For the past 15 years, users of the NOAA ARL web-based HYSPLIT transport and dispersion model have been addressing questions and comments to the ARL Webmaster via email. This required the HYSPLIT developers to monitor the email and respond to the questions on a regular basis. During this time, the HYSPLIT user community has grown significantly and so have the number of emails. This email communication method did not engage all the users as a community, but rather provided a user-to-developer only stream of information, information that could be useful to many more users. In an attempt to better inform and broaden user engagement, a HYSPLIT web-based forum was created to allow users of the HYSPLIT dispersion model to communicate with the developers and each other. Users can post questions related to the model and engage in discussions with other users which should foster continued growth of the model among the user community and provide developers with ideas on future directions for development. Anyone can view the forum topics, however,, registration is required to post to the forum. Posts are approved by ARL moderators before being made visible on the forum. The URL of the HYSPLIT forum is: https://hysplitbbs.arl.noaa.gov/ glenn.rolph@noaa.gov

2. HYSPLIT Modeling System Presented to EPA and Japan Atomic Energy Agency

Glenn Rolph and Ariel Stein presented at a meeting held between the Japan Atomic Energy Agency (JAEA) and the U.S. EPA at the Office of Radiation and Indoor Air in Washington, DC. Their presentation covered an introduction to the HYSPLIT modeling system and its applications with a particular emphasis on the Fukushima nuclear accident. The EPA is responsible for the national radiation monitoring network (RADNET) that would detect radiation above background levels in the event of a radiological release. EPA is interested in HYSPLIT dispersion forecasts to determine when the radiological plume may impact their monitors. The JAEA presented modeling results of the Fukushima accident both in the air and also the transport of radioactive materials in the water.

3. Transport and Dispersion Modeling

A draft Software Quality Assurance (SQA) plan for a radiological application of HYSPLIT, developed by ARL's Field Research Division (FRD) in collaboration with Roland Draxler and Glenn Rolph from ARL headquarters, was finalized. This radiological application has been designated HYSPLIT Radiological (HYRad). The SQA plan was explicitly written to include all of the following main elements: the core HYSPLIT dispersion code, and the radiological components, the user interface, and the scripts controlling model execution presently being used in the Idaho National Laboratory Emergency Operations Center (EOC) application. Other elements include user's guide documentation, verification and validation, version control, and problem reporting and tracking. The change in designation from EOC HYSPLIT (EHY) to HYRad, together with some upgrades, resulted in the release of HYRad version 1.2, replacing EHY version 1.1. A gap analysis, also in collaboration with ARL headquarters, was prepared for the HYRad SQA. The HYRad SQA and gap analysis were submitted to DOE's Subcommittee on Consequence Assessments and Protective Actions (SCAPA) for review and approval of HYRad for inclusion in their consequence assessment toolbox. If HYRad is approved for inclusion in the SCAPA toolbox, this would carry with it approval of HYSPLIT since it has been explicitly included in the HYRad SQA. dennis.finn@noaa.gov

Brad Reese, Rick Eckman, and Dennis Finn participated in beta testing of a dispersion modeling system that combines the source-term algorithms of the National Ocean Service's (NOS) Areal Locations of Hazardous Atmospheres (ALOHA) model and the dispersion algorithms of the ARL HYSPLIT model. The system is browser based and is a collaborative effort between the NOS, Office of Response and Restoration (the developers of ALOHA) and ARL. Overall, the system appears to be pretty stable, and the web interface for specifying the source term will be familiar to anyone who has used the Windows version of ALOHA. dennis.finn@noaa.gov

4. Project Sagebrush

FRD moved forward with preparations for a field study that will follow up and expand upon the benchmark dispersion experiment known as Project Prairie Grass (1956) and other subsequent plume dispersion field experiments. A planning meeting was held, and the project was officially given the designation of Project Sagebrush. Horizontal and vertical plume dispersion coefficients and plume concentration fluctuations will be measured. An experimental plan summary was drafted in late December to circulate among prospective expert reviewers and partners who might be interested in participating. It is anticipated that the first phase of field measurements will begin in fall, 2013. kirk.clawson@noaa.gov, Rick Eckman, Dennis Finn, Roger Carter

5. Birch Creek Valley Study

FRD began a long term research study on flows in the Birch Creek Valley. The Birch Creek Valley is a long North-Northwest trending valley, bounded by two large ranges with relief up to 5000 feet, which exits onto the Snake River Plain near the north end of the Idaho National Laboratory (INL). From the available mesonet data gathered over the years, it is known that this general area is subject to complex flow patterns, but the details of that are largely lacking. The primary purpose of the study is to better understand flows in complex terrain, including plume dispersion; particularly plume dispersion around the INL. The study would also be useful in the evaluation of wind energy potential.

