Comments on Satellite measurements of atmospheric aerosols by Rudy Husar
Most of my comments are intended to improve the readability of the chapter, particularly
for new readers who come with an experimental background and want to understand how
and why Satellite measurements are important.
1) Page budget: The chapter was assigned 15 book pages. Each book page consists
of 500 words; figures count 250 words. Your draft has 12500 words (including
figures), which is about 25 pages. We can allow about 15% increase in initially
assigned page numbers. That means the draft needs to be cut down to 18 book
pages, including references and figures. I believe this is quite doable without
comprising on the quality of the draft. Number of figures can be reduced by at
least 7 without substantially affecting the discussion (that saves about 4 book
pages). Section on Physical and Optical Properties can be substantially reduced by
referring the readers to chapters by Walter John and Chris Sorensen (I am sending
both drafts for your reference).
2) The introduction directly delves into satellite measurements, without explaining
the preliminaries. After reading the introduction. the reader fails to understand
what specific basic aerosol properties (size, mass conc., PSD?) are measurable
using satellite data. Most readers of this book will have an experimental
background in aerosol measurements. Therefore, the introduction should clearly
identify merits of satellite measurements over ground-based or aircraft aerosol
measurements. Introduction does allude to these merits; a clearer juxtaposition
would help understand the importance and relevance of satellite measurements to
most new readers. Also, a direct mention of what specific application areas (air
pollution/public health, global climate change, etc..) are sought after would be
useful.
3) The chapter lacks clear definitions of terminologies. Many terms have been
somewhat abruptly used without proper introduction (particularly, for new
readers); few examples are: optical thickness, AOT, phase function, bext,
reflectance, radiance, BDRF, TOMS, aerosol field, aerosol retrieval, aerosol
burden, columnar burden, columnar properties, etc.. Many of these terms are very
specific to satellite measurements and a general reader can not be expected to be
familiar with these terms. I recommend including a table that clearly defines these
terms. This table should be introduced early on in the introduction, so that people
are aware and can refer to it whenever needed. Also, this table can list of the
symbols used in this chapter.
4) As noted by the reviewer, I also think that the discussion on Fig 4 is somewhat
abrupt, and the readers left to deal with many terminologies and concepts. This is
an important figure and the discussion can be substantially improved. I think the
reviewer makes an excellent point (“And the meta-point that presumably
motivated the figure – that higher concentrations and lower visibilities are
associated with larger particles and more forward-biased scattering – is
delivered only as an aside that “This pattern is consistent with the notion that
…” ). This suggestion can be incorporated to substantially improve the discussion.
5) I also recommend using the minimum number of these terms and being consistent
in their usage. For instance, is AOT same as AOD? Aerosol burden, columnar
burden? If so, only one should be used. Also, the context for usage of reflectance,
radiance etc. is not clear. It is fair to assume that most readers will be familiar
with basic terminology of single-particle and multi-particle light scattering
(Sorensen’s chapter). Is it possible to first use this standard terminology and then
link to context-specific terminologies (such as reflectance, radiance etcl). In any
case, a minimal and consistent usage of terminology will be easy for readers to
understand.
6) I understand that most optical literature uses particle radius instead of diameter.
Most chapter use particle diameter as measure of size. Is it possible to refer to
diameter instead of radius? This is a minor issue.
7) Following Figures could be dropped to reduce the page count: Figures 2, 3, 4(a),
5(a), 6(a), 7, 10. I don’t think this will affect the discussion much. If you wish,
you can be creative and combine information from multiple figures into one to
reduce figure count.
8) There needs to be a clear reference to Beer’s law (Lambert-Beer’s law) when
introducing basic optics. Readers can again be referred to Sorensen’s chapter.
9) Do you need copyright permissions from any of the figures. If you are borrowing
any of these figures from published works, then we must have CR permissions.
10) I have attached a list of symbols; please use consistent symbols.
11) Some figures are numbered wrongly. Figures must be referred in the text in the
order consistent with their numbering.
12) The overall quality of figures could be somewhat improved. Some labeling is hard
to read. Consistent font style/sizes, labeling style, axis titles should be used.
13) I must know asap how many figures are to be printed in color. We can print only
8 figures in color for this book. I recommend choosing only those figures that
must be printed in color to convey key information. The figures will be printed in
B&W in the chapter; a color reproduction will appear in the centerfold. The figure
caption will guide readers to the color version.
14) Many abbreviations have been used without defining them. Abbreviation must be
defined/spelled out at first use.
15) Many aerosol products (MODIS, MISR) etc have been mentioned in the text. A
table that lists these products, along with typical features/use of each would be
helpful.