Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 601 - 630 of 984

Full-Text Articles in Climate

Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk Jan 2016

Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk

Dartmouth Scholarship

Forests are more frequently being managed to store and sequester carbon for the purposes of climate change mitigation. Generally, this practice involves long-term conservation of intact mature forests and/or reductions in the frequency and intensity of timber harvests. However, incorporating the influence of forest surface albedo often suggests that long rotation lengths may not always be optimal in mitigating climate change in forests characterized by frequent snowfall. To address this, we investigated trade-offs between three ecosystem services: carbon storage, albedo-related radiative forcing, and timber provisioning. We calculated optimal rotation length at 498 diverse Forest Inventory and Analysis forest sites in …


Umphlett Qci 2015, Natalie A. Umphlett Dec 2015

Umphlett Qci 2015, Natalie A. Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Late Hard Freeze

Late Freezes Extended Growing Season

Warm Fall Delays Bird Migrations

Monitoring Water Resources Across the Basin

3-Month Precipitation and Temperature Outlooks


Validation Of The Global Distribution Of Co2 Volume Mixing Ratio In The Mesosphere And Lower Thermosphere From Saber, L. Rezac, Y. Jian, J. Yue, J. M. Russell Iii, A. Kutepov, R. Garcia, K. Walker, P. Bernath Dec 2015

Validation Of The Global Distribution Of Co2 Volume Mixing Ratio In The Mesosphere And Lower Thermosphere From Saber, L. Rezac, Y. Jian, J. Yue, J. M. Russell Iii, A. Kutepov, R. Garcia, K. Walker, P. Bernath

Chemistry & Biochemistry Faculty Publications

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite has been measuring the limb radiance in 10 broadband infrared channels over the altitude range from ~ 400 km to the Earth's surface since 2002. The kinetic temperatures and CO2 volume mixing ratios (VMRs) in the mesosphere and lower thermosphere have been simultaneously retrieved using SABER limb radiances at 15 and 4.3 μm under nonlocal thermodynamic equilibrium (non-LTE) conditions. This paper presents results of a validation study of the SABER CO2 VMRs obtained with a two-channel, self-consistent …


A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary Oct 2015

A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary

USF Tampa Graduate Theses and Dissertations

Because nitrogen isotopes are fractionated along the soil-plant-insect-bat-guano pathway, it may be possible to reconstruct environmental and climatic changes reflected in the nitrogen isotopic composition of guano. A 1.5-m core of bat guano from Zidită Cave (western Romania) provides a record of climatic and anthropogenic influence on the regional nitrogen cycle and paleoenvironmental controls on nitrogen transforming processes. Increasing and decreasing trends of nitrogen isotopic composition (δ15N values) correspond well with changes in the influence of farming practices, deforestation, and forest expansion. These influences likely had a significant effect on the openness of the nitrogen cycle, resulting in …


Ocean Forcing Of Quaternary East Antarctic Ice Sheet Evolution: An Ice-Proximal Sedimentary Perspective, Michelle E. Guitard Oct 2015

Ocean Forcing Of Quaternary East Antarctic Ice Sheet Evolution: An Ice-Proximal Sedimentary Perspective, Michelle E. Guitard

USF Tampa Graduate Theses and Dissertations

Antarctica and the Southern Ocean play a critical role in Earth’s climate system. Antarctica’s ice sheets contain enough ice to raise global sea level by ~58 m, and the Southern Ocean distributes climate signals and nutrients to the major ocean basins and the deep ocean. Antarctica’s largest ice sheet, the East Antarctic Ice Sheet (EAIS), was considered stable compared to those in West Antarctica and the Antarctic Peninsula because it was thought to be grounded above sea level. However, subglacial topography now reveals vast submarine basins and measurements of ice velocity in the Pacific sector indicate marine-terminating outlet glacier thinning …


