TCCON Meeting Agenda

May 15, 2008, California Institute of Technology

Salvatori Room – 3rd floor S Mudd, (NE corner of Wilson and California Blvd)

The Courtyard-Marriott shuttle bus will leave the hotel at 8:30, 8:40 and 8:50 to transport people to Caltech

9:00  Paul Wennberg:   Welcome, Introduction, Logistics, Announcements, etc.

9:15  Paul Wennberg:   "Scientific Motivation"
Use of greenhouse gas columns for estimating surface exchange. In addition to their role in validation of satellite retrievals of CO2, the TCCON observations point to the value of total columns for evaluation of key aspects of the carbon cycle.

9:30  Gretchen Keppel Aleks:   "Carbon Weather"
Measurements of the CO2 column abundance over Park Falls Wisconsin show unexpectedly high temporal variability during summer. This variability is correlated with variability in the large scale synoptic structures in the atmosphere – suggesting carbon weather. This variability is significantly underestimated in simulations. 

9:45  Dietrich G. Feist:   "CO2-footprint calculations for proposed and existing FTIR stations"

10:00  Brian Connor, Chip Miller, Ross Salawitch:  "OCO Validation"

10:15  Geoff Toon: "Progress towards understanding the O2 variations"
The dry-air mole-fraction of O2 retrieved from TCCON spectra exhibits long-term variations of ~0.5%, which far exceed the measurement precision (0.1%) or the natural variation of O2 (<0.01%). This variation must therefore be due to unknown systematic errors. The small ILS drifts seen in the HCl cell spectra appear not to be correlated with the O2 variations and are in any case too small to be their cause. We currently assume that the systematic errors that cause the O2 variations affect CO2 similarly, so that they cancel in the CO2/O2 ratio.

10:30  Coffee Break

11:00  Brian Connor: "Determination of the Mean Tropospheric VMR of N2O"

11:15  Ronald Macatangay, Thorsten Warneke, Justus Notholt: "Recent development of CO2 observations by the University of Bremen and at several sites"

11:30   Debra Wunch: "Airmass-dependent artifacts in XCO2" 
Observations of XCO2 from Darwin, Park Falls, and Pasadena, show similar airmass-dependent artifacts. Although the airmass bias is less than 1% for SZA less than 70 deg, this is a significant fraction of the total error budget for the TCCON network.   In addition, this error can introduce a seasonally-dependant bias to the TCCON observations.

11:45  Linda Brown: "Near Infra-Red spectroscopy of CO2, CH4 and O2"
Several recent near-IR laboratory studies of these three important atmospheric molecules are the likely updates for  HITRAN and GEISA. The resulting improvements of these line parameters will be summarized.

12:05   Lunch (Chandler Cafeteria, Caltech)

13:20  Vanessa Sherlock, Brian Connor: "Status of Lauder TCCON activities"
We will describe the current status of the FTS and in-situ measurement programs at the TCCON site in Lauder New Zealand and present up-to-date intercomparisons of FTS retrievals with the measurements from the surface monitoring station at Baring Head. We will also briefly raise a number of outstanding questions concerning the Lauder FTS measurements.

13:45   Nick Deutcher, David Griffith, et al.: "CO2 calibration and data from the Darwin TCCON site"
We present the first two years XCO2 time series obtained from the Darwin TCCON site, and its calibration to the WMO CO2 scale via integrated aircraft profiles. We will also give an overview of one year of in situ data from the site, including two north-south Australian continental transects from Darwin to Adelaide during the 2008 monsoon season.

14:00  Rebecca Batchelor, Kim Strong, Debra Wunch: " Adventures in the Arctic: Experimental NIR measurements at Eureka"
In April 2008, the NASA DC-8 and P-3 aircraft flew over the Arctic in support of the ARCTAS mission. On April 8th, their flight plan included a spiral over Eureka. To take advantage of this opportunity, in early April we gathered near-infrared measurements with the new Bruker 125 HR at the Polar Environment Atmospheric Research Laboratory (PEARL) at Eureka. While we are not yet fully equipped for these measurements, these 'proof of concept' measurements look promising. This presentation will look at the results from these and some earlier measurements, as well as introducing our site, our set-up, and discussing future plans.

14:15   Thomas Blumenstock, Frank Hase, et al.: "Preliminary TCCON results from Izana"

14:30  Ralf Sussmann: "TCCON site Garmisch: Steps towards operationality in 2007"
An overview on the TCCON activities at Garmisch during 2007 is given. The site was technically adapated to fulfill the TCCON requirements, and regular NIR measurements were started whenever weather conditions allow. The Bruker 125 HR instrument has been supplemented with an InGaAs Detector and a Si-Diode for DC dual acquisition mode. A Hg barometer as well as a pressure transducer were implemented and routine HCl gas cell measurements in the solar beam started. First experiences with the GFIT software as well as LINEFIT analysis of the HCL cell measurements have been obtained.

14:45  Geoff Toon:  "Software Update"
The latest changes to the GGG software will be described.

15:15  Coffee Break

15:45  All:  Discussion of Future Plans, Data Protocol, Data Processing, CIMEL instruments, Validation Latency

16:45  Meeting Adjourns

Shuttle bus leaves Caltech at 17:15, 17:25 and 17:35 to take people back to the Courtyard-Marriott hotel