ARL Weekly News – October 15, 2021

Previous Events

NOAA Administrator visits ARL’s Special Operations and Research Division

Administrator Spinrad visited ARL’s SORD (Special Operations and Research Division), in Las Vegas NV on Oct 19.  This division specializes in meteorology and atmospheric transport and dispersion to  provide information to decision makers, primarily at the DOE, to not only protect the atmosphere and human health but also support U.S. non-proliferation national security experiments.

The Administrator met with the DOE facility manager, Dr. David Bowman. The visit included a trip to the Desert Rock Weather Observatory, which hosts the local mesonet, a US Climate Reference Network Station, surface radiation, and lightning detection sites.  A weather balloon release was also planned.

State Department Interagency Air Quality Briefing

ARL’s HyunCheol Kim presented to the US Department of State’s Interagency Air Quality meeting on October 20, 2021. He presented findings on regional air quality in East Asia and its association with weather and climate. His collaborators include South Korea’s National Institute of Environmental Research (NIER) and a number of universities that model air quality in Southeast Asia. The modeling work Dr. Kim performs not only demonstrates the effect of climate change to regional air quality, but also aids in isolating the true signals of emissions variations by removing meteorological impacts.

Long Island Sound Tropospheric Ozone Study (LISTOS) virtual workshop

Xinrong Ren and Allison Ring attended the Long Island Sound Tropospheric Ozone Study (LISTOS) virtual workshop on October 14-15, 2021 and gave a presentation (together with Russ Dickerson from University of Maryland), entitled “Aircraft Measurements of Greenhouse Gases (GHGs) and Black Carbon during LISTOS and COVID-19”. The presentation summarized some results on ozone photochemistry and emissions of GHGs and black carbon in New York City based on aircraft observations. There were ~80 participants in the workshop from state and federal agencies and academia, and most of the attendees were involved in field measurements and modeling activities.

The main goal of LISTOS was to improve the understanding of ozone chemistry and transport from New York City and upwind regions to downwind areas, particularly over Long Island Sound. The workshop brought the science team together to assess emissions inventories over the region and investigate the complicated chemistry and dynamic patterns associated with Long Island Sound and its coastlines. At the end of the workshop, possible areas for future work relevant to air quality and climate planning needs in the LISTOS region were also discussed.

Story posted:

Atmospheric Mercury Monitoring Installation Completed at Barrow Observatory


Paper published: Optimizing Carbon Cycle Parameters Drastically Improves Terrestrial Biosphere Model Underestimates of Dryland Mean Net CO2 Flux and its Inter-Annual Variability

Kashif Mahmud, Russell L. Scott , Joel A. Biederman , Marcy E. Litvak, Thomas Kolb, Tilden P. Meyers, Praveena Krishnan, Vladislav Bastrikov, and Natasha MacBean. Optimizing Carbon Cycle Parameters Drastically Improves Terrestrial Biosphere Model Underestimates of Dryland Mean Net CO2 Flux and its Inter-Annual Variability. Journal of Geophysical Research: Biogeosciences, 126, e2021JG006400.

Abstract: Drylands occupy ∼40% of the land surface and are thought to dominate global carbon (C) cycle inter-annual variability (IAV). Therefore, it is imperative that global terrestrial biosphere models (TBMs), which form the land component of IPCC earth system models, are able to accurately simulate dryland vegetation and biogeochemical processes. However, compared to more mesic ecosystems, TBMs have not been widely tested or optimized using in situ dryland CO2 fluxes. Here, we address this gap using a Bayesian data assimilation system and 89 site-years of daily net ecosystem exchange (NEE) data from 12 southwest US Ameriflux sites to optimize the C cycle parameters of the ORCHIDEE TBM. The sites span high elevation forest ecosystems, which are a mean sink of C, and low elevation shrub and grass ecosystems that are either a mean C sink or “pivot” between an annual C sink and source. We find that using the default (prior) model parameters drastically underestimates both the mean annual NEE at the forested mean C sink sites and the NEE IAV across all sites. Our analysis demonstrated that optimizing phenology parameters are particularly useful in improving the model’s ability to capture both the magnitude and sign of the NEE IAV. At the forest sites, optimizing C allocation, respiration, and biomass and soil C turnover parameters reduces the underestimate in simulated mean annual NEE. Our study demonstrates that all TBMs need to be calibrated for dryland ecosystems before they are used to determine dryland contributions to global C cycle variability and long-term carbon-climate feedbacks