haruspex said:What is the minimum value for solar forcing since 1900?
What temperature difference would that account for?
You are told climate sensitivity of 0.5K per watt per square meter.courtneywetts said:The minimum value for solar forcing would be .06 right?
But how would I know the temperature difference?
haruspex said:You are told climate sensitivity of 0.5K per watt per square meter.
That means, for each extra watt per square meter the temperature rises 0.5K.
If the solar forcing has been 0.6 watt per square meter, how much would that have increased the temperature?
More precisely (tracking the units) .5K(Wm-2)-1 x .06(Wm-2) = .5 x .06 Kcourtneywetts said:So would this mean I would do .5K x .06W/m^2 ?
haruspex said:More precisely (tracking the units) .5K(Wm-2)-1 x .06(Wm-2) = .5 x .06 K
Now what about the maximum forcing?
Please try to get the units right.courtneywetts said:So for the maximum forcing would I do
.5K x .24 W/m^2?
So how much of the .9C of warming can solar forcing explain? (Might be they're expecting it as a percentage - hard to know.)Is there more to this problem though?
haruspex said:Please try to get the units right.
So how much of the .9C of warming can solar forcing explain? (Might be they're expecting it as a percentage - hard to know.)
See post #6. You wrote .5K x .24 W/m^2. The sensitivity is not .5K, it's .5K/(W/m2), which could also be written .5K(Wm-2)-1 or .5Km2W-1. When you multiply by solar forcing in units Wm-2 then Wm-2 cancels (Wm-2)-1 to give an answer in K.courtneywetts said:What do you mean by the right units?
You don't know how to find one number as a percentage of another?And how would I find this as a percentage?
haruspex said:See post #6. You wrote .5K x .24 W/m^2. The sensitivity is not .5K, it's .5K/(W/m2), which could also be written .5K(Wm-2)-1 or .5Km2W-1. When you multiply by solar forcing in units Wm-2 then Wm-2 cancels (Wm-2)-1 to give an answer in K.
You don't know how to find one number as a percentage of another?
No. You are given:courtneywetts said:Would I do .06 W/m^2 x .5K =.03K
and .24 W/m^2 x .5K= .12 K
No. You have calculated the minimum and maximum temperature rises that could have come from solar forcing. You are asked what portion of the observed .9 C rise could be a result of solar forcing, i.e. the largest possible portion.and then do .03K/.12 K= .25K or 25%?
haruspex said:No. You are given:
Climate sensitivity = .5K per W per m2. That means .5 K(Wm-2)-1, or more simply .5 KW-1m2.
Solar forcing = .24 Wm-2.
Climate sensitivity * Solar forcing = .5 KW-1m2 * .24 Wm-2, which simplifies to (.5 * .24) K. That's reasonable because the answer should be a temperature.
You wrote .24 W/m2 x .5K. That would give the result (.5 * .24) KWm-2, which is not a temperature.
Do you see the difference?
No. You have calculated the minimum and maximum temperature rises that could have come from solar forcing. You are asked what portion of the observed .9 C rise could be a result of solar forcing, i.e. the largest possible portion.
courtneywetts said:So I would use the maximum amount to find the ration? This would be .12K right?
How would I then use the .9 C. This is also in Celsius so would I need to convert?
haruspex said:The .12K and the .9C are both changes in temperature. The K and C scales only differ by a constant, so a change of some number of degrees C is a change of the same number of degrees K. No conversion to be done.
Finding what? .12 as a percentage of .9?courtneywetts said:How would I go about finding this then?
haruspex said:Finding what? .12 as a percentage of .9?
You don't now how to find a percentage? If you invest $100 and get back $105 you've made $5 profit. What percentage did you earn?courtneywetts said:Would I put this into a ratio? If so how would I set this up?