Progress 03/15/18 to 03/14/24
Outputs
Target Audience:Our research efforts have directly impacted scientists, land managers, and commodity groups who are concerned about reactive nitrogen in the environment and climate change. For instance, our research has been published in journals such as Geophysical Research Letters, Communications, Earth & Environment (a Nature Journal), Nature Food, Journal of Geophysical Research and our work has been presented at conferences such as the American Geophysical Union, American Meteorological Association, Soil Science Society of America, the Minnesota Corn Growers Association, Discovery Farms, Minnesota Farm Expo, and a number of invited talks at other Universities. Finally, our work has been presented to Commodity Groups and State Legislators who are interested in mitigating the reactive nitrogen problem. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?During this project two graduate students and three postdoctoral students have been trained to perform biometeorology research. They have gained new technical skills related to boundary layer measurements, trace gas measurements, flux-gradient and chamber-based flux approaches, and have gained valuable experience working with numerical models including the WRF-CHEM model and the Stochastic Inverted Lagrangian Transport model. These students have been involved in field measurements and computer modeling and have presented their findings at national meetings such as the American Meteorological Society, the American Geophysical Union, and regional meetings specializing in reactive nitrogen emissions. How have the results been disseminated to communities of interest?The results have mainly been disseminated to communities of interest through scientific publications, presentations at professional society meetings, and through courses at the University of Minnesota. What do you plan to do during the next reporting period to accomplish the goals?This is a final report, however, we plan to finish our aircraft ammonia work.
Impacts
What was accomplished under these goals?
During the final year of this project we focused our attention on analyzing and preparing a manuscript related to the airborne ammonia (NH3) measurements for quantifying sinks/sources and comparisons with tall tower and satellite-based observations. To investigate ammonia emissions hotspots and sources, aircraft-based measurements of atmospheric NH3 in the Midwestern Corn Belt were collected in May of 2021 within the atmospheric boundary layer. Observed NH3 was compared with WRF-CHEM modeled NH3 data generated using the 2017 National Emission Inventory (NEI), and to Cross-track Infrared Sounder (CrIS) retrieved concentrations. Flight-averaged boundary layer concentrations ranged from 16.3 ± 6.5 ppb in northeast Nebraska to 3.5 ± 0.7 ppb in central Minnesota, with the highest concentrations observed in northeast Nebraska. Flight-path averaged measurement to model concentration ratios ranged from 0.7 to 5, with the highest ratios (revealing model underestimates) occurring over Central Minnesota (5), Northeast Nebraska (3.4), and Northwest Iowa (2.9). Flight-path averaged measurement to model differences ranged from -2 ppb to 9.8 ppb, with the largest differences (indicating model underestimates) occurring over Northeast Nebraska (9.8 and 7.1 ppb), and smallest (indicating model overestimates) occurring over southern Minnesota (-2 ppb). The ratio and concentration difference suggest large model underestimates of ammonia in Northeast Nebraska. The locations of observed ammonia peaks, downwind of dairy and feedlot operations, suggest that cattle-related sources are likely responsible for the unaccounted spring ammonia peaks. Additionally, concentrations observed in central MN were significantly higher than modeled values despite the relative remoteness, indicating that fluxes from and transport to this region may be higher than previously estimated. Satellite retrievals allow for estimations of ammonia in the atmosphere over large geographic regions. To assess the agreement of retrievals from the Cross Track Infared Sounder with flight observations, we compare retrievals to the flight-observed NH3 values. CrIS retrievals were collected near midday (around 1:30 local time), whereas flight-based observations were collected over about 6 hours, so the temporal difference between flight and CrIS observation may explain some discrepancies between the measurements. To compare the retrievals and aircraft observations at the day and region scale, a linear regression of the average observed and retrieved concentrations for each flight day was performed, and model-to-retrieval ratios were calculated. Correlations between average flight NH3 and averaged retrieved NH3 were weak (R2=0.33, P>0.05), although better than those for the model case. Flight averaged measurement to averaged retrievals ranged from 0.7 to 2.0, generally aligning better with the observed values than the WRF-CHEM approach. The improved ratio but lack of correlation may reflect the time displacement