Quantifying microclimate heterogeneity within a contemporary plant growth facility

"December 2013.""A Thesis presented to the Faculty of the Graduate School at the University of Missouri--Columbia In Partial Fulfillment of the Requirements for the Degree M.S. Natural Resources Emphasis: Water Resources."Thesis advisor: Jason A. Hubbart, Ph.D.Three separate contemporary climate controlled greenhouse rooms in the Sears Plant Growth Facility located at the University of Missouri, Columbia, MO, USA were selected for microclimate analysis. Temperature, relative humidity, and incoming solar radiation data were logged hourly between 5/9/12 and 9/5/12 to test the efficacy of current management practices and to improve understanding of the spatial and temporal climate variability inside the greenhouse rooms. The average horizontal temperature gradient was 0.08 °C₉m⁻¹ and the maximum horizontal temperature gradient was 0.83 ðC₉m⁻¹. The average vertical temperature gradient was 2.27 °C₉m⁻¹ and the maximum lapse rate was 11.65 °C₉m⁻¹. Vapor pressure deficit (VPD) calculations were made using data as a proxy to assess plant physiological response to internal conditions. The average horizontal VPD gradient was 0.025 kPam⁻¹ and the maximum VPD gradient was 0.350 kPa₉m⁻¹ . Collectively, results indicate a heterogenous distribution of temperature and vapor pressure deficit created primarily by the active cooling system. Several recommendations are supplied to improve the homogeneity of the internal greenhouse climate, which will lead to increased productivity and profits for greenhouse managers.Includes bibliographical references (pages 115-121)

The horizontal redistribution of anomalous vertical heat fluxes at tropical latitudes /

A study was conducted to improve quantitative understanding of how anomalous vertical heat fluxes associated with the El Nio-Southern Oscillation (ENSO) are transported poleward to maintain climate equilibrium. State-of-the-art atmospheric reanalysis output was used to quantify anomalous horizontal, tropospheric mean fluxes of sensible and latent heat monthly over a global domain during all ENSO events that occurred between January 1979 and June 2016. Results showed coherent spatial patterns (p less than 0.05) of horizontal fluxes of latent heat connecting ENSO and Pacific North American (PNA) pattern regions implying potential to quantify the interrelationship between ENSO and PNA patterns. Spatial patterns of anomalous sensible heat fluxes showed anomalous circulation dipoles consistent with PNA and North Atlantic Oscillation (NAO) patterns. Results indicated a linear relationship between ENSO, PNA, and NAO patterns that was most apparent for the PNA (NAO) pattern during January (November). Strong ENSO forcing produced a more temporally consistent linear relationship between ENSO, PNA, and NAO patterns, but was shown to transition to a non-linear relationship during January of weak ENSO forcing. Results suggested the most substantial climate impacts occurred across North America during strong El Nio and weak La Nia events when the anomalous circulations were closest to the west coast of North America. Finally, the methods presented in this work provide a mechanism for monitoring ENSO related climate impacts for North America and Western Europe in near real-time.Dissertation Co-advisors: Jason A. Hubbart, Ph.D. and Anthony Lupo, Ph.D.|Includes vita.Includes bibliographical references

Observed Mesoscale Hydroclimate Variability of North America’s Allegheny Mountains at 40.2° N

Spatial hydroclimatic variability of Eastern North America’s Allegheny Mountain System (AMS) is commonly oversimplified to elevation differences and the rain-shadow effect. Descriptive and higher order statistical properties of hourly meteorological observations (1948–2017) from seven airports were analyzed to better understand AMS climatic complexity. Airports were located along a longitudinal transect (40.2 °N) and observation infrastructure was positioned to minimize climatic gradients associated with insolation, slope, and aspect. Results indicated average ambient temperature was well correlated with airport elevation (R2 = 0.97). However, elevation was relatively poorly correlated to dew point temperature (R2 = 0.80) and vapor pressure deficit (R2 = 0.61) heterogeneity. Skewness and kurtosis of ambient and dew point temperatures were negative at all airports indicating hourly values below the median were more common and extreme values were less common than a normal distribution implies. Westerly winds accounted for 54.5% of observations indicating prevailing winds misrepresented nearly half of AMS weather phenomena. The sum of maximum hourly precipitation rates was maximized in Philadelphia, PA implying a convective precipitation maximum near the border of Piedmont and Coastal Plain provinces. Results further indicate the AMS represents a barrier to omnidirectional moisture advection suggesting physiographic provinces are characterized by distinct evapotranspiration and precipitation regimes. The current work draws attention to observed mesoscale hydroclimatic heterogeneity of the AMS region and identifies mechanisms influencing local to regional water quantity and quality issues that are relevant to many locations globally

