Jessie M. Creamean

• Ph.D.
• Researcher at Colorado State University

Action at a Distance Snowfall in the Sierra Nevada provides a large fraction of the water that California receives as precipitation. Knowing what factors influence the amount of snow that falls is thus critical for projecting how water availability may change in the future. Aerosols have an important effect on cloud processes and precipitation. Cre...

Aerosols that serve as cloud condensation nuclei (CCN) and ice nuclei (IN) have the potential to profoundly influence precipitation processes. Furthermore, changes in orographic precipitation have broad implications for reservoir storage and flood risks. As part of the CalWater field campaign (2009–2011), the variability and associated impacts of d...

The contribution of trans-Pacific dust estimated from satellite observations has been shown to be three times greater than domestic dust in North America throughout the year. Thus, a quantitative understanding of the frequency and locations where Asian dust is transported is necessary to improve global dust modeling for weather and climate predicti...

Determining the major sources of particles that act as cloud condensation nuclei (CCN) represents a critical step in the development of a more fundamental understanding of aerosol impacts on cloud formation and climate. Reported herein are direct measurements of the CCN activity of newly formed ambient particles, measured at a remote rural site in...

In the central Arctic, warm and moist air intrusions (WAMIs) are increasingly prevalent during winter and spring, significantly impacting the near-surface energy budget. This study investigates WAMI-induced transport and wet deposition of black carbon (BC) and its subsequent influence on snow properties and melting. Using a modeling approach combin...

The Alaskan Layered Pollution and Chemical Analysis (ALPACA) field campaign included deployment of a suite of atmospheric measurements in January–February 2022 with the goal of better understanding atmospheric processes and pollution under cold and dark conditions in Fairbanks, Alaska. We report on measurements of particle composition, particle siz...

The Arctic is sensitive to cloud radiative forcing. Due to the limited number of aerosols present throughout much of the year, cloud formation is susceptible to the presence of cloud condensation nuclei and ice nucleating particles (INPs). Primary biological aerosol particles (PBAP) contribute to INPs and can impact cloud phase, lifetime, and radia...

The interactions between aerosols and clouds are still one of the largest sources of uncertainty in quantifying anthropogenic radiative forcing. To reduce this uncertainty, we must first determine the baseline...

The rapid melt of snow and sea ice during the Arctic summer provides a significant source of low-salinity meltwater to the surface ocean on the local scale. The accumulation of this meltwater on, under, and around sea ice floes can result in relatively thin meltwater layers in the upper ocean. Due to the small-scale nature of these upper-ocean feat...

Polar environments are among the fastest changing regions on the planet. It is a crucial time to make significant improvements in our understanding of how ocean and ice biogeochemical processes are linked with the atmosphere. This is especially true over Antarctica and the Southern Ocean where observations are severely limited and the environment i...

Multiomics approaches need to be applied in the central Arctic Ocean to benchmark biodiversity change and to identify novel species and their genes. As part of MOSAiC, EcoOmics will therefore be essential for conservation and sustainable bioprospecting in one of the least explored ecosystems on Earth.

The increased fraction of first year ice (FYI) at the expense of old ice (second-year ice (SYI) and multi-year ice (MYI)) likely affects the permeability of the Arctic ice cover. This in turn influences the pathways of gases circulating therein and the exchange at interfaces with the atmosphere and ocean. We present sea ice temperature and salinity...

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of...

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of...

As the Arctic warms at twice the global rate, radiative feedbacks from clouds will lead to compounding impacts on the surface energy budget that affect both regional and global weather, and climate. In a future warmer world, the Arctic is projected to become cloudier. However, the formation and evolution of Arctic clouds remain highly uncertain in...

Ice-nucleating particles (INPs) have been found to influence the amount, phase and efficiency of precipitation from winter storms, including atmospheric rivers. Warm INPs, those that initiate freezing at temperatures warmer than -10 ∘C, are thought to be particularly impactful because they can create primary ice in mixed-phase clouds, enhancing pre...

Ice crystal numbers can exceed the numbers of ice-nucleating particles (INP) observed in mixed-phase clouds by several orders of magnitude also at temperatures that are colder than required for the Hallett-Mossop process (−3 °C to −8 °C). These observations provide circumstantial evidence of secondary ice formation. Attempting a more direct observa...

This study investigates the interactions between cloud dynamics and aerosols in idealized large-eddy simulations of an Arctic mixed-phase stratocumulus cloud observed at Oliktok Point, Alaska in April 2015. This case was chosen because it allows the cloud to form in response to radiative cooling starting from a cloud-free state, rather than requiri...