between flights and retrievals. Since ammonia is a reactive gas undergoing significant chemical and depositional loss, observed fluxes are not an estimate of emissions through the target region, but instead represent an estimate of the net effect of all source and sink processes. The deposition and chemical removal of ammonia drive observed fluxes to be lower than true emissions. So, in these cases, the flux can be treated as a lower bound of the emissions that occurred in the target region. To help differentiate meteorological-driven emission changes, fluxes were also compared to the spread of fluxes calculated over the modeling period (19 days). For 8 out of 10 areas, the estimated NH3 fluxes were larger than the emissions prescribed by the emissions inventories. The regions that most closely aligned with the apriori emissions were S-MN(1 and 2), with both flight days having one area with fluxes greater and one with fluxes less than, the prescribed emissions. Notably, the prescribed emissions on these two flight days were also quite different, with S-MN(1) displaying some of the highest a priori emissions observed prescribed during the model period and S-MN(2) more typical emissions . This observation suggests that the parameterization of the emissions inventory that adjusts for meteorological conditions was functioning relatively well in these regions. Mass fluxes were much (>200%) higher than a priori emissions for 5 of the target areas, NW-IA (1.1 & 1.2), NE-NE (1.1), and C-MN(1.1 & 1.2). Fluxes for NE-NE(1.1) and the C-MN areas were not only larger than the emissions prescribed on the day of their respective flights, but also larger than any emissions prescribed for the regions during the WRF-CHEM modeling period. This inventory underestimates suggest that unaccounted or under accounted sources of NH3 exist within these regions. Over the next few months, we hope to finalize the airborne analyses and submit this work for publication.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2024
Citation:
"Hydrologic connectivity regulates riverine N2O sources and dynamics", M. Hu, Z. Yu, T.J. Griffis, W.H. Yang, J. Mohn, D.B. Millet, J.M. Baker, and D. Wang (Environmental Science & Technology, 2024, 58, 22, 9701-9713, https://doi.org/10.1021/acs.est.4c01285)
- Type:
Book Chapters
Status:
Awaiting Publication
Year Published:
2024
Citation:
"Agroecosystems and the reactive nitrogen dilemma: Sources, impacts, and potential solutions", C. Hsiao, T.J. Griffis, Z. Yu and R.T. Venterea, Book Chapter, Treatise on Geochemistry, 3rd Edition, Elsevier (2024, https://doi-org.ezp2.lib.umn.edu/10.1016/B978-0-323-99762-1.00096-6, in press)
- Type:
Journal Articles
Status:
Submitted
Year Published:
2024
Citation:
"Isotopic constraints on nitrous oxide emissions from the US Corn Belt", T.J. Griffis, Z. Yu, J.M. Baker, and D.B. Millet (submitted for review)
|
Progress 03/15/22 to 03/14/23
Outputs
Target Audience:Our research efforts have directly impacted scientists, land managers, and commodity groups who are concerned about reactive nitrogen in the environment and climate change. For instance, our research has been published in journals such as Geophysical Research Letters, Communications, Earth & Environment (a Nature Journal), Nature Food, Journal of Geophysical Research and our work has been presented at conferences such as the American Geophysical Union, American Meteorological Association, Soil Science Society of America, the Minnesota Corn Growers Association, Discovery Farms, Minnesota Farm Expo, and a number of invited talks at other Universities. Finally, our work has been presented to Commodity Groups and State Legislators who are interested in mitigating the reactive nitrogen problem. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?During this project two graduate students and three postdoctoral students have been trained to perform biometeorology research. They have gained new technical skills related to boundary layer measurements, trace gas measurements, flux-gradient and chamber-based flux approaches, and have gained valuable experience working with numerical models including the WRF-CHEM model and the Stochastic Inverted Lagrangian Transport model. These students have been involved in field measurements and computer modeling and have presented their findings at national meetings such as the American Meteorological Society, the American Geophysical Union, and regional meetings specializing in reactive nitrogen emissions. How have the results been disseminated to communities of interest?The results have mainly been disseminated to communities of interest through scientific publications, presentations at professional society meetings, and through courses at the University of Minnesota. What do you plan to do during the next reporting period to accomplish the goals?The primary goal is to finalize a manuscript describing airborne observations of ammonia for the Upper Midwest. My former postdoctoral student has promised to complete this work in Fall 2024.
Impacts
What was accomplished under these goals?
