19 Matching Annotations
  1. Oct 2018
    1. trends noted here as being independent of the observational and analysis techniques used

      The trends noted here appear to be real and not due to an error in the analysis, instruments, or observations.

      Airplane weather measurements have been extensively compared against satellite data, especially for the North Atlantic, and has been shown to well estimate hurricane categories through satellite imagery.

      As all the satellite images were analyzed in a similar fashion (the Dvorak scheme of cloud pattern comparison), the trends of increasing category 4 and 5 hurricanes are not caused by some problem with the analysis and thus appear to be driven by an environmental trend.

    2. large increase was seen in the number and proportion of hurricanes reaching categories 4 and 5

      After examining decades worth of satellite data on storms, it is now more likely a category 4 or 5 hurricane will form than how many used to occur in the 1970's. Thus the number of intense, life-threatening storms appears to have increased over the 35 year record of satellite data analyzed in this article.

  2. Sep 2018
    1. global data indicate a 30-year trend toward more frequent and intense hurricanes

      There appear to be more category 4 and 5 hurricanes forming in the 2000's than there were thirty years ago according to analyzed satellite data.

      This trend towards an increased frequency of some of the strongest, most intense storms has also been a result of other studies and model simulations.

    2. These changes occur in all of the ocean basins.

      There has been an increase in the number of storms that reach a category 4 or 5. This increase has occurred in every ocean basin: the Pacific, Atlantic, and Indian Oceans.

    3. has decreased monotonically as a percentage of the total number of hurricanes throughout the 35-year period

      There are fewer category 1 hurricanes in the 2000's relative to the other category storms than there were in the 1970's.

      A monotonic decrease means that for the whole of the record, there has been a decline in the percentage of category 1 storms. There were few if any periods where percentage values were constant or increasing.

    4. a simple attribution of the increase in numbers of storms to a warming SST environment is not supported

      Based on the satellite data from the 1970's to 2004, it is not possible to link warming ocean temperatures with a change in the number of hurricanes per year.

      While the North Atlantic may be showing an increase in hurricane days with warming temperatures, the same is not happening in other ocean basins.

    5. decreasing by 40% from 1995 to 2003

      The number of hurricanes and storm days in the west Pacific Ocean increased from the mid 1970's to the early 1990's before declining to 2004.

      Sea surface temperatures have been increasing in the west Pacific from the 1970's to 2000's. So there is not a clear relationship between storm frequency and sea surface temperatures for this ocean region.

    6. Decadal variability is particularly evident in the eastern Pacific

      There have been changes to the number of hurricanes and storm days per year that occur on the order of ten years or less in the eastern Pacific Ocean.

      Examining Fig. 3, the eastern Pacific (EPAC) has a maximum number of storms occurring around 1984 and again near 1993. Between 1993 and 2004, the number of hurricanes and storm days has been declining.

      Check out Fig. 1 again. Temperatures in the eastern Pacific have increased from the 1970's to 1992 before beginning to decline around 1993 to 2001.

    7. North Atlantic Ocean, which possesses an increasing trend in frequency and duration

      Of all the ocean basins examined, only the North Atlantic had a trend of increasing hurricane and storm days from 1970 to 2004.

    8. a substantial decadal-scale oscillation

      Between 1990 and 2000, there was a decade-long period of more frequent cyclonic storm days.

    9. None of these time series shows a trend that is statistically different from zero over the period

      Both the number of hurricanes and the number of storms, there was no statistical trends in the data. Thus it is not possible to state that the number of hurricane and storm events has increased over the period 1970 to 2004.

    10. trends in each of the ocean basins are significantly different from zero at the 95% confidence level or higher, except for the southwest Pacific Ocean

      From the 1970's to the 2000's, sea surface temperatures have been increasing through time for every ocean basin except the southwest Pacific Ocean. The statistics performed (Kendall Test) suggest this trend is real and significant.

  3. Mar 2018
    1. Significance

      Climate change will result in a shifting of where plants are usually located on the planet. Southern plants will move into higher latitudes, for example.

    2. (H2) Flower and leaf bud break of high Arctic plants should be more sensitive to temperature increases than those of low Arctic and alpine plants.

      The trends found indicated that high-elevation Arctic plants grew, flowered and aged at lower heat thresholds than low-elevation Arctic and alpine plants.

    3. Flower and leaf bud break are occurring earlier as sites become warmer.

      There was a strong negative relationship between the temporal trend of phenological events and the summer temperature trend for each species and site.

    4. temporal trends of heat sums (βTDD_x_YEAR) showed significantly increased heat sums over time for greening but a tendency for lower heat sums over time for flowering and senescence.

      The accumulated daily temperature required for plant growth has increased over time.

      The accumulated daily temperature required for flowering and aging has decreased over time.

    5. Trends in the timing of events as represented by βDOY_x_YEAR showed significantly later greening (positive slope) but tendencies for earlier flowering and earlier senescence (negative slopes) over the study.

      With warmer temperatures, plants are growing at a later time in the year but flowering and aging at an earlier time in the year.

    6. Plant phenological responses to these increases in season length and temperature are uncertain, but understanding changes as they occur is essential for predicting future changes in tundra vegetation processes

      Constantly observing and following the seasonal changes that occur with these plants is very important in understanding the future of the plants and their habitat.

  4. Feb 2018
    1. First, anti-ISIS agencies can thwart development of large aggregates that are potentially far more potent (21) by breaking up smaller ones.

      This result may seem counter-intuitive, but it makes sense when we consider the costs of shutting down larger aggregates versus the costs of shutting down smaller ones. It is easier to shut down smaller aggregates.