New SynFlux dataset published

The SynFlux dataset of atmosphere-biosphere fluxes of ozone is now published in Biogeosciences. Jason’s paper demonstrates that ozone uptake by vegetation can be accurately calculated at flux tower sites in the United States and Europe, even without local ozone measurements. SynFlux dramatically expands the spatial and temporal coverage of ozone flux data, by orders of magnitude, for evaluating atmospheric chemistry models and assessing air pollution impacts on vegetation. Our ongoing work is developing these applications.

SynFlux: Synthetic stomatal ozone flux at 100 sites. Values are averages over the daytime growing season. Vegetation uptake tends to be high in wet climates, where stomatal conductance is high, and not necessarily in places with high ozone concentrations.

New GRL paper on biomass burning

Holly’s paper using Florida fire records to test the ability of satellites to detect fires is now available in Geophysical Research Letters. We found that current satellites detect only one-quarter of the fire area in Florida. Moreover, the satellites do not detect the slight decrease in fire area during drought in Florida, which is a sign that the state’s prescribed fire policy is helping to reduce the risk of fire to people and property. These same results likely apply to broad areas of South America, Africa, and Asia, where fire types similar to Florida are found.

Left: Fire types found in Florida, from government records. Right: Comparison of fire area detected by satellites (BAECV version 1.1 and GFED version 4.1s) to the reported fire area (FFS+FPA FOD). All data averaged 2004-2015. The satellite detect only 25% of the reported fire area.

For more information:

Nowell, H. K., Holmes, C. D., Robertson, K., Teske, C., & Hiers, J. K. (2018). A new picture of fire extent, variability, and drought interaction in prescribed fire landscapes: Insights from Florida government records. Geophysical Research Letters, 45.

Methane paper in JAMES

The “methane feedback” is an interaction between methane concentrations and atmospheric chemistry that amplifies changes in methane emissions by almost 40%. As a result, the methane feedback is responsible for nearly 0.3 W/m² of radiative forcing. In a paper recently published in JAMES, we provide the first detailed assessment of how the feedback strength depends on climate and ozone precursor emissions. We show that the conventional view of the methane feedback, as a simple result of OH loss controlled by CH4, is only partially correct. The feedback strength also depends on autocatalytic OH production and OH buffering by atmospheric VOCs.

For those conducting research in the field, the paper also reviews the mathematical and chemical basis for understanding the feedback and summarizes practical formulas needed to quantify it.

For more information

Holmes, C. D. (2018). Methane feedback on atmospheric chemistry: Methods, models, and mechanisms. Journal of Advances in Modeling Earth Systems, 10, 1087–1099. [pdf]

Red Hills Fire Festival

Many group members volunteered at the Red Hills Fire Festival at Tall Timbers Research Station. The event drew 900 attendees to the lawn of the historic Beadle House for prescribed fire demonstrations and exhibits about local ecology. Our group hosted a table with atmospheric science demonstrations, illustrating how fires can be detected from space and how to measure humidity, among other things.  

New NASA grant to join FIREX-AQ

NASA announced that our group will receive a grant to participate in the FIREX-AQ field campaign. FIREX-AQ aims to better quantify emissions from fires and monitor the chemical aging of smoke plumes. The campaign will use NASA and NOAA aircraft in summer 2019. Together with Dr. Henry Fuelberg, our group will provide weather, fire, and smoke forecasting for the flight planning team.

Kelly Graham wins NASA fellowship

Kelly was awarded a NASA Earth and Space Science Fellowship to continue her research on Arctic CO2 fluxes. She plans to analyze using O-Buoy and OCO-2 observations with the GEOS-Chem model to better understand the effect of changing sea ice on CO2 in the Arctic. The NESSF fellowship will support Kelly for 3 years. Congratulations!

New NASA grant to study fires

NASA awarded Holly and Chris a 3-year grant to study biomass burning in the Southeast US. The project will develop an improved inventory of fire emissions in the region and better understanding of their impacts on regional air quality and global climate. Research partners for the project include Tall Timbers Research Station and Land Conservancy and the Florida Department of Health.