During this project we have accomplished the following major goals: 1. We have tested two different laser-based ammonia analyzers at our tall tower facility in Minnesota 2. We have made near continuous and high frequency measurements of ammonia at our tall tower facility in Minnesota at the 100 m and 56 m levels from April 2017 to July 2023. 3. We have computed hourly fluxes of ammonia based on a modified flux-gradient approach at the the tall tower facility for the period 2017 through 2019. 4. We have analyzed these ammonia flux data and calculated annual emissions for the region and compared those estimates with state-of-the-art inventories over the period 2017 to 2021. 5. We have performed ammonia and nitrous oxide flux measurements within our mesocosm facility to assess emissions associated with different agricultural management practices including conventional vs aspiration (split nitrogen applicaton and manure scenarios). 6. We have performed nitrous oxide flux measurement within our mesocosm facility and evaluated the impact of rain event frequency and magnitude on nitrous oxide emissions. 7. We have started to evaluate the efficacy of using designer microbes (i.e. Pivot Bio ProveN) to reduce nitrous oxide emissions while lower synthetic nitrogen use and have evaluated the impact on corn yields. 8. We have enabled the Weather Research and Forecasting Chemistry (WRF-CHEM) model at our Supercomputing Institute and have tested the model against the tall tower ammonia observations calculated from 2017 to present. 9. We have used the WRF-CHEM simulations and tall tower data to help identify hotspots and hot momments in the US Corn Belt over the past four years. 10. We used our tall tower observations and WRF-CHEM simulations to plan our aircraft NH3 measurement campaign for the Upper Midwetern United states. Those aircraft campaigns were delayed due to COVID 19, but were completed in spring 2021. 11. Our tall tower CO2 observations have been analyzed for the period 2007 to present to help understand how climate and agriculture are impacting the CO2 budget of the region. We have shown that warming temperatures within the region has reduced the amount of mid-summer carbon sequestration. We have shown that this signal is present in multiple tall tower datasets from within the region. 13. We have made advances in measuring the carbon dioxide budget of ecosystems using open-path technology by providing new insights regarding the long-standing biases in open-path technology caused by the so-called "sensor self heating" problem. 14. We performed regional aircraft observations of ammonia emissions and examined regional gradients and assessed emissions from large feedlots within the Corn Belt. Approximately 10 days of aircraft measurements were obtained. These data are now been used with tall tower and satellite observations to improve our understanding of hot spots and hot momments of ammonia emissions within the region. We are now combining our tall tower ammonia measurements with satellite observations of ammonia to better constrain our inverse modeling efforts to improve our understanding of hot spots and hot momments in the Upper Midwest, United States. 16. A manuscript summarizing the aircraft NH3 observations is near completing and will be submitted for review in fall 2024. 17. We have quantified the influence of land management techniques (i.e. variable fertilizer rate, use of Pivot Bio) and climate (i.e. variable precipitation frequency and rate) on nitrous oxide emissions in our mesocosm facility. 18. Data from our project have been shared with other modeling groups who are using artificial intelligence to improve simulations of nitrous oxide emissions. Multiple datasets have been published online. 19. Key papers based on these results have been published in: Journal of Geophysical Research -Biogeosciences; Journal of Geophysical Research - Atmospheres; Geophysical Research Letters; Communications Earth & Environment; Nature Food; Journal of Environmental Quality; Agricultural and Forest Meteorology; Geoscientific Model Development; Environmental Science and Technology, with others in preparation for review.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
"A coupled equilibrium boundary layer model with stable water isotopes and its application to local water recycling", K. Xiao, T.J. Griffis, X. Lee, W. Xiao, and J.M. Baker (Agricultural and Forest Meteorology, 2023, 339, 109572, https://doi.org/10.1016/j.agrformet.2023.109572)
|
Progress 03/15/21 to 03/14/22
Outputs
Target Audience:Our research efforts have directly impacted scientists, land managers, and commodity groups who are concerned about reactive nitrogen in the environment and climate change. For instance, our research has been published in journals such as Geophysical Research Letters, Communications, Earth & Environment (a Nature Journal), Nature Food, Journal of Geophysical Research and our work has been presented at conferences such as the American Geophysical Union, American Meteorological Association, Soil Science Society of America, the Minnesota Corn Growers Association, Discovery Farms, Minnesota Farm Expo, and a number of invited talks at other Universities. Changes/Problems:The only problems we have had are related to the negative impacts of COVID19 on various aspects of the project - especially the aircraft measurement campaign. The other problem we have had is related to hiring highly qualified personnel. What opportunities for training and professional development has the project provided?Over the first four years of this project two graduate students and three postdoctoral students have been trained to perform biometeorology research. They have gained new technical skills related to boundary layer measurements, trace gas measurements, flux-gradient and chamber-based flux approaches, and have gained valuable experience working with numerical models including the WRF-CHEM model and the Stochastic Inverted Lagrangian Transport model. These students have been involved in field measurements and computer modeling and have presented their findings at national meetings such as the American Meteorological Society, the American Geophysical Union, and regional meetings specializing in reactive nitrogen emissions. How have the results been disseminated to communities of interest?The results have mainly been disseminated to communities of interest through scientific publications, presentations at professional society meetings, invited talks at other Universities, and through courses at the University of Minnesota. What do you plan to do during the next reporting period to accomplish the goals?We have three major goals for the next reporting period: 1. We are establishing a side-by-side treatment comparison of conventional vs aspirational corn-soybean cropping systems. The conventional system will make use of synthetic N fertlizer input while the aspirational system will make use of a kura companion cropping system. Eddy covariance and flux-gradient techniques will be used to compare the greenhouse gas and reactive nitrogen budget of these systems over the next 2 years. 2. We are currently working toward estimating the regional greenhouse gas budget and reactive nitrogen budget for the Upper Midwest Corn Belt region based on our tall tower and inverse model analyses. This synthesis will include analysis of nitrous oxide data from 2010 to 2021, ammonia data from 2017 to 2021, and methane data from 2016 to 2021. During my spring semester leave (2021) I performed most of the model footprint analsyses to facilitate the inverse budget analyses. We believe these relatively long-term tall tower analyses will provide significant new insights regarding the overall footprint of agricultural systems on the atmosphere and their sensitivity to climate variations. I am currently writing this manuscript with a planned submission date of fall 2022. 3. A major goal is to finalize a manuscript related to our aircraft ammonia measurements. This work is very novel and I am very excited to see its completion. Unfortunately, this part of the project was delayed due to the impacts of COVID19.
