semidiurnal
Occurring twice daily
Semidiurnal means occurring twice a day.
The term appears most often in oceanography, where semidiurnal tides produce two high tides and two low tides in roughly twenty-four hours: The Atlantic coast experiences semidiurnal tides.
In astronomy, semidiurnal describes half the arc a celestial body traces from rising to setting.
Every two weeks
- semiweeklyTwice per week
- fortnightlyEvery fourteen days
- dailyPer diem, repeated
- hourlyOnce each sixty minutes
periodic · interval · recurring · regular · cyclical · repetition · schedule · timing
Gradual retreat seaward
- flowUnbroken forward movement
- tidalOf sea rhythms
- intertidalZone between high and low watermarks
- springtideMaximum tidal range
highwater · tidal range · lunar · gravitational pull · estuary · coastline · marine · littoral
Daily biological cycle
- biologicalRelating to living organisms
- entrainmentRhythmic systems aligning naturally
- melatoninCircadian rhythm regulator
- endogenousOriginating from within
periodicity · oscillation · phase · rhythm · sleep · wakefulness · chronotype · body clock
biweekly
Every two weeks
- semiweeklyTwice per week
- fortnightlyEvery fourteen days
- dailyPer diem, repeated
hourly · periodic · interval · recurring · regular · cyclical · repetition · schedule · timing
ebb
Gradual retreat seaward
- flowUnbroken forward movement
- tidalOf sea rhythms
- intertidalZone between high and low watermarks
springtide · highwater · tidal range · lunar · gravitational pull · estuary · coastline · marine · littoral · foreshore
circadian
Daily biological cycle
- biologicalRelating to living organisms
- entrainmentRhythmic systems aligning naturally
- melatoninCircadian rhythm regulator
endogenous · periodicity · oscillation · phase · rhythm · sleep · wakefulness · chronotype · body clock
semidiurnaldiurnal
Active during daylight
once daily · daily · circadian · monthly · annual
semidiurnalirregular
Deviating from normal patterns
arrhythmic · random · unpredictable · sporadic · intermittent