Use of CAMS near Real-Time Aerosols in the HARMONIE-AROME NWP Model

Round 1

Reviewer 1 Report

see attached, major corrections are needed.

Comments for author File: Comments.pdf

NA

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Review for “Use if CAMS near real-time aerosols in the HARMONIE-AROME NWP  model” by D.M. Perez, E. Gleeson, P. Maalampi, L. Rontu

General comment

This paper is dedicated to the introduction of aerosol’s mass mixing ratio issued from Copernicus aerosol model in the HARMONIE-AROME numerical prediction model in order to improve the description of the cloud droplet number concentration used in microphysics and radiation parameterization schemes. View the quality of both scientific content and clear presentation, I suggest to accept this paper with minor revision concerning some complements that could be added.

Some comments and suggestion of modifications:

1. Introduction

Line 22: suppressed “the”

Line 52: Cycle 46h1 I presume version 1 for 46h forecast

2. Description of the CAMS aerosol types

Line 79: seven in place of six

3. Advection and removal aerosols

Line 170: Here, concerning the omission of dry deposition for both aerosol and cloud droplet, even if this point is evocated in the conclusion, I suggest to had a comment. First, I think that aerosol deposition is taken into account in CAMS because it is an important process that govern air quality close to the earth surface. For fog, it is also convenient to add this term in order to improve the estimation of the visibility near the ground surface. Simple parameterization can be used following for example Zhang et al, 2001 A size-segregated particle dry deposition scheme for an atmospheric aerosol module. Atmospheric Environment 35:549-560 that can be adapted to cloud droplets.

Line 155: fs (Table 2) is the fraction of aerosol …

4. Calculation of the particle number concentration (PNC), cloud condensation nuclei (CCN) and cloud droplet number concentration (CDNC)

Line 183 or 209: As sea salt, desert dust, organic matter and black carbon have different lognormal modes, I am a little surprised that Abdul-Razzak and Ghan, 2000: “A parameterization of aerosol activation 2. Multiple activation types”, which is dedicated to this aspect, is not cited.

Line 263-264: The limit of 2 µm is perhaps a little too high to describe fog microphysics

Line 298: If you want describe radiation fog you have to add a term due to the infrared radiative cooling in the calculation of the ambient super saturation:

5. Description of the microphysical parameterizations in HARMONIE-AROME

Line 332: This is possibly due to the lake of fog droplet deposition at the ground surface that depends on land use coverage.

6. Impact on radiation

Line 404: Add Tegen between sulphates and [45] in order to introduce this term that is later often employed in the text.

Line 418 to line 426: You don’t mention if you use CAMS output to also modified asymmetry factor and single scattering albedo that depends on chemical species of aerosols.

Line 435-436: Aerosols don’t change only the equivalent radius of the cloud droplet which impact cloud optical depth but also the single scattering albedo which can depends on the droplet concentration in black carbon (see for example Chylek and al., 1996: Black carbon and absorption of solar radiation by clouds). In addition, are the interstitial aerosols in the cloud layers taking into account in the radiative schemes.

7. Test cases

We can regret that this part is reduced to the study of some cases even if it is necessary to understand the impact of the introduced modifications. Nevertheless, I encourage the authors to study this impact over a long period that is the only way to really measure the quality of improvements for prediction 

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I am satisfied with corrections.

NA