Methane, Ozone & Other Trace Gases

Date: 
Wednesday, July 20, 2016 -
08:30 to 10:00
Agenda: 

Agenda:

-          Introductions (ALL) – 5min

-          Presentation on Summit ozonesondes (Bahramvash) – 20min

-          Presentation on Met Office Unified Model (Xin, Yang) – 20min

-          Discussion (ALL) – 20min

-          Open questions for future work (ALL) – 20min

Minutes: 

IASOA Ozone Working Group

July 20, 2016

 

Attendees: Sara Crepinsek, Taneil Uttal, Irina Petropavlovskikh, Kristof Bognar, Shima Bahramvashshams, Von Walden, David Tarasick, Kim Strong, Xiaoyi Zhao, Xin Yang

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Introduction of group members, new member introduction

Brief discussion of surface ozone installation at Eureka – NOAA PSD-POP group is in the process of calibrating and installing a Thermo Scientific 49i ozone analyzer at the Eureka station to be located at 0PAL

Presentation on Development of the Arctic Ozone Profile Climatology from NOAA Ozone Sonde Dataset – Review of development of the Arctic ozone profile climatology from NOAA ozone sonde dataset launched at the NSF Summit station, Greenland. Provided discussion on the seasonal, inter-annual and vertical variability of ozone in the Arctic atmosphere. This information is required to improve the ozone retrieval from the FTIR instrument located in Greenland.  Also discussed the method of extension of ozone sonde profiles above the burst level to calculate total ozone column. The method was discussed and results were presented

Suggestion to contact Bryan Johnson (NOAA) to verify the noise in the ozone measurements observed at the top of the profile. He was concerned that it was an instrumental artic=fact and not a real ozone variability. It was also suggested to check how this could affect the merging with the climatological profile above the burst ozone sonde level

Proposed to use ozone sonde records from other Arctic stations in comparisons with FTIR instruments and for the development of Arctic ozone profile climatology

Question whether or not the climatology can be developed for ozone below 5 km? - The altitude of Summit station is already at 3 km and it might be difficult to derive climatology, but it will be possible to attempt

Presentation on the UM-UKCA Model– The UM-UKCA model was used in Zhao 2015 Eureka study of Bromine explosions and ozone depletion event.

Special tropospheric chemistry is used in the model to reproduce Bromine explosion events. The release from the snow under heterogeneous chemistry processes and formation of aerosols from blowing snow (Yang et al., 2008). Attention needs to be paid to the level of the salinity of the snow and possible non-linear relation with the Bromide releases. The model captures representative spatial and temporal distributions of BrO columns as observed by GOME-2 satellite (Yang et al, 2010). A preliminary comparison of the model with several surface ozone records (Barrow, Summit, Villum, Tiksi)  for the short time period in 2001 (March-April) was presented, where it appears that model is underestimating levels of surface ozone observations. However, there are some ozone depletion events that can be simulated by the model. The new observations suggest much lower salinity of the snow, which can explain previously modeled surface ozone levels to be too low.

“Though lots of work has been done in terms of evaluating model’s BrO in polar regions (mainly through comparison with satellite data), bromine effect on tropospheric ozone, particularly on polar boundary layer ozone, has not been well addressed.”

Discussion: Presentation is a great opportunity to continue with systematic comparisons of  the model with IASOA ozone observations. Pointed out very interesting spatial patterns in BrO distribution in the Arctic. Suggested collaboration to advance further comparisons in collaboration with IASOA. Suggested to use Summit ozone data as special case study that is should have a low salinity of the snow, as compared to other stations that are located close to the coastal area with high snow salinity. Explanation that model does not use salinity for the inland location. Ozone depletion occurs in the boundary layer. Share the N.Miller et al., 2013 paper that discussed boundary layer condition at Summit. Mentioned that aerosol working group recently submitted the paper that provides analysis of the aerosol measurements of the sea-salt in Arctic, which can help to understand transport of the coastal air to Summit boundary. Question about spatial resolution of the model and potential issue with the low resolution in model grid for comparisons with station data. 

 

Action Items:

  • Discussion with Bryan Johnson on collaboration on ozone sonde climatology paper from Summit, Greenland – Johnson, Bahramvashshams, Miller
  • Start dialog on how to model data comparisons, follow up discussion at next meeting – Yang