Background

The Regional Office has conducted the retrieval of data from the automated weather stations in Carmen, Catigbian, and Loboc in Bohol. These data were handed over by CENRO Tagbilaran City. The data collected was an accumulation of monthly data from the whole year of 2023.

Moreover, data retrieved from this activity were observations from the old and new automated weather station instruments. There was a total of six raw data files; two from each site location.

Limitations

A series of data inspections were conducted; cleaning, sorting, and validation of data. Upon inspection, it was noticed that data observations were inconsistent. This was due to low battery and disruptions caused by unprecedented weather conditions leading to missing observations.

Each raw data files consist of at least 18 parameters; included are time stamps, readings from the Davis Cup Anemometer, PYR Solar Radiation, Precipitation, Humidity, Temperature, Soil Moisture, Battery, and readings from the Barometer.

An AWS reading records in 15 minutes per hour. This is 96 observations for a single day and 35,040 for a year. The problem is that some recordings did not start on the first day of the Month, some Dates and Times have not been recorded, and there are months with no observations.

The inconsistency of data will lead to poor analysis and a major loss of information.

Methods

Time series analysis was used to illustrate the movement of wind speed, gust speed, and air temperature among others in the areas of Carmen, Catigbian, and Loboc in Bohol. Also, polar plots were used to determine wind directions in reference to the wind rose direction table by Laidler et al. (2007).

The analysis was limited only to the processing of the average monthly data due to data inconsistencies.

R statistical software was used to generate statistical results.

Wind Rose Direction Table

Wind Direction Degree Range Wind Direction Label
348.75-11.25 N
11.25-33.75 NNE
33.75-56.25 NE
56.25-78.75 ENE
78.75-101.25 E
101.25-123.75 ESE
123.75-146.25 SE
146.25-168.75 SSE
168.75-191.25 S
191.25-213.75 SSW
213.75-236.25 SW
236.25-258.75 WSW
258.75-281.25 W
281.25-303.75 WNW
303.75-326.25 NW
326.25-348.75 NNW

Results

Carmen

Wind Direction

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The numerical data retrieved from the Carmen Automated Weather Station (AWS) was converted according to the sixteen wind rose directions and their corresponding degree ranges by Laidler et al. (2007).

The polar and bar graph above shows that the average monthly winds for Carmen from last year are mostly blown from the north (NNE). This indicates calm and cold winds mostly covered the area throughout the year.

Wind Speed

The average monthly wind speed for Carmen last year was seen to be at its peak in February and July. The trend line was also observed to be leaning downwards starting from March until the rest of Q2, however, Q4 showed a gradual rise in the wind speed.

Gust Speed

The average monthly gust speed for Carmen had its peak gust speed in February and July. The trend line was seen to be slightly vertical with the result of the average monthly wind speed in the same place which also peaked in the same months. It might be because wind speed and gust speed are closely related.

Adame (2020) identified that the fundamental difference between wind speed and gust speed is duration. He further stated that an anemometer will constantly measure the wind speed and that those measurements will be average for at least 2 minutes to calculate the wind speed while gust speed is considered to be faster than that.

Wind speed is shown in blue while gust speed is shown in red. Both peaked in the months of February and July.

Solar Radiation

The average monthly energy emitted by the sun for Carmen from last year was seen to be at its peak from June until August. The trend line significantly dropped in September and began to rise again in October and somewhat stayed still until the end of the year. This drop in the trend line may be due to the effects of the rainy season.

Precipitation

Precipitation was at its peak in February, July, and October for Carmen last year.

Air Temperature

Carmen tallied its average monthly air temperature the most between the 20th and 30th point mark. It somehow indicates normal air temperature for the whole year. Trend line irregularities are due to data inconsistencies.

Relative Humidity

Carmen tallied its average monthly relative humidity with a trend line slightly congruent to the results of the average monthly air temperature from the same area. There are no major fluctuations, only in months with no recorded data.

The time series analysis for the average air temperature and relative humidity has an almost steady trend line except for months with no data. The air temperature which is hypothetically normal indicates the amount of vapor in the air was high.

Atmospheric Pressure

The average monthly atmospheric pressure in Carmen for last year was consistent throughout the year. Irregular fluctuations are due to data inconsistencies.

Water Content

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The graph above shows the average monthly water content for Carmen according to two observations. The first observation lasted until September while the second was for the remaining months. The trend line can be seen as slightly steady throughout the year.

Catigbian

Wind Direction

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The same metric was used for Catigbian in the conversion of numerical data according to its specific wind rose directions. From the results, the wind for this specific area is mostly coming from the North. Calm and cold air is predominant in the area.

Wind Speed

Winds in Catigbian last year were faster in January, March, and December based on the average monthly wind speed shown above. Furthermore, a downward trend can be observed for the subsequent months following March.

Gust Speed

The average monthly gust speed for Catigbian last year showed a vertical result from that of the average monthly wind speed in the same area. It also peaked in March and showed a downward trend coming to Q2 and for the rest of the months except November and December.

A clearer illustration for both parameters showed the average monthly wind speed and gust speed in Carmen both in blue and red lines, respectively.

Solar Radiation

The average monthly solar radiation for Catigbian last year was higher for September. The sudden rise coming this month might be due to the loss of data for August.

Air Temperature

There was a sudden rise in the average monthly air temperature for Catigbian last year from August to September, a gradual rise from February to April, and a trend line leaning downwards from April to August.

Relative Humidity

Major fluctuations were visible for the average monthly relative humidity in Catigbian in 2023. However, it peaked at the highest in August.

The relative humidity shows an inversely proportional result to that of the air temperature. The line in blue is for the air temperature while the line in red is for the humidity.

Atmospheric Pressure

Water Content

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Loboc

Wind Direction

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The same method was also used in the conversion of numerical data to its designated wind rose direction. It shows that Loboc in 2023 was experiencing winds coming from the North.

Wind Speed

The wind was faster at Loboc in July.

Gust Speed

The average monthly gust speed for Loboc in 2023 peaked in July and was low for the succeeding months.

Solar Radiation

November logs the highest in terms of the average monthly solar radiation in Loboc last year. There was an upward trend of solar radiation coming to the end of the year but a sudden drop was observed in December.

Precipitation

The average monthly precipitation in Loboc last year showed a significant rise from October to November.

Relative Humidity

The average monthly relative humidity shows major fluctuations throughout the year. There was a downward trend from January to March, however, an upward trend was observed from March until June. A slight fluctuation in August and a sudden downward trend in November.

Atmospheric Pressure

The average monthly atmospheric pressure in Loboc last year showed an upward trend for January until March. A sudden downfall was observed in March which lasted until July. Fluctuations still occur for the remaining months of the year.

Reference

Adame, M. E. (2020, August 7). The difference between wind speed and wind gusts. Spectrum News NY1. https://ny1.com/nyc/all-boroughs/weather/2020/08/07/all-wind-is-not-created-equal#:~:text=The%20fundamental%20difference%20between%20the,typically%20lasts%20under%2020%20seconds.

Laidler, G.J., Ford, J., Gough, W.A., Ikummaq, T., Gagnon, A.S., Kowal, S., Qrunnut,K., and Irngaut C. (2007). Travelling and hunting in a changing Arctic: Assessing Inuitvulnerability to sea ice change in Igloolik, Nunavut. Climate Change, 94(3-4), pp. 363-397.