Skip to main content

Table 3 Means and standard deviations for seasonal integrated exposure to illuminance and irradiance in the range 450–500 nm during the six time periods during the day

From: Annual variation in daily light exposure and circadian change of melatonin and cortisol concentrations at a northern latitude with large seasonal differences in photoperiod length

Season   Time period of the day
(hh:mm–hh:mm)
   04:00–08:00 08:00–12:00 12:00–16:00 16:00–20:00 20:00–24:00 00:00–04:00
Winter Mean (lux*min) 3499 31,829 39,325 12,227 4304 182
N = 15 SD (lux*min) 3573 12,142 16,712 5697 3335 524
Spring Mean (lux*min) 20,848 77,887 174,058 79,184 4275 116
N = 15 SD (lux*min) 13,858 31,940 91,305 50,529 2474 176
Summer Mean (lux*min) 71,518 172,843 371,683 726,036 52,033 88
N = 15 SD (lux*min) 38,046 95,915 252,050 344,795 69,369 119
Autumn Mean (lux*min) 14,753 85,219 200,564 170,479 5873 277
N = 15 SD (lux*min) 8210 44,098 127,800 95,712 4141 402
Winter Mean (μW/cm2*min) 97 3386 5238 916 267 16
N = 14 SD (μW/cm2*min) 136 3142 4777 782 719 34
Spring Mean (μW/cm2*min) 2718 8157 14,023 5850 384 22
N = 14 SD (μW/cm2*min) 2990 5357 9833 7371 802 46
Summer Mean (μW/cm2*min) 8503 13,762 28,070 60,170 3500 23
N = 14 SD (μW/cm2*min) 11,181 12,943 30,928 58,643 5016 37
Autumn Mean (μW/cm2*min) 1347 7598 15,834 13,711 337 20
N = 14 SD (μW/cm2*min) 1392 5525 15,032 17,066 660 46