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Articles 31 - 60 of 110

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

The O2/N2 Ratio And Co2 Airborne Southern Ocean Study, Britton Stephens, Matthew Long, Ralph Keeling, Eric Kort, Colm Sweeney, Eric Apel, Elliot Atlas, Stuart Beaton, Jonathan Bent, Nicola Blake, James Bresch, Joanna Casey, Bruce Daube, Minghui Diao, Ernesto Diaz, Heidi Dierssen, Valeria Donets, Bo-Cai Gao, Michelle Gierach, Robert Green, Justin Haag, Matthew Hayman, Alan Hills, Martín Hoecker-Martínez, Shawn Honomichl, Rebecca Hornbrook, Jorgen Jensen, Rong-Rong Li, Ian Mccubbin, Kathryn Mckain, Eric Morgan, Scott Nolte, Jordan Powers, Bryan Rainwater, Kaylan Randolph, Mike Reeves, Sue Schauffler, Katherine Smith, Mackenzie Smith, Jeff Stith, Gregory Stossmeister, Darin Toohey, Andrew Watt Feb 2018

The O2/N2 Ratio And Co2 Airborne Southern Ocean Study, Britton Stephens, Matthew Long, Ralph Keeling, Eric Kort, Colm Sweeney, Eric Apel, Elliot Atlas, Stuart Beaton, Jonathan Bent, Nicola Blake, James Bresch, Joanna Casey, Bruce Daube, Minghui Diao, Ernesto Diaz, Heidi Dierssen, Valeria Donets, Bo-Cai Gao, Michelle Gierach, Robert Green, Justin Haag, Matthew Hayman, Alan Hills, Martín Hoecker-Martínez, Shawn Honomichl, Rebecca Hornbrook, Jorgen Jensen, Rong-Rong Li, Ian Mccubbin, Kathryn Mckain, Eric Morgan, Scott Nolte, Jordan Powers, Bryan Rainwater, Kaylan Randolph, Mike Reeves, Sue Schauffler, Katherine Smith, Mackenzie Smith, Jeff Stith, Gregory Stossmeister, Darin Toohey, Andrew Watt

Faculty Publications, Meteorology and Climate Science

The Southern Ocean plays a critical role in the global climate system by mediating atmosphere–ocean partitioning of heat and carbon dioxide. However, Earth system models are demonstrably deficient in the Southern Ocean, leading to large uncertainties in future air–sea CO2 flux projections under climate warming and incomplete interpretations of natural variability on interannual to geologic time scales. Here, we describe a recent aircraft observational campaign, the O2/N2 Ratio and CO2 Airborne Southern Ocean (ORCAS) study, which collected measurements over the Southern Ocean during January and February 2016. The primary research objective of the ORCAS campaign was to improve observational constraints …


Hurricane Fred (2015): Cape Verde's First Hurricane In Modern Times: Observations, Impacts, And Lessons Learned, Gregory Jenkins, Ester Brito, Emanuel Soares, Sen Chiao, Jose Lima, Benvendo Tavares, Angelo Cardoso, Francisco Evora, Maria Monteiro Jan 2018

Hurricane Fred (2015): Cape Verde's First Hurricane In Modern Times: Observations, Impacts, And Lessons Learned, Gregory Jenkins, Ester Brito, Emanuel Soares, Sen Chiao, Jose Lima, Benvendo Tavares, Angelo Cardoso, Francisco Evora, Maria Monteiro

Faculty Publications, Meteorology and Climate Science

During 31 August 2015, Hurricane Fred traversed through the Cape Verde islands, passing near Boa Vista and possibly making landfall over São Nicolau during the evening hours. Hurricane Fred was a category 1 storm with maximum winds of 75 kt and a sea level pressure of 986 hPa during 31 August. The African easterly wave associated with Tropical Cyclone (TC) Fred emerged from Guinea on 29 August and was named Tropical Storm Fred on 30 August. Prior to impacting Cape Verde, the storm caused the sinking of a ship and the loss of seven lives off the coast of Guinea-Bissau …


Global Climate Change I-Ii, Kendall Barrett Sooter, Dione Rossiter, Costanza Rampini Jan 2018

Global Climate Change I-Ii, Kendall Barrett Sooter, Dione Rossiter, Costanza Rampini

Faculty Publications, Environmental Studies

Many different scientific observations and measurements indicate that Earth is experiencing global-scale changes in climate, i.e., in the long-term distributions of temperature, cloud cover, precipitation, and extreme weather events. Scientific consensus considers most these changes to be caused or accelerated by human activities. The economic, ecological, social, and cultural challenges caused by global climate change will affect everyone on the planet, and are very likely to have disproportionate impacts on developing nations. In this course, we will study global climate change from an interdisciplinary perspective, incorporating natural and social science approaches to understanding processes and effects. We will study the …