Impacts
What was accomplished under these goals?
During the first four years of this project we have accomplished the following major goals: 1. We have tested two different laser-based ammonia analyzers at our tall tower facility in Minnesota 2. We have made near continuous and high frequency measurements of ammonia at our tall tower facility in Minnesota at the 100 m and 56 m levels from April 2017 to July 2022. 3. We have computed hourly fluxes of ammonia based on a modified flux-gradient approach at the the tall tower facility for the period 2017 through 2019. 4. We have analyzed these ammonia flux data and calculated annual emissions for the region and compared those estimates with state-of-the-art inventories over the period 2017 to 2021. 5. We have performed ammonia and nitrous oxide flux measurements within our mesocosm facility to assess emissions associated with different agricultural management practices including conventional vs aspiration (split nitrogen applicaton and manure scenarios). 6. We have performed nitrous oxide flux measurement within our mesocosm facility and evaluated the impact of rain event frequency and magnitude on nitrous oxide emissions. 7. We have started to evaluate the efficacy of using designer microbes (i.e. Pivot Bio ProveN) to reduce nitrous oxide emissions while lower synthetic nitrogen use and have evaluated the impact on corn yields. 8. We have enabled the Weather Research and Forecasting Chemistry (WRF-CHEM) model at our Supercomputing Institute and have tested the model against the tall tower ammonia observations calculated from 2017 to present. 9. We have used the WRF-CHEM simulations and tall tower data to help identify hotspots and hot momments in the US Corn Belt over the past four years. 10. We used our tall tower observations and WRF-CHEM simulations to plan our aircraft NH3 measurement campaign for the Upper Midwetern United states. Those aircraft campaigns were delayed due to COVID 19, but were completed in spring 2021. 11. Our tall tower CO2 observations have been analyzed for the period 2007 to present to help understand how climate and agriculture are impacting the CO2 budget of the region. We have shown that warming temperatures within the region has reduced the amount of mid-summer carbon sequestration. We have shown that this signal is present in multiple tall tower datasets from within the region. 13. We have made advances in measuring the carbon dioxide budget of ecosystems using open-path technology by providing new insights regarding the long-standing biases in open-path technology caused by the so-called "sensor self heating" problem. 14. We performed regional aircraft observations of ammonia emissions and examined regional gradients and assessed emissions from large feedlots within the Corn Belt. Approximately 10 days of aircraft measurements were obtained. These data are now been used with tall tower and satellite observations to improve our understanding of hot spots and hot momments of ammonia emissions within the region. We are now combining our tall tower ammonia measurements with satellite observations of ammonia to better constrain our inverse modeling efforts to improve our understanding of hot spots and hot momments in the Upper Midwest, United States. 15. Data from our project have been shared with other modeling groups who are using artificial intelligence to improve simulations of nitrous oxide emissions. Multiple datasets have been published online. 16. Key papers based on these results have been published in: Journal of Geophysical Research -Biogeosciences; Journal of Geophysical Research - Atmospheres; Geophysical Research Letters; Communications Earth & Environment; Nature Food; Journal of Environmental Quality; Agricultural and Forest Meteorology; Geoscientific Model Development; and others are currently in preparation.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
"A multi-year constraint on ammonia emissions and deposition within the U.S. Corn Belt", C. Hu, T.J. Griffis, A. Frie, J.M. Baker, J.D. Wood, D.B. Millet, Z. Yu, X. Yu, and A.C. Czarnetzki (Geophysical Research Letters, 2021, 48, e2020GL090865. https://doi.org/10.1029/2020GL090865)
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
"Warming temperatures lead to reduced summer carbon sequestration in the U.S. corn belt" Z. Yu, T.J. Griffis, and J.M. Baker (Communications, Earth, & Environment, 2021, 2, 53, https://doi.org/10.1038/s43247-021-00123-9),
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