FRD deployed a sodar and sonic anemometer at its Blue Dome mesonet site in Birch Creek Valley. For two other sites on the INL, FRD drafted an experimental plan and had it approved by the appropriate jurisdictions. In December, a sodar and sonic anemometer were placed near the exit of the valley onto the eastern Snake River Plain, and a sodar and radar wind profiler were placed near an existing mesonet site near the north end of the INL.

FRD sought potential partners (U.S. Forest Service Fire Laboratory and Boise State University) who could enhance the existing measurement capabilities within the valley itself. It is anticipated that these partners will deploy sodars and anemometers in the valley. However, since almost all of the land within the valley is under the jurisdiction of the Bureau of Land Management (BLM), it will be necessary to submit an experimental application for their approval. It is anticipated that the experimental plan will be drafted and submitted to the BLM in January. When it's approved, the hope is to have full project deployment by collaborators as early as March, weather permitting. Measurements are planned through late summer when the instrumentation will then be redeployed for Project Sagebrush. kirk.clawson@noaa.gov, Dennis Finn, Rick Eckman, Roger Carter, Brad Reese

6. Mesoscale Forecast Modeling

A probabilistic point forecast system is under development as part of the Weather Research Forecast (WRF) modeling at FRD. The system uses a Bayesian statistical approach to estimate both random and systematic errors in the forecasts from the WRF model. Right now the system forecasts statistical distributions for 2 meter high temperature and 10 meter high winds. Plots showing both the interquartile range and the range from the 10th percentile to the 90th percentile are generated from these distributions. The probability distributions are updated as new data come in from the NOAA/INL mesonet. So far, the system has been updated using mesonet data from December 2012. The plots are expected to be posted to the FRD web site in the second quarter. (richard.eckman@noaa.gov)

7. Consequence Assessment for the NNSS

James Wood and Walt Schalk participated in a tabletop venue emergency response drill and a full- scale emergency response exercise as the Consequence Assessment Team (CAT) for the National Nuclear Security Administration, Nevada Site Office. The exercise was conducted on the Nevada National Security Site (NNSS). In the drill, Walt and James were prepared to provide dispersion expertise, hazardous material plume projections, and weather data and forecasts. This "active shooter" drill was in preparation for the full-scale emergency response exercise. The full-scale exercise was conducted to comply with DOE Emergency Response Directives. Walt and James provided site specific weather data and weather forecasts, and they generated several "what-if" scenarios based on the worst case event scenario for the facility involved. The exercise did not involve a simulated airborne release of hazardous materials. (james.s.wood@noaa.gov, walter.w.schalk@noaa.gov)

8. DOE Meteorological Coordinating Council Activities

Walt Schalk participated in the first full working group meeting to address the updating of the American Nuclear Society /American National Standards Institute (ANS/ANSI) 3.11, Determining Meteorological Information at Nuclear Faccilities Standard. This voluntary consensus standard is a key component in the siting and maintenance of meteorological mesonets at nuclear reactor and Department of Energy sites. An initial overview and history was presented, as well as a basic outline of the work to be done and the path forward.

Walt also participated in the Working Group meeting of the new ANS 2.31 Standard, "Determining Design Basis Onsite Flooding Caused By Precipitation at Nuclear Facility Sites". The purpose of the meeting was to resolve comments provided after the first review of the draft standard.