Ice Nucleation Parameterization And Relative Humidity Distribution In Idealized Squall-Line Simulations, Minghui Diao, George Bryan, Hugh Morrison, Jorgen Jensen Sep 2017

Ice Nucleation Parameterization And Relative Humidity Distribution In Idealized Squall-Line Simulations, Minghui Diao, George Bryan, Hugh Morrison, Jorgen Jensen

Faculty Publications, Meteorology and Climate Science

Output from idealized simulations of a squall line are compared with in situ aircraft-based observations from the Deep Convective Clouds and Chemistry campaign. Relative humidity distributions around convection are compared between 1-Hz aircraft observations (≈250-m horizontal scale) and simulations using a double-moment bulk microphysics scheme at three horizontal grid spacings: Δx = 0.25, 1, and 4 km. The comparisons focus on the horizontal extent of ice supersaturated regions (ISSRs), the maximum and average relative humidity with respect to ice (RHi) in ISSRs, and the ice microphysical properties during cirrus cloud evolution, with simulations at 0.25 and 1 km providing better …


A Lab-On-Chip Phosphate Analyzer For Long-Term In Situ Monitoring At Fixed Observatories: Optimization And Performance Evaluation In Estuarine And Oligotrophic Coastal Waters, Maxime Grand, Geraldine Clinton-Bailey, Alexander Beaton, Allison Schaap, Thomas Johengen, Mario Tamburri, Douglas Connelly, Matthew Mowlem, Eric Achterberg Aug 2017

A Lab-On-Chip Phosphate Analyzer For Long-Term In Situ Monitoring At Fixed Observatories: Optimization And Performance Evaluation In Estuarine And Oligotrophic Coastal Waters, Maxime Grand, Geraldine Clinton-Bailey, Alexander Beaton, Allison Schaap, Thomas Johengen, Mario Tamburri, Douglas Connelly, Matthew Mowlem, Eric Achterberg

Faculty Publications

The development of phosphate sensors suitable for long-term in situdeployments in natural waters, is essential to improve our understanding of the distribution, fluxes, and biogeochemical role of this key nutrient in a changing ocean. Here, we describe the optimization of the molybdenum blue method for in situ work using a lab-on-chip (LOC) analyzer and evaluate its performance in the laboratory and at two contrasting field sites. The in situ performance of the LOC sensor is evaluated using hourly time-series data from a 56-day trial in Southampton Water (UK), as well as a month-long deployment in the subtropical oligotrophic waters of …


The Mean And Turbulent Properties Of A Wildfire Convective Plume, Neil Lareau, Craig Clements Aug 2017

The Mean And Turbulent Properties Of A Wildfire Convective Plume, Neil Lareau, Craig Clements

Faculty Publications, Meteorology and Climate Science

The time-mean and time-varying smoke and velocity structure of a wildfire convective plume is examined using a high-resolution scanning Doppler lidar. The mean plume is shown to exhibit the archetypal form of a bent-over plume in a crosswind, matching the well-established Briggs plume-rise equation. The plume cross section is approximately Gaussian and the plume radius increases linearly with height, consistent with plumerise theory. The Briggs plume-rise equation is subsequently inverted to estimate the mean fire-generated sensible heat flux, which is found to be 87 kW m22 . The mean radial velocity structure of the plume indicates flow convergence into the …


Direct Comparisons Of Ice Cloud Macro- And Microphysical Properties Simulated By The Community Atmosphere Model Version 5 With Hippo Aircraft Observations, Chenglai Wu, Xiaohong Liu, Minghui Diao, Kai Zhang, Andrew Gettelman, Zheng Lu, Joyce Penner, Zhaohui Lin Apr 2017

Direct Comparisons Of Ice Cloud Macro- And Microphysical Properties Simulated By The Community Atmosphere Model Version 5 With Hippo Aircraft Observations, Chenglai Wu, Xiaohong Liu, Minghui Diao, Kai Zhang, Andrew Gettelman, Zheng Lu, Joyce Penner, Zhaohui Lin

Faculty Publications, Meteorology and Climate Science

In this study we evaluate cloud properties simulated by the Community Atmosphere Model version 5 (CAM5) using in situ measurements from the HIAPER Pole-to-Pole Observations (HIPPO) campaign for the period of 2009 to 2011. The modeled wind and temperature are nudged towards reanalysis. Model results collocated with HIPPO flight tracks are directly compared with the observations, and model sensitivities to the representations of ice nucleation and growth are also examined. Generally, CAM5 is able to capture specific cloud systems in terms of vertical configuration and horizontal extension. In total, the model reproduces 79.8 % of observed cloud occurrences inside model …


