Sentences with phrase «on precipitation frequency»

This means that precipitation effects are dependent on precipitation frequency as well as annual amount.

Not exact matches

Mean temperature, mean monthly precipitation, frequency of hot / cold days / nights, and indices of extreme precipitation are all estimated for each country based on observed and modeled data.

Accordingly, there is less certainty about the changes in frequency and intensity of tropical cyclones on a regional basis than for temperature and precipitation changes.

For the entire Northern Hemisphere, there is evidence of an increase in both storm frequency and intensity during the cold season since 1950,1 with storm tracks having shifted slightly towards the poles.2, 3 Extremely heavy snowstorms increased in number during the last century in northern and eastern parts of the United States, but have been less frequent since 2000.11,15 Total seasonal snowfall has generally decreased in southern and some western areas, 16 increased in the northern Great Plains and Great Lakes region, 16,17 and not changed in other areas, such as the Sierra Nevada, although snow is melting earlier in the year and more precipitation is falling as rain versus snow.18 Very snowy winters have generally been decreasing in frequency in most regions over the last 10 to 20 years, although the Northeast has been seeing a normal number of such winters.19 Heavier - than - normal snowfalls recently observed in the Midwest and Northeast U.S. in some years, with little snow in other years, are consistent with indications of increased blocking (a large scale pressure pattern with little or no movement) of the wintertime circulation of the Northern Hemisphere.5 However, conclusions about trends in blocking have been found to depend on the method of analysis, 6 so the assessment and attribution of trends in blocking remains an active research area.

Based on process understanding and agreement in 21st century projections, it is likely that the global frequency of occurrence of tropical cyclones will either decrease or remain essentially unchanged, concurrent with a likely increase in both global mean tropical cyclone maximum wind speed and precipitation rates.

Groisman et al. (1999) developed a simple statistical model of the frequency of daily precipitation based on the gamma distribution.

The weather prediction model used in this research is advantageous because it assesses details about future climate at a smaller geographic scale than global models, providing reliable simulations not only on the amounts of summer precipitation, but also on its frequency and timing.

«Relatively cool waters in the eastern Pacific often result in stubborn summer high - pressure systems over the eastern states that block storms, reducing the frequency of precipitation below normal,» noted study co-author Richard Healy of the Woods Hole Oceanographic Institution, Woods Hole, Mass. «Less frequent storms result in higher surface and atmospheric temperatures that then feedback on the atmospheric circulation to further reduce storm frequency and raise surface temperatures even more.»

But California droughts are also fundamentally linked to the quantities and timing of precipitation, the dynamics of storm formation in the Pacific Ocean, the impacts of climate change on the frequency and intensity of El Niño and La Niña events and the Pacific Decadal Oscillation, and the behavior of the jet stream as conditions in the Arctic change.

UKCIP08 will provide a statistical «weather generator,» which will allow users to see what daily (or even hourly) sequences of weather could look like at specified locations, given changes in basic aspects of climate such as average temperature, frequency of dry days, and average precipitation on wet days.

Based on our published results and as well as those of other modeling groups, we conclude that at the global scale: a future increase in tropical cyclone precipitation rates is likely; an increase in tropical cyclone intensity is likely; an increase in very intense (category 4 and 5) tropical cyclones is more likely than not; and there is medium confidence in a decrease in the frequency of weaker tropical cyclones.

Zhanqing Li, lead author of a paper published in Nature Geoscience and University of Maryland atmospheric scientist, says, «Using a 10 - year dataset of atmospheric measurements, we have uncovered the long - term, net impact of aerosols on cloud height and thickness and the resulting changes in precipitation frequency and intensity.»