Role Of The Strengthened El Nino Teleconnection In The May 2015 Floods Over The Southern Great Plains, S.-Y. Wang, W.-R. Huang, H.-H. Hsu, R. R. Gillies Oct 2015

Role Of The Strengthened El Nino Teleconnection In The May 2015 Floods Over The Southern Great Plains, S.-Y. Wang, W.-R. Huang, H.-H. Hsu, R. R. Gillies

Plants, Soils, and Climate Faculty Publications

The climate anomalies leading to the May 2015 floods in Texas and Oklahoma were analyzed in the context of El Niño teleconnection in a warmer climate. A developing El Niño tends to increase late-spring precipitation in the southern Great Plains, and this effect has intensified since 1980. Anthropogenic global warming contributed to the physical processes that caused the persistent precipitation in May 2015: Warming in the tropical Pacific acted to strengthen the teleconnection toward North America, modification of zonal wave 5 circulation that deepened the stationary trough west of Texas, and enhanced Great Plains low-level southerlies increasing moisture supply from …


Management Options For Water-Repellent Soils In Australian Dryland Agriculture, M. M. Roper, S. L. Davies, P. S. Blackwell, D. J. M. Hall, D. Bakker, R. Jongepier, P. R. Ward Oct 2015

Management Options For Water-Repellent Soils In Australian Dryland Agriculture, M. M. Roper, S. L. Davies, P. S. Blackwell, D. J. M. Hall, D. Bakker, R. Jongepier, P. R. Ward

Natural Resources Research Articles

Water-repellent (‘non-wetting’) soils are a major constraint to agricultural production in southern and south-west Australia, affecting >10 Mha of arable sandy soils. The major symptom is dry patches of surface soil, even after substantial rainfall, directly affecting agricultural production through uneven crop and pasture germination, and reduced nutrient availability. In addition, staggered weed germination impedes effective weed control, and delayed crop and pasture germination increases the risk of wind erosion. Water repellency is caused by waxy organic compounds derived from the breakdown of organic matter mostly of plant origin. It is more prevalent in soils with a sandy surface texture; …


Linking Seasonal Predictions To Decision-Making And Disaster Management In The Greater Horn Of Africa, Tsegaye Tadesse, Tonya Haigh, Nicole Wall, Andualem Shiferaw, Ben Zaitchik, Shimelis Beyene, Getachew Berhan, Jacob Petr Oct 2015

Linking Seasonal Predictions To Decision-Making And Disaster Management In The Greater Horn Of Africa, Tsegaye Tadesse, Tonya Haigh, Nicole Wall, Andualem Shiferaw, Ben Zaitchik, Shimelis Beyene, Getachew Berhan, Jacob Petr

National Drought Mitigation Center: Faculty Publications

Seventy-six participants, including experts from seven countries from the Greater Horn of Africa (GHA) and project coinvestigators from the United States, met to discuss experimental seasonal prediction models and products for the GHA, to engage decision-makers and users in the assessment of hydroclimatic information requirements, and to use feedback to build a framework to support decision-making and disaster management. In pre- and postworkshop surveys, workshop participants were asked how the utility of forecasts to decision-makers might be improved. Their recommendations are presented


The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- October 2015, Martha Shulski, Natalie Umphlett, Bill Sorensen, Glen Roebke, Crystal J. Stiles Oct 2015

The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- October 2015, Martha Shulski, Natalie Umphlett, Bill Sorensen, Glen Roebke, Crystal J. Stiles

Prairie Post: Quarterly Newsletter of the High Plains Regional Climate Center

Inside this issue:

Message from the director........................................1

Staff spotlight...........................1

New website design and products.....................................2

Training workshops................3

AWDN information.................4

Update on regional climate conditions and El Niño..........4

Research highlight..................5

Outreach/engagement.........5

Recent and upcoming travel and activities.............................6


Droughtscape, Fall 2015, Kelly Smith Oct 2015

Droughtscape, Fall 2015, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Director’s column.