Climatic Trends of West Virginia: A Representative Appalachian Microcosm

During the late 19th and very early 20th centuries widespread deforestation occurred across the Appalachian region, USA. However, since the early 20th century, land cover rapidly changed from predominantly agricultural land use (72%; 1909) to forest. West Virginia (WV) is now the USA’s third most forested state by area (79%; 1989–present). It is well understood that land cover alterations feedback on climate with important implications for ecology, water resources, and watershed management. However, the spatiotemporal distribution of climatic changes during reforestation in WV remains unclear. To fill this knowledge gap, daily maximum temperature, minimum temperature, and precipitation data were acquired for eighteen observation sites with long periods of record (POR; ≥77 years). Results indicate an increasingly wet and temperate WV climate characterized by warming summertime minimum temperatures, cooling maximum temperatures year-round, and increased annual precipitation that accelerated during the second half (1959–2016) of the POR. Trends are elevation dependent and may be accelerating due to local to regional ecohydrological feedbacks including increasing forest age and density, changing forest species composition, and increasing globally averaged atmospheric moisture. Furthermore, results imply that excessive wetness may become the primary ecosystem stressor associated with climate change in the USA’s rugged and flood prone Appalachian region. The Appalachian region’s physiographic complexity and history of widespread land use changes makes climatic changes particularly dynamic. Therefore, mechanistic understanding of micro- to mesoscale climate changes is imperative to better inform decision makers and ensure preservation of the region’s rich natural resources

Changing Climatic Averages and Variance: Implications for Mesophication at the Eastern Edge of North America’s Eastern Deciduous Forest

Observed conversion of xerophytic warm genera species to mesophytic cool genera species in North America’s Eastern Deciduous Forest (EDF) suggests species composition is in disequilibrium with recent climatic warming. However, increasing annual average temperatures is an oversimplification of long-term climatic change and the importance of climate variance is often neglected. Seven-year moving averages and standard deviations of annually averaged maximum temperatures, minimum temperatures, daily precipitation, and vapor pressure deficits (VPD) in West Virginia, USA were quantified over a 111-year period of record (1906–2016). Maximum temperatures decreased significantly (−5.3%; p \u3c 0.001), minimum temperatures increased significantly (7.7%; p \u3c 0.001), and precipitation increased (2.2%; p = 0.107). Additionally, maximum temperature variance decreased (−17.4%; p = 0.109), minimum temperature variance decreased significantly (−22.6%; p = 0.042), and precipitation variance increased significantly (26.6%; p = 0.004). Results indicate a reduced diurnal temperature range and significant reductions in estimated VPD (10.3%; p \u3c 0.001) that imply increased relative humidity, cloud cover, and soil moisture that may support increasingly abundant mesophytic cool genera species. Feedback mechanisms associated with extensive changes in land use, fire suppression, and browser population may have exacerbated climatic changes. Long-term assessments of changing climatic averages and variance are needed to ensure sustainability of forest ecosystem services, health, and productivity in a swiftly changing climate across the broader EDF region and similar temperate forest ecosystems globally

Symmetry of Energy Divergence Anomalies Associated with the El Niño-Southern Oscillation

The El Niño-Southern Oscillation (ENSO) is a dominant source of global climate variability. The effects of this phenomenon alter the flow of heat from tropical to polar latitudes, resulting in weather and climate anomalies that are difficult to forecast. The current work quantified two components of the vertically integrated equation for the total energy content of an atmospheric column, to show the anomalous horizontal redistribution of surface heat flux anomalies. Symmetric and asymmetric components of the vertically integrated latent and sensible heat flux divergence were quantified using ERA-Interim atmospheric reanalysis output on 30 model layers between 1979 and 2016. Results indicate that asymmetry is a fundamental component of ENSO-induced weather and climate anomalies at the global scale, challenging the common assumption that each phase of ENSO is equal and opposite. In particular, a substantial asymmetric component was identified in the relationship between ENSO and patterns of extratropical climate variability that may be proportional to differences in sea surface temperature anomalies during each phase of ENSO. This work advances our understanding of the global distributions of source and sink regions, which may improve future predictions of ENSO-induced precipitation and surface temperature anomalies. Future studies should apply these methods to advance understanding and to validate predictions of ENSO-induced weather and climate anomalies