The construction portion of the new Weather Operations Center (WOC) project in the old Weather Bay room of the North Las Vegas DOE Building has been completed. The WOC consists of a Weather Forecast Desk, a Consequence Assessment/Special Project Support area, a Research Lab, and an IT Workshop/Office. Currently, we are waiting on the computer order from NOAA IT purchasing, furniture acquisitions, and telephone installations. The WOC is expected to be operational next quarter. (walter.w.schalk@noaa.gov)

AIR QUALITY

9. National Air Quality Forecasting Capability

Pius Lee presented an annual report of the National Air Quality Forecasting Capability (NAQFC) project to a panel of 6 external reviewers. Significant improvement has been made in forecasting the accuracy of the mid-day concentration peaks of ground-level ozone relative to previous years, both in terms of capturing exceedances and reducing false alarm rates. A request to the NWS NAQFC Project Manager from lead forecasters in the states and local agencies is to maintain the current modeling configuration for next year. Pius also presented work on estimating accurate real time wild fire emissions and their impact on air quality forecasting.

10. Great Lakes Restoration Initiative

As part of the 2nd phase of the Great Lakes Restoration Initiative (GLRI), Mark Cohen conducted sensitivity analyses and extended model evaluation as part of the overall model-based analysis of atmospheric mercury deposition to the Great Lakes. The work focused on understanding the reasons for subtle differences in simulation results when different computers, compilers, and compilation options were used. It is important to understand these factors in the context of the overall sensitivity analysis. It was found that some of the reasons for the numerical differences stemmed from a small -- and very rarely encountered -- array issue in the HYSPLIT model. A fix for this issue was implemented into the HYSPLIT-Hg model, a special version of the HYSPLIT model being used to carry out atmospheric mercury simulations.

It was also found that there remained inherent differences in simulation results under different model compilation/execution environments. In general, there appears to be a trade-off between speed and accuracy in carrying out the HYSPLIT-Hg simulations, in terms of the optimization options selected during the compilation of the computer code. Fortunately, all of the array and compilation issues investigated resulted in relatively small differences in simulation results. For example, atmospheric deposition to the Great Lakes from a given source over a year-long simulation only varied on the order of a few percent or less. The sensitivity of the simulation results to a least some of the physical and chemical parameters and algorithms used is much greater than this, and these sensitivities will be analyzed and summarized in the coming months. mark.cohen@noaa.gov

11. Mercury Profiling Flights with University of Tennessee Space Institute

Steve Brooks and Xinrong Ren continued their mercury speciation profiling flights with the University of Tennessee Space Institute (UTSI) in Tullahoma, TN. Results from the October and November flights continued to show oxidized mercury species in the air are greater than concentrations measured at ground level. The primary measurements collected were continuous gaseous elemental mercury, reactive gaseous mercury (RGM), and fine particulate mercury (FPM) at multiple altitudes. While RGM and FPM were both very low at ground level, they were significantly elevated in the air, with average concentrations peaking at 10,000 and 14,000 feet, respectively. There were also seasonal variations, where RGM average monthly concentrations were 60, 44, 18, and 14 pico grams/m³ for August, September, October, and November, respectively. FPM average monthly concentrations were 46 and 24 pico grams/m³ in October and November, respectively. This correlates well with ground observations throughout the Eastern U.S. showing highest RGM and FPM concentrations in the summer and lowest concentrations in the winter. Measurement flights with UTSI will continue in January and conclude in February. steve.brooks@noaa.gov, Xinrong Ren.

12. Ammonia Air-Surface Exchange Study

ATDD staff continued to analyze data from the 2012 ambient ammonia study at the University of Tennessee and the findings were presented at the fall American Geophysical Union (AGU) meeting in December in an oral presentation entitled, Measurement of ambient ammonia and surface-level meteorological forcing variables near an agricultural emission source. Ammonia concentrations averaged 18.4±33.4 ppb with daily maximums usually occurring in the early mornings (~0800 local time) and minimums around midday (see below). There were two events, urea fertilization of a nearby plot and changes in meteorology at the site (due to a frontage passage), that contributed to distinct changes in ambient levels. Ammonia increased by several hundred ppb immediately after the fertilization event and remained elevated for ~ 48 hours. After the front, there was less variability in concentrations and the diurnal pattern was different. Early morning maximums gradually declined throughout the afternoon to minimums in early evening (~1800 local time). latoya.myles@noaa.gov and M.W. Heuer

13. Air-Surface Exchange Studies

Rick Saylor co-chaired a session on Remote and Regional Atmospheric Aerosols at the 31st American Association for Aerosol Research Annual Conference in Minneapolis, MN, on October 12 and also presented a paper in the session entitled "An Investigation of Secondary Organic Aerosol Precursors and Formation Processes in and above Deciduous Forest Canopies." The paper described recent work on the development and initial application of the new biosphere-atmosphere exchange modeling system referred to as the Atmospheric Chemistry and Canopy Exchange Simulation System (ACCESS). rick.saylor@noaa.gov.

