Water and Energy Balance Results for Puerto Rico (1-km spatial resolution)




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Example input/output results from GOES-PRWEB.

In GOES-PRWEB, an energy balance approach, similar to Yunhao et al. (2001), is used to estimate actual evapotranspiration, which is then incorporated into a water balance calculation. Solar radiation is derived from a physical model for estimating incident solar radiation at the surface from GOES satellite data, first proposed by Gautier et al. (1980) (see also Diak et al. 1996; Okin et al. 2005; and Sumner et al., 2008). The ground level, 1-km resolution solar radiation product became available in Puerto Rico in March of 2009. Net radiation is estimated from the solar radiation using the method of Allen et al., 1998. Photosynthetically active radiation (PAR) is estimated from net radiation using a regression equation developed in Florida (pre-fire equation, Sumner, 2001). Twenty-four hour rainfall is obtained from NOAA’s Advanced Hydrologic Prediction Service (AHPS) website (http://water.weather.gov/precip/). In Puerto Rico, the source of the AHPS rainfall is NEXRAD radar and rain gauge data. Runoff is estimated using the Curve Number method of the USDA Natural Resource Conservation Service (U.S. SCS, 1973, Fangmeier et al., 2005).

Two sets of wind speed data have been used during the life of the operational model.  Data set 1. January 1, 2009 through September 30, 2015:  average of eight 3-hour values of wind speed obtained from the National Weather Service’s National Digital Forecast Database (NDFD, 2010).  Data set 2. October 1, 2015 through present:  average of twenty-four hourly values of wind speed obtained from the CARICOOS Weather Research Forecast (WRF) 1-km resolution model.   On days when the 1-km resolution model data are not available, the WRF 2-km data are used.  The 10-m wind speeds are adjusted to the “virtual instrument height”, depending on the height of the vegetation.  Significant overestimation of the NDFD and CARICOOS wind speed data were observed relative to weather station-measured wind speeds, and therefore, a single correction factor of 0.5 has been applied to all values in GOES-PRWEB.   Minimum, average, maximum and dew point air temperatures are obtained from the NDFD website (NDFD, 2010). A detailed description of the methodology used in GOES-PRWEB (coded in MatLab) is presented by Harmsen et al. (2009 and 2010).


Results from GOES-PRWEB are available at the following links:
YESTERDAY’S RESULTS (available around 2:15 pm each day)
GOES-PRWEB daily images and csv files (csv files are available starting in jan 2009)
GOES-PRWEB monthly averages and totals (jpg and csv files available starting in Jan 2009)
GOES-PRWEB annual averages and totals (jpg and csv files available starting in 2009)

Frequently Asked Questions about GOES-PRWEB (for example, “How does it calculate….”)

ACKNOWLEDGEMENTS: This research received partial funding from the following sources: NOAA-CREST (grant NA06OAR4810162) and USDA Hatch Project (Hatch-402). Special thanks to Dr. John Mecikalski for providing the solar radiation data, Alejandra Rojas and Luz Torres for GIS support, Victor Reventos for operationalization Python code development and Dr. Luis Aponte for the map plotting Matlab code.

DISCLAIMER: The information on this website is provided “as is”, should be considered provisional and is subject to change. The authors and publishers of this information disclaim any loss or liability, either directly or indirectly as a consequence of applying the information provided herein, or in regard to the use and application of said information. No guarantee is given, either expressed or implied, in regard to the accuracy, or acceptability of the information.

Allen, R. G., L. S. Periera, D. Raes, and M. Smith. 1998. Crop evapotranspiration: Guidelines for computing crop requirements. Irrigation and Drainage Paper No. 56. Rome, Italy: FAO.

Diak, G. R., W.L. Bland, and J. Mecikalski, 1996: A note on first estimates of surface insolation from GOES-8 visible satellite data. Agric. For. Meteorol., 82, 219-226.

Fangmeier, D. D., W. J. Elliot, S. R. Workman, R. L. Huffman, and G. O. Schwab, 2005. Soil and Water Conservation Engineering, Fifth Edition. pp. 528.

Gautier, C., G. R. Diak, and S. Masse, 1980: A simple physical model to estimate incident solar radiation at the surface from GOES satellite data. J. Appl. Meteor.,19, 1007–1012.

Goyal, M. R., E. A. González, C. Chao de Báez, 1988. Temperature versus elevation relationships for Puerto Rico. J. Agric. UPR 72(3):449-67.

Harmsen, E. W., J. Mecikalski, A. Mercado and P. Tosado Cruz, 2010. Estimating evapotranspiration in the Caribbean Region using satellite remote sensing. Proceedings of the AWRA Summer Specialty Conference, Tropical Hydrology and Sustainable Water Resources in a Changing Climate. San Juan, Puerto Rico. August 30-September 1, 2010.

Harmsen, E. W., J. Mecikalski, M. J. Cardona-Soto, A. Rojas Gonzalez and R. Vasquez, 2009. Estimating daily evapotranspiration in Puerto Rico using satellite remote sensing. WSEAS Transactions on Environment and Development. Vol. 6(5):456-465.

Otkin, A. J., M. C. Anerso, J. R. Mecikalski and G. R. Diak, 2005. Validation of GOES-Based Insolation Estimates Using Data from the U.S. Climate Reference Network. J. of Hydrometeorology, Vol. 6, August:460-475.

Sumner, D. M, C. S. Pathak, J. R. Mecikalski, S. fJ. Paech, Q. Wu, and T. Sangoyomi, 2008. Calibration of GOES-derived Solar Radiation Data Using Network of Surface Measurements in Florida, USA.  Proceedings of the ASCE World Environmental and Water Resources Congress 2008 Ahupua’a.

Sumner, D. M., 2001. Evapotranspiration from a cypress and pine forest subjected to natural fires in Volusia County, Florida, 1998-99. U. S. Geological Survey Water-Resources Investigations Report 01-4245. Washington, D.C.: U.S. Geological Survey.

U.S. Soil Conservation Service, 1973. A Method for Estimating Volume and Rate of Runoff in Small Watersheds. SCS-TP-149, Washington, D.C.

Yunhao C., L. Xiaobing and S.Peijun, 2001. Estimation of regional evapotranspiration over Northwest China by using remotely sensed data.  Journal of Geophysical Sciences, Vol. 11, No. 2, pp 140-148.


11 thoughts on “Water and Energy Balance Results for Puerto Rico (1-km spatial resolution)



  3. Pingback: Monthly Average Solar Radiation Images Available for Puerto Rico | PRAGWATER

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  5. Pingback: Hydrologic Information and Data for the Caribbean | PRAGWATER


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  8. Pingback: Good News!! GOES-13 is back online. Solar Radiation Data is Available For Downloading | PRAGWATER


  10. Pingback: Daily Photosynthetically Active Radiation (PAR) now available for Puerto Rico | PRAGWATER

  11. Pingback: 2016 Annual averages/totals for various hydroclimate variables for Puerto Rico | PRAGWATER

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