Peaks of Fine Particulate Matter May Modulate the Spreading and Virulence of COVID-19.

A probe of a patient, seeking help in an emergency ward of a French hospital in late December 2019 because of Influenza like symptoms, was retrospectively tested positive to COVID-19. Despite the early appearance of the virus in Europe, the prevalence and virulence appeared to be low for several weeks, before the spread and severity of symptoms increased exponentially, yet with marked spatial and temporal differences. Here, we compare the possible linkages between peaks of fine particulate matter (PM2.

Development of a combined empirical index for a 5-day forecast of heavy precipitation over the Bernese Alps.

The Bernese Alps are a region that is very prone for the initiation of thunderstorms. In fact, the flow and convergence of air and water vapor from the Swiss Plateau to the Swiss Alps is frequently favouring the formation of isolated rainfall events, which then may cause loss and damage in settlements. Due to the complex topography of the Bernese Alps, the forecasting and nowcasting of heavy convective precipitation remain challenging.

Anticipating cascading effects of extreme precipitation with pathway schemes - Three case studies from Europe.

Extreme precipitation events with high local precipitation intensities, heavy snowfall or extensive freezing rain can have devastating impacts on society and economy. Not only is the quantitative forecast of such events sometimes difficult and associated with large uncertainties, also are the potential consequences highly complex and challenging to predict. It is thus a demanding task to anticipate or nowcast the impacts of extreme precipitation, even more so in situations where human lives or critical infrastructure might be at risk.

On the extraordinary winter flood episode over the North Atlantic Basin in 1936.

In this study, we analyze the linkage between atmosphere and ocean modes and winter flood variability over the 20th century based on long-term flow-discharge series, historical archives, and tree-ring records of past floods in the North Atlantic Basin (NAB). The most extreme winter floods occurred in 1936 and had strong impacts on either side of the Atlantic. We hypothesize that the joint effects of sea surface temperatures (SSTs) over the Atlantic and Pacific Oceans and the Arctic Oscillation (AO), which is closely related to the North Atlantic Oscillation, play a significant role when describing flood variability in North America and Europe since 1900.

Missing (in-situ) snow cover data hampers climate change and runoff studies in the Greater Himalayas.

The Himalayas are presently holding the largest ice masses outside the polar regions and thus (temporarily) store important freshwater resources. In contrast to the contemplation of glaciers, the role of runoff from snow cover has received comparably little attention in the past, although (i) its contribution is thought to be at least equally or even more important than that of ice melt in many Himalayan catchments and (ii) climate change is expected to have widespread and significant consequences on snowmelt runoff. Here, we show that change assessment of snowmelt runoff and its timing is not as straightforward as often postulated, mainly as larger partial pressure of H2O, CO2, CH4, and other greenhouse gases might increase net long-wave input for snowmelt quite significantly in a future atmosphere.