npj Climate and Atmospheric Science

http://www.nature.com/npjclimatsci

List of Papers (Total 48)

Frequency of severe thunderstorms across Europe expected to increase in the 21st century due to rising instability

We show that the frequency of damaging convective weather events including lightning, hail and severe wind gusts will likely increase over Europe until the end of this century. We apply a set of additive regression models to an ensemble of 14 regional climate simulations and find that convective instability will increase as a result of rising humidity near the earth’s surface...

Long-lead ENSO control of the boreal summer intraseasonal oscillation in the East Asian-western North Pacific region

The boreal summer 30–60-day intraseasonal oscillation (ISO) in the East Asian-western North Pacific (EAWNP) region strongly influences persistent heavy rainfall in East Asia and tropical cyclone activities in the tropical western Pacific. In this study, we show that there exists a significant interannual south-north shift of the EAWNP-ISO activity between the equatorial eastern...

Improved calculation of warming-equivalent emissions for short-lived climate pollutants

Anthropogenic global warming at a given time is largely determined by the cumulative total emissions (or stock) of long-lived climate pollutants (LLCPs), predominantly carbon dioxide (CO2), and the emission rates (or flow) of short-lived climate pollutants (SLCPs) immediately prior to that time. Under the United Nations Framework Convention on Climate Change (UNFCCC), reporting...

Aerosol-induced modification of organised convection and top-of-atmosphere radiation

Aerosol effects on cloud cover and precipitation could affect the global climate but have proven difficult to verify, because cloud and rain amounts are so strongly influenced by local meteorological conditions. Here model and observational evidence is presented that an increase in CCN concentration slightly invigorates mixed-phase convective clouds and narrows tropical...

‘Eastern African Paradox’ rainfall decline due to shorter not less intense Long Rains

An observed decline in the Eastern African Long Rains from the 1980s to late 2000s appears contrary to the projected increase under future climate change. This “Eastern African climate paradox” confounds use of climate projections for adaptation planning across Eastern Africa. Here we show the decline corresponds to a later onset and earlier cessation of the long rains, with a...

Using the standard deviational ellipse to document changes to the spatial dispersion of seasonal tornado activity in the United States

Recent studies have documented possible ongoing changes to the climatology of tornadoes in the United States. Observed changes include increasing tornado counts in the Southeast and Midwest Regions, decreasing tornado counts in the Great Plains, and increased clustering of tornadoes on fewer days of the year. This study illustrates that the spatial dispersion of tornadoes in the...

Hurricane stalling along the North American coast and implications for rainfall

The average speed of tropical cyclone (TC) translation has slowed since the mid 20th century. Here we report that North Atlantic (NA) TCs have become increasingly likely to “stall” near the coast, spending many hours in confined regions. The stalling is driven not only by slower translation, but also by an increase in abrupt changes of direction. We compute residence-time...

Little evidence of reduced global tropical cyclone activity following recent volcanic eruptions

The impact of volcanic aerosols on recent global tropical cyclone (TC) activity is examined in observations, reanalysis, and models (the Coupled Model Intercomparison Project phase 5 - CMIP5 multi-model, and one single model large ensemble). In observations, we find a reduction of TC activity only in the North Atlantic following the last three strong volcanic eruptions; that...

Robust skill of decadal climate predictions

There is a growing need for skilful predictions of climate up to a decade ahead. Decadal climate predictions show high skill for surface temperature, but confidence in forecasts of precipitation and atmospheric circulation is much lower. Recent advances in seasonal and annual prediction show that the signal-to-noise ratio can be too small in climate models, requiring a very large...

Methane emissions from groundwater pumping in the USA

Atmospheric methane accumulation contributes to climate change, hence quantifying methane emissions is essential to assess and model the impacts. Here, we estimate methane emissions from groundwater pumping in the Los Angeles Basin (LAB), north-eastern Pennsylvania, and the Principal aquifers of the USA using the average concentrations of methane in groundwater and annual...

A dichotomy between model responses of tropical ascent and descent to surface warming

Simulations of tropical atmospheric circulation response to surface warming vary substantially across models, causing large uncertainties in projections of regional precipitation change. Understanding the physical processes that drive the model spread in tropical circulation changes is critically needed. Here we employ the basic mass balance and energetic constraints on tropical...