Dynamical Conditions Of Ice Supersaturation And Ice Nucleation In Convective Systems: A Comparative Analysis Between In Situ Aircraft Observations And Wrf Simulations, John D'Alessandro, Minghui Diao, Chenglai Wu, Xiaohong Liu, Ming Chen, Hugh Morrison, Trude Eidhammer, Jorgen Jensen, Aaron Bansemer, Mark Zondlo, Joshua Digangi Mar 2017

Dynamical Conditions Of Ice Supersaturation And Ice Nucleation In Convective Systems: A Comparative Analysis Between In Situ Aircraft Observations And Wrf Simulations, John D'Alessandro, Minghui Diao, Chenglai Wu, Xiaohong Liu, Ming Chen, Hugh Morrison, Trude Eidhammer, Jorgen Jensen, Aaron Bansemer, Mark Zondlo, Joshua Digangi

Faculty Publications, Meteorology and Climate Science

Occurrence frequency and dynamical conditions of ice supersaturation (ISS, where relative humidity with respect to ice (RHi) > 100%) are examined in the upper troposphere around convective activity. Comparisons are conducted between in situ airborne observations and the Weather Research and Forecasting model simulations using four double‐moment microphysical schemes at temperatures ≤ −40°C. All four schemes capture both clear‐sky and in‐cloud ISS conditions. However, the clear‐sky (in‐cloud) ISS conditions are completely (significantly) limited to the RHi thresholds of the Cooper parameterization. In all of the simulations, ISS occurrence frequencies are higher by ~3–4 orders of magnitude at higher updraft speeds ( …


Assessment Of An Atmospheric Transport Model For Annual Inverse Estimates Of California Greenhouse Gas Emissions, Justin Bagley, Seongeun Jeong, Xinguang Cui, Sally Newman, Jingsong Zhang, Chad Priest, Mixtli Campos-Pineda, Arlyn Andrews, Laura Bianco, Matthew Lloyd, Neil Lareau, Craig Clements, Marc Fischer Feb 2017

Assessment Of An Atmospheric Transport Model For Annual Inverse Estimates Of California Greenhouse Gas Emissions, Justin Bagley, Seongeun Jeong, Xinguang Cui, Sally Newman, Jingsong Zhang, Chad Priest, Mixtli Campos-Pineda, Arlyn Andrews, Laura Bianco, Matthew Lloyd, Neil Lareau, Craig Clements, Marc Fischer

Faculty Publications, Meteorology and Climate Science

Atmospheric inverse estimates of gas emissions depend on transport model predictions, hence driving a need to assess uncertainties in the transport model. In this study we assess the uncertainty in WRF-STILT (Weather Research and Forecasting and Stochastic Time-Inverted Lagrangian Transport) model predictions using a combination of meteorological and carbon monoxide (CO) measurements. WRF configurations were selected to minimize meteorological biases using meteorological measurements of winds and boundary layer depths from surface stations and radar wind profiler sites across California. We compare model predictions with CO measurements from four tower sites in California from June 2013 through May 2014 to assess …


Estimating Methane Emissions From Biological And Fossil-Fuel Sources In The San Francisco Bay Area, Seongeun Jeong, Xinguang Cui, Donald Blake, Ben Miller, Stephen Montzka, Arlyn Andrews, Abhinav Guha, Philip Martien, Ray Bambha, Brian Lafranchi, Hope Michelsen, Craig Clements, Pierre Glaize, Marc Fischer Jan 2017

Estimating Methane Emissions From Biological And Fossil-Fuel Sources In The San Francisco Bay Area, Seongeun Jeong, Xinguang Cui, Donald Blake, Ben Miller, Stephen Montzka, Arlyn Andrews, Abhinav Guha, Philip Martien, Ray Bambha, Brian Lafranchi, Hope Michelsen, Craig Clements, Pierre Glaize, Marc Fischer

Faculty Publications, Meteorology and Climate Science

We present the first sector-specific analysis of methane (CH4) emissions from the San Francisco Bay Area (SFBA) using CH4 and volatile organic compound (VOC) measurements from six sites during September – December 2015. We apply a hierarchical Bayesian inversion to separate the biological from fossil-fuel (natural gas and petroleum) sources using the measurements of CH4 and selected VOCs, a source-specific 1 km CH4 emission model, and an atmospheric transport model. We estimate that SFBA CH4 emissions are 166–289 Gg CH4/yr (at 95% confidence), 1.3–2.3 times higher than a recent inventory with much of the underestimation from landfill. Including the VOCs, …