"Response of nitrous oxide emissions to individual rain events and future changes in precipitation", L.T. Miller, T.J. Griffis, M. D. Erickson, P.A. Turner, M.J. Deventer, Z. Chen, Z. Yu, R.T. Venterea, J.M. Baker, and A. L. Frie (Journal of Environmental Quality, 2022, 51, 312-324)
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
"KGML-ag: A Modeling Framework of Knowledge-Guided Machine Learning to Simulate Agroecosystems: A Case Study of Estimating N2O Emission using Data from Mesocosm Experiments", L. Liu, S. Xu, Z. Jin, J. Tang, K. Guan, T. J. Griffis, M.D. Erickson, A.L. Frie, X.Jia, T. Kim, L. T. Miller, B. Peng, S. Wu, Y. Yang, W. Zhou, and V. Kumar (Geoscientific Model Development, 2022, 15, 28392858, https://doi.org/10.5194/gmd-2021-317)
|
Progress 03/15/20 to 03/14/21
Outputs
Target Audience:Our research efforts have directly impacted scientists, land managers, and commodity groups who are concerned about reactive nitrogen in the environment and climate change. For instance, over the past year our research has been published in journals such as Geophysical Research Letters, Communications, Earth & Environment (a Nature Journal), Nature Food, and Journal of Geophysical Research-Atmospheres. Our work has been presented at conferences such as the American Geophysical Union, American Meteorological Association, the Minnesota Corn Growers Association, Discovery Farms, Minnesota Farm Expo, and others. Changes/Problems:Some of our field and aircraft measurements were not possible during 2020 due to the COVID19 pandemic. However, we have managed to maintain many of our measurement systems and were able to carry out many of the proposed modeling activities. What opportunities for training and professional development has the project provided?Over the first three years of this grant one graduate student and two postdoctoral students have been trained to perform biometeorology research. They have gained new technical skills related to boundary layer measurements, trace gas measurements, flux-gradient and chamber-based flux approaches, and have gained valuable experience working with numerical models including the WRF-CHEM model and the Stochastic Inverted Lagrangian Transport model. How have the results been disseminated to communities of interest?The results of our research have been presented at national meetings such as the American Meteorological Society and the American Geophysical Union. We have also presented our research to commodity groups including the Minnesota Corn Growers Association and Discovery Farms. Key papers have been published in: Journal of Geophysical Research -Biogeosciences; Journal of Geophysical Research - Atmospheres; Geophysical Research Letters; Communications Earth & Environment; Nature Food; and Agricultural and Forest Meteorology. What do you plan to do during the next reporting period to accomplish the goals?We have four major goals for the next reporting period: 1. We are establishing a side-by-side treatment comparison of conventional vs aspirational corn-soybean cropping systems. The conventional system will make use of synthetic N fertlizer input while the aspirational system will make use of dairy manure as its N source. Eddy covariance and flux-gradient techniques will be used to compare the greenhouse gas and reactive nitrogen budget of these systems over the next 2 years. 2. We are establishing the same conventional vs aspirational treatments at our mesocosm facility. Here, we will assess, under highly controlled conditions, if the greenhouse gas and reactive nitrogen budgets differ significantly between these two treatment effects. 3. We are currently working toward estimating the regional greenhouse gas budget and reactive nitrogen budget for the Upper Midwest Corn Belt region based on our tall tower and inverse model analyses. This synthesis will include analysis of nitrous oxide data from 2010 to 2021, ammonia data from 2017 to 2021, and methane data from 2016 to 2021. During my spring semester leave (2021) I have performed most of the model footprint analsyses to facilitate the inverse budget analyses. We believe these relatively long-term tall tower analyses will provide significant new insights regarding to overall footprint of agricultural systems on the atmosphere and their sensitivity to climate variations. 4. With some of these major accomplishments described above - we have planned our aircraft measurements to assess ammonia and nitrous oxide emissions from major livestock facilities within the region. These flights are scheduled for May 2021 and will be used to further enhance our understanding of NH3 sink/source behavior across the region.
Impacts
What was accomplished under these goals?
