Figure 9.  Monthly Total Solar Radiation at Near Field and Cactus Flats during December 1997 - November 1999 The low value for June 1999 at Cactus Flats resulted when the sensor was damaged by a lightning strike. Figure 10.  Monthly Total UVB Radiation Measured at Near Field and Cactus Flats during December 1998 - November 1999 *Cactus Flats sensor inoperative during 28 April - 30 July 1999.