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In this study interregnal variability of two major components of climate, including temperature and precipitation have been addressed. It is an effort to characterize the surface seasonal temperature and precipitation variability at national and regional scales. By making use of Empirical Orthogonal Function (EOF) as a main diagnostic tool, this research identifies anomalous spatial-temporal patters of temperature and precipitation variability with regional detail in Pakistan over the period of 1961-2006. This pattem scion relationship with atmospheric circulation anomalies at different geopotential height fields and global sea surface temperature (SST) anomalies.
The examination through trend coefficient and standard deviation show that Pakistan experiences wide range of temperature and precipitation that varies from region to region, month to month and season to season which validates the scope of the study. In case of temperature, winter and summer reflects larger variance, landforms induced seasonal pattem and larger variance in mountains than plains is obvious. Winter has warming and summer has slight cooling trends with interregnal variability. The month of January reflects interregnal variability with obvious warming trend. On the contrary, July show sinter annual variability with slight cooling trend, but parts of the county like Baluchistan and central esteem Punjab shows the warming trend. In case of precipitation, the wet seasons and regions with maximum precipitation show larger variance in both cases of winter-spring (February-March-Arid and summer precipitation. Negative trend coefficient prevails neither over nor them rugged parts of Khyber-Phakhtoonkhwa (KP) and Azad Kashmir (AK) region extending into nor them Punjab and western border ranges. The summer precipitation has high interregnal variability with inter decadal signals and increasing trend. In this context, major parts of Pakistan north of 29°N has positive trend coefficient while south of the said latitude negative trend coefficient is dominant.
We observed two significant patters of winter surface temperature in Pakistan. The leading mode is evident of warming (cooling) surface temperature. This patted of variability has association with the weak (strong) subtropical MEWJ. Dependent on weak (strong) westerly Jet the Wads are also weak (strong), therefore its chilly impact over Pakistan is reduced (increased) resulting into surface temperatures above (below) normal. The principal component also shows correlation with warm(cool) SST anomalies of remote global oceans but the most significant amongst all are Arabian Sea in the proximity of the study area the warm(cool) SST anomalies in other parts of the northemIndian Ocean and we stem Pacific warm pool region. The second patted is warm(cool)and cool(warm) in Baluchistan and central we stem parts of the KP-TA and Peshawar valley and Azad Kashmir (PVAK) axis respectively, its relation has been traced with positive(negative) phase of NAO and AAO. The SST warm (cool) anomalies neither in nor them Indian Ocean and particularly in Arabian Sea and warm pool region of the we stem Pacific basin are found significant.
We have identified three major summer temperature anomalous patters in Pakistan. In the leading patted, we identified a consistent patted with dominating warm (cool) surface temperature throughout the country. The strengthening (weakening) of subtropical jet and weak (strong) ISM are the apparent reasons behind the slight warm (cod surface temperature in summer. The warm (cool) SST anomalies based in central tropical Pacific Ocean may discourage the weak (strong) ISM, eventually may lead to warm (cool) surface temperature in Pakistan. The second patted identifies warm (cool) southeaster and cool (warm) northwester spatial patted of summer temperature with inter annual variability. This pattern can be assigned to two major factors one is the weak (strong) summer monsoon in the wake of El Nino (La Nina) and other is the presence of strong (week) westerly. The third patted acknowledges a complicated multicolor structure which has relation with global SST anomalies especially in the tropics.
Two major winter-spring precipitation anomalous patters have been identified. The leading mode has a single-pole spatial patted. More (or less) precipitation has relation with strong (weak) westerly jet over Middle East and capable of inducing intensified (weakened) Wads and potentially may increases (decreases) the chances of precipitation in the study region. In relation to Pacific SST anomalies, this patted show slink with post monsoon and early winter El Nino (La Nina). The second anomalous pattern is found with more Oases) rainfall over Quetta-Karat and northeaster Punjab, and less (more) precipitation in GB-AK/KP-TA (north/we stem Pakistan). In response to this patted the positive (negative) phase of NAO and AAO were found significant. In relation to this pattern, the soothe Indian and Atlantic oceans show warm (cool) and stable-SST anomalies in the southern mid-latitudes of their respective basins.
In case of summer precipitation three different anomalous patters has been recognized. The first spatial patted reflects more(less) summer rainfall in Pakistan whichs embedded in the strength (weakness) of ISM. The strong (weak) Somali Jet lead to more vapors influx that may lead to more(less) summer rainfall in Pakistan. It has been recognized from the anomalous SST response of the tropical Pacific basin that first modes associated with La Na?f (El Nino). The spatial patted of the second mode represents appositive(negative) node over northeastern Punjab, the negatively(positively) signed node over south-eastern parts of the country in Sind and third negative(positive) node is centered over AK area that stretches over to the adjacent parts of Himalaya, Karakoram and Hindu Kush (HKH), Peshawar valley and northern parts of Postwar Plateau. This patted has association with the positive(negative) SST anomalies of we stem Pacific warm pool region in late winter through spring and also reflects association with negative(positive) phase of EAP teleconnection patted The third patted of summer precipitation is multicolor. The patted figures out relation with NAO and Pacific winter-spring SST anomalies especially in the esteem equatorial Pacific basin.