Ice nucleating particles (INP) have been found to influence the amount, phase, and efficiency of precipitation from winter storms, including atmospheric rivers. Warm INP, those that initiate freezing at temperatures warmer than −10°C, are thought to be particularly impactful because they can create primary ice in mixed-phase clouds, enhancing preci...

Aerosols have a profound impact on cloud microphysics through their ability to serve as ice nucleating particles (INPs). As a result, cloud radiative properties and precipitation processes can be modulated by such aerosol–cloud interactions. However, one of the largest uncertainties associated with atmospheric processes is the indirect effect of ae...

Aerosols that serve as ice nucleating particles (INPs) have the potential to modulate cloud microphysical properties and can therefore impact cloud radiative forcing and precipitation formation processes. In remote regions such as the Arctic, aerosol-cloud interactions are severely understudied yet may have significant implications for the surface...

Unmanned aerial capabilities offer exciting new perspectives on the Arctic atmosphere and the US Department of Energy is working with partners to offer such perspectives to the research community. Thorough understanding of aerosols, clouds, boundary layer structure and radiation is required to improve representation of the Arctic atmosphere in weat...

Aerosols have a profound impact on cloud microphysics through their ability to serve as ice nucleating particles (INPs). As a result, cloud radiative properties and precipitation processes are modulated by such aerosol-cloud interactions. However, one of the largest uncertainties associated with atmospheric processes is the indirect effect of aeros...

The Arctic is warming at an alarming rate, yet the processes that contribute to the enhanced warming are not well understood. Arctic aerosols have been targeted in studies for decades due to their consequential impacts on the energy budget, both directly and indirectly through their ability to modulate cloud microphysics. Even with the breadth of k...

Due to their importance for the radiation budget, liquid-containing clouds are a key component of the Arctic climate system. Depending on season, they can cool or warm the near-surface air. The radiative properties of these clouds depend strongly on cloud drop sizes, which are governed in part by the availability of cloud condensation nuclei. Here,...

There has been increasing interest in ice nucleation research in the last decade. To identify important gaps in our knowledge of ice nucleation processes and their impacts, two international workshops on ice nucleation were held in Vienna, Austria in 2015 and 2016. Experts from these workshops identified the following research needs: (1) uncovering...

The Arctic is warming at an alarming rate, yet the processes that contribute to enhanced warming are not well understood. Arctic aerosols have been targeted in studies for decades due to their consequential impacts on the energy budget directly and indirectly through their ability to modulate cloud microphysics. Even with the breadth of knowledge a...

Due to their importance for the radiation budget, liquid-containing clouds are a key component of the Arctic climate system. Depending on season, they can cool or warm the near-surface air. The radiative properties of these clouds depend strongly on cloud drop sizes, which are governed by the availability of cloud condensation nuclei. Here, we inve...

Biomass burning plumes containing aerosols from forest fires can be transported long distances, which can ultimately impact climate and air quality in regions far from the source. Interestingly, these fires can inject aerosols other than smoke into the atmosphere, which very few studies have evidenced. Here, we demonstrate a set of case studies of...

Ice formation in orographic mixed-phase clouds can enhance precipitation and depends on the type of aerosols that serve as ice nucleating particles (INPs). The resulting precipitation from these clouds is a viable source of water, especially for regions such as the California Sierra Nevada. Thus, a better understanding of the sources of INPs that i...

The aerosols that influence the initiation and amount of precipitation are cloud condensation nuclei (CCN), giant CCN, and ice nuclei. Aerosols are ever-present, their properties are variable, and their abundance is dynamic. Therefore, the extent of their impact on the outcome of meteorological contexts that are favorable for rain are difficult to...

Orographic snowfall in the Sierra Nevada Mountains is an important source of water for California and can vary significantly on an annual basis. The microphysical properties of orographic clouds and subsequent formation of precipitation are impacted, in part, by aerosols of varying size, number, and chemical composition, which are incorporated into...

Biomass burning plumes containing aerosols from forest fires can be transported long distances, which can ultimately impact climate and air quality in regions far from the source. Interestingly, these fires can inject aerosols other than smoke into the atmosphere, which very few studies have evidenced. Here, we demonstrate a set of case studies of...

Transported mineral dust deposition to remote mountain snow decreases snow albedo and increases absorption of solar radiation, which accelerates snowpack melt and alters water supply. Mineralogy and chemical composition determine dust particle optical properties, which vary by source region. While impacts of dust deposition at remote mountain sites...

