Paul W. Staten

Indiana University Bloomington | IUB · Department of Earth and Atmospheric Sciences

The Hadley circulation is the most prominent atmospheric meridional circulation, reducing the radiatively driven equator-to-pole temperature gradient. While the Hadley cell extent varies by several degrees from year to year, the detailed dynamical mechanisms behind such variations have not been well elucidated. During the expanded phase of the Hadl...

A poleward shift of the Hadley cell (HC) edge in a warming climate, which contributes to the expansion of drought-prone subtropical regions, has been widely documented. The question addressed here is whether this shift is reversible with CO2 removal. By conducting large-ensemble experiments where CO2 concentrations are systematically increased and...

Climate change is expected to have far‐reaching effects at both the global and regional scale, but local effects are difficult to determine from coarse‐resolution climate studies. Dynamical downscaling can provide insight into future climate projections on local scales. Here, we present a new dynamically downscaled dataset for Indiana and the surro...

The strength of Pacific Walker circulation (PWC) significantly affects the global weather patterns, the distribution of mean precipitation, and modulates the rate of global warming. Different indices have been used to assess the PWC strength. Evaluated on different datasets for various study periods, the indices show large discrepancies between the...

As they circumnavigate the planet, the tropospheric jet streams slowly drift north and south over about 30 days, longer than the normal limit of weather prediction. Understanding the source of this “memory” could improve our knowledge of how the atmosphere organizes itself and our ability to make long-term forecasts. Current theories have identifie...

Stratospheric aerosol geoengineering has been proposed as a potential solution to reduce climate change and its impacts. Here, we explore the responses of the Hadley circulation (HC) intensity and the intertropical convergence zone (ITCZ) using the strategic stratospheric aerosol geoengineering, in which sulfur dioxide was injected into the stratos...

Models disagree on how much the hydrologic cycle could intensify under climate change. These changes are expected to scale with the Clausius-Clapeyron relation but may locally diverge due to the uncertain response of the general circulation, causing the hydrologic cycle to inherit this uncertainty. To identify how the circulation contributes, we li...

In this paper, we present a new method to study global atmospheric processes and their changes during the last decade. A cosmogenic radionuclide measured at ground-level, beryllium-7, is utilized as a proxy to study atmospheric dynamics. Beryllium-7 has two advantages: First, this radionuclide, primarily created in the lower stratosphere, attaches...

This presentation shows how beryllium-7, which is a known atmospheric tracer, can be used to track the changes in tropopause height, such as tropopause breathing or multi annual variation. Data: The dataset used are beryllium-7 monthly mean compared to GPS-RO data which are satellite measurements for tropopause height. Findings: 1. High correlat...

Over the past 15 years, numerous studies have suggested that the sinking branches of Earth’s Hadley circulation and the associated subtropical dry zones have shifted poleward over the late 20 th century and early 21 st century. Early estimates of this tropical widening from satellite observations and reanalyses varied from 0.25° to 3° latitude per...

The width of the tropical Hadley circulation (HC) has garnered intense interest in recent decades, owing to the emerging evidence for its expansion in observations and models and to the anticipated impacts on surface climate in its descending branches. To better clarify the causes and impacts of tropical widening, this work generalizes the zonal me...

In the past decade, a number of studies have suggested that the subtropical edges of Earth’s Hadley circulationare shifting poleward. However, these estimates for so-called tropical expansion have spanned a large range, andestimates from the upper end of this range are significantly larger than that predicted by global climate models.In this talk,...

Previous studies have documented a poleward shift in the subsiding branches of Earth's Hadley circulation since 1979 but have disagreed on the causes of these observed changes and the ability of global climate models to capture them. This synthesis paper reexamines a number of contradictory claims in the past literature and finds that the tropical...

In the version of this Review originally published, the affiliations for author Sean M. Davis were incomplete. An additional affiliation, “Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado, USA”, has now been added.

Observational and modeling studies suggest that Earth's tropical belt has widened over the late 20th century and will continue to widen throughout the 21st century. Yet, estimates of tropical-width variations differ significantly across studies. This uncertainty, to an unknown degree, is partly due to the large variety of methods used in studies of...

Observations reveal a poleward expansion of the tropics in recent decades, implying a potential role of human activity. However, although theory and modelling suggest increasing GHG concentrations should widen the tropics, previous observational-based studies depict disparate rates of expansion, including many that are far higher than those simulat...

Observational and modeling studies suggest that Earth's tropical belt has widened over the late 20th century and will continue to widen throughout the 21st century. Yet estimates of tropical width variations differ significantly across studies. This uncertainty, to an unknown degree, is partly due to the large variety of methods used in studies of...

There is mounting evidence that the width of the tropics has increased over the last few decades, but there are large differences in reported expansion rates. This is, likely, in part due to the wide variety of metrics that have been used to define the tropical width. Here we perform a systematic investigation into the relationship among nine metri...

In recent decades, the subtropical edges of Earth's Hadley circulation have shifted poleward. Some studies have concluded that this observed tropical expansion is occurring more rapidly than predicted by global climate models. However, recent modeling studies have shown that internal variability can account for a large fraction of the observed circ...