Rick Saylor presented two seminars describing recent results from research designed to gain an improved understanding of biosphere-atmosphere exchange processes, especially those processes related to the formation of secondary organic matter in fine aerosols. On October 30, a seminar entitled "The Atmospheric Chemistry and Canopy Exchange Simulation System (ACCESS): Motivation, Model Description and Initial Results" was presented by Dr. Saylor at Oak Ridge National Laboratory (ORNL) in the Environmental Sciences Division. The seminar, hosted by Dr. Meng-Dawn Cheng of ORNL, described the development and initial application of the ACCESS modeling system to the Walker Branch forest canopy in the Oak Ridge Reservation.

Another seminar was presented on November 8 entitled "Investigating the Role of Southeastern U. S. Forests in Producing Secondary Organic Aerosol" in the University of Tennessee Department of Civil and Environmental Engineering (hosted by Prof. Joshua Fu) as part of the fall 2012 Environmental Engineering Seminar series. The seminar described recent work and future plans aimed at achieving a better understanding of secondary organic aerosol formation from biogenic sources. The ACCESS modeling system will be used to analyze field measurements made as part of NOAA's Southeastern Nexus (SENEX) study and the National Science Foundation's (NSF) Southeastern Oxidant and Aerosol Study (SOAS), which are scheduled for the summer of 2013. Results from these investigations will be used to improve the treatment of biosphere-atmosphere exchange processes in 3-D atmospheric chemistry models. rick.saylor@noaa.gov

14. Interagency Monitoring of Protected Visual Environments

As the current NOAA representative, Rick Saylor participated in the 2012 Steering Committee meeting of the Interagency Monitoring of Protected Visual Environments (IMPROVE) network at the University of California-Davis Tahoe Environmental Research Center in Incline Village, NV. The IMPROVE program is a cooperative measurement effort between the U.S. EPA, federal land management agencies, and state agencies to monitor, evaluate, and assess progress toward national visibility goals on protected federal lands such as National Parks and Wilderness Areas. The IMPROVE Steering Committee meets annually to review network operations and advise on future directions of the program. rick.saylor@noaa.gov

CLIMATE

15. Advancing understanding of upper-air temperature changes

Dian Seidel hosted a workshop of the Stratospheric Temperature Trend Assessment Panel in Silver Spring, MD. The panel was established by the SPARC (Stratospheric Processes And their

Role in Climate), a core project of the World Climate Research Programme. The workshop on Remotely Sensed Stratospheric Temperature Data explored details of observations of stratospheric temperature and identified several open questions that the panel will explore in 2013. Dian.seidel@noaa.gov

16. Climate Reference Network

ATDD staff made 18 annual maintenance visits to Climate Reference Network (CRN) sites. Two unscheduled maintenance visits were made to sites in Alabama and Tok, Alaska. In addition, staff installed equipment at the Marshall Test Site in Boulder, CO. mark.e.hall@noaa.gov

ARL 1^st Quarter Publications

Published:

Dobosy, R., E. Dumas, D. Senn, B. Baker, D. Sayres, M. Witinksi, C. Healy, J.

Munster, and J. Anderson. (2012). Calibration and quality assurance of an airborne turbulence probe in an aeronautical wind tunnel. Early On-Line Release in Journal of Atmospheric and Oceanic Technology. doi:10.1175/JTECH-D-11-00206.1.

Hicks, B., E. Novakovskaia, R. Dobosy, W. Pendergrass, and W. Callahan. (2012). Temporal and Spatial Aspects of Velocity Variance in the Urban Surface Roughness Layer, Early On-Line Release in Journal of Applied Meteorology and Climatology. doi:10.1175/JAMC-D-11-0266.1.

