It is the agency that monitors climate change and its attendant global warming. It is also the agency that monitors meteorological phenomena which originates and formed due to the behavior of the ocean such as: tropical cyclones and the extreme climatic variabilities (e.g. El Nino and La Nina). The interaction between the ocean and the atmosphere is very dynamic and is evident in the manifestations of the characteristics of El Nino and La Nina. This is the reason why these two phenomena are regarded as oceanographic phenomenon.
The necessity of promoting and strengthening of the global oceanographic observation for climate change prediction is imperative. PAGASA, in anyway it can actively participate in this endeavor within the limits of its capabilities. The PAGASA undertakes researches and studies regarding climatic changes and variabilities, among others, in order to have a better understanding of the effect of the ocean to the atmosphere and to the climate in the long run. As an example of these are the changes in the average annual temperature of selected cities in the country. Please see Figure 1. The three metropolitan cities considered are Manila, Cebu and Baguio. It can be gleaned from the figure that indeed there is an increasing trend of temperature in these places.
As for the study on the effect of extreme climatic variabilities in the Philippines, it can be deduced that for El Nino, its effect is generally drought. That is the annual rainfall during an El Nino year is less than the normal annual rainfall average of the country. Figure 2 shows the rainfall distribution during El Nino year compared to that of a normal year. On the other hand, during the advent of La Nina, the effect is the opposite. During La Nina, generally, the country received more rainfall than the normal annual average. Figure 3 shows the comparison of rainfall between La Nina and normal year during the northeast monsoon and the southwest monsoon.
The Philippine Area of Responsibility (PAR) as reflected in Fig. 4 has an annual frequency of about 20 tropical cyclones. This is regarded as the highest frequency all over the globe. A study was undertaken in the aspect of comparing the number of tropical cyclone formation within the PAR during normal year and those of El Nino and La Nina years, a summary of which is shown in Table 1. Table 1 shows an increase on the number of tropical cyclone during the advent of La Nina. On the otherhand, there are fewer tropical cyclones formed within the PAR during El Nino year.