Future increase in extreme El Nino events under greenhouse warming increases Zika virus incidence in South America

The Zika virus (ZIKV) was first found in Zika forest, Uganda in 1947. The disease appeared in the Americas, Northeast Brazil in May 2015. ZIKV propagated rapidly across the Americas and the World Health Organization (WHO) in February 2016 declared this as a public health emergency of international concern. The temperature conditions related to extreme El Niño of 2015–16 were...

The changing validity of tropical cyclone warnings under global warming

Hurricanes and typhoons are a regular threat to large populations across the globe. Facing the potential of a storm disaster the warning process and associated administrative activities across the western North Pacific are confounded by various tropical cyclone classifications. Here, we show that current storm warning categories have suffered from the warming environment over the...

Terrestrial evaporation response to modes of climate variability

Large-scale modes of climate variability (or teleconnection patterns), such as the El Niño Southern Oscillation and the North Atlantic Oscillation, affect local weather worldwide. However, the response of terrestrial water and energy fluxes to these modes of variability is still poorly understood. Here, we analyse the response of evaporation to 16 teleconnection patterns, using a...

Trends in weather type frequencies across North America

While 20th century changes in many individual meteorological variables are well documented, the trends in multivariate synoptic-scale air masses—or weather types—largely remain unexplored. Utilizing a recently developed gridded weather typing classification system, this research investigates the changes in the frequency of weather types (WTs) across North America, 1979–2017...

The influence of the Atlantic multidecadal oscillation on the eastern Andes low-level jet and precipitation in South America

The South America low-level jet (SALLJ) on the eastern slopes of the Andes is a unique climatological feature in the continent. The SALLJ transports large amounts of moisture and controls the spatiotemporal variability of precipitation in southeast South America. This study shows a remarkable influence of the Atlantic Multidecadal Oscillation (AMO) on decadal-to-multidecadal...

Discovery of a lunar air temperature tide over the ocean: a diagnostic of air-sea coupling

The lunar semidiurnal (L2) tide in the Earth’s atmosphere is unique as a purely mechanically forced periodic signal and it has been detected in upper atmosphere winds and temperature and in surface barometric pressure. L2 signals in surface air temperature, L2(T), have only been detected at a single land station (results published almost a century ago). We report observational...

Spatial trends in United States tornado frequency

Severe thunderstorms accompanied by tornadoes, hail, and damaging winds cause an average of 5.4 billion dollars of damage each year across the United States, and 10 billion-dollar events are no longer uncommon. This overall economic and casualty risk—with over 600 severe thunderstorm related deaths in 2011—has prompted public and scientific inquiries about the impact of climate...

Short Black Carbon lifetime inferred from a global set of aircraft observations

Black Carbon (BC) aerosols substantially affect the global climate. However, accurate simulation of BC atmospheric transport remains elusive, due to shortcomings in modeling and a shortage of constraining measurements. Recently, several studies have compared simulations with observed vertical concentration profiles, and diagnosed a global-mean BC atmospheric residence time of <5...

Response of surface ozone over the continental United States to UV radiation declines from the expected recovery of stratospheric ozone

The response of surface ozone concentrations to decreases in ultraviolet (UV) radiation that are expected from the recovery of stratospheric ozone by the end of the twenty-first century is examined with the regional WRF–Chem model. The study is performed over the continental United States for the summer of 2010 at 12 km horizontal resolution which, compared to previous studies...

Global urban climatology: a meta-analysis of air temperature trends (1960–2009)

Air temperature trends (1960–2009) based on stations in cities, minus those based on global surface temperature datasets, are defined herein as urban heat island (UHI) trends. Urban climate was examined globally by comparing UHI trends with indices of geophysical factors, including background climate, latitude, and diurnal temperature range (DTR) and indices of artificial factors...

Evidence for a volcanic underpinning of the Atlantic multidecadal oscillation

The Atlantic multidecadal oscillation (AMO) is a 60–70 year pattern of sea-surface temperature (SST) variability in the North Atlantic commonly ascribed to internal ocean dynamics and changes in northward heat transport. Recent modeling studies, however, suggest that SSTs fluctuate primarily in response to major volcanic eruptions and changes in atmospheric circulation. Here, we...

Wildfire-driven thunderstorms cause a volcano-like stratospheric injection of smoke

Intense heating by wildfires can generate deep, smoke-infused thunderstorms, known as pyrocumulonimbus (pyroCb), which can release a large quantity of smoke particles above jet aircraft cruising altitudes. Injections of pyroCb smoke into the lower stratosphere have gained increasing attention over the past 15 years due to the rapid proliferation of satellite remote sensing tools...