Orbital modulation of subtropical versus subantarctic moisture sources in the southeast Pacific mid-latitudes.

Reconstructing rainfall variability and moisture sources is a critical aspect to understand past and future hydroclimate dynamics. Here, we use changes in the deuterium content of land-plant leaf waxes from two marine sediment cores located off Chile to reconstruct changes in rainfall amount and variation in moisture sources over the last ~50 ka. The records indicate increased moisture in central Chile during precession maxima, but an obliquity modulation is evident in southern Chile.

Widespread synchronous decline of Mediterranean-type forest driven by accelerated aridity.

Large-scale, abrupt ecosystem change in direct response to climate extremes is a critical but poorly documented phenomenon. Yet, recent increases in climate-induced tree mortality raise concern that some forest ecosystems are on the brink of collapse across wide environmental gradients. Here we assessed climatic and productivity trends across the world's five Mediterranean forest ecosystems from 2000 to 2021 and detected a large-scale, abrupt forest browning and productivity decline in Chile (>90% of the forest in <100 days), responding to a sustained, acute drought.

Volatile organic compounds measured by proton transfer reaction mass spectrometry over the complex terrain of Quintero Bay, Central Chile.

This research provides new evidence regarding the different kinds of air quality episodes, and their underlying mechanisms, that frequently impact the urban area of Quintero Bay in Central Chile, which is located along complex coastal terrain and is surrounded by industries. The monitoring campaign was carried out in January 2022 and encompassed two distinctive meteorological regimes. The first part of the month was dominated by a coastal low centered to the south of Quintero, which resulted in prevailing northerly flow (or weak southerlies) and a deep cloud-topped marine boundary layer.

Oceanography time series reveals annual asynchrony input between oceanic and estuarine waters in Patagonian fjords.

The postglacial Patagonian fjord system along the west coast of southern South America is one of the largest stretches of the southern hemisphere (SH) fjord belt, influenced by the SH westerly wind belt and continental freshwater input. This study reports a 3-year monthly time series (2017-2020) of physical and biogeochemical parameters obtained from the Reloncaví Marine Observatory (OMARE, Spanish acronym) at the northernmost embayment and fjord system of Patagonia. The main objective of this work was to understand the land-atmosphere-ocean interactions and to identify the mechanisms that modulate the density of phytoplankton.

Hydrological droughts in the southern Andes (40-45°S) from an ensemble experiment using CMIP5 and CMIP6 models.

The decrease in freshwater input to the coastal system of the Southern Andes (40-45°S) during the last decades has altered the physicochemical characteristics of the coastal water column, causing significant environmental, social and economic consequences. Considering these impacts, the objectives were to analyze historical severe droughts and their climate drivers, and to evaluate the hydrological impacts of climate change in the intermediate future (2040-2070). Hydrological modelling was performed in the Puelo River basin (41°S) using the Water Evaluation and Planning (WEAP) model.

Multiscale physical background to an exceptional harmful algal bloom of Dinophysis acuta in a fjord system.

Dinophysis acuta produces diarrhetic shellfish poisoning (DSP) toxins and pectenotoxins (PTX). It blooms in thermally-stratified shelf waters in late summer in temperate to cold temperate latitudes. Despite its major contribution to shellfish harvesting bans, little effort has been devoted to study its population dynamics in Chilean Patagonia.

Extreme Drought Affects Visitation and Seed Set in a Plant Species in the Central Chilean Andes Heavily Dependent on Hummingbird Pollination.

Rising temperatures and increasing drought in Mediterranean-type climate areas are expected to affect plant-pollinator interactions, especially in plant species with specialised pollination. Central Chile experienced a mega drought between 2010 and 2020 which reached an extreme in the austral summer of 2019-2020. Based on intensive pollinator sampling and floral studies we show that the subalpine form of (Asteraceae) is a specialised hummingbird-pollinated species.

Hydroclimatic conditions trigger record harmful algal bloom in western Patagonia (summer 2016).

A harmful algal bloom (HAB) of the raphidophyta alga Pseudochattonella cf. verruculosa during the 2016 austral summer (February-March) killed nearly 12% of the Chilean salmon production, causing the worst mass mortality of fish and shellfish ever recorded in the coastal waters of western Patagonia. The HAB coincided with a strong El Niño event and the positive phase of the Southern Annular Mode that altered the atmospheric circulation in southern South America and the adjacent Pacific Ocean.