We are deeply concerned with the trend toward the purchase of commercial weather and climate data by the National Oceanic and Atmospheric Administration (NOAA) and other government agencies that may follow. One major concern is for the stability of both the raw and processed forms of these datasets as commercial enterprises come and go. Also of con...

Understanding how regional hydrological extremes would respond to warming is a grand challenge to the community of climate change research. A novel diagnostic framework based on the wave activity is developed for column integrated water vapor (CWV) to afford the probe into the higher moments of the hydrological cycle. Applying the CWV wave activity...

The response of the atmospheric circulation to greenhouse gas-induced SST warming is investigated using large ensemble experiments with two AGCMs, with a focus on the robust feature of the poleward shift of the eddy driven jet. In these experiments, large ensembles of simulations are conducted by abruptly switching the SST forcing on from January 1...

This paper describes a cloud type radiance record derived from NOAA polar-orbiting weather satellites using cloud properties retrieved from the Advanced Very High Resolution Radiometer (AVHRR) and spectral brightness temperatures (Tb) observed by the High Resolution Infrared Radiation Sounder (HIRS). The authors seek to produce a seamless, global-s...

Cold frontal passages are a common occurrence throughout the eastern United States. Previous observational research showed the surprising result that there is only a very weak, statistically nonsignificant relationship between a cold front's maximum 2-min sustained wind and the across-front temperature gradient. By using the WRF-ARW model to simula...

Cold frontal passages are a relatively common occurrence throughout the eastern United States. Such frontal systems are often accompanied by intense winds capable of causing damage to forests and human-built structures. Previous research has shown that while a cold front's maximum 2-minute sustained winds (ASOS-measured) do tend to increase with in...

The recent poleward shift of the southern hemisphere midlatitude jet, though largely reproducible in climate simulations, is not well understood. To study the underlying mechanisms, we apply idealized, instantaneous forcings in a realistic atmospheric general circulation model (GFDL AM2.1). The prescribed forcings include greenhouse gas increases,...

Over the past billion years, Indiana has experienced many climate extremes. In this talk, we will review some climate change events from Indiana’s deep paleoclimate history, like ice ages and thermal maxima, along with more recent climate events like the year without a summer, and the recent cold winters in the Northeast. We will discuss why Bloomi...

The difficulty of modeling and observing cloud processes continue to stymie efforts at tracking and projecting cloud behavior in a changing climate. While robust determination of the global cloud feedback remains elusive, the ~30-year radiance record from High Resolution Infrared Radiation Sounders (HIRS) and the corresponding visible imagery datab...

Tropospheric circulation shifts have strong potential to impact surface climate. However, the magnitude of these shifts in a changing climate and the attending regional hydrological changes are difficult to project. Part of this difficulty arises from the lack of understanding of the physical mechanisms behind the circulation shifts themselves. To...

Tropospheric circulation shifts have strong potential to impact surface climate. However, the magnitude of these shifts in a changing climate and the attending regional hydrological changes are difficult to project. Part of this difficulty arises from the lack of understanding of the physical mechanisms behind the circulation shifts themselves. To...

This study explores the relationship between latitudinal shifts in the eddy-driven jet and in the Hadley cell edge as depicted in models and reanalyses. We calculate an interannual shift ratio of approximately 1.5:1 between the eddy-driven jet and the Hadley cell edge over the Southern Hemisphere during austral summer in model data. We further find...

This study describes simulated changes in the general circulation during the twentieth and twenty-first centuries due to a number of individual direct radiative forcings and warming sea surface temperatures, by examining very long time-slice simulations created with an enhanced version of the Geophysical Fluid Dynamics Laboratories Atmospheric Mode...

A confounding factor in understanding the mechanisms behind tropospheric circulation change is that the atmosphere responds not only to radiative forcings but also to the resulting sea surface temperature (SST) changes. The additional effect of SST changes may be termed the indirect response. Previous research has documented mainly the net atmosphe...

1] The abundant atmospheric data provided by radio occultation (RO) via the Global Positioning System satellite network have improved short and long-term forecasts and have demonstrated the potential to provide a long-term, consistent, and independent climate dataset. Previous studies have already verified the consistency and reliability of the RO...

Long-term trends in tropopause height and temperature may be indicators of changes in critical components of the atmospheric general circulation, such as the Hadley cell and the Brewer-Dobson circulation. Unfortunately, the global tropopause has historically been poorly observed. Tropopause records derived from reanalysis may be unreliable due to c...

Research suggests that changes in tropopause structure can both indicate and impact changes in the global climate system. The Global Positioning System radio occultation (RO) technique shows tremendous potential for monitoring the global tropopause due to its precision, temporal consistency, and global measurement density. This study examines the c...

Microscopic imaging, when combined with spectroscopic methods, can enable assessments of habitability based on observations of mineralogy at a scale relevant to microbial life. The Multispectral Microscopic Imager (MMI) is being developed to provide this capability.

Research suggests that changes in tropopause structure can both indicate and impact changes in the global climate system. The Global Positioning System radio occultation (RO) technique shows tremendous potential for monitoring the global tropopause due to its precision, temporal consistency, and global measurement density. This study examines the c...