The authors have improved the paper substantially taking into account the reviewer's comments.

Here are some minor details:

Abstract

You are reporting lower UV values for the 17018 period. Then the reader waits to read why this happened. The answer is a bit general: “Cloud cover, the strength of the polar vortex and the stratospheric ozone depletion are the primary factors that influence the surface UV radiation levels in Marambio.” So maybe you could be more specific here for 2017-2018 conditions.

So maybe pointing out that it can partly explained ( fig 6) that mostly ozone difference is the most important and that this ozone is due to polar vortex discussion in the paper. Or a summary of the discussion you have already for the ozone (partly – some months) , clouds also partly, albedo ( negligible) and the polar vortex as an indirect effect through ozone.

Introduction

Again if “Cloud cover, the strength of the polar vortex and the stratospheric ozone depletion are the primary factors that influence the surface UV radiation levels in Marambio”, I think you would have to include a paragraph describing the literature on other than ozone ( this exists) factors.

Lines 165-170

The drift: From what I understand here you sum the 5% drift and the 5% calibration uncertainty in order to end up with a 7% total uncertainty. Wouldn’t be easier to take into account this drift in your measurements and correct them ? Because in this case there is a systematic underestimation (based on this drift) of the measured irradiance compared with previous years.

Figure 2 is nice also showing that most probably different filters did not drift so differently over this period as this would cause GUV TOC retrieval problems.

226 maybe part of this polar vortex text can go to the introduction.

Figure 7 : Would 2017-2018 would be one of the lowest UV years overall ?

Congratulations for a very interesting work. Indeed the scientific and technical effort to measure so sensitive and important parameters as solar UV irradiance and Ozone in such location(s) is huge.

Continuation of such measurements and publications provide the essential information for scientists and the public to follow year to year ozone changes in the ozone hole related area.