Evaluation of four different climate sources on pavement mechanistic-empirical design and impact of surface shortwave radiation

ABSTRACT

This paper compares the predicted distresses (via in the AASHTOWare Pavement ME Design software (PMED)) of asphalt concrete (AC) and jointed plain concrete pavement (JPCP) using four different climate data sources. These sources also include the Modern Era Retrospective Analysis for Research and Application (MERRA) Versions 1.0 and 2.0 (MERRA-1 and MERRA-2). Pavement performance predictions generated using these data showed disagreement among some of the climate data sources, especially for MERRA-2. Comprehensive diurnal and other time-series analyses of the raw climate data found significant disagreements in the percent sunshine estimates. Percent sunshine is used in the PMED environmental effects model to semi-empirically estimate the downwelling shortwave radiation reaching the pavement surface. Both MERRA data (MERRA -1 and MERRA-2) independently provide direct predictions of downwelling surface shortwave radiation (SSR). The direct model predictions of SSR were used to back calculate ‘synthetic’ per cent sunshine for input into the PMED. The use of the synthetic per cent sunshine derived from the predicted SSR eliminated nearly all discrepancies in the predicted pavement performance using MERRA-1 versus MERRA-2 data. Based on these results, the authors recommend that SSR rather than per cent sunshine be used as a direct input to the PMED.

KEYWORDS:

• Pavement analyses
• climate effects
• Mechanistic Empirical Pavement Design Guide (MEPDG)
• Ground-Based Weather Stations (GBWS)
• Modern era Retrospective Analysis for Research and Applications (MERRA)
• North American Regional Reanalysis (NARR)

Acknowledgements

The contents of this paper reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents of this paper do not necessarily reflect the official views of the Georgia Department of Transportation.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Barton A. Forman http://orcid.org/0000-0001-6410-9978

Additional information

Funding

This study was funded by Georgia Department of Transportation (GDOT).