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Why does it get colder at sunrise?

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    Why does it get colder at sunrise?

    Seems like I can be comfortable before sunrise, but right before shooting light the temperature drops 15*. It makes no sense, why does this happen?

    #2
    Oh Johnny?

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      #3
      Sun heats the earth. Just before sunrise is the longest point the earth has been without sun (heat) since dusk the day before. Ie... it is the coldest part of a TYPICAL day that does not have a cold font coming in.

      BTW... the shortest distance between two points is a straight line.

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        #4
        Thats like asking why the Denver Broncos suck. I dunno!

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          #5
          idrathebehuntin is right, it has to do with emitted radiation. All day the Earth soaks up radiation and emits it, (that's why it is hottest around 4:00 pm not 12:00 Noon) just before sunrise is the longest period without a 'recharge' so the emitted radiation is low, so it gets colder.

          Dew point is usually hit pretty close to this time as well, again, due to the cooling, and the rising dew causes temperatues to feel colder. The more humid the air the colder it feels. water is eight times as dense as air and even small spikes in humidity cause us to loose heat faster (feels colder).

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            #6
            Originally posted by Lulhorse View Post
            Thats like asking why the Denver Broncos suck. I dunno!
            I do his initials are MS

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              #7
              How soon do you get to your stand before sunrise?

              How much are you exterting yourself getting to the stand. Do you think the sweat is causing you to get colder as your waiting for the sun to come up?

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                #8
                Ok then why do the Boncos suck?

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                  #9
                  Ok thanks so they should ***** can Shanahan!
                  Actually saw that on Tshirts they were peddling at the game Sunday

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                    #10
                    Who cares about the Broncos?

                    Good question Jon. I have always wantted to know the answer to that one!!!

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                      #11
                      Its been a long run for Mike. Hes a good coach, but its time for a change. A new coach tends to be very motivated to be succesful in his own way. With a new team as far as players now would be the time to make this change.

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                        #12
                        I think I am going to get one of those buddy heaters for the blind for next season

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                          #13
                          I don't buy the "coldest part of the day" theory. Sure, it's the coldest part of the day, that doesn't explain a sudden temperature drop.

                          The dew point/humidity spike is interesting. Even on cold, dry mornings I get that sudden cold, just at first light. Would that mean that stuff is getting warmer and releasing moisture?

                          It's not cooling sweat. I go in lightly dressed, and bundle up on stand. I can be comfortable in the dark for 45 minutes or so, then it gets light, and ****!

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                            #14
                            Wondered the same thing.
                            Considered the same things discussed regarding legth of time since the air has been heated.
                            I also wonder if the air over the horizon that is being heated causes the air in front of it to be pushed causing the slight breeze just before sunrise. The cooled air combined with a slight breeze increases the windchill?

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                              #15
                              Originally posted by TXJon View Post
                              I don't buy the "coldest part of the day" theory. Sure, it's the coldest part of the day, that doesn't explain a sudden temperature drop.
                              Often the temperature does fall for a short time after sunrise, though it is only a degree or two at most. And even if the temperature doesn’t fall as the sun is rising, the air may actually feel colder to you. That is because we are used to it being colder when it’s dark and warmer when it’s light. So as the sky begins to brighten in the morning and the temperature remains nearly the same, we might perceive that it is colder than it actually is. Also, wind generally increases during the day. The air sometimes begins to stir just after sunrise, and an increase in wind would make us feel colder.

                              If there are no fronts or precipitation nearby, the daily temperature cycle is primarily controlled by the radiation budget. This is a comparison between the incoming radiation from the sun (sunlight) and the terrestrial radiation given off by the earth’s surface (felt as heat.) Think of the sunlight shining down on earth as the same as putting pennies into a jar. As long as you keep putting pennies in, the money adds up. In the same way, as long as the sun is shining down on earth, the amount of radiation adds up. Let’s say that at some point you decide to stop depositing pennies into the jar and begin to take them out. Even though you’re withdrawing pennies, you still may have a lot of money in the jar. Likewise, when the sun goes down, the incoming radiation from the sun stops, but there is still a lot of radiation that has been absorbed by the earth, so we still feel heat near the earth even after the sun goes down. At night, the “withdrawals” of terrestrial radiation continue, and the ground and the air near it cool. Earth’s surface is typically in radiation “debt” from a couple of hours before sunset to near sunrise. When the sun comes up and the “deposits” of incoming radiation from the sun equalize with the “withdrawals” of radiation from earth, we get the coolest temperature of the day. Sometimes in winter when the sun is low in the sky, the earth’s surface can remain in radiation debt longer, and the coldest temperature of the day can actually occur as much as an hour after sunrise. As the sun gets higher in the sky, earth’s surface is in radiation surplus (the deposits exceed withdrawals), so the ground and the air near it warm.

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