Spatio-temporal variation of the change in total water storage and precipitation using GRACE and TRMM data: Lima - Callao in PeruJuan

Authors

Mendoza, Juan

Rojas, Joel

Jimenez, Cesar

Leva, Antenor

Ortega, Yesmi

Abstract

Spatio-temporal variation of the anomalies of the gravity field associated with the change in total water storage and precipitation in Lima - Callao was analyzed. GRACE (Gravity Recovery and Climate Experiment) and TRMM (Tropical Rainfall Measuring Mission) data monthly were introduced in this study. Autocorrelation, cross-correlation and decomposition analysis of the time series was performed, finding that both series present annual cycles but with different intra-annual variations. The gravitational anomalies increased and decreased in an annual cycle, positive gravitational anomalies varied from December to May and negatives gravitational anomalies vary from June to November. Precipitation mainly presents an annual cycle, although other frequencies of lower spectral power of 6, 4 and 3 months were found, precipitation increases from August to March, decreases rapidly until May followed by a dry period from May to August. Cross correlation was applied between both time series obtaining a maximum correlation coefficient of 0.8677 for a lag of two months, this lag seems to be related to the recharge mechanisms of the total water storage, which reveals that the Lima - Callao region receives indirect recharge.