Teaching In The Age Of Humans Helping Students Think About Climate Change., Grinell Smith Jan 2017

Teaching In The Age Of Humans Helping Students Think About Climate Change., Grinell Smith

Faculty Publications

To convey the magnitude and rapidity of current climate change and the severity of predictions for the next century, I present essential climate science information using four key sets of data and contextualize that information with personal anecdotes. I then consider the reasons for the large gap between the scientific consensus about anthropogenic climate change and public perceptions of that consensus. With several known challenges to climate change education in mind, I offer four recommendations for teachers that map relevant social psychology to pedagogy: (1) establish a learning community that works to disrupt in-group favoritism and reduce attribution bias; (2) …


Environmental And Climate Justice Along The Brahmaputra River In Northeast India, Costanza Rampini Jan 2017

Environmental And Climate Justice Along The Brahmaputra River In Northeast India, Costanza Rampini

Faculty Publications, Environmental Studies

The glaciers of the Himalayas are the source of all of Asia’s major rivers and are crucial to Asia’s water supply, economies, and livelihoods. The Himalayan region is uniquely vulnerable to the impacts of anthropogenic climate change, while also becoming one of the most dammed regions in the world. This case study explores the unequal distribution of the impacts of climate change and dam building along the Brahmaputra River in Northeast India. It examines how the combined impacts of these two processes negatively affect local communities and explores environmental and climate justice issues. In discussing climate change impacts and hydropower …


An Assessment Of The Radiative Effects Of Ice Supersaturation Based On In Situ Observations, Xiaoxiao Tan, Yi Huang, Minghui Diao, Aaron Bansemer, Mark Zondlo, Joshua Digangi, Rainer Volkamer, Yongyun Hu Oct 2016

An Assessment Of The Radiative Effects Of Ice Supersaturation Based On In Situ Observations, Xiaoxiao Tan, Yi Huang, Minghui Diao, Aaron Bansemer, Mark Zondlo, Joshua Digangi, Rainer Volkamer, Yongyun Hu

Faculty Publications, Meteorology and Climate Science

We use aircraft observations combined with the reanalysis data to investigate the radiative effects of ice supersaturation (ISS). Our results show that although the excess water vapor over ice saturation itself has relatively small radiative effects, mistaking it as ice crystals in climate models would lead to considerable impacts: on average, +2.49 W/m2 change in the top of the atmosphere (TOA) radiation, −2.7 W/m2 change in surface radiation, and 1.47 K/d change in heating rates. The radiative effects of ISS generally increase with the magnitudes of supersaturation. However, there is a strong dependence on the preexisting ice water path, which …


Alongcoast Structure And Interannual Variability Of Seasonal Midshelf Water Properties And Velocity In The Northern California Current System, B. Hickey, S. Geier, N. Kachel, S. Ramp, P. Kosro, Thomas Connolly Oct 2016

Alongcoast Structure And Interannual Variability Of Seasonal Midshelf Water Properties And Velocity In The Northern California Current System, B. Hickey, S. Geier, N. Kachel, S. Ramp, P. Kosro, Thomas Connolly

Faculty Publications

Moored sensors were maintained for ∼5 years on the northern California Current System (CCS) midshelf. The alongcoast sensor array spanned the area of influence of the plume from the Columbia River, several submarine canyons, as well as a coastal promontory where the equatorward coastal jet frequently separates from the shelf. Upwelling-favorable wind stress magnitude decreases poleward by more than a factor of three over the latitudinal range and shelf width varies by a factor of two. In spite of the alongcoast structure in setting, both seasonal and interannual patterns in subsurface layer water properties were remarkably similar at all sites. …


Environmental Controls On Pyrocumulus And Pyrocumulonimbus Initiation And Development, Neil Lareau, Craig Clements Jan 2016

Environmental Controls On Pyrocumulus And Pyrocumulonimbus Initiation And Development, Neil Lareau, Craig Clements

Faculty Publications, Meteorology and Climate Science

In this paper we present the first direct observational evidence that the condensation level in pyrocumulus and pyrocumulonimbus clouds can be significantly higher than the ambient lifted condensation level. In addition, we show that the environmental thermodynamic profile, day-to-day variations in humidity, and ambient wind shear all exert significant influence over the onset and development of pyroconvective clouds. These findings are established using a scanning Doppler lidar and mobile radiosonde system during two large wildfires in northern California, the Bald Fire and the Rocky Fire. The lidar is used to distinguish liquid water from smoke backscatter during the plume rise, …


