GMD Seminars
For questions about GMD seminars, contact Irina Petropavlovskikh, Phone: (303) 497-6279 or Ann Thorne, Phone: (303) 497-4600. Visitors from outside the NOAA campus need to contact Irina or Ann at least one day before the seminar date to be added to the visitor's list at the security gate.

*NEW Additional Requirement for Visitors:* Names of all off-site visitors without a U.S. government issued ID badge must be collected and submitted to security in advance of every seminar. Please call Ann Thorne at 303-497-4600 (leave a message including your name) or send an e-mail to Irina Petropavlovskikh by the day before the seminar if you plan to attend.

Speaker: Dr. Christopher Barnet, Integrated Observing System Science and Product Development Team (IOSSPDT) NOAA/NESDIS/STAR, Camp Springs, MD
Date/Time: Thursday, September 11, 2008 03:30PM
Location: Multi-purpose Room (GC-402) David Skaggs Research Center (DSRC) NOAA Building - DOC Boulder Campus
Title: Deriving atmospheric trace gas products from hyperspectral sounders.

ABSTRACT
Operational hyperspectral thermal sounders, designed for retrieving high accuracy global atmospheric temperature, moisture, and cloud products for weather and climate applications, are also capable of retrieval of trace gases. At NOAA/NESDIS we have been exploring the use of these instruments for the retrieval of ozone, carbon monoxide, methane, carbon dioxide, nitric acid, and nitrous oxide. The Atmospheric Infrared Sounder (AIRS), launched on the NASA Aqua platform in 2002, has been used to characterize these products and an assessment of the current capabilities will be discussed in the context of AIRS and other existing and planned satellite assets. This presentation will focus on the advantages and limitations of thermal sounders and will encourage discussion on the potential utility of these long-term, global, multi-gas datasets in climate and carbon-cycle applications.

Speaker: Charles Miller, Climate, Oceans and Solid Earth Science, Jet Propulsion Laboratory, Pasadena, CA
Date/Time: Wednesday, September 17, 2008 10:00AM
Location: Multi-purpose Room (GC-402) David Skaggs Research Center (DSRC), NOAA Building - DOC Boulder Campus
Title: The Orbiting Carbon Observatory (OCO)

ABSTRACT
The Orbiting Carbon Observatory (OCO) is scheduled for launch into the Earth Observing System Afternoon Constellation (A-Train) in January 2009. This NASA Earth System Science Pathfinder (ESSP) mission will make spatially resolved measurements of the column averaged CO2 dry air mole fraction, XCO2, over the sunlit hemisphere of the Earth. These measurements will be analyzed with chemical tracer transport models to infer CO2 sources and sinks on regional scales and quantify their variability over the seasonal cycle. The observatory consists of a 3-axis stabilized spacecraft bus that carries and points a single instrument. The instrument incorporates 3 bore sighted, high resolution grating spectrometers that will make coincident measurements of reflected sunlight in near-infrared CO2 and molecular oxygen (O2) bands. High spectral resolution (λ/Δλ > 20,000) measurements within the CO2 absorption bands near 1.61 and 2.06 μm yield column abundance estimates that are most sensitive to the CO2 mixing ratios near the surface, where most sources and sinks are located. High resolution (λ/Δλ > 17,000) measurements within the 0.765-μm O2 A-band spectra yield clear sky surface pressure estimates with accuracies near 1 mbar over most of the sunlit hemisphere and constrain cloud and aerosol profiles to reduce uncertainties associated with multiple scattering. The instrument integration and test was completed at the NASA Jet Propulsion Laboratory in March 2008. Analysis of the test data indicate that all 3 spectrometers meet the stringent spectroscopic performance requirements needed to yield regional-scale XCO2 estimates with errors and systematic biases no larger than 0.3% (1 ppm).  Recently instrument-spacecraft integration was completed at Orbital Sciences in Dulles, VA. Operational tests of the science data processing system are under way.  The launch will take place from Vandenberg Air Force Base.  The first space-based data is anticipated in early 2009.

Speaker: John Lupton, NOAA Pacific Marine Environmental Laboratory, Newport, Oregon
Date/Time: Friday, October 3, 2008 10:00AM
Location: Multi-purpose Room (GC-402) David Skaggs Research Center (DSRC) NOAA Building, DOC Boulder Campus
Title: Natural CO2 from Submarine Hydrothermal Systems

ABSTRACT
Although dozens of mid-ocean ridge (MOR) hydrothermal systems have been studied over the past few decades, a significant discharge of a pure gas phase has been found at only one site on the Explorer Ridge, northeast Pacific. In contrast to MOR systems, recent studies of submarine volcanoes on volcanic arcs have found several sites that, in addition to discharging hot vent fluid, are also venting a separate CO2 -rich phase either in the form of gas bubbles or liquid CO2 droplets. Submersible dives on 22 active submarine volcanoes on the Mariana and Tonga-Kermadec Arcs have discovered systems on 6 of these volcanoes that are venting a free gas phase in addition to hot vent fluids.

This talk will focus on the Champagne vent field on NW Eifuku volcano in the northern Mariana Arc, which is discharging cold droplets of liquid CO2 as well as hot gas-rich vent fluid. The other 5 volcanoes in this study are shallower and therefore the free gas discharge takes the form of gas bubbles rather than liquid CO2 droplets. At NW Eifuku, collecting samples of the liquid CO2 droplets required the development of special sampling technology that could be deployed from a robotic submersible. The carbon flux from this small vent field is quite large, estimated at 23 moles/s, about 0.1% of the global mid-ocean ridge carbon flux. Detailed analysis of the helium and carbon discharging at the Champagne site has provided clues to the origin of this high carbon flux. One follow-up biological study at NW Eifuku has shown that the mussels at the Champagne site are drastically affected by the low pH environment. Thus these CO2 -rich systems may be important natural laboratories for studying the effects of high CO2 concentrations on marine ecosystems, with relevance to ocean acidification and seabed sequestration of anthropogenic carbon.