I-69 ORX: A Bistate Megaproject = Project Management2

Managing a large project is full of challenges. Needs grow exponentially when you’re managing a bistate megaproject with two clients and twice the number of agencies, elected leaders, community groups, media outlets, and other stakeholders. The I-69 Ohio River Crossing team will share strategies to improve internal and external communications, streamline processes, build consensus, increase collaboration, and maximize stakeholder engagement—all while maintaining an accelerated schedul

Scoring IPM Adoption in Ohio: It Really Adds Up

Ohio has developed Integrated Pest Management (IPM) definitions for over 20 major crops, including field crops, fruits, and vegetables. These crop definitions are actual criteria that allow growers and researchers to evaluate a selected crop production system and determine how many IPM practices the producer has adopted. There are six sections to complete, and points are awarded based on proper implementation for that particular crop. The goal for growers is to achieve 80% or more of the points in the crop definition

Photoionization Loss of Mercury’s Sodium Exosphere: Seasonal Observations by MESSENGER and the THEMIS Telescope

We present the first investigation and quantification of the photoionization loss process to Mercury’s sodium exosphere from spacecraft and ground‐based observations. We analyze plasma and neutral sodium measurements from NASA’s MESSENGER spacecraft and the THEMIS telescope. We find that the sodium ion (Na+) content and therefore the significance of photoionization varies with Mercury’s orbit around the Sun (i.e., true anomaly angle: TAA). Na+ production is affected by the neutral sodium solar‐radiation acceleration loss process. More Na+ was measured on the inbound leg of Mercury’s orbit at 180°–360° TAA because less neutral sodium is lost downtail from radiation acceleration. Calculations using results from observations show that the photoionization loss process removes ∼1024 atoms/s from the sodium exosphere (maxima of 4 × 1024 atoms/s), showing that modeling efforts underestimate this loss process. This is an important result as it shows that photoionization is a significant loss process and larger than loss from radiation acceleration.Plain Language SummaryMercury has a thin sodium collision‐less atmosphere (i.e., an exosphere). A variety of processes add or subtract sodium particles to and from the exosphere. Photoionization is a loss process, and we investigate it in this paper by analyzing data from NASA’s MESSENGER spacecraft and ground‐based observations made by the THEMIS telescope. Mercury has an eccentric (noncircular) orbit, which means the planet’s distance from the Sun changes throughout its orbit. This, first of all, affects how much sodium is lost due to acceleration of neutral sodium by radiation (i.e., how much sodium is accelerated away from Mercury by radiation from the Sun). This subsequently affects how much sodium is left to be photoionized. Therefore, the amount of sodium lost due to photoionization varies throughout a Mercury‐year. We calculate that ∼1024 atoms/s of sodium are lost due to photoionization, and that it is a significant loss process in comparison to acceleration by radiation.Key PointsPhotoionization can be a significant loss process to the sodium exosphere with peak loss estimates of 4 × 1024 atoms/sThe photoionization loss process of Mercury’s sodium exosphere varies throughout the planet’s orbit around the SunMore sodium is lost due to photoionization on the inbound leg (true anomaly angle of 180°–360°) of Mercury’s orbit than the outbound legPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/167426/1/grl62199.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167426/2/grl62199_am.pd

Photoionization Loss of Mercury's Sodium Exosphere: Seasonal Observations by MESSENGER and the THEMIS Telescope

We present the first investigation and quantification of the photoionization loss process to Mercury’s sodium exosphere from spacecraft and ground‐based observations. We analyze plasma and neutral sodium measurements from NASA’s MESSENGER spacecraft and the THEMIS telescope. We find that the sodium ion (Na+) content and therefore the significance of photoionization varies with Mercury’s orbit around the Sun (i.e., true anomaly angle: TAA). Na+ production is affected by the neutral sodium solar‐radiation acceleration loss process. More Na+ was measured on the inbound leg of Mercury’s orbit at 180°–360° TAA because less neutral sodium is lost downtail from radiation acceleration. Calculations using results from observations show that the photoionization loss process removes ∼1024 atoms/s from the sodium exosphere (maxima of 4 × 1024 atoms/s), showing that modeling efforts underestimate this loss process. This is an important result as it shows that photoionization is a significant loss process and larger than loss from radiation acceleration.Plain Language SummaryMercury has a thin sodium collision‐less atmosphere (i.e., an exosphere). A variety of processes add or subtract sodium particles to and from the exosphere. Photoionization is a loss process, and we investigate it in this paper by analyzing data from NASA’s MESSENGER spacecraft and ground‐based observations made by the THEMIS telescope. Mercury has an eccentric (noncircular) orbit, which means the planet’s distance from the Sun changes throughout its orbit. This, first of all, affects how much sodium is lost due to acceleration of neutral sodium by radiation (i.e., how much sodium is accelerated away from Mercury by radiation from the Sun). This subsequently affects how much sodium is left to be photoionized. Therefore, the amount of sodium lost due to photoionization varies throughout a Mercury‐year. We calculate that ∼1024 atoms/s of sodium are lost due to photoionization, and that it is a significant loss process in comparison to acceleration by radiation.Key PointsPhotoionization can be a significant loss process to the sodium exosphere with peak loss estimates of 4 × 1024 atoms/sThe photoionization loss process of Mercury’s sodium exosphere varies throughout the planet’s orbit around the SunMore sodium is lost due to photoionization on the inbound leg (true anomaly angle of 180°–360°) of Mercury’s orbit than the outbound legPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/167426/1/grl62199.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167426/2/grl62199_am.pd