Kochendorfer, John, Tilden P. Meyers, John Frank, William J. Massman, and Mark W. Heuer (2012). How Well Can We Measure the Vertical Wind Speed? Implications for Fluxes of Energy and Mass. Boundary Layer Meteorology. Volume 145, Issue 2, pp 383-398. doi: 10.1007/s10546-012-9738-1.

Lan, X., R. Talbot, M. Castro, K. Perry, and W. Luke. (2012) Seasonal and diurnal variations of atmospheric mercury across the US determined from AMNet monitoring data, Atmospheric Chemistry and Physics. 12, 10569-10582, doi:10.5194/acp-12-10569-2012.

Seidel, D. J., M. Free, and J. S. Wang (2012), Reexamining the warming in the tropical upper troposphere: Models versus radiosonde observations, Geophysical Research Letters, 39, L22701, doi:10.1029/2012GL053850.

The paper explored the vertical amplification of tropospheric warming in the tropics, attempting to reproduce the results of an earlier publication (Fu et al., 2011), which found that climate models exaggerate the vertical amplification of warming in the tropics as compared with satellite observations. The study, using radiosonde rather than satellite observations, lends partial support to that finding, but identifies uncertainties associated with the choice of dataset used and the choice of vertical levels analyzed.

Thomas, J. L., Dibb, J. E., Stutz, J., von Glasow, R., Brooks, S., Huey, L. G., and Lefer, B. (2012) Overview of the 2007 and 2008 campaigns conducted as part of the Greenland Summit Halogen-HOx Experiment (GSHOX). Atmospheric Chemistry and Physics. 12(22): 10833-10839. doi:10.5194/acp-12-10833-2012.

Thompson, David W. J. Dian J. Seidel, William J. Randel, Cheng-Zhi Zou, Amy H. Butler, Roger Lin, Craig Long, Carl Mears, Albert Osso (2012) The mystery of recent stratospheric temperature trends. Nature. 491,692-697. doi:10.1038/nature11579.

The paper raised basic questions about our understanding of temperature trends in the stratosphere, in regions where only satellite observations are available for study. Two versions of Stratospheric Sounding Unit data show highly disparate trends during 1970-2005. Dian Seidel presented these findings at the Annual Meeting of the American Meteorological Society (January 2013) and at a meeting of the Scientific Steering Group of the Stratospheric Processes and their Role in Climate (SPARC) program of the World Climate Research Program (WCRP, November 2012).

Vellinga, O. S., Ronald J. Dobosy, Edward J. Dumas, Beniamino Gioli, Jan A. Elbers, and Ronald W. A. Hutjes (2012). Calibration and Quality Assurance of Flux Observations from a Small Research Aircraft. Early On-Line Release in Journal of Atmospheric and Oceanic Technology. doi: 10.1175/jtech-d-11-00138.1

Conference Presentations

Several staff attended the 11th Annual Community Modeling and Analysis System (CMAS) Conference held in Chapel Hill, NC. The CMAS Conferences are funded by EPA. The following poster presentations were made by ARL staff:

Daniel Tong: SATMAQ: bringing satellite data to the CMAQ community
Daniel Tong: Recent updates in the CMAQ windblown dust emission module
Li Pan: How does the concentration of surface ozone change in CONUS due to a new paradigm for emission upgrade for the national forecasting system
Jong-Jae Lee: Simulation of source-receptor relationships for ozone in South Korea

The following oral talks were given:

Hyuncheol Kim: Springtime Transport of Central American Fire Emissions to the United States
Tianfeng Chai: Chemical data assimilation with CMAQ and DISCOVER-AQ field measurements
Pius Lee: Fine resolution Air Quality forecasting capability for limited-area domains over Eastern Texas.

LaToya Myles gave a talk on ammonia flux studies at the 2012 Research Coordination Network on Reactive Nitrogen Workshop: Impacts of Excess Nitrogen in the Environment on Human Health. The workshop was held at the National Institutes of Health in November. A brief synopsis of her talk will be incorporated into a workshop fact sheet.

