Sentences with phrase «seasonal trend over»

Gold price in USD per ounce, seasonal trend over the past 20 years.

When the authors looked at seasonal trends over the same time period, the most notable expansion of the Sahara occurred in summer, resulting in a nearly 16 percent increase in the desert's average seasonal area over the 93 - year span covered by the study.

Not exact matches

Fuel prices have been declining over the past month due to seasonal trends and the falling price of crude, said Patrick DeHaan, a senior petroleum analyst for GasBuddy.com.

A new study, the most comprehensive ever on seasonal distribution patterns and historic trends in abundance of white sharks (Carcharodon carcharias) in the western North Atlantic Ocean, used records compiled over more than 200 years to update knowledge and fill in gaps in information about this species.

Seasonal Shift Of course, looking for trends in tornado data is fraught with potential pitfalls owing to changes in how tornadoes have been reported over time.

The ability of a sampling method to accurately measure seasonal variability does not indicate that the method is valid for estimating trends over centennial time scales.

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.

In this context, energy producers need to anticipate resources, their variability at seasonal timescales and their trends over decades.

Evidence suggests that the negative phase of the Arctic Oscillation was driven in part by warm air (air warmed by the dramatic seasonal loss of Arctic sea ice) 9 as well as by changes in snow cover over Eurasia driven by climate change.10 This event is part of an emerging trend in which a warming climate may paradoxically bring colder, snowier winters to northern Europe and the eastern United States.11

By that standard, last week in Rochester we should have stopped preparing for winter given that we had several days of warm temperatures that surely made the temperature trends over some reasonable time period of a week or more positive rather than negative, as would be expected if this seasonal cycle theory was real.

Of course the trend in CO2 is the difference over a full seasonal cycle, as I said before, but the seasonal cycle doesn't cause the trend, doesn't influence the trend and simply has nothing to do with the trend, whatever the real cause of the trend is.

There is no clear trend in seasonal precipitation when averaging over the whole of the European domain.

The length of the growing season in interior Alaska has increased 45 % over the last century7 and that trend is projected to continue.8 This could improve conditions for agriculture where moisture is adequate, but will reduce water storage and increase the risks of more extensive wildfire and insect outbreaks across much of Alaska.9, 10 Changes in dates of snowmelt and freeze - up would influence seasonal migration of birds and other animals, increase the likelihood and rate of northerly range expansion of native and non-native species, alter the habitats of both ecologically important and endangered species, and affect ocean currents.11

In particular, the characterization of the urban temperature trend was investigated using a seasonal unit root analysis of monthly mean air temperature data over the period of January 1970 to December 2013.

Nicholas, the natural variability after a full seasonal cycle is only + / - 1 ppmv around the trend over the past 55 years, which is recently over 2 ppmv / year net increase with human emissions of around 4.5 ppmv / year.

Her research focuses on understanding variability and trends in the seasonal cycle of rainfall over Africa.

The primary functions of treeclim are to (1) perform bootstrapped response and correlation functions; (2) conduct seasonal correlation analysis with tree growth; (3) conduct forward and backward evolution analyses for temporal stability tests; (4) evaluate trends on correlations betwen tree growth and climate over time; and (5) evaluate reconstruction skills for use in dendroclimatology and dendroecology.

It is exactly for the same reason that the temperature trend here in Rochester over a period of, say, a week or so can be negative in the spring even though there is no denying that the seasonal cycle is strong here and that the predicted temperature trend in the spring is positive.

With the summer real estate season upon us, many Americans are following the seasonal real estate trend and considering purchasing a home over the next few months.