Atmospheric Chemistry and Physics Discussions Interactive comment on “Model calculations of the age of firn air across the Antarctic continent ” by

• Main Authors: K. A. Kaspers, C. Trudinger (referee
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2004
• Subjects: Antarctic; The Antarctic; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.515.1220; http://www.cosis.net/copernicus/EGU/acpd/4/S708/acpd-4-S708_p.pdf?PHPSESSID=894d28d5e40ae49277eb2eae9cbb6d5a

General comments This paper describes the development of parameterisations for pore close-off depth (PCOD) and the age of CO2 in firn air at the PCOD in terms of meteorological con-ditions. The authors use relationships between the physical properties of polar firn and meteorological conditions, and a firn diffusion model, to develop these parameter-isations, which they then apply to the whole Antarctic continent. Their motivation for creating the parameterisations is to allow them to be used in the field to predict the pore close-off depth and corresponding age of CO2, from knowledge of the meteorological conditions, without having to tune a firn diffusion model. This idea of parameterising the PCOD and CO2 age in terms of the meteorology is an S708 interesting one, but I would like some indication of how widely applicable the equations are, and how reliable they are for other sites, to know whether they really are useful in the field. In the study, the oldest CO2 is found for conditions of deep PCOD, low temperature