Chemical Transport by the Asian Monsoon Anticyclone Brainstorm discussion for the SEAC4RS Campaign

• What are the key science questions?

• What do we know from the satellite data and model studies?

• What would be the most effective/useful samplings that complement the satellite studies? Provide model diagnostics?

• What are the necessary pre-campaign studies for the flight planning purpose?

A list of materials to assist the discussion

• Satellite perspective - Some key figures from Randel and Park

• Timing of the campaign dates - Location and movement of the anticyclone – modes – vertical structure – potential chemical impact (Yan et al., 2011)

• Transport pathways – trajectory results

Some thought-starter questions

• What are the main source regions feeding into the anticyclone? (Bay of Bengal vs. Plateau &Eastern China?)

• What drives the ascent from the level of main convective outflow (200 hPa?) to the top level of the anticyclone (~ 100 hPa?)

• At what level the vertically lifted air mass begin to disperse horizontally? How confined is the air mass?

• What is the chemical lifetime of the air mass in the anticyclone?

• What is the distribution of transport after lifting, high latitudes vs TTL?

Randel and Park 2006

Randel et al. 2010

Randel and Park 2006

Park et al., 2009

Park et al., 2008

Park et al., 2009

Anticyclone location and movement/oscillations

Plots from Leigh Munchak, Shawn Honomichl, and recent Yan et al.

Bimodal distribution of the center

Yan et al., 2011

100 hPa level GPH and wind

MLS: O3 and CO anomalies associated with the two modes Yan et al., 2011.

Vertical structure of the Anticyclone: selected GPH contour at 4 pressure surfaces

Initial attempt to identify the time series of the migration: center (dots) and south boundary (line) color coded by time. Some red dots will have no line indicating the post anticyclone period. (will iterate this plot) Black circled dots indicating multiple centers.

Probing the transport pathways into the Anticyclone

Trajectory studies– work in progress by Federico Fierli and Laura Pan

ECMWF operational analyses winds, 10-day back trajectory

Parcels initiated at 200 hPa

Type II: Parcels BL origins below 750 hPa

Type I: Parcels BL origins above 750 hPa