NDMC 20th anniversary 2

Employment opportunity

Third quarter 2015 climate summary

Third quarter 2015 impacts summary

Workshop in Ethiopia

San Antonio multi-hazard tournament

Healthy soil is drought buffer

U2U Award

Cost-benefit analysis for utilities managing drought

NDMC helps with rural poll questions on climate

Introducing our post-docs

South Korean visitors


Source-Specific Molecular Signatures For Light-Absorbing Organic Aerosols, Amanda Susan Willoughby Oct 2015

Source-Specific Molecular Signatures For Light-Absorbing Organic Aerosols, Amanda Susan Willoughby

Chemistry & Biochemistry Theses & Dissertations

Organic aerosols (OA) are universally regarded as an important component of the atmosphere based on quantitative significance as well as the far-reaching impact they have on global climate forcing and human health. Despite the acknowledged importance, OA amounts and impacts remain the largest uncertainties regarding radiative forcing estimates. Incomplete chemical characterization of aerosol organic matter (OM) and a lack of concrete source apportionment is a major source of this uncertainty. The primary focus of this study is to provide much needed molecular details regarding ambient OA from key emission sources, and establish links between molecular and optical properties.

Complete chemical …


Coastal Ice-Core Record Of Recent Northwest Greenland Temperature And Sea-Ice Concentration, Erich C. Osterberg, Robert L. Hawley, Gifford Wong, Ben Kopec, David Ferris, Jennifer Howley Sep 2015

Coastal Ice-Core Record Of Recent Northwest Greenland Temperature And Sea-Ice Concentration, Erich C. Osterberg, Robert L. Hawley, Gifford Wong, Ben Kopec, David Ferris, Jennifer Howley

Dartmouth Scholarship

Coastal ice cores provide an opportunity to investigate regional climate and sea-ice variability in the past to complement hemispheric-scale climate reconstructions from ice-sheet-interior ice cores. Here we describe robust proxies of Baffin Bay temperature and sea-ice concentration from the coastal 2Barrel ice core collected in the Thule region of northwest Greenland. Over the 1990–2010 record, 2Barrel annually averaged methanesulfonic acid (MSA) concentrations are significantly correlated with May–June Baffin Bay sea-ice concentrations and summer temperatures. Higher MSA is observed during warmer years with less sea ice, indicative of enhanced primary productivity in Baffin Bay. Similarly, 2Barrel annually averaged deuterium excess (d-excess) …


Umphlett Qci Sept 2015, Natalie Umphlett Sep 2015

Umphlett Qci Sept 2015, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalie

Streamflow

Heavy Rains Continued

Positive and Negative Impacts to Agriculture

Persistent Smoke from Wildfires

3-Month Precipitation and Temperature Outlooks


Participatory Research Workshop On Seasonal Prediction Of Hydroclimatic Extremes In The Greater Horn Of Africa, Tsegaye Tadesse, Deborah Bathke, Nicole Wall, Jacob Petr, Tonya Haigh Aug 2015

Participatory Research Workshop On Seasonal Prediction Of Hydroclimatic Extremes In The Greater Horn Of Africa, Tsegaye Tadesse, Deborah Bathke, Nicole Wall, Jacob Petr, Tonya Haigh

National Drought Mitigation Center: Faculty Publications

Sixty participants, including experts from seven countries from the Greater Horn of Africa (GHA) and project coinvestigators from the United States, met to discuss seasonal prediction of hydroclimatic extremes across the GHA, engage decision-makers in the assessment of information requirements, and use feedback to orient prediction models to address user needs. Perceptions of current climate change impacts in the GHA were assessed using pre- and postworkshop surveys. Participatory research was conducted through small group discussions on water, agriculture, impacts, and data sharing.