Climatic Trends of West Virginia: A Representative Appalachian Microcosm

During the late 19th and very early 20th centuries widespread deforestation occurred across the Appalachian region, USA. However, since the early 20th century, land cover rapidly changed from predominantly agricultural land use (72%; 1909) to forest. West Virginia (WV) is now the USA’s third most forested state by area (79%; 1989–present). It is well understood that land cover alterations feedback on climate with important implications for ecology, water resources, and watershed management. However, the spatiotemporal distribution of climatic changes during reforestation in WV remains unclear. To fill this knowledge gap, daily maximum temperature, minimum temperature, and precipitation data were acquired for eighteen observation sites with long periods of record (POR; ≥77 years). Results indicate an increasingly wet and temperate WV climate characterized by warming summertime minimum temperatures, cooling maximum temperatures year-round, and increased annual precipitation that accelerated during the second half (1959–2016) of the POR. Trends are elevation dependent and may be accelerating due to local to regional ecohydrological feedbacks including increasing forest age and density, changing forest species composition, and increasing globally averaged atmospheric moisture. Furthermore, results imply that excessive wetness may become the primary ecosystem stressor associated with climate change in the USA’s rugged and flood prone Appalachian region. The Appalachian region’s physiographic complexity and history of widespread land use changes makes climatic changes particularly dynamic. Therefore, mechanistic understanding of micro- to mesoscale climate changes is imperative to better inform decision makers and ensure preservation of the region’s rich natural resources

Symmetry of Energy Divergence Anomalies Associated with the El Niño-Southern Oscillation

The El Niño-Southern Oscillation (ENSO) is a dominant source of global climate variability. The effects of this phenomenon alter the flow of heat from tropical to polar latitudes, resulting in weather and climate anomalies that are difficult to forecast. The current work quantified two components of the vertically integrated equation for the total energy content of an atmospheric column, to show the anomalous horizontal redistribution of surface heat flux anomalies. Symmetric and asymmetric components of the vertically integrated latent and sensible heat flux divergence were quantified using ERA-Interim atmospheric reanalysis output on 30 model layers between 1979 and 2016. Results indicate that asymmetry is a fundamental component of ENSO-induced weather and climate anomalies at the global scale, challenging the common assumption that each phase of ENSO is equal and opposite. In particular, a substantial asymmetric component was identified in the relationship between ENSO and patterns of extratropical climate variability that may be proportional to differences in sea surface temperature anomalies during each phase of ENSO. This work advances our understanding of the global distributions of source and sink regions, which may improve future predictions of ENSO-induced precipitation and surface temperature anomalies. Future studies should apply these methods to advance understanding and to validate predictions of ENSO-induced weather and climate anomalies

Climatic Trends of West Virginia: A Representative Appalachian Microcosm

During the late 19th and very early 20th centuries widespread deforestation occurred across the Appalachian region, USA. However, since the early 20th century, land cover rapidly changed from predominantly agricultural land use (72%; 1909) to forest. West Virginia (WV) is now the USA’s third most forested state by area (79%; 1989−present). It is well understood that land cover alterations feedback on climate with important implications for ecology, water resources, and watershed management. However, the spatiotemporal distribution of climatic changes during reforestation in WV remains unclear. To fill this knowledge gap, daily maximum temperature, minimum temperature, and precipitation data were acquired for eighteen observation sites with long periods of record (POR; ≥77 years). Results indicate an increasingly wet and temperate WV climate characterized by warming summertime minimum temperatures, cooling maximum temperatures year-round, and increased annual precipitation that accelerated during the second half (1959−2016) of the POR. Trends are elevation dependent and may be accelerating due to local to regional ecohydrological feedbacks including increasing forest age and density, changing forest species composition, and increasing globally averaged atmospheric moisture. Furthermore, results imply that excessive wetness may become the primary ecosystem stressor associated with climate change in the USA’s rugged and flood prone Appalachian region. The Appalachian region’s physiographic complexity and history of widespread land use changes makes climatic changes particularly dynamic. Therefore, mechanistic understanding of micro- to mesoscale climate changes is imperative to better inform decision makers and ensure preservation of the region’s rich natural resources

Seasonal Lifting Condensation Level Trends: Implications of Warming and Reforestation in Appalachia’s Deciduous Forest

Lifting condensation level (LCL) has long been used to estimate cloud base heights. However, spatial and temporal patterns of cloud bases embedded within atmospheric currents flowing over mountainous terrain still need to be more adequately described. To advance understanding, hourly observations of barometric pressure and ambient and dew point temperatures from 1948 to 2017 were acquired for seven airports located at 40.21° N (average) and crossing the Allegheny Mountains of the northeastern United States. Daily LCL trends were quantified, and large positive (2.3 m yr−1) and negative (−1.3 m yr−1) LCL trends were found to be greatest near seasonal transition dates (17 April and 9 November 2022). Cool season LCLs (795 m) increased significantly (p < 0.007) at five sites resulting in an average LCL increase of 81 m and implying a deeper and drier sub-cloud layer. Average warm season LCLs (773 m) decreased by 23 m, suggesting a deeper convective cloud layer and less sub-cloud evaporation that may facilitate higher hydrometeor growth and precipitation rates. Collective results indicate divergent seasonally averaged LCLs characterized by more rapid seasonal transitions, warmer and less cloudy cool seasons, and cloudier and more humid warm seasons that may be partly attributable to aggressive reforestation and contribute to more significant rainfall events and higher flood risks