Long-Term, High Frequency In Situ Measurements Of Intertidal Mussel Bed Temperatures Using Biomimetic Sensors, Brian Helmuth, Francis Choi, Allison Matzelle, Jessica Torossian, Scott Morello, K.A.S. Mislan, Lauren Yamane, Denise Strickland, P. Szathmary, Sarah Gilman, Alyson Tockstein, Thomas Hilbish, Michael Burrows, Anne Marie Power, Elizabeth Gosling, Nova Mieszkowska, Christopher Harley, Michael Nishizaki, Emily Carrington, Bruce Menge, Laura Petes, Melissa Foley, Angela Johnson, Megan Poole, Mae Noble, Erin Richmond, Matt Robart, Jonathan Robinson, Jerod Sapp, Jackie Sones, Bernardo Broitman, Mark Denny, Katharine Mach, Luke P. Miller, Michael O'Donnell, Philip Ross, Gretchen Hofmann, Mackenzie Zippay, Carol Blanchette, J. Macfarlan, Eugenio Carpizo-Ituarte, Benjamin Ruttenberg, Carlos Peña Mejía, Christopher Mcquaid, Justin Lathlean, Cristián Monaco, Katy Nicastro, Gerardo Zardi Jan 2016

Long-Term, High Frequency In Situ Measurements Of Intertidal Mussel Bed Temperatures Using Biomimetic Sensors, Brian Helmuth, Francis Choi, Allison Matzelle, Jessica Torossian, Scott Morello, K.A.S. Mislan, Lauren Yamane, Denise Strickland, P. Szathmary, Sarah Gilman, Alyson Tockstein, Thomas Hilbish, Michael Burrows, Anne Marie Power, Elizabeth Gosling, Nova Mieszkowska, Christopher Harley, Michael Nishizaki, Emily Carrington, Bruce Menge, Laura Petes, Melissa Foley, Angela Johnson, Megan Poole, Mae Noble, Erin Richmond, Matt Robart, Jonathan Robinson, Jerod Sapp, Jackie Sones, Bernardo Broitman, Mark Denny, Katharine Mach, Luke P. Miller, Michael O'Donnell, Philip Ross, Gretchen Hofmann, Mackenzie Zippay, Carol Blanchette, J. Macfarlan, Eugenio Carpizo-Ituarte, Benjamin Ruttenberg, Carlos Peña Mejía, Christopher Mcquaid, Justin Lathlean, Cristián Monaco, Katy Nicastro, Gerardo Zardi

Faculty Publications, Biological Sciences

At a proximal level, the physiological impacts of global climate change on ectothermic organisms are manifest as changes in body temperatures. Especially for plants and animals exposed to direct solar radiation, body temperatures can be substantially different from air temperatures. We deployed biomimetic sensors that approximate the thermal characteristics of intertidal mussels at 71 sites worldwide, from 1998-present. Loggers recorded temperatures at 10–30 min intervals nearly continuously at multiple intertidal elevations. Comparisons against direct measurements of mussel tissue temperature indicated errors of ~2.0–2.5 °C, during daily fluctuations that often exceeded 15°–20 °C. Geographic patterns in thermal stress based on biomimetic …


Topography And Tropical Cyclone Structure Influence On Eyewall Evolution In Typhoon Sinlaku (2008), Cheng-Hsiang Chih, Kun-Hsuan Chou, Sen Chiao Oct 2015

Topography And Tropical Cyclone Structure Influence On Eyewall Evolution In Typhoon Sinlaku (2008), Cheng-Hsiang Chih, Kun-Hsuan Chou, Sen Chiao

Faculty Publications, Meteorology and Climate Science

Typhoon Sinlaku (2008) was a tropical system that affected many countries in East Asia. Besides the loss of life and economic damage, many scientific questions are associated with this system that need to be addressed. A series of numerical simulations were conducted in this study using V3.2 of the advanced research version of the Weather Research and Forecasting (WRF-ARW) model to examine the impacts of different terrain conditions and vortex structures on the eyewall evolution when Sinlaku was crossing Taiwan. The sensitivity experiments using different vortex structures show that a storm of the same intensity with a larger eyewall radius …


Comparisons Of Cirrus Cloud Properties Between Polluted And Pristine Air Based On In-Situ Observations From The Nasa Attrex, Nsf Hippo And Eu Inca Campaigns, Minghui Diao, Jorgen Jensen Jul 2015