LaToya Myles participated in Ignite@AGU2012, a fast-paced event where presenters get five minutes and 20 slides (slides auto-advance every 15 seconds) to cover an Earth or space science topic. Her talk was entitled "What Goes Up Must Come Down: Emission and Deposition of Trace Gases" and is available online: http://www.youtube.com/watch?v=xwiblh64Q2c&list=PL_NxU6SzEHUHFWYzpeLMCrtIe5wUp7XKg

LaToya Myles was co-author of an oral presentation entitled "The Role of Alumni Groups as Pathways to Increasing Diversity Efforts in STEM-Related Fields" during the Building a Diverse Geoscience Workforce session at the Fall AGU Meeting. She was also co-author of a poster presentation "Linking Urban Youth to STEM Research: Outcomes of Educational Outreach in Diverse K-12 Schools" during the Developing K-12 Research Synergies to Inspire Young Scientists session.

Hyuncheol Kim and Pius Lee presented at the 4th International Workshop on Air Quality Forecasting Research (IWAQFR) in Geneva. The participation in the IWAQFR has grown significantly from approximately 17 countries attending the 3^rd IWAQFR in 2011 to about 29 counties attending in 2012. Kim and Lee presented the following talk and posters:

- Talk 1: High spatial resolution Air Quality forecasting capability for limited domains over Eastern Texas for validation of near real-time satellite detected air pollution events

- Poster 1: Trans-boundary Transport of Springtime Wildfire Pollutants from Central American to the United States

- Poster 2: Using DISCOVER-AQ field measurements to verify where and how Chemical data assimilation provided strong constraints for CMAQ forecast

- Poster 3: Windblown Dust Emission Module in CMAQ version 5.0

- Poster 4: Impact of emission upgrade on surface ozone forecast performance of the US National Air Quality Forecasting Capability

- Poster 5: Ozone source-receptor relationships for South Korea

Awards, Honors, Recognition

Rick Saylor was appointed as Research Associate Professor in the Department of Civil and Environmental Engineering at the University of Tennessee, Knoxville (UTK). The appointment will facilitate research collaborations between ARL/Atmospheric Turbulence and Diffusion Division scientists and UTK faculty, and allow Dr. Saylor to teach classes and directly supervise graduate students and post-doctoral associates in Civil and Environmental Engineering. rick.saylor@noaa.gov.

Outreach

ARL headquarters staff conducted multiple interviews related to the ribbon cutting for the NOAA Center for Weather and Climate Prediction. This included a TV interview Ariel Stein provided to Telemundo explaining the research activities ARL performs at the NOAA Center for Weather and Climate Prediction building. The interview may be viewed at: http://www.holaciudad.com/reportaje-especial-edificio-ecologico-noaa-n268467. Interviews also resulted in segments on local television stations and contributed to an article about the new building in Physics Today.

Paul Kelley and Winston Luke traveled to the Exploratorium, a hands-on science museum in San Francisco, to participate in widely-attended workshop discussions surrounding the museum's move to its new facility at Pier 15. A "wired pier" observation system will be installed at the new location to collect and display real-time data relating to the air and water quality, climate, currents, etc. in the San Francisco Bay Area. ARL's discussion with museum staff, both formal and informal, centered on the selection, installation, and operation of air quality instrumentation, data visualization, and educational outreach to museum visitors. ARL staff suggested several pilot studies that could be implemented to introduce museum visitors to issues of topical interest in air quality research. Other topics addressed at the workshop included: physical conditions within the Bay and their effect on plankton and biological communities; the carbon cycle and ocean acidification; alternative energy; climate change, weather, and sea level; the physics of instrumentation; coastal upwelling, plankton blooms and productivity along the west coast; topographical and microclimate effects on local weather; earthquakes, tsunamis and undersea volcanic activity; science education in the classroom; and arts and the environment. Winston.luke@noaa.gov; Paul Kelly

LaToya Myles continues to serve as secretary for the NOAA Graduate Science Program (GSP) Alumni. The group promotes professional development of former and current NOAA GSP participants and expansion of networking opportunities for participants.

LaToya Myles and Rick Saylor visited local air quality monitoring sites in Knox County, TN. County Air quality officials led the tour and explained data collection and reporting standards. Myles, Saylor, and Will Pendergrass will continue to meet with county officials, as well as researchers from the University of Tennessee, to discuss particulate matter monitoring efforts in the region.