During the first three years of this project we have accomplished the following major goals: 1. We have tested two different laser-based ammonia analyzers at our tall tower facility in Minnesota 2. We have made near continuous and high frequency measurements of ammonia at our tall tower facility in Minnesota at the 100 m and 56 m levels from April 2017 to April 2021. 3. We have computed hourly fluxes of ammonia based on a modified flux-gradient approach at the the tall tower facility for the period 2017 through 2019. 4. We have analyzed these ammonia flux data and calculated annual emissions for the region and compared those estimates with state-of-the-art inventories. 5. We have performed ammonia flux measurements within our mesocosm facility to assess emissions associated with different agricultural management practices including conventional vs aspiration (split nitrogen applicaton and manure scenarios). 6. We have enabled the Weather Research and Forecasting Chemistry (WRF-CHEM) model at our Supercomputing Institute and have tested the model against the tall tower ammonia observations calculated from 2017 to present. 7. We have used the WRF-CHEM simulations and tall tower data to help identify hotspots and hotmomments in the US Corn Belt over the past four years. 8. We have use our tall tower observations and WRF-CHEM simulations to plan our aircraft NH3 measurement campaign for the Upper Midwetern United states. Scientific Aviation will be conducting ammonia flight campaigns from in May 2021. These flights were not possible in 2020 due to the conronvirus pandemic. 9. Our tall tower CO2 observations have been analyzed for the period 2007 to present to help understand how climate and agriculture are impacting the CO2 budget of the region. We have shown that warming temperatures within the region of reduced the amount of mid-summer carbon sequestration. We have shown that this signal is present in multiple tall tower datasets from within the region. 10. We have made advances in measuring the carbon dioxide budget of ecosystems using open-path technology by providing new insights regarding the long-standing biases in open-path technology caused by so-called "sensor self heating". 11. We are now combining our tall tower ammonia measurements with satellite observations of ammonia to better constrain our inverse modeling efforts to improve our understanding of hot spots and hot momments in the Upper Midwest, United States. 12. Key papers based on these results have been published in: Journal of Geophysical Research -Biogeosciences; Journal of Geophysical Research - Atmospheres; Geophysical Research Letters; Communications Earth & Environment; Nature Food; and Agricultural and Forest Meteorology.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Modeling the sources and transport processes associated with extreme ammonia episode in the U.S. Corn Belt C. Hu, T.J. Griffis, J.M. Baker, J.D. Wood, D.B. Millet and X. Lee (Journal of Geophysical Research - Atmospheres, 2020, 125, e2019JD031207, doi.org/10.1029/2019JD031207)
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Alternative nitrogen management improves air quality in China" T.J. Griffis and J.M. Baker (Nature Food, Invited News and Views, 1, 597-598)
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Biases in open-path carbon dioxide flux measurements: Roles of instrument surface heat exchange and analyzer temperature sensitivity", M.J. Deventer, D.T. Roman, I. Bogoev, R. K. Kolka, M. Erickson, X. Lee, J.M. Baker, D.B. Millet, and T.J. Griffis (Agricultural and Forest Meteorology, 2021, 296, 108216)
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Warming temperatures lead to reduced summer carbon sequestration in the U.S. corn belt" Z. Yu, T.J. Griffis, and J.M. Baker (Communications, Earth, & Environment, 2021, 2, 53, https://doi.org/10.1038/s43247-021-00123-9)
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
"A multi-year constraint on ammonia emissions and deposition within the U.S. Corn Belt", C. Hu, T.J. Griffis, A. Frie, J.M. Baker, J.D. Wood, D.B. Millet, Z. Yu, X. Yu, and A.C. Czarnetzki (Geophysical Research Letters, 48, e2020GL090865. https://doi.org/10.1029/2020GL090865)
- Type:
Journal Articles
Status:
Accepted
Year Published:
2021
Citation:
Modern dairy forage production practices result in unsustainable carbon losses" J.D. Gamble, G.W. Feyereisen, T.J. Griffis, C.D. Wente, and J.M. Baker (Agricultural and Forest Meteorology, 2021, in press)
|
Progress 03/15/19 to 03/14/20
Outputs
Target Audience:Our stakeholders include the broader scientific community and atmospheric science specialists who are concerned with atmospheric composition, radiative forcing, and climate prediction. Our stakeholders also include agencies such as MPCA, land managers/livestock managers, and farmers who aim to reduce the reactive nitrogen and greenhouse gas emissions related to agricultural activities. Changes/Problems:The only major concern on the horizon is the potenial impact of the coronavirus pandemic on our 2020 research plans. At the present, we are severely limited with ability to conduct field research. We hope that in the coming weeks that this situation will improve. What opportunities for training and professional development has the project provided?Over the first two years of this grant one graduate student and two postdoctoral students have been trained to