The examination through trend coefficient and standard deviation show that Pakistan experiences wide range of temperature and precipitation that varies from region to region, month to month and season to season which validates the scope of the study. In case of temperature, winter and summer reflects larger variance, landforms induced seasonal pattem and larger variance in mountains than plains is obvious. Winter has warming and summer has slight cooling trends with interregnal variability. The month of January reflects interregnal variability with obvious warming trend. On the contrary, July show sinter annual variability with slight cooling trend, but parts of the county like Baluchistan and central esteem Punjab shows the warming trend. In case of precipitation, the wet seasons and regions with maximum precipitation show larger variance in both cases of winter-spring (February-March-Arid and summer precipitation. Negative trend coefficient prevails neither over nor them rugged parts of Khyber-Phakhtoonkhwa (KP) and Azad Kashmir (AK) region extending into nor them Punjab and western border ranges. The summer precipitation has high interregnal variability with inter decadal signals and increasing trend. In this context, major parts of Pakistan north of 29°N has positive trend coefficient while south of the said latitude negative trend coefficient is dominant.
We observed two significant patters of winter surface temperature in Pakistan. The leading mode is evident of warming (cooling) surface temperature. This patted of variability has association with the weak (strong) subtropical MEWJ. Dependent on weak (strong) westerly Jet the Wads are also weak (strong), therefore its chilly impact over Pakistan is reduced (increased) resulting into surface temperatures above (below) normal. The principal component also shows correlation with warm(cool) SST anomalies of remote global oceans but the most significant amongst all are Arabian Sea in the proximity of the study area the warm(cool) SST anomalies in other parts of the northemIndian Ocean and we stem Pacific warm pool region. The second patted is warm(cool)and cool(warm) in Baluchistan and central we stem parts of the KP-TA and Peshawar valley and Azad Kashmir (PVAK) axis respectively, its relation has been traced with positive(negative) phase of NAO and AAO. The SST warm (cool) anomalies neither in nor them Indian Ocean and particularly in Arabian Sea and warm pool region of the we stem Pacific basin are found significant.
We have identified three major summer temperature anomalous patters in Pakistan. In the leading patted, we identified a consistent patted with dominating warm (cool) surface temperature throughout the country. The strengthening (weakening) of subtropical jet and weak (strong) ISM are the apparent reasons behind the slight warm (cod surface temperature in summer. The warm (cool) SST anomalies based in central tropical Pacific Ocean may discourage the weak (strong) ISM, eventually may lead to warm (cool) surface temperature in Pakistan. The second patted identifies warm (cool) southeaster and cool (warm) northwester spatial patted of summer temperature with inter annual variability. This pattern can be assigned to two major factors one is the weak (strong) summer monsoon in the wake of El Nino (La Nina) and other is the presence of strong (week) westerly. The third patted acknowledges a complicated multicolor structure which has relation with global SST anomalies especially in the tropics.
Two major winter-spring precipitation anomalous patters have been identified. The leading mode has a single-pole spatial patted. More (or less) precipitation has relation with strong (weak) westerly jet over Middle East and capable of inducing intensified (weakened) Wads and potentially may increases (decreases) the chances of precipitation in the study region. In relation to Pacific SST anomalies, this patted show slink with post monsoon and early winter El Nino (La Nina). The second anomalous pattern is found with more Oases) rainfall over Quetta-Karat and northeaster Punjab, and less (more) precipitation in GB-AK/KP-TA (north/we stem Pakistan). In response to this patted the positive (negative) phase of NAO and AAO were found significant. In relation to this pattern, the soothe Indian and Atlantic oceans show warm (cool) and stable-SST anomalies in the southern mid-latitudes of their respective basins.
In case of summer precipitation three different anomalous patters has been recognized. The first spatial patted reflects more(less) summer rainfall in Pakistan whichs embedded in the strength (weakness) of ISM. The strong (weak) Somali Jet lead to more vapors influx that may lead to more(less) summer rainfall in Pakistan. It has been recognized from the anomalous SST response of the tropical Pacific basin that first modes associated with La Na?f (El Nino). The spatial patted of the second mode represents appositive(negative) node over northeastern Punjab, the negatively(positively) signed node over south-eastern parts of the country in Sind and third negative(positive) node is centered over AK area that stretches over to the adjacent parts of Himalaya, Karakoram and Hindu Kush (HKH), Peshawar valley and northern parts of Postwar Plateau. This patted has association with the positive(negative) SST anomalies of we stem Pacific warm pool region in late winter through spring and also reflects association with negative(positive) phase of EAP teleconnection patted The third patted of summer precipitation is multicolor. The patted figures out relation with NAO and Pacific winter-spring SST anomalies especially in the esteem equatorial Pacific basin.