Facilitating The Use Of Drought Early Warning Information Through Interactions With Agricultural Stakeholders, Jason A. Otkin, Mark Shafer, Mark Svoboda, Brian Wardlow, Martha C. Anderson, Christopher Hain, Jeffrey Basara Jul 2015

Facilitating The Use Of Drought Early Warning Information Through Interactions With Agricultural Stakeholders, Jason A. Otkin, Mark Shafer, Mark Svoboda, Brian Wardlow, Martha C. Anderson, Christopher Hain, Jeffrey Basara

National Drought Mitigation Center: Faculty Publications

No abstract provided.


Droughtscape, Summer 2015, Kelly Smith Jul 2015

Droughtscape, Summer 2015, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Director’s column

New Drought Risk Management Research Center

Second quarter 2015 climate summary

Second quarter 2015 impacts summary

Caribbean region an innovator in drought early warning

Wind River Reservation tribes move toward drought planning

Ranchers, U.S. Forest Service, University of Arizona co-develop drought plans

Summer blockbuster from CoCoRaHS: Assessing Drought in the U.S

Western states drought coordinators meet


The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- July 2015, Martha Shulski, Natalie Umphlett, Bill Sorensen, E. Hunt, Crystal J. Stiles Jul 2015

The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- July 2015, Martha Shulski, Natalie Umphlett, Bill Sorensen, E. Hunt, Crystal J. Stiles

Prairie Post: Quarterly Newsletter of the High Plains Regional Climate Center

Inside this issue:

Message from the director........................................1

Staff spotlight...........................1

Visit from Office of Science and Technology Policy...........2

Partnership spotlight.............2

AWDN information.................3

Update on regional climate conditions..................................3

Product highlight....................4

Research highlight..................4

Outreach/engagement.........5

Recent and upcoming travel and activities.............................6


Dramatic Loss Of Glacier Accumulation Area On The Tibetan Plateau Revealed By Ice Core Tritium And Mercury Records, S. Kang, F. Wang, U. Morgenstern, Y. Zhang, B. Grigholm, Susan D. Kaspari, M. Schwikowski, J. Ren, T. Yao, D. Qin, P. A. Mayewski Jun 2015

Dramatic Loss Of Glacier Accumulation Area On The Tibetan Plateau Revealed By Ice Core Tritium And Mercury Records, S. Kang, F. Wang, U. Morgenstern, Y. Zhang, B. Grigholm, Susan D. Kaspari, M. Schwikowski, J. Ren, T. Yao, D. Qin, P. A. Mayewski

All Faculty Scholarship for the College of the Sciences

Two ice cores were retrieved from high elevations (~5800 m a.s.l.) at Mt. Nyainqêntanglha and Mt. Geladaindong in the southern and central Tibetan Plateau region. The combined tracer analysis of tritium (3H), 210Pb and mercury, along with other chemical records, provided multiple lines of evidence supporting that the two coring sites had not received net ice accumulation since at least the 1950s and 1980s, respectively. These results implied an annual ice loss rate of more than several hundred millimeter water equivalent over the past 30–60 years. Both mass balance modeling at the sites and in situ data …


Umphlett Qci June 2015, Natalie A. Umphlett Jun 2015

Umphlett Qci June 2015, Natalie A. Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Drought Conditions

Water Supplies Recovering

Heavy Rains Cause Flooding

Agriculture Impacts

3-Month Precipitation and Temperature Outlooks


Recent Shoreline Erosion Rates Along Black River Bay, Jamaica: Erosion And Recovery After Hurricane Ivan In 2004, Karen Louise Zelzer May 2015

Recent Shoreline Erosion Rates Along Black River Bay, Jamaica: Erosion And Recovery After Hurricane Ivan In 2004, Karen Louise Zelzer

Graduate Theses/Dissertations

Rising sea level is threatening coastal areas, particularly those in the Caribbean which rely heavily on tourism and marine resources to support local economies. The purpose of this study is to analyze shoreline position along the south coast of Jamaica to determine the locations and rates of coastal change. IKONOS satellite imagery sets for 2003, 2007 and 2012 were used to monitor land use and shoreline changes along Black River Bay, including Galleon Beach Fish Sanctuary, in St. Elizabeth, Jamaica. In particular, the effect of Hurricane Ivan in 2004 on shoreline changes was evaluated. Erosion rates were significantly higher during …


