Daily Rainfall Variability over Northeastern Argentina in the La Plata River Basin

Abstract

We did a brief description of the climatic behavior and after this we analyzed the temporal variation in the total number of days a year with rainfall and the number of days a year with rainfall above the 100 mm threshold at the rain gauging stations in northeastern Argentina south of the La Plata River basin. The results show an increase both in the frequency of daily rainfall, especially during the winter season, and the frequency of days with heavy rainfall starting in the early 1970s. The increase in frequency of occurrence is more significant in the case of heavy rainfall. The annual maximum rainfall was calculated for periods of 1, 3, 5, 7, and 10 consecutive days at regional rain gauging stations for the respective historical periods, and the rain intensity-duration-return period curves (IDT) were determined on a frequency analysis. The IDT curves were compared with rainfall intensity-duration data of critical storms occurring in the last decades. We noticed that the rain intensities of critical storms (mostly convective) widely exceeded the intensities given by the 100-year IDT curves, particularly for short durations. The increase in both the frequency of heavy rainfall occurrence and rain intensity from the 1970s onward shows an increase in frequency and intensity of the meso-scale convective systems in the region resulting from climatic change. These systems tend to produce rainfall of very high intensity that is spatially concentrated and which generally produces significant floods in the local rivers.

Precipitation event distribution in Central Argentina: spatial and temporal patterns

“…The plains of central Argentina span 1000 km from the eastern foot slope of the Andes to the Atlantic coast, along which mean precipitation increases from ~100 to ~1000 mm year −1 . During the 20th century, the entire region experienced a dry period (1930–1960) followed by a wet one (1960–2000) (Minetti et al ., ; García and Pedraza, ). These climatic shifts, which had been linked to long‐term atmosphere/ocean circulation oscillations (Agosta and Compagnucci, ), and also to climate warming (Villalba et al ., ; Labraga and Villalba, ), were accompanied by a contraction of the cultivated area during the first half of the century and a very strong expansion during the second half (Aizen et al ., ), favoured, in this last period, by technological changes and high international grain prices (Viglizzo et al ., ).…”

Modulation of Pulmonary Vascular Remodeling in Hypoxia: Role of 15-LOX-2/15-HETE-MAPKs Pathway

“…In contrast, p38MAPK has been found to be involved in apoptosis, endotoxic response, and osmotic stress [15][16][17][18]. JNK/stress activated protein kinase (SAPK) is response to growth factors, cytokines, environmental stress, ultraviolet light, oxidative stress, and heat shock [19][20][21][22][23]. It has been shown that activation of JNK by 5-hydroxytryptamine results in the enhanced proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) [24].…”