Ivanka Stajner

NAQFC Developmental Forecast Guidance for Fine Particulate Matter (PM2.5)

AbstractThe National Air Quality Forecasting Capability (NAQFC) upgraded its modeling system that provides developmental numerical predictions of particulate matter smaller than 2.5 μm in diameter (PM2.5) in January 2015. The issuance of PM2.5 forecast guidance has become more punctual and reliable because developmental PM2.5 predictions are provided from the same system that produces operational ozone predictions on the National Centers for Environmental Prediction (NCEP) supercomputers.There were three major upgrades in January 2015: 1) incorporation of real-time intermittent sources for particles emitted from wildfires and windblown dust originating within the NAQFC domain, 2) suppression of fugitive dust emissions from snow- and/or ice-covered terrain, and 3) a shorter life cycle for organic nitrate in the gaseous-phase chemical mechanism. In May 2015 a further upgrade for emission sources was included using the U.S. Environmental Protection Agency’s (EPA) 2011 National Emission Inventory (NEI). Emiss...

Season of breast cancer diagnosis and probability of death from breast cancer in the United States

Dear Editor, Analysis of long-term survival depending on the season of cancer diagnosis found mortality reduction among breast cancer patients in England that were diagnosed in the autumn. This could indicate a seasonally protective mechanism, possibly due to the higher vitamin D status in the autumn. We investigate whether long-term survival in the United States is affected by the season of diagnosis of breast cancer.

Improving NOAA NAQFC PM2.5 Predictions with a Bias Correction Approach

AbstractParticulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) is a critical air pollutant with important impacts on human health. It is essential to provide accurate air quality forecasts to alert people to avoid or reduce exposure to high ambient levels of PM2.5. The NOAA National Air Quality Forecasting Capability (NAQFC) provides numerical forecast guidance of surface PM2.5 for the United States. However, the NAQFC forecast guidance for PM2.5 has exhibited substantial seasonal biases, with overpredictions in winter and underpredictions in summer. To reduce these biases, an analog ensemble bias correction approach is being integrated into the NAQFC to improve experimental PM2.5 predictions over the contiguous United States. Bias correction configurations with varying lengths of training periods (i.e., the time period over which searches for weather or air quality scenario analogs are made) and differing ensemble member size are evaluated for July, August, September, and No...

Comment on interaction of hormone replacement therapy with calcium and vitamin D supplementation on colorectal cancer risk

There is an apparent typographical error in the data that they based their primary analysis on. The correct HR for estrogenalone supplementation is 1.15 instead of 1.51 that was used by Ding et al. Use of the correct HR is expected to make HR for women on estrogen therapies less suggestive of increased risk. In addition, the increased HR for women on estrogen1progestin therapy is suggestive of the importance of progestin therapy, rather than estrogen therapy, in the interaction with calcium and Vitamin D supplementation on colorectal cancer. Ding et al. address an important question of interaction between Vitamin D, calcium and hormone replacement therapy (HRT) in prevention of colorectal cancer. Statistical analysis in their study relies on data reported from the Women’s Health Initiative (WHI) trial. The primary analysis uses hazard ratio (HR) for calcium plus Vitamin D supplementation in 4 groups that were randomized by HRT use: Estrogen (E)alone active, E-alone placebo, Estrogen1Progestin (E1P) active and E1P placebo. The reanalysis by Ding et al. combines the E-alone active group with the E1P active group to form a group of women currently on estrogen therapies. The E-alone placebo and E1P placebo groups are combined to form the group of women that are not on estrogen therapies. The HR for the women on estrogen therapies was found to be 1.50 (95% CI: 0.96–2.33), which was said to be ‘‘borderline suggestive of the increased risk.’’

Incremental Development of Air Quality Forecasting System with Off-Line/On-Line Capability: Coupling CMAQ to NCEP National Mesoscale Model

The National Air Quality Forecast Capability (NAQFC) is based on the EPA Community Multiscale Air Quality (CMAQ) model driven by meteorological data from the NOAA North American Mesoscale (NAM) Non-hydrostatic Meso-scale Model (NMM). Currently, NMM meteorological data on Arakawa E-grid are interpolated on a CMAQ’s Arakawa C-grid using the processors PRODGEN and PREMAQ to handle map-projection transform, vertical layer collapsing, and other emission and meteorological data feed issues. The FY11 pre-implementation version of NAM has undergone significant changes in the vertical layering, horizontal grid projection and improved science components for its FY11 upcoming major upgrade release. This provides an opportunity to improve the coupling methodology between NMM and CMAQ that reduces uncertainties both in the meteorological and emission inputs for the off-line air quality modeling and helps development of on-line NMM-CMAQ version. Three major tasks are needed to achieve a tighter coupling between them: (1) Adapt to NAM’s vertical hybrid pressure and grid structure; (2) Change CMAQ to use the same rotated latitude longitude B staggered horizontal grid structure as NAM, (3) Modify emission model to provide generic inputs for the B staggered grid and hybrid vertical structure of NAM. The first task achieves consistent matching of dynamics between the two systems, despite the possible necessity of layer-collapsing to fit within operational time-lines. The second task removes unnecessary interpolation of meteorology data for air quality simulations. The third task involves modification of the U.S. EPA Sparse Matrix Object Kernel Emission (SMOKE) model to handle the staggered B grid. At this time only the first of these three steps has been accomplished, and the test result from this test focusing on the selected test period has been compared to that produced by the operational NAQFC. Further work with all these three modifications concurrently in place is underway.