Trace Element Variations In A Stalagmite From Southwest Mexico: Implications For Paleoclimate, Chad Michael Crotty May 2015

Trace Element Variations In A Stalagmite From Southwest Mexico: Implications For Paleoclimate, Chad Michael Crotty

UNLV Theses, Dissertations, Professional Papers, and Capstones

The combination of stable isotope and trace element concentrations in speleothems has been shown to be a valuable indicator for interpreting paleoclimatic conditions. Anomalous spikes in trace element concentrations have also been shown to indicate anthropogenic environmental changes to the surface, such as deforestation events. In this study, trace element concentrations (24Mg, 25Mg, 84Sr, 88Sr, 137Ba, and 238U) of a stalagmite (JX-6) from Juxtlahuaca Cave, in southwestern Mexico, were measured using an inductively coupled plasma mass spectrometer (ICP-MS). These trace element concentrations were compared to previously analyzed δ18O and δ13C values from JX-6, and to the results of previous studies …


Twentieth Century Dust Lows And The Weakening Of The Westerly Winds Over The Tibetan Plateau, Bjorn Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, U. Morgenstern, M. Schwikowski, Susan D. Kaspari, V. Aizen, E. Aizen, N. Takeuchi, K. A. Maasch, S. Birkel, M. Handley, S. Sneed Apr 2015

Twentieth Century Dust Lows And The Weakening Of The Westerly Winds Over The Tibetan Plateau, Bjorn Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, U. Morgenstern, M. Schwikowski, Susan D. Kaspari, V. Aizen, E. Aizen, N. Takeuchi, K. A. Maasch, S. Birkel, M. Handley, S. Sneed

All Faculty Scholarship for the College of the Sciences

Understanding past atmospheric dust variability is necessary to put modern atmospheric dust into historical context and assess the impacts of dust on the climate. In Asia, meteorological data of atmospheric dust is temporally limited, beginning only in the 1950s. High‐resolution ice cores provide the ideal archive for reconstructing preinstrumental atmospheric dust concentrations. Using a ~500 year (1477–1982 A.D.) annually resolved calcium (Ca) dust proxy from a Tibetan Plateau (TP) ice core, we demonstrate the lowest atmospheric dust concentrations in the past ~500 years during the latter twentieth century. Declines in late nineteenth to twentieth century Ca concentrations significantly correspond with …


Accelerated Glacier Melt On Snow Dome, Mount Olympus, Washington, Usa, Due To Deposition Of Black Carbon And Mineral Dust From Wildfire, Susan D. Kaspari, S. Mckenzie Skiles, Ian Delaney, Daniel Dixon, Thomas H. Painter Apr 2015

Accelerated Glacier Melt On Snow Dome, Mount Olympus, Washington, Usa, Due To Deposition Of Black Carbon And Mineral Dust From Wildfire, Susan D. Kaspari, S. Mckenzie Skiles, Ian Delaney, Daniel Dixon, Thomas H. Painter

All Faculty Scholarship for the College of the Sciences

Assessing the potential for black carbon (BC) and dust deposition to reduce albedo and accelerate glacier melt is of interest in Washington because snow and glacier melt are an important source of water resources, and glaciers are retreating. In August 2012 on Snow Dome, Mount Olympus, Washington, we measured snow surface spectral albedo and collected surface snow samples and a 7 m ice core. The snow and ice samples were analyzed for iron (Fe, used as a dust proxy) via inductively coupled plasma sector field mass spectrometry, total impurity content gravimetrically, BC using a single-particle soot photometer (SP2), and charcoal …


The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- April 2015, Martha Shulski, Natalie A. Umphlett, Bill Sorensen, Crystal J. Stiles Apr 2015

