Dear Dr. Mitchell,

There have been two excellent thorough reviews of your article -- my appreciation to the reviewers for their efforts -- and I am generally satisfied with the response. Your article presents a useful contribution to providing climatologies of cirrus particle number and size. I encourage extension of the method to years beyond 2008 and 2013 in a future ACP submission.

There are a few items I would like to see addressed.

1. The reference to photon tunneling seems out of place. The Nussenwieg papers that are referenced discuss a wave phenomenon, and for the interactions of light with particles defined by length dimensions, a wave description would be most appropriate. The text on Atmospheric Radiation by Bohren and Clothiaux casts a very dim light on the concept of photon tunneling, and I request removal of any reference to those terms from the article. Wave resonance is fine, especially with a short description of the mechanics of the physics.

2. Reviewer criticisms about the absence of consideration of shape assumption for small crystals do not seem to have been appropriately addressed. The response that "Thirdly, this retrieval is most sensitive to the smaller ice particles in a PSD where the variance in ice particle shape is minimal" seems at odds with observations of columns, plates, bullets, and even bullet rosettes at sizes <50 um. I do not see how frozen particles that grow through diffusional processes at cold temperatures can be "quasi-spherical", even if they look that way in coarse resolution imagery, or that they can all be similar shape.

3. The figures are of low resolution. Fits on the figures should be expressed with the appropriate variables, with the appropriate number of significant digits, and in scientific not engineering notation.

Best regards,

Tim Garrett