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Firstly this has had to be translated from Norwegian so it doesn't read too well!
Quote
The code is broken! Now scientists have found a formula for future extreme precipitation.
- It was a very special experience to create, what days. It feels a bit like having broken one of nature's codes, admits the Norwegian climate researcher Rasmus Benestad.
The mystery is solved
- The formula is very useful to say something about the weather becomes more extreme in the future, said Benestad.
Together with his research colleagues on the other side of the Atlantic at the National Center for Atmospheric Research , the starting point in how precipitation varies from 33,000 weather stations worldwide.
The ingredients in the formula
Researchers have found that large amounts of precipitation can be calculated for a future climate if you know:
The amount of precipitation that falls on average for a typical rainy day
Number of rain days
Distance from coast
Altitude
- We can now associate changes in rainfall levels up to the trends we see the typical rainy days. Will it be wetter we also get more extreme amounts if the number of rainy days does not change anything significant, telling Benestad.
How the formula
- The key is that you only bring rain days in the math, and supporting calculations on a particular mathematical curve and mathematical method, said Benestad.
Thus, removing fair-weather days and find the average rainfall for all rainy days.
- If you know the location, frequency, and a lot of it tends to rain there, you can now with this new formula to calculate how much rain it can get an extreme precipitation event.
Can be used on past and future
The same formula applies if you go back in time or forward in time.
- We could also say something about how often such an extreme case might occur, said Benestad.
Researchers can thus sit at their desks and calculate the extreme precipitation using the old observations from the world's meteorological institutes.
Must distinguish between weather and climate
- The formula can tell us something about the risk of extreme precipitation and probability of flooding.
It will therefore not be used in specific weather forecasts to report extreme precipitation, but in the climate context.
- We do not hang us up when it comes but how often that happens, says climate researcher.
- It was a very special experience to create, what days. It feels a bit like having broken one of nature's codes, admits the Norwegian climate researcher Rasmus Benestad.
The mystery is solved
- The formula is very useful to say something about the weather becomes more extreme in the future, said Benestad.
Together with his research colleagues on the other side of the Atlantic at the National Center for Atmospheric Research , the starting point in how precipitation varies from 33,000 weather stations worldwide.
The ingredients in the formula
Researchers have found that large amounts of precipitation can be calculated for a future climate if you know:
The amount of precipitation that falls on average for a typical rainy day
Number of rain days
Distance from coast
Altitude
- We can now associate changes in rainfall levels up to the trends we see the typical rainy days. Will it be wetter we also get more extreme amounts if the number of rainy days does not change anything significant, telling Benestad.
How the formula
- The key is that you only bring rain days in the math, and supporting calculations on a particular mathematical curve and mathematical method, said Benestad.
Thus, removing fair-weather days and find the average rainfall for all rainy days.
- If you know the location, frequency, and a lot of it tends to rain there, you can now with this new formula to calculate how much rain it can get an extreme precipitation event.
Can be used on past and future
The same formula applies if you go back in time or forward in time.
- We could also say something about how often such an extreme case might occur, said Benestad.
Researchers can thus sit at their desks and calculate the extreme precipitation using the old observations from the world's meteorological institutes.
Must distinguish between weather and climate
- The formula can tell us something about the risk of extreme precipitation and probability of flooding.
It will therefore not be used in specific weather forecasts to report extreme precipitation, but in the climate context.
- We do not hang us up when it comes but how often that happens, says climate researcher.
Quote
Extreme precipitation can cause flooding, result in substantial damages and have detrimental effects on ecosystems1, 2. Climate adaptation must therefore account for the greatest precipitation amounts that may be expected over a certain time span3. The recurrence of extreme-to-heavy precipitation is notoriously hard to predict, yet cost–benefit estimates of mitigation and successful climate adaptation will need reliable information about percentiles for daily precipitation. Here we present a new and simple formula that relates wet-day mean precipitation to heavy precipitation, providing a method for predicting and downscaling daily precipitation statistics. We examined 32,857 daily rain-gauge records from around the world and the evaluation of the method demonstrated that wet-day precipitation percentiles can be predicted with high accuracy. Evaluations against independent data demonstrated high skill in both space and time, indicating a highly robust methodology.
Problem is that if you want to read more about the published paper you either need to subscribe already to the journal Nature or pay to view
http://www.nature.co...limate1497.html
