JWG
Active Member
- Joined
- Oct 22, 2007
- Messages
- 1,786
- Reaction score
- -47
Hi Bev,
Like you, I am trying to pinpoint the day, and I don't quite understand how you get five days either (even after reading your explanation).
Here is how I come up with my numbers:
Accumulated degree day (ADD) is simply the sum of the mean temperature of one or more consecutive days.
Example: given the following mean temperatures (in Celsius) for each of three consecutive days -28, 30, 32 - then ADD = 22 + 30 + 27 = 79.
Now, the forensic report suggests the chemistry supports 90 ADD. The authors assume a mean temperature for that time of year in Orlando as 35 C.
90 / 35 = 2.571 which rounds to 2.6 days, the estimate given in the report.
In my post #187, I show three temperature data sets from Orlando for the dates June 15 to June 27. The first represents the average across a number of reporting stations in the greater Orlando area. The other two are from the two stations closest to AL. For each data set I calculate the mean temperature from June 16 through June 20, which are the most likely days the body was in the trunk. As it turns out, the temperatures in the Orlando area were pretty stable over the entire June 15 to June 27 period, so any window I use yields a pretty consistent average.
Example data set 1: 25.1 (June 16) + 27.4 (June 17) + 27 (June 18) + 26.4 (June 19) + 26.9 (June 20) = 26.56 average.
Now I take the three averages and divide them into 90 and round to get days:
Data set 1: 90 ADD / 26.56 C = 3.4 days
Data set 2: 90 ADD / 24.18 C = 3.7 days
Data set 3: 90 ADD / 27.20 C = 3.3 days
However, we don't know the actual temperature in the trunk. At best it would be equal to the air temperature outside, but given that Casey always parked outside on pavement, the heat absorption properties of the asphalt would tend to heat the car to a temperature greater than the pavement. Because there was frequent rain and cloud cover, I would expect that effect to be minimized. So I am guessing the internal temperature of the trunk was about 30 C, or 3 to 6 C warmer on average than the outside air temperature (more during the day, less at night).
90 ADD / 30 C = 3 days
Like you, I am trying to pinpoint the day, and I don't quite understand how you get five days either (even after reading your explanation).
Here is how I come up with my numbers:
Accumulated degree day (ADD) is simply the sum of the mean temperature of one or more consecutive days.
Example: given the following mean temperatures (in Celsius) for each of three consecutive days -28, 30, 32 - then ADD = 22 + 30 + 27 = 79.
Now, the forensic report suggests the chemistry supports 90 ADD. The authors assume a mean temperature for that time of year in Orlando as 35 C.
90 / 35 = 2.571 which rounds to 2.6 days, the estimate given in the report.
In my post #187, I show three temperature data sets from Orlando for the dates June 15 to June 27. The first represents the average across a number of reporting stations in the greater Orlando area. The other two are from the two stations closest to AL. For each data set I calculate the mean temperature from June 16 through June 20, which are the most likely days the body was in the trunk. As it turns out, the temperatures in the Orlando area were pretty stable over the entire June 15 to June 27 period, so any window I use yields a pretty consistent average.
Example data set 1: 25.1 (June 16) + 27.4 (June 17) + 27 (June 18) + 26.4 (June 19) + 26.9 (June 20) = 26.56 average.
Now I take the three averages and divide them into 90 and round to get days:
Data set 1: 90 ADD / 26.56 C = 3.4 days
Data set 2: 90 ADD / 24.18 C = 3.7 days
Data set 3: 90 ADD / 27.20 C = 3.3 days
However, we don't know the actual temperature in the trunk. At best it would be equal to the air temperature outside, but given that Casey always parked outside on pavement, the heat absorption properties of the asphalt would tend to heat the car to a temperature greater than the pavement. Because there was frequent rain and cloud cover, I would expect that effect to be minimized. So I am guessing the internal temperature of the trunk was about 30 C, or 3 to 6 C warmer on average than the outside air temperature (more during the day, less at night).
90 ADD / 30 C = 3 days