Decadal Wind Trends at the Savannah River Site. Allen H. Weber §, Robert L. Buckley, and Matthew J....
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Transcript of Decadal Wind Trends at the Savannah River Site. Allen H. Weber §, Robert L. Buckley, and Matthew J....
Decadal Wind Trends at the Savannah River Site
Allen H. Weber§, Robert L. Buckley, and Matthew J. Parker
Savannah River National Laboratory, Aiken, South Carolina
§ret.
§Corresponding author address: A. Weber, 820 Jackson Ave., North Augusta, SC 29841.
Southeast Stations Used
Wind and Temperature Observations
• NWS and SRNL data show the mean annual daytime and nighttime temperatures are increasing ~0.04 and ~0.05 ºC respectively, per year.
• The wind speed is decreasing for this area of the Southeast.
Increasing SRNL Temperature Trend
Decreasing Wind Speed Trend in the SE
Decreasing Wind Speed Trend at SRNL
Constant Sigma-Azimuth
Increasing Sigma-Elevation
Slopes of Trends
Day Night Tota l Mean Slope (per yr) Tota l
Mean Slope (per
yr) Speed (mps) 3.78 -9.00E-03 4.11 -1.41E-02
A (deg) 18.61 3.28E-02 8.02 -1.05E-02 E (deg) 12.21 9.96E-02 4.81 2.71E-02
Temperature (ºC)
19.48 3.85E-02 16.29 5.10E-02
Seasonal Slopes of Trends
Day Night Variable Season Mean Slope (per
yr) Mean Slope (per
yr) Speed (mps) Winter 4.11 -7.40E-03 4.36 -3.90E-03
Spring 4.21 -1.58E-02 4.39 -1.85E-02 Summer 3.34 -8.60E-03 3.59 -1.13E-02 Autumn 3.62 -3.00E-03 4.09 -2.29E-02
A (deg) Winter 17.60 5.90E-02 9.04 -8.18E-02 Spring 19.02 1.67E-02 8.77 9.70E-03 Summer 20.19 8.14E-02 9.38 5.11E-02 Autumn 18.88 -3.44E-02 8.09 -3.00E-04
Seasonal Slopes of Trends
Day Night Variable Season Mean Slope (per
yr) Mean Slope (per
yr)
E (deg) Winter 11.80 1.15E-01 5.71 -1.23E-02 Spring 12.64 9.76E-02 5.57 4.49E-02 Summer 13.25 1.11E-01 5.29 5.22E-02 Autumn 12.49 7.24E-02 4.92 3.49E-02
Temperature (ºC)
Winter 9.81 -6.54E-02 8.71 -4.82E-02
Spring 18.96 9.10E-02 16.73 9.53E-02 Summer 26.46 2.28E-02 24.18 4.29E-02 Autumn 19.56 8.52E-02 17.50 1.11E-01
E and A for Daytime and Nighttime
E for daytime and nighttime from SRNL Area Towers is increasing at a rate of ~0.03 and ~0.01 degrees per year, respectively.
A for daytime from the SRNL Area Towers is increasing at a rate of ~0.03 degrees per year. Nighttime values are decreasing by ~0.10 degrees per year.
Conclusions
• Daytime and nighttime temperatures are increasing ~4 and ~5 ºC respectively, per century.
• Daytime and nighttime speeds are decreasing ~0.9 and ~1.4 m/s respectively, per century
• Increases in E for daytime and nighttime suggest that convective turbulence is increasing. This is probably due to a decrease in the thermal stability between the surface and the 60-m level.
• The daytime rate for E is increasing more rapidly than the nighttime rate.