RadarNet-Sur First Weather Radar Network in Tropical High Mountains

Abstract

Weather radar networks are indispensable tools for forecasting and disaster prevention in industrialized countries. However, they are far less common in the countries of South America, which frequently suffer from an underdeveloped network of meteorological stations. To address this problem in southern Ecuador, this article presents a novel radar network using cost-effective, single-polarization, X-band technology: the RadarNet-Sur. The RadarNet-Sur network is based on three scanning X-band weather radar units that cover approximately 87,000 km2 of southern Ecuador. Several instruments, including five optical disdrometers and two vertically aligned K-band Doppler radar profilers, are used to properly (inter) calibrate the radars. Radar signal processing is a major issue in the high mountains of Ecuador because cost-effective radar technologies typically lack Doppler capabilities. Thus, special procedures were developed for clutter detection and beam blockage correction by integrating ground-based and satelliteborne measurements. To demonstrate practical applications, a map of areas frequently affected by intense rainfall is presented, based on a time series of one radar that has been in operation since 2002. Such information is of vital importance to, for example, infrastructure management because rain-driven landslides are a major issue for road maintenance and safety throughout Ecuador. The presented case study of exceptionally strong rain events during the recent El Niño in March 2015 highlights the system’s practicality in weather forecasting related to disaster management. For the first time, RadarNet-Sur warrants a spatial-explicit observation of El Niño-related heavy precipitation in a transect from the coast to the highlands in a spatial resolution of 500 m.

Spatial functional data analysis for regionalizing precipitation seasonality and intensity in a sparsely monitored region: Unveiling the spatio‐temporal dependencies of precipitation in Ecuador

“…Despite the important finding of regions C.1 and C.2, there are some drawbacks in the regionalization of precipitation seasonality obtained in the present study. The seasonality along the eastern escarpments of the Andes (e.g., close to Pastaza or San Simon) as shown in Bendix and Lauer (), has not been captured. Similarly, unimodal, bimodal, and trimodal seasonality were found in small areas of southern Ecuador (Celleri et al, ; Campozano et al, ).…”

“…Nevertheless, the micro-climates and local precipitation variability (originated by mountain-valley breezes and local convection), were not captured by our Mean distance (km) to validation rain gauges approach because of the coarse resolution of TRMM. Yet we expect that more localized seasonality patterns could also be revealed with the use of larger spatial resolutions, such as those provided by radar images (Bendix et al, 2017), the recently launched GPM Core Satellite, with its IMERG product (Huffman et al, 2014) and downscaled TRMM products (Manz et al, 2016;Ulloa et al, 2017).…”

Strongest MJO on Record Triggers Extreme Atacama Rainfall and Warmth in Antarctica

“…This extreme Antarctic heat wave triggered a significant melting on the Larsen C ice sheet (Munneke et al, 2018) and was ultimately traced to foehn-induced warming that resulted from a landfalling atmospheric river (Bozkurt et al, 2018). Floods and extreme precipitation were also reported during the second half of March 2015 along the semiarid coast of Northern Peru and Ecuador (Bendix et al, 2017) Given the rarity of these events, the extreme nature of these environments and the fact that they occurred simultaneously over a large region of the Eastern Pacific, we look for a common large-scale origin of this compound extreme event. Barotropic linear ray tracing theory and wave activity fluxes are used as dynamical diagnoses to argue for a Rossby wave propagation from the tropics.…”

Climate seasonality and tree growth strategies in a tropical dry forest

“…This may be interpreted in two ways. On the one hand, and since the amount of precipitation can strongly vary between valley bottoms and mountain summits, or even between contiguous valleys (Bendix et al, ), it is possible that stem increments at the beginning of the growing season are more affected by common, coarse‐scale temperature increases than by varying, local‐scale rainfall amounts. The positive significant correlation between monthly temperature and rainfall over the study period, and the stronger response of monthly stem increments to temperature than to rainfall, support this interpretation.…”

“…This may be interpreted in two ways. On the one hand, and since the amount of precipitation can strongly vary between valley bottoms and mountain summits, or even between contiguous valleys (Bendix et al, 2017), it is possible that stem TA B L E 2 Results of variable coefficient models comparing intra-annual stem increment curves of pairs of species Notes: p-Values for the spline curves modeling the deviation of the increment pattern of one of the species from the spline fitted for both species together are shown. ***p < 0.001.…”