The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- April 2015, Martha Shulski, Natalie A. Umphlett, Bill Sorensen, Crystal J. Stiles

Prairie Post: Quarterly Newsletter of the High Plains Regional Climate Center

Inside this issue:

Message from the director........................................1

Staff spotlight...........................1

Stakeholder engagement activities......................................2

Partnership spotlight.............2

AWDN information.................3

Update on regional climate conditions..................................3

Product highlight....................4

Research highlight..................4

Outreach events......................5

Recent and upcoming travel and activities.............................6


Drougthscape, Spring 2015, Kelly Smith Apr 2015

Drougthscape, Spring 2015, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Director’s column.

South Plains ranch workshops 3

First quarter drought summary

First quarter impacts summary

Gary’s favorite pond, D1-4

NDMC’s Haigh leads U2U pubs

SW Montana watersheds convene

Wind River monitors drought

Morocco’s new drought index

Northeast Brazil drought monitoring

EU’s drought initiative

U.S. Drought Monitor Forum

How Colorado tourism coped in 2012


Umphlett Qci March 2015, Natalie Umphlett Mar 2015

Umphlett Qci March 2015, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Mountain Snowpack

Agriculture

Recreation and Tourism

Forestry

Drought Impacts Continue

3-Month Precipitation and Temperature Outlooks

U.S. Seasonal Drought Outlook


Hydroclimatic Shifts In Northeast Thailand During The Last Two Millennia — The Record Of Lake Pa Kho, Sakonvan Chawchai, Akkaneewut Chabangborn, Sherilyn C. Fritz, Minna Väliranta, Carl-Magnus Mörth, Maarten Blaauw, Paul J. Reimer, Paul J. Kusic, Ludvig Löwemark, Barbara Wohlfarth Mar 2015

Hydroclimatic Shifts In Northeast Thailand During The Last Two Millennia — The Record Of Lake Pa Kho, Sakonvan Chawchai, Akkaneewut Chabangborn, Sherilyn C. Fritz, Minna Väliranta, Carl-Magnus Mörth, Maarten Blaauw, Paul J. Reimer, Paul J. Kusic, Ludvig Löwemark, Barbara Wohlfarth

Department of Earth and Atmospheric Sciences: Faculty Publications

The Southeast Asian mainland is located in the central path of the Asian summer monsoon, a region where paleoclimatic data are still sparse. Here we present a multi-proxy (TOC, C/N, δ13C, biogenic silica, and XRF elemental data) study of a 1.5 m sediment/peat sequence from Lake Pa Kho, northeast Thailand, which is supported by 20 AMS 14C ages. Hydroclimatic reconstructions for Pa Kho suggest a strengthened summer monsoon between BC 170–AD 370, AD 800–960, and after AD 1450; and a weakening of the summer monsoon between AD 370–800, and AD 1300–1450. Increased run-off and a higher nutrient supply after AD …


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 …


Mapping The Decision Points And Climate Information Use Of Agricultural Producers Across The U.S. Corn Belt, Tonya Haigh, Eugene S. Takle, Jeffrey Andresen, Melissa Widhalm, J. Stuart Carlton, Jim Angel Feb 2015

Mapping The Decision Points And Climate Information Use Of Agricultural Producers Across The U.S. Corn Belt, Tonya Haigh, Eugene S. Takle, Jeffrey Andresen, Melissa Widhalm, J. Stuart Carlton, Jim Angel

National Drought Mitigation Center: Faculty Publications

The usefulness of climate information for agricultural risk management hinges on its availability and relevance to the producer when climate-sensitive decisions are being made. Climate information providers are challenged with the task of balancing forecast availability and lead time with acceptable forecast skill, which requires an improved understanding of the timing of agricultural decision making. Achieving a useful balance may also require an expansion of inquiry to include use of non-forecast climate information (i.e. historical climate information) in agricultural decision making. Decision calendars have proven valuable for identifying opportunities for using different types of climate information. The extent to which …