It appears that UVB is a bit more intense than I had expected it to be down near the equator. The reading in the picture was taken at 1300 (1pm) in the Guayas River -- Guayaquil, Ecuador is in the background. The readings below were taken from a ship enroute from Guayaquil to Portland, Oregon. Note that the declination of the sun is about 20 degrees Sth. If the Sun's declination was 0, I would expect noon UVB to be above 500 on the equator.
Reading, Location, Time, Date, Atmosphere
440 0-18N 84-06W 1200 1/21/2005 Clear Off the coast of Ecuador 55ft.
480 0-32N 84-18W 1300 1/21/2005 Clear Off the coast of Ecuador 55ft.
440 0-42N 84-29W 1400 1/21/2005 Clear Off the coast of Ecuador 55ft.
350 0-55N 84-44W 1500 1/21/2005 Clear Off the coast of Ecuador 55ft.
225 1-06N 84-55W 1600 1/21/2005 Lt.Clouds Off the coast of Ecuador 55ft.
120 1-16N 85-06W 1700 1/21/2005 Lt.Clouds Off the coast of Ecuador 55ft.
430 4-29N 88-59W 1200 1/22/2005 Clear 270' NNE of Galapagos Islands 55ft.
380 8-35N 93-47W 1200 1/23/2005 Clear 345' SSW of Guatemala 55ft.
345 12-44N 98-58W 1200 1/24/2005 Clear 205' SW of Mexico 55ft.
310 16-44N 104-00W 1200 1/25/2005 Clear 190' SW of Mexico 55ft.
280 25-06N 114-01W 1230 1/27/2005 Clear 100' WNW of Mag.Bay, Baja CA 55ft.
260 29-58N 119-56W 1230 1/28/2005 Clear 52' NE of Guadalupe IS., Baja CA 55ft.
175 34-37N 121-16W 1130 1/29/2005 Clear 31' W of Pt. Arguello, CA 55ft.
168 39-39N 124-38W 1230 1/30/2005 Clear 40' WNW of Ft. Braggs, CA 55ft.
80 45-33N 124-37W 1200 1/31/2005 Clear 41' W of Tillamook Bay, OREGON 55ft.