Comparisons Of Cirrus Cloud Properties Between Polluted And Pristine Air Based On In-Situ Observations From The Nasa Attrex, Nsf Hippo And Eu Inca Campaigns, Minghui Diao, Jorgen Jensen

Faculty Publications, Meteorology and Climate Science

Cirrus clouds, covering about 30% of the Earth’s surface area, play an important role in the climate and weather systems. Cirrus cloud radiative forcing (cooling or warming) is influenced by their microphysical (e.g., ice crystal number concentration and size distribution) and macroscopic (e.g., spatial extent) properties. Currently it is still unclear how the formation of cirrus clouds and their microphysical properties are influenced by anthropogenic emissions. In this work, we use in-situ observations from three flight campaigns to compare the cirrus cloud properties between polluted and pristine regions. Our dataset includes: (1) the NASA Airborne Tropical Tropopause Experiment (ATTREX) campaign …


Distributions Of Ice Supersaturation And Ice Crystals From Airborne Observations In Relation To Upper Tropospheric Dynamical Boundaries, Minghui Diao, Jorgen Jensen, Laura Pan, Cameron Homeyer, Shawn Honomichl, James Bresch, Aaron Bansemer May 2015

Distributions Of Ice Supersaturation And Ice Crystals From Airborne Observations In Relation To Upper Tropospheric Dynamical Boundaries, Minghui Diao, Jorgen Jensen, Laura Pan, Cameron Homeyer, Shawn Honomichl, James Bresch, Aaron Bansemer

Faculty Publications, Meteorology and Climate Science

Ice supersaturation (ISS) is the prerequisite condition for cirrus cloud formation. To examine multiscale dynamics' influences on ISS formation, we analyze in situ aircraft observations (~200 m scale) over North America in coordinates relative to dynamical boundaries in the upper troposphere and lower stratosphere. Two case studies demonstrate that ISS formation is likely influenced by mesoscale uplifting, small-scale waves, and turbulence. A collective analysis of 15 flights in April–June 2008 shows that the top layers of ISS and ice crystal distributions are strongly associated with thermal tropopause height. In addition, the average occurrence frequencies of ISS and ice crystals on …


Comparing The Model-Simulated Global Warming Signal To Observations Using Empirical Estimates Of Unforced Noise, Patrick T. Brown, Wenhong Li, Eugene C. Cordero, Steven A. Mauget Apr 2015

Comparing The Model-Simulated Global Warming Signal To Observations Using Empirical Estimates Of Unforced Noise, Patrick T. Brown, Wenhong Li, Eugene C. Cordero, Steven A. Mauget

Faculty Publications, Meteorology and Climate Science

The comparison of observed global mean surface air temperature (GMT) change to the mean change simulated by climate models has received much public and scientific attention. For a given global warming signal produced by a climate model ensemble, there exists an envelope of GMT values representing the range of possible unforced states of the climate system (the Envelope of Unforced Noise; EUN). Typically, the EUN is derived from climate models themselves, but climate models might not accurately simulate the correct characteristics of unforced GMT variability. Here, we simulate a new, empirical, EUN that is based on instrumental and reconstructed surface …


Dissolved Fe And Al In The Upper 1000 M Of The Eastern Indian Ocean: A High‐Resolution Transect Along 95°E From The Antarctic Margin To The Bay Of Bengal, Maxime Grand, Christopher Measures, Mariko Hatta, William Hiscock, William Landing, Peter Morton, Clifton Buck, Pamela Barrett, Joseph Resing Mar 2015

Dissolved Fe And Al In The Upper 1000 M Of The Eastern Indian Ocean: A High‐Resolution Transect Along 95°E From The Antarctic Margin To The Bay Of Bengal, Maxime Grand, Christopher Measures, Mariko Hatta, William Hiscock, William Landing, Peter Morton, Clifton Buck, Pamela Barrett, Joseph Resing