Aerosols that serve as cloud condensation nuclei (CCN) and ice nuclei (IN) have the potential to profoundly influence precipitation processes. Furthermore, changes in orographic precipitation have broad implications for reservoir storage and flood risks. As part of the CalWater field campaign (2009-2011), the variability and associated impacts of d...

Atmospheric rivers (ARs) are narrow regions of enhanced water vapor transport, usually found on the warm-sector side of the polar cold front in many midlatitude storms formed primarily over the oceans. Nonbrightband (NBB) rain is a shallow orographic rainfall process driven by collision and coalescence that has been observed in some of these storms...

Particles are frequently incorporated into clouds or precipitation, influencing climate by acting as cloud condensation or ice nuclei, taking up coatings during cloud processing, and removing species through wet deposition. Many of these particles, particularly ice nuclei, can remain suspended within cloud droplets/crystals as insoluble residues. W...

Aerosols that serve as cloud condensation nuclei (CCN) and ice nuclei (IN) have the potential to profoundly influence precipitation processes. Furthermore, changes in orographic precipitation have broad implications for reservoir storage and flood risks. As part of the CalWater field campaign (2009–2011), the variability and associated impacts of d...

Vertically pointing S-band radar (S-PROF) observations collected during the CalWater field campaign winter wet seasons are analyzed to partition the observed rainfall into three primary categories: brightband (BB) rain, non-brightband (NBB) rain, and convective rain. NBB rain is primarily a shallow, warm rain process driven by collision and coalesc...

To assess the sources of cloud-active aerosol and their influence on the hydrological cycle in California, the CalWater Experiment took place in winter 2011 in the foothills of the Sierra Nevada Mountains. During this experiment, we coupled the capabilities of demonstrated miniaturized instrumentation - cloud condensation nuclei (CCN), water conden...

Cloud condensation nuclei (CCN) are aerosol particles that participate in the formation of clouds, and consequently, play a significant role in the influence of anthropogenic aerosols on atmospheric processes and climate change. Ultimately, the CCN of the most interest occupy the part of the atmosphere where cloud processes are occurring. A questio...

The CalWater 2011 campaign took place in the California Sierra Nevada with the objective of determining the effects atmospheric rivers and aerosols have on California precipitation. To meet this goal, the role of chemistry on atmospheric aerosols' ability to act as cloud condensation nuclei (CCN) needed to be evaluated because not all aerosols are...

Climate projections for the remainder of this century for the U.S. Southwest, including parts of California, suggest a drying trend (reductions ~ 10 -15 %). Thus, understanding factors which could potentially influence the amount and type of precipitation is critical to future water resources in California. Previous studies suggest aerosols transpo...

Aerosols that have the ability to act as ice nuclei (IN) can impact cloud formation and alter the type, amount, and location of precipitation. IN such as dust and biological aerosols can lead to early initiation of the ice phase that enhances riming and thus precipitation. Depending on temperature conditions, this can lead to increased snowfall at...

Aerosol particles play a crucial role in affecting cloud processes by serving as cloud nuclei. However, our understanding of which particles actually form cloud and ice nuclei limits our ability to treat aerosols properly in climate models. In recent years, it has become possible to measure the chemical composition of individual cloud nuclei within...

Organosulfate species have recently gained attention for their potentially significant contribution to secondary organic aerosol (SOA); however, their temporal behavior in the ambient atmosphere has not been probed in detail. In this work, organosulfates derived from isoprene were observed in single particle mass spectra in Atlanta, GA during the 2...

Asian dust is transported to North America and incorporated into cloudsCloud top dust glaciates supercooled drops or acts as IN increasing precipComparison of precipitation during 2 atmospheric rivers, one Asian with dust

Organosulfate species have recently been identified as a potentially significant class of secondary organic aerosol (SOA) species, yet little is known about their behavior in the atmosphere. In this work, organosulfates were observed in individual ambient aerosols using single particle mass spectrometry in Atlanta, GA during the 2002 Aerosol Nuclea...

Ultrafine particles (

Atmospheric rivers constitute a significant source of precipitation in the mid-latitudes of the northern hemisphere over relatively short time periods, but questions remain about the influence of external factors, such as aerosols, on precipitation locally and regionally. During the CalWater Early Start Campaign (Feb-Mar 2009) sampling aerosol meas...

Anthropogenic atmospheric aerosols play a large role in climate change by acting as cloud condensation nuclei (CCN) and influencing cloud reflectivity. The ability of anthropogenic aerosols to contribute to cloud droplet activation depends on particle size and composition. Up to 90% of fine particle mass (PM2.5) is composed of carbonaceous (element...