perform biometeorology research. They have gained new technical skills related to boundary layer measurements, trace gas measurements, flux-gradient and chamber-based flux approaches, and have gained valuable experience working with numerical models including the WRF-CHEM model and the Stochastic Inverted Lagrangian Transport model. These students have been involved in field measurements and computer modeling and have presented their findings at national meetings such as the American Meteorological Society and the American Geophysical Union. How have the results been disseminated to communities of interest?The results have mainly been disseminated to communities of interest through scientific publications, presentations at professional society meetings, through courses at the University of Minnesota. What do you plan to do during the next reporting period to accomplish the goals?We have four major goals for the next reporting period: 1. We are currently establishing a side-by-side treatment comparison of conventional vs aspirational corn-soybean cropping systems. The conventional system will make use of synthetic N fertlizer input while the aspirational system will make use of dairy manure as its N source. Eddy covariance and flux-gradient techniques will be used to compare the greenhouse gas and reactive nitrogen budget of these systems over the next 3 years. 2. We are establishing the same conventional vs aspiration treatment at our mesocosm facility. Here, we will assess, under highly controlled conditions, if the greenhouse gas and reactive nitrogen budgets differ significantly between these two treatment effects. 3. We are currently working toward estimating the regional greenhouse gas budget and reactive nitrogen budget for the Upper Midwest Corn Belt region based on our tall tower and inverse model analyses. This synthesis will include analyzer nitrous oxide data from 2010 to present, ammonia data from 2017 to present, methane data from 2016 to present, and carbon dioxide data from 2007 to present. We believe these relatively long-term tall tower analyses will provide significant new insights regarding to overall footprint of agricultural systems on the atmosphere. 4. With some of these major accomplishments described above - we have planned our aircraft measurements to assess ammonia and nitrous oxide emissions from major livestock facilities within the region. We are hoping to accomplish this task in June 2020, however, the conronavirus pandemic might alter these plans.
Impacts
What was accomplished under these goals?
During the first two years of this project we have accomplished the following major goals: 1. We have tested two different laser-based ammonia analyzers at our tall tower facility in Minnesota 2. We have made near continuous and high frequency measurements of ammonia at our tall tower faciility in Minnesota at the 100 m and 56 m levels from April 2017 to April 2020. 3. We have computed hourly fluxes of ammonia based on a modified flux-gradient approach at the the tall tower facility for the period 2017 through 2018. 4. We have analyzed these ammonia flux data and calculated annual emissions for the region and compared those estimates with state-of-the-art inventories. 5. We have performed ammonia flux measurements within our mesocosm facility to assess emissions associated with different agricultural management practices including conventional vs aspiration (split nitrogen applicaton and manure scenarios). 6. We have enabled the Weather Research and Forecasting Chemistry (WRF-CHEM) model at our Supercomputing Institute and have tested the model against the tall tower ammonia observations calculated from 2017 to present. 7. We have used the WRF-CHEM simulations and tall tower data to help identify hotspots and hotmomments in the US Corn Belt over the past three years. 8. We have use our tall tower observations and WRF-CHEM simulations to plan our aircraft NH3 measurement campaign for the Upper Midwetern United states. We are hoping that Scientific Aviation will be able to conduct these flights in June 2020, but the conronvirus pandemic might alter these plans. 9. Our tall tower CO2 observations have been analyzed for the period 2007 to present to help understand how climate and agriculture are impacting the CO2 budget of the region. 10. We have made advances in measuring the carbon dioxide budget of ecosystems using open-path technology by providing new insights regarding the long-standing biases in open-path technology caused by so-called "sensor self heating". 11. A number of papers have now been published or are currently in review.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
"Tall tower ammonia observations and emission estimates in the US Midwest", T.J. Griffis, C. Hu, J.M. Baker, J.D. Wood, D.B. Millet, M. Erickson, Z. Yu, J. Deventer, C. Winker, and Z. Chen (Journal of Geophysical Research-Biogeosciences, 2019, 124, 3432-3447, doi: 10.1029/2019JG005172)
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
"Modeling the sources and transport processes during extreme ammonia episodes in the US Corn Belt", C. Hu, T.J. Griffis, J.M. Baker, J.D. Wood, D.B. Millet and X. Lee (Journal of Geophysical Research - Atmospheres, 2020, 125, e2019JD031207, doi.org/10.1029/2019JD031207)
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Progress 03/15/18 to 03/14/19
Outputs