Faculty Publications

A high‐resolution section of dissolved iron (dFe) and aluminum (dAl) was obtained along ~95°E in the upper 1000 m of the eastern Indian Ocean from the Antarctic margin (66°S) to the Bay of Bengal (18°N) during the U.S. Climate Variability and Predictability (CLIVAR) CO2 Repeat Hydrography I08S and I09N sections (February–April 2007). In the Southern Ocean, low concentrations of dAl (<1 n M) reflect the negligible dust inputs impacting the water masses subducted in the circumpolar domain. The low dAl concentrations characterizing the Southern Ocean terminate near 45°S, probably because of the advection of subtropical water masses that received dust and sedimentary inputs in their formation region. Our subsurface dFe data near the southern Kerguelen Plateau were significantly higher than historical observations in other Indian sectors of the Southern Ocean. We surmise that the offshore advection of dFe‐rich waters along the western flank of the southern Kerguelen plateau and enhanced vertical mixing could contribute to this elevated subsurface dFe inventory. Elevated subsurface particulate and dFe levels downstream of the northern Kerguelen Plateau may reflect long‐range lateral transport from the plateau's sediments and/or remineralization inputs. At the northern edge of the south Indian subtropical gyre, the deposition of Australian dust, possibly combined with the advection of dAl‐enriched waters from the Indonesian Throughflow, creates a region of elevated dAl in the upper 400 m but without a corresponding enrichment in dFe. In the northern Indian Ocean, the South Equatorial Current constitutes a remarkable biogeochemical front separating the oxygen‐rich and dFe‐poor subtropical gyre waters from the dFe‐rich and oxygen‐depleted waters of the northern Indian Ocean. By tracing the accumulation of macronutrients and dFe along the advective pathway of Indian Central Water, we show that the central waters of the northern Indian Ocean receive excess dFe in addition to that produced by remineralization inputs. The resuspension of shelf sediments and release of pore waters probably contribute to the elevated dFe and dAl levels observed below the highly stratified upper layers of the Bay of Bengal.


Dust Deposition In The Eastern Indian Ocean: The Ocean Perspective From Antarctica To The Bay Of Bengal, Maxime Grand, Christopher Measures, Mariko Hatta, William Hiscock, Clifton Buck, William Landing Mar 2015

Dust Deposition In The Eastern Indian Ocean: The Ocean Perspective From Antarctica To The Bay Of Bengal, Maxime Grand, Christopher Measures, Mariko Hatta, William Hiscock, Clifton Buck, William Landing

Faculty Publications

Atmospheric deposition is an important but still poorly constrained source of trace micronutrients to the open ocean because of the dearth of in situ measurements of total deposition (i.e., wet + dry deposition) in remote regions. In this work, we discuss the upper ocean distribution of dissolved Fe and Al in the eastern Indian Ocean along a 95°E meridional transect spanning the Antarctic margin to the Bay of Bengal. We use the mixed layer concentration of dissolved Al in conjunction with empirical data in a simple steady state model to produce 75 estimates of total dust deposition that we compare …


Observations Of Fire-Induced Turbulence Regimes During Low-Intensity Wildland Fires In Forested Environments: Implications For Smoke Dispersion, Warren Heilman, Craig Clements, Daisuke Seto, Xindi Bian, Kenneth Clark, Nicholas Skowronski, John Hom Jan 2015

Observations Of Fire-Induced Turbulence Regimes During Low-Intensity Wildland Fires In Forested Environments: Implications For Smoke Dispersion, Warren Heilman, Craig Clements, Daisuke Seto, Xindi Bian, Kenneth Clark, Nicholas Skowronski, John Hom

Faculty Publications, Meteorology and Climate Science

Low-intensity wildland fires occurring beneath forest canopies can result in particularly adverse local air-quality conditions. Ambient and fire-induced turbulent circulations play a substantial role in the transport and dispersion of smoke during these fire events. Recent in situ measurements of fire–atmosphere interactions during low-intensity wildland fires have provided new insight into the structure of fire-induced turbulence regimes and how forest overstory vegetation can affect the horizontal and vertical dispersion of smoke. In this paper, we provide a summary of the key turbulence observations made during two low-intensity wildland fire events that occurred in the New Jersey Pine Barrens.


Cold Smoke: Smoke-Induced Density Currents Cause Unexpected Smoke Transport Near Large Wildfires, Neil Lareau, Craig Clements Jan 2015

Cold Smoke: Smoke-Induced Density Currents Cause Unexpected Smoke Transport Near Large Wildfires, Neil Lareau, Craig Clements

Faculty Publications, Meteorology and Climate Science

The first observations of smoke-induced density currents originating from large wildfires are presented. Using a novel mobile Doppler lidar and additional in situ measurements, we document a deep (~ 2 km) smoke-filled density current that propagates more than 25 km at speeds up to 4.5 m s−1 near a large forest fire in northern California. Based on these observations we show that the dynamics governing the spread of the smoke layer result from differential solar heating between the smoke-filled and smoke-free portions of the atmospheric boundary layer. A calculation of the theoretical density current speed agrees well with the observed …