Proton Precipitation in Mercury’s Northern Magnetospheric Cusp

Ion precipitation onto Mercury’s surface through its magnetospheric cusps acts as a source of planetary atoms to both Mercury’s exosphere and magnetosphere. Through the process of ion sputtering, solar wind ions (∼95% protons) impact the surface regolith and liberate material, mostly as neutral atoms. We have identified 2760 northern magnetospheric cusp crossings throughout the MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) mission, based on enhancements in proton flux observed by the Fast Imaging Plasma Spectrometer (FIPS). We find cusp crossings spanning 50–85° in magnetic latitude with a geometric center typically at 60–70°. The cusp center is stable about its average but its latitudinal extent varies orbit-to-orbit. The mean latitude weakly depends on the magnitude of the interplanetary magnetic field (IMF), dropping by about 1.3° magnetic latitude for each increase of 10 nT in IMF strength. We have used these identified cusp boundaries to estimate the flux of protons which will precipitate onto Mercury’s surface. We find an average proton precipitation flux of 1.0 × 107 cm−2 s−1, ranging 3.3 × 104–6.2 × 108 cm−2 s−1, and that this flux can vary substantially between subsequent 10-s measurements. We also tabulated the peak precipitation fluxes for each cusp crossing. They range 9.8 × 104–1.4 × 109 cm−2 s−1, with a mean of 3.7 × 107 cm−2 s−1. We find strong dependencies on the local time of the cusp crossing as well as on Mercury’s orbit around the Sun, which warrant further investigation.Key PointsMercury’s northern cusp was found at 50°–85° magnetic latitude in 2760 MErcury Surface, Space ENvironment, GEochemistry and Ranging orbits, falling by 1.3° per 10 nT increase in interplanetary magnetic fieldAverage proton precipitation flux was 1.0 × 107 cm−2 s−1, ranging 3.3 × 104–6.2 × 108 cm−2 s−1 in the 707 orbits with B vector in viewProton precipitation flux can vary by two orders of magnitude in subsequent 10-s measurements with peak fluxes up to 1.4 × 109 cm−2 s−1Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/175086/1/jgra57456.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175086/2/2022JA030397-sup-0001-Supporting_Information_SI-S01.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/175086/3/jgra57456_am.pd

MESSENGER observations of planetary ion enhancements at Mercury's northern magnetospheric cusp during Flux Transfer Event Showers

At Mercury, several processes can release ions and neutrals out of the planet's surface. Here we present enhancements of dayside planetary ions in the solar wind entry layer during flux transfer event (FTE) "showers" near Mercury's northern magnetospheric cusp. The FTE showers correspond to the intervals of intense magnetopause reconnection of Mercury's magnetosphere, which form a solar wind entry layer equatorward of the magnetospheric cusps. In this entry layer, solar wind ions are accelerated and move downward (i.e. planetward) toward the cusps, which sputter upward-moving planetary ions within 1 minute. The precipitation rate is enhanced by an order of magnitude during FTE showers and the neutral density of the exosphere can vary by >10% due to this FTE-driven sputtering. These in situ observations of enhanced planetary ions in the entry layer likely correspond to an escape channel of Mercury's planetary ions, and the large-scale variations of the exosphere observed on minute-timescales by Earth observatories. Comprehensive, future multi-point measurements made by BepiColombo will greatly enhance our understanding of the processes contributing to Mercury's dynamic exosphere and magnetosphere.Comment: 34 pages, 10 figures, 1 tabl