Target Audience:Our stakeholders include the broader scientific community and atmospheric science specialists who are concerned with atmospheric composition, radiative forcing, and climate prediction. Our stakeholders also include agencies such as MPCA, land managers/livestock managers, and farmers who aim to reduce the reactive nitrogen and greenhouse gas emissions related to agricultural activities. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Over the first year of this grant one graduate student and one postdoctoral student have been trained to perform biometeorology research. They have gained new technical skills related to boundary layer measurements, trace gas measurements, flux-gradient and chamber-based flux approaches, and have gained valuable experience working with numerical models including the WRF-CHEM model and the Stochastic Inverted Lagrangian Transport model. These students have been involved in field measurements and computer modeling and have presented their findings atthe American Meteorological Society and seminars at the University of Minnesota. How have the results been disseminated to communities of interest?So far these early results have mainly been disseminated to communities of interest through scientific publications, presentations at professional socieity meetings, and at a major international symposium held in Nanjing China. What do you plan to do during the next reporting period to accomplish the goals?We have four major goals for the next reporting period: 1. We are currently establishing a side-by-side treatment comparison of conventional vs aspirational corn-soybean cropping systems. The conventional system will make use of synthetic N fertlizer input while the aspirational system will make use of dairy manure as its N source. Eddy covariance and flux-gradient techniques will be used to compare the greenhouse gas and reactive nitrogen budget of these systems over the next 3 years. 2. We are establishing the same conventional vs aspiration treatment at our mesocosm facility. Here, we will assess, under highly controlled conditions, if the greenhouse gas and reactive nitrogen budgets differ significantly between these two treatment effects and will assess how best to reduce emissions. 3. We are currently working toward estimating the regional greenhouse gas budget and reactive nitrogen budget for the Upper Midwest Corn Belt region based on our tall tower and inverse model analyses. This synthesis will include analyses ofnitrous oxide data from 2010 to present, ammonia data from 2017 to present, methane data from 2016 to present, and carbon dioxide data from 2007 to present. We believe these relatively long-term tall tower analyses will provide significant new insights regarding theoverall footprint of agricultural systems on the atmosphere's greenhouse gas and reactive nitrogen budgets. 4. With some of these major accomplishments described above - we will begin planning our aircraft measurements to assess ammonia and nitrous oxide emissions from major livestock facilities within the region. The above accomplishments will help us decide when and when it is best to apply the aircraft measurements.
Impacts
What was accomplished under these goals?
During the first year of this project we have accomplished the following goals: 1. We have tested two different laser-based ammonia analyzers at our tall tower facility in Minnesota 2. We have made near continuous and high frequency measurements of ammonia at our tall tower faciility in Minnesota at the 100 m and 56 m levels. 3. We have computed hourly fluxes of ammonia based on a modified flux-gradient approach at the the tall tower facility. 4. We have analyzed these ammonia flux data and calculated annual emissions for the region and compared those estimates with state-of-the-art inventories 5. We have performed ammonia flux measurements within our mesocosm facility to assess emissions associated with different agricultural management practices including conventional vs aspiration (split nitrogen applicaton scenarios). 6. We have enabled the Weather Research and Forecasting Chemistry (WRF-CHEM) model at our Supercomputing Institute and have tested the model against the tall tower ammonia observations calculated from 2017 to present. 7. We have used the WRF-CHEM simulations and tall tower data to help identify hotspots and hotmomments in the US Corn Belt over the past two years. These analyses are still in progress.
Publications
- Type:
Journal Articles
Status:
Submitted
Year Published:
2019
Citation:
Tall tower ammonia observations and emission estimates in the US Midwest, T.J. Griffis, C. Hu, J.M. Baker, J.D. Wood, D.B. Millet, M. Erickson, Z. Yu, J. Deventer, C. Winker, and Z. Chen (Journal of Geophysical Research-Biogeosciences)
- Type:
Journal Articles
Status:
Accepted
Year Published:
2019
Citation:
Anthropogenic methane emission and its partitioning for the Yangtze River Delta region of China, C. Hu, T.J. Griffis, S. Liu, W. Xiao, N. Hu, W. Huang, D. Yang, X. Lee (Journal of Geophysical Research-Biogeosciences, in press)
- Type:
Journal Articles
Status:
Other
Year Published:
2019
Citation:
Modeling the sources and transport processes associated with high ammonia episodes in the US Corn Belt, C. Hu, T.J. Griffis, J.M. Baker, J.D. Wood, D.B. Millet and X. Lee (Journal of Geophysical Research - Atmospheres, to be submitted April 2019)
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