Distributions Of Ice Supersaturation And Ice Crystals From Airborne Observations In Relation To Upper Tropospheric Dynamical Boundaries, Minghui Diao, Jorgen Jensen, Laura Pan, Cameron Homeyer, Shawn Honomichl, James Bresch, Aaron Bansemer, Eric Jensen Dec 2014

Distributions Of Ice Supersaturation And Ice Crystals From Airborne Observations In Relation To Upper Tropospheric Dynamical Boundaries, Minghui Diao, Jorgen Jensen, Laura Pan, Cameron Homeyer, Shawn Honomichl, James Bresch, Aaron Bansemer, Eric Jensen

Faculty Publications, Meteorology and Climate Science

Cirrus clouds are one of the largest sources of uncertainties in predicting future climate. Ice nucleation and ice crystal growth inside cirrus clouds require ice supersaturation (ISS). Previously, remote sensing observations have shown that the locations of cirrus clouds’ cloud top height are highly correlated with the thermal tropopause height (Pan and Munchak, 2011). However, it is unclear if the initial conditions of cirrus clouds – ice supersaturated region (ISSRs) – have similar features in the extratropical upper troposphere and lower stratosphere (UT/LS). In fact, the dynamical processes and conditions that contribute to ISS formation from the microscale (~100 m) …


Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part I: Temperature, Eugene C. Cordero, Steven A. Mauget Dec 2014

Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part I: Temperature, Eugene C. Cordero, Steven A. Mauget

Faculty Publications, Meteorology and Climate Science

The optimal ranking regime (ORR) method was used to identify intradecadal to multidecadal (IMD) time windows containing significant ranking sequences in U.S. climate division temperature data. The simplicity of the ORR procedure’s output—a time series’ most significant nonoverlapping periods of high or low rankings—makes it possible to graphically identify common temporal breakpoints and spatial patterns of IMD variability in the analyses of 102 climate division temperature series. This approach is also applied to annual Atlantic multidecadal oscillation (AMO) and Pacific decadal oscillation (PDO) climate indices, a Northern Hemisphere annual temperature (NHT) series, and divisional annual and seasonal temperature data during …


Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part Ii: Precipitation And Streamflow, Steven A. Mauget, Eugene C. Cordero Dec 2014

Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part Ii: Precipitation And Streamflow, Steven A. Mauget, Eugene C. Cordero

Faculty Publications, Meteorology and Climate Science

In Part I of this paper, the optimal ranking regime (ORR) method was used to identify intradecadal to multidecadal (IMD) regimes in U.S. climate division temperature data during 1896–2012. Here, the method is used to test for annual and seasonal precipitation regimes during that same period. Water-year mean streamflow rankings at 125 U.S. Hydro-Climatic Data Network gauge stations are also evaluated during 1939–2011. The precipitation and streamflow regimes identified are compared with ORR-derived regimes in the Pacific decadal oscillation (PDO), the Atlantic multidecadal oscillation (AMO), and indices derived from gridded SST anomaly (SSTA) analysis data. Using a graphic display approach …


Hemispheric Comparison Of Cirrus Cloud Evolution Using In Situ Measurements In Hiaper Pole-To-Pole Observations, Minghui Diao, Mark Zondlo, Andrew Heymsfield, Stuart Beaton Jul 2014

Hemispheric Comparison Of Cirrus Cloud Evolution Using In Situ Measurements In Hiaper Pole-To-Pole Observations, Minghui Diao, Mark Zondlo, Andrew Heymsfield, Stuart Beaton

Faculty Publications, Meteorology and Climate Science

The radiative forcing of cirrus clouds is highly sensitive to their microphysical properties as well as their evolution. However, there are very limited observations and analyses on the cirrus cloud formation and evolution with both microscale resolution and global scale coverage. The lack of such observations limits the overall comparison of cirrus cloud evolution between the two hemispheres. In fact, the previous hemispheric comparisons of cirrus cloud microphysics using in situ observations were only based on the sampling over two locations at 55°N and 55°S (Ovarlez et al., 2002; Gayet et al., 2004). Here we use a more comprehensive aircraft-based …


Metr 12: Global Warming Course Redesign, Eugene Cordero Apr 2014

Metr 12: Global Warming Course Redesign, Eugene Cordero

Innovative Teaching – Course Redesign Project Posters 2014

Poster summarizing course redesign activities for METR 12: Global Warming.


Metr 060 & 061: Introduction To Meteorology Course Redesign, Alison Bridger Apr 2014

Metr 060 & 061: Introduction To Meteorology Course Redesign, Alison Bridger

Innovative Teaching – Course Redesign Project Posters 2014

Poster summarizing course redesign activities for METR 060 & 061: Introduction to Meteorology.