as asked under 2) used directly for the RF calculations? | ||
+ | |||
+ | The AOD reported to AeroCom is 550 nm. For RF calculations, | ||
+ | |||
+ | 4) Would you consider the diagnosed AOD provided to the Aerocom database as representative for clear-skies? | ||
+ | |||
+ | Not necessary - but we are doing it anyway. We don't have quantitative numbers to show on monthly averaged basis how much the differences are. | ||
+ | |||
+ | 5) If you diagnose a clear-sky | ||
+ | |||
+ | N/A | ||
+ | |||
+ | 6) Which humidity growth factor and variation do you use ? How does it depend on RH? Do you include sub-grid variability in relative humidity? | ||
+ | |||
+ | Based on GADS (aka OPAC). No we don't include sub-grid variability of RH. | ||
+ | |||
+ | 7) Do you diagnose the aerosol water mass or aerosol water AOD? How? | ||
+ | |||
+ | Yes. Aerosol water = ambient AOD - dry AOD (i.e., no hygroscopic growth). | ||
+ | |||
+ | 8) Is the diagnosed sea salt and sulfate AOD computed at ambient RH? And eventually is that using clear-sky or all-sky RH? | ||
+ | |||
+ | Yes they are computed at ambient RH under all sky conditions. | ||
+ | |||
+ | 9) Do you average nighttime and daytime values of AOD into daily averages? | ||
+ | |||
+ | Yes. | ||
+ | |||
+ | 10) What is the single-scattering albedo of your BC, POM, DUST? Does it vary as a function of size, RH? How roughly? Which range? | ||
+ | |||
+ | At 550 nm: | ||
+ | SSA for BC: 0.2080, 0.2086, 0.2139, 0.2481, 0.3227, 0.3830, 0.4594, 0.5359 at 0, 50, 70, 80, 90, 95, 98, 99% RH. | ||
+ | |||
+ | SSA for POM: 0.9618, 0.9773, 0.9819, 0.9851, 0.9897, 0.9932, 0.9960, 0.9972 at 0, 50, 70, 80, 90, 95, 98, 99% RH. | ||
+ | |||
+ | SSA for dust: 0.9675, 0.9652, 0.9507, 0.9196, 0.8717, 0.8107, 0.7314, 0.6601 for dust effective radius of 0.14, 0.24, 0.45, 0.80, 1.4, 2.4, 4.5, 8.0 um. No hygroscopic growth is considered. | ||
+ | |||
+ | 11) What is the absorption coefficient of BC? How is it calculated? | ||
+ | |||
+ | I assume you mean "mass absorption efficiency" | ||
+ | |||
+ | At 550 nm: | ||
+ | MAE for BC: 7.3529, 7.4091, 0.4491, 8.5266, 8.0192, 9.7856, 10.190, 10.521 m2/g at 0, 50, 70, 80, 90, 95, 98, 99% RH. | ||
+ | |||
+ | They are calculated from the Mie code with refractive indices (BC/water volume weighted), size distributions, | ||
+ | |||
+ | |||
+ | 12) Please provide the refractive index at 0.55 microns for each aerosol species? And eventually further information on the hygroscopicity for each species. | ||
+ | |||
+ | BC: 1.75 - 0.44i | ||
+ | POM: 1.53-0.006i | ||
+ | SO4: 1.43-10^(-8)i | ||
+ | Dust: 1.53-0.0055i | ||
+ | Seasalt: 1.50-10^(-8)i | ||
+ | (see Table 2 in Chin et al., Ann. Geophys., 2009) | ||
+ | |||
Line 574: | Line 819: | ||
1) Do you assume and how internal mixing when computing optical properties of total | 1) Do you assume and how internal mixing when computing optical properties of total | ||
- | aerosol? Is Size varying? Which mixing assumption? | + | aerosol? Is Size varying? Which mixing assumption? |
+ | |||
+ | INCA uses 5 modes, two insoluble (accumulation, | ||
+ | Size variation is not taken into account in the AOD calculation. Optical properties assume mean size for each mode. | ||
2) Do you differentiate between clear-sky and all-sky relative humidity and | 2) Do you differentiate between clear-sky and all-sky relative humidity and | ||
which one do you use for the AOD calculation, | which one do you use for the AOD calculation, | ||
+ | |||
+ | In the LMDzT host model instantaneous clear-sky relative humidity is computed. This is used to compute hygroscopic growth factors, used in tabulated form, to get to AOD. | ||
+ | |||
+ | NOTE: The meaning of the clear-sky humidity in the LMDzT model has recently changed. Not clear how this affected the results. | ||
2b) If you differentiate, | 2b) If you differentiate, | ||
- | 3) Is the reported-to-AeroCom AOD as asked under 2) used directly for the RF calculations? | + | All-sky AOD was never calculated. |
+ | |||
+ | 3) Is the reported-to-AeroCom AOD as asked under 2) used directly for the RF calculations? | ||
+ | |||
+ | No - The AeroCom AOD diagnostics are computed for a given wavelength. RF uses the broadband AOD for the SW and NIR bands used in the RF calculation. | ||
4) Would you consider the diagnosed AOD provided to the Aerocom database as representative for clear-skies? | 4) Would you consider the diagnosed AOD provided to the Aerocom database as representative for clear-skies? | ||
+ | |||
+ | yes | ||
5) If you diagnose a clear-sky | 5) If you diagnose a clear-sky | ||
+ | |||
+ | Growth factors for each mode are interpolated. | ||
6) Which humidity growth factor and variation do you use ? How does it depend on RH? Do you include sub-grid variability in relative humidity? | 6) Which humidity growth factor and variation do you use ? How does it depend on RH? Do you include sub-grid variability in relative humidity? | ||
- | 7) Do you diagnose the aerosol water mass or aerosol | + | 11 tabulated growth factors between 0 and 90% RH and one at 95% RH. |
+ | No inclusion of sub-grid variability. | ||
- | 8) Is the diagnosed sea salt and sulfate AOD computed at ambient RH? And eventually is that using clear-sky or all-sky | + | 7) Do you diagnose the aerosol water mass or aerosol water AOD? How? |
+ | |||
+ | Yes, but it does not correspond strictly to the growth factors used for AOD computation. | ||
+ | |||
+ | 8) Is the diagnosed sea salt and sulfate AOD computed at ambient RH? And eventually is that using clear-sky or all-sky RH? | ||
+ | Yes, clear-sky RH. | ||
+ | |||
9) Do you average nighttime and daytime values of AOD into daily averages? | 9) Do you average nighttime and daytime values of AOD into daily averages? | ||
- | 10) What is the single-scattering albedo of your BC, POM, DUST? Does it vary as a function of size, RH? How roughly? Which range? | + | daily averages |
+ | |||
+ | 10) What is the single-scattering albedo of your BC, POM, DUST? Does it vary as a function of size, RH? How roughly? Which range? | ||
+ | |||
+ | Depending on wavelength and RH | ||
+ | BC soluble SSA varies between 0.41 and 0.53 | ||
+ | BC insoluble SSA varies between 0.30 and 0.42 | ||
+ | OA SSA varies between 0.94 and 0.99 | ||
+ | DUST SSA varies between 0.944 and 0.987 | ||
11) What is the absorption coefficient of BC? How is it calculated? | 11) What is the absorption coefficient of BC? How is it calculated? | ||
+ | |||
+ | from SSA | ||
12) Please provide the refractive index at 0.55 microns for each aerosol species? And eventually further information on the hygroscopicity for each species. | 12) Please provide the refractive index at 0.55 microns for each aerosol species? And eventually further information on the hygroscopicity for each species. | ||
+ | |||
+ | |||