Spectra of Mauna Loa Wind Speed Data

Spectra of Mauna Loa Wind Speed Data (2011-2014)

Wind speed data spectra shown below were made using data provided through the Future Learn Course  Data Science for Environmental Modelling and Renewables. The course is provided through the University of Glasgow with a team of instructors lead by Professor Marian Scott. 

Daily average wind speeds (Figure 1) were calculated from hourly data in R using the course program intro_windpower. Note maximum windspeeds occur around annually around the new year with average daily speeds of 15-20 mph. 

 

Figure 1: Average daily wind speed Mauna Loa, Hawaii calculated over the 2011-2014.

Spectra generated for daily average wind speed data from Mauna Loa reveal the presence of some cyclical wind patterns (Figure 2).More pronounced peaks reveal the presence of annual periodicity in the wind speed patterns along with a series of 39-56 day cycles. There is a band of periodic behavior that stands above the background between 4.5 and 14 day cycles.

Figure 2: Amplitude spectrum of daily mean Mauna Loa wind speed data. 

A closeup view of periodic wind speed behavior out to 10 day periods (Figure 3) shows spectral response down to 10 day cycles. Relative to the peak annual amplitude, these secondary peaks may be more speculative. 39-56 day cycles do stand out. We also see what may be a 27 day cycle in the wind speeds.

Figure 3: Closeup view of longer period wind speed variations observed on Mauna Loa.

Spectral analysis reveals a prominent annual trend with some additional periodic winds occurring at approximately 40 - 60 day intervals (Figure 3). Reference back to the average wind speed data (Figure 1) suggests these 40-60 day patterns emerge early in the year and are also superimposed on the annual peaks.

Climate risk maps

There is a wealth of information available on the climate.gov web site [https://www.climate.gov/maps-data]. On the global climate dashboard one can pull up a variety of informative maps. I’ve displayed the global climate dashboard showing data relevant to some of the topics we’ve been discussing over the past 3 weeks on the futurelearn.com course Climate Change: The Science through the University of Exeter. Below are trends for sea ice extent, heat trapping gasse, etc. some example displays. 

The site also has many other interesting maps including the map below of the average temperature trends in the US (lower 48) since 1895. 

Below we see that average annual precipitation trends (1988-2017) show drier than average conditions in northern and southern California, for example. This past fall these areas saw widespread wildfires and tragic loss of life. 

The site allows the user to display different parameters ( such as temperature and precipitation trends) and to specify maps of average trends for a give month, season or annual period. 

You’ll also find a variety of teaching resources at https://www.climate.gov/climate-and-energy-topics/climate-system.

Climate change is predicted to proceed at an accelerated pace as we enter the Anthropocene. The maps found at https://www.businessinsider.com/best-countries-escape-climate-change-map-2018-1 show anticipated levels of climate change impact globally and on a more detailed regional scale. The figure below gives global scale perspectives. 

There you will see that the most significant carbon emitters can turn out to be at less risk for climate impact. But - as shown above, even in the US, these impacts are not spread evenly across the area. The northwestern states are seeing higher averahe temperature trends, for example.