T. Giambelluca
M. Nullet
Geography, U. Hawaii
28 August 2000

We have the following raw data from the logger (see CSI manual):

For diurnal statistics, we use the subscript h for hourly.

Each of 24 1-hour diurnal resultant wind direction values is calculated for a given month as:

The subscript i (i=1 to 24) refers to each hour of the mean diurnal cycle (i.e. 0100, 0200 … 2400) for a particular month. The subscript j refers to the number of valid data points for a given hour in a given month (i = 1 to 28, 29, 30, or 31 if no data are missing).

Similarly, each of 24 1-hour diurnal resultant wind speed values is calculated for a given month as:

Diurnal resultant wind speed is not currently reported in tables or charts.

For daily statistics, we use the subscript d.

Each daily resultant wind direction value is calculated as:

Similarly, each daily resultant wind speed value is calculated as:

where the subscripts k and j indicate the day and the hour of the day, respectively. Daily resultant wind speed is not currently reported in tables or charts.

For monthly statistics, we use the subscript m.

Monthly resultant wind direction is calculated based on the 24 diurnal values calculated using Eqs. 1 and 2.

The subscript n refers to the month (n=1 to 12). All 24 diurnal values are required for a valid monthly value.

The monthly resultant wind speed value is calculated as:

Monthly resultant wind speed is not currently reported in tables or charts.

For annual statistics, we use the subscript A.

The annual resultant wind direction is calculated as:

Long-term monthly resultant wind velocity is calculated as:

For long-term statistics, we use the subscript LT for monthly values and A for annual values.

The long-term monthly resultant wind direction is calculated as:

The subscript y refers to year.

Long-term monthly resultant wind velocity is calculated as:

The long-term annual resultant wind direction is calculated as:

Long-term monthly resultant wind velocity is calculated as:

For further information contact Tom Giambelluca: thomas@hawaii.edu
Page last modified 28 August 2000