HR: 1350h
AN: U23C-1453    [Abstracts]
TI: A Future Network for Monitoring the Driving Function of Global Warming
AU: * Evans, W F
EM: wayne@nwra.com
AF: North West Research Associates, PO Box 3027, Bellevue, WA 98009-3027, United States
AB: A new future network is proposed to monitor the radiative forcing of global warming by greenhouse gases. The greenhouse radiation is the downward infrared heat radiation from greenhouse gases, otherwise known as the surface forcing radiation. The increase in this radiation due to increased carbon dioxide and other greenhouse gases is the driving function of global warming. In an experimental project, the calibrated spectrum of the greenhouse radiation at the surface has been measured for the last 10 years in the Great Lakes area. From these measurements the radiative flux from each greenhouse gas has been extracted. There is a 10 year record of the radiative fluxes from carbon dioxide, methane, nitrous oxide and CFCs. The increases in these fluxes represent the forcing function of global warming. It is an experimental version of radiative forcing similar to but different from the radiative forcing used by IPCC. It is proposed that this radiative forcing should be monitored in a fashion similar to our monitoring of the ozone layer. A world monitoring network like the world total ozone monitoring network of Brewer and Dobson spectrophotometers should be setup. The AERI instrument already exists and there are 12 of them deployed around the world; it is manufactured by ABB BOMEM. The methodology will be to process the AERI infrared spectrometer measurements into the downward surface radiation flux in W/m2 from each of the major greenhouse gases. Well calibrated infrared spectral measurements of the downward infrared long wave radiation have been routinely made by the AERI instruments at the three main DOE ARM sites for over 7 years with a 12 year record at the SGP site. These are being processed into long wave radiation fluxes from each of the major greenhouse gases using a methodology already developed for similar measurements at 44° N in the Great Lakes area. The uses of the data would be to investigate the seasonal and climate regime variations of the surface greenhouse radiation flux, compare the measurements with climate model simulations of the surface forcing radiation fluxes for each greenhouse gas, evaluate the reduction of the surface forcing radiation by various types of clouds by measuring the reduction in surface radiation forcing under cloudy conditions, conduct complementary measurements of surface radiation forcing with radiative trapping measured from space with overpasses of satellites and monitor the increase with time of the forcing radiation from each gas. This network will provide a new experimental dataset which would complement the calculated radiative forcings from climate models which are currently used for policy determination of safe levels of greenhouse gases in the atmosphere. The new network will give us the experimental capability to conduct long-term monitoring of the increases in greenhouse radiation due to increases in the individual greenhouse gases without using an intervening climate model. This also adds a new climate observable which could potentially be used to compare changes in the long wave radiation balance of the atmosphere with other climate variables. Hence, the world should monitor this important variable instead of relying solely on model calculations of radiative forcing since it is the fundamental forcing function of global warming. The analysis of the data from ARM AERI sites would represent a big step towards building a world monitoring network for this very important climate observable. With AERI instruments deployed around the globe, a first step in building a network to monitor radiative forcing similar to the world ozone monitoring network has already taken place. This future network emphasizes the extreme importance of continuing the DOE ARM AERI measurements for the foreseeable future.
DE: 1600 GLOBAL CHANGE
DE: 1610 Atmosphere (0315, 0325)
DE: 1626 Global climate models (3337, 4928)
DE: 1637 Regional climate change
DE: 6620 Science policy (0485)
SC: Union [U]
MN: 2007 Fall Meeting