Studies of Emissions & Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC 4 RS) Brian Toon Department of Atmospheric and Oceanic Sciences Laboratory for Atmospheric and Space Physics University of Colorado, Boulder

Where-Houston, TX; Palmdale, CA What- Studied the North American Monsoon, smoke from fires, and South Eastern U.S. air chemistry-focusing on critical climatic processes, clouds, and chemical inputs to the atmosphere- as well as satellite validation. Who-scientists and aircrew from NASA, NOAA, NCAR, universities, and companies When-August -September 2013

SEAC 4 RS used airborne and ground-based instruments NASA’s DC-8 with 28 remote sensing and in-situ instruments to provide chemistry and cloud measurements. NASA’s ER-2 with 15 remote sensing instruments and in situ instruments SPEC Inc Learjet with 15 probes to study cloud properties Balloon launches for water, ozone Instruments for aerosols and air chemical composition

Where Did We Go?

Goal 1. To understand air chemistry in the Southeast U.S. Broad range of data on isoprene, terpene and their products in a variety of thermal, NO x, urban, rural, cloud and aerosol environments OMI H 2 CO August MODIS AOT September MODIS AOT Augus t OMI H 2 CO September D. Jacob, J. Reid

Some preliminary SEAC 4 RS results on Southeast U.S. chemistry First vertical flux measurements from DC-8 of isoprene and its products. Isoprene inferred from satellite measurements of formaldehyde. SEAC4RS finds relationship depends on chemical regime and vertical mixing. Inconsistent ground and satellite observations imply free tropospheric layers of biogenic aerosols. SEAC 4 RS observed elevated layers of organic aerosols associated with biomass burning. SOA formation can be investigated.

Goal 2. Determine the evolution of gases and aerosols in deep convective outflow and implications for UT/LS chemistry. Many penetrations of clouds were made, as well as many profiles in the UT/LS Alan Fried

Some preliminary SEAC 4 RS results on vertical transport Tropospheric chemistry Enhanced aerosols and organic gases observed around cloud tops Detailed in situ observations of cloud properties together with radar and remote sensing data Stratospheric chemistry Stratospheric tracers provide data to constrain transport times and mechanisms for redistributing tracers through the lower and middle stratosphere on seasonal time scales Enhanced water vapor layers above the tropopause suggesting convective input

Goal 3. Identify the influences of aerosols on meteorology and climate through the atmospheric heat budget or microphysical changes in clouds Bob Yokelson SEAC 4 RS measured the properties of many types of aerosols, and their interactions with clouds

Some preliminary SEAC 4 RS results on aerosols Observations made in ~30 smoke plumes from forest fires and agricultural burning. Unprecedented data set including in situ data on heating rates, optical depths, single scattering albedos, composition, response to humidity, coating thickness, etc and remote sensing observations. Many data obtained in conjunction with AERONET and other ground sites

Goal 4. To serve as a calibration/validation test bed for future satellite instruments and missions. MODIS smoke optical depths SEAC 4 RS made many remote sensing observations of aerosols and clouds that were coincident with in situ observations

Some preliminary SEAC 4 RS results on satellite validation and instrument development Several prototype instruments flown on ER- 2 with successful measurements. Observations made in complex scenes, such as aerosols over clouds, and aerosols embedded in clouds AERONET validation studies conducted for absorbing aerosols

SEAC4RS next steps Preliminary data in archive April Final data in archive and released in October Investigators can collaborate with anyone, or release final data, in advance of October 2014