edu.ucar.opensky::articles:17041 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T14:56:58.662900 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7n29z6d https://doi.org/10.5065/D6M043C6 https Related Dataset #1 NCEP FNL Operational Model Global Tropospheric Analyses, continuing from July 1999 https://doi.org https Related Dataset #2 TDL U.S. and Canada Surface Hourly Observations A comprehensive evaluation of seasonal simulations of ozone in the northeastern U.S. during summers of 2001-2005 2010-01-05T00:00:00Z publication https://n2t.org/ark:/85065/d7n29z6d https://doi.org/10.5194/acp-10-9-2010 Mao, H. author Chen, Ming author Hegarty, J. author Talbot, R. author Koermer, J. author Thompson, A. author Avery, M. author UCAR/NCAR - Library publisher Regional air quality simulations were conducted for summers 2001–2005 in the eastern US and subjected to extensive evaluation using various ground and airborne measurements. A brief climate evaluation focused on transport by comparing modeled dominant map types with ones from reanalysis. Reasonable agreement was found for their frequency of occurrence and distinctness of circulation patterns. The two most frequent map types from reanalysis were the Bermuda High (22%) and passage of a Canadian cold frontal over the northeastern US (20%). The model captured their frequency of occurrence at 25% and 18% respectively. The simulated five average distributions of 1-h ozone (O₃) daily maxima using the Community Multiscale Air Quality (CMAQ) modeling system reproduced salient features in observations. This suggests that the ability of the regional climate model to depict transport processes accurately is critical for reasonable simulations of surface O₃. Comparison of mean bias, root mean square error, and index of agreement for CMAQ summer surface 8-h O₃ daily maxima and observations showed –0.6±14 nmol/mol, 14 nmol/mol, and 71% respectively. CMAQ performed best in moderately polluted conditions and less satisfactorily in highly polluted ones. This highlights the common problem of overestimating/underestimating lower/higher modeled O₃ levels. Diagnostic analysis suggested that significant overestimation of inland nighttime low O₃ mixing ratios may be attributed to underestimates of nitric oxide (NO) emissions at night. The absence of the second daily peak in simulations for the Appledore Island marine site possibly resulted from coarse grid resolution misrepresentation of land surface type. Comparison with shipboard measurements suggested that CMAQ has an inherent problem of underpredicting O₃ levels in continental outflow. Modeled O₃ vertical profiles exhibited a lack of structure indicating that key processes missing from CMAQ, such as lightning produced NO and stratospheric intrusions, are important for accurate upper tropospheric representations. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright Author(s) 2010. This work is distributed under the Creative Commons Attribution 3.0 License. None eng geoscientificInformation