Two major sources of radiation hazards at commercial aviation altitudes have been known for decades and those are galactic cosmic rays (GCRs) as well as solar energetic particles (SEPs). GCRs are produced outside the solar system in high-energy explosive events and consist mostly of energetic protons slowly modulated by the strength of the Sun’s interplanetary magnetic field (IMF). SEPs come from either solar coronal mass ejections (CMEs) related to flaring events or from IMF shocks. In the latter case fast CMEs plow through a slower solar wind creating a shock front to produce energetic protons. Recently, a third radiation source has been identified that originates from relativistic electron precipitation (REP) associated with the Van Allen radiation belts and have been called radiation clouds although a physical perspective is likely to be flight through a γ-ray beam. This ensemble radiation field creates safety concerns for aviation. Because of this safety hazard, a broad community is seeking to i)define the requirements for real-time monitoring of the charged particle radiation environment to protect the health and safety of crew and passengers during space weather events; ii)define the scope and requirements for a real-time reporting system that conveys situational awareness of the radiation environment to orbital, suborbital, and commercial aviation users during space weather events; and iii)develop or improve models for the real-time assessment of radiation levels at commercial flight altitudes. While benchmarks for ionizing radiation related to aviation have included characterizing an occurrence frequency of 1 in 100 years and an intensity level at the theoretical maximum for radiation events, it is also important to develop a baseline radiation environment for GCRs, SEPs, and REPs against which events can be compared. We describe functional, analytical baselines for describing the ionizing radiation environment for commercial aviation based on observations and modeling as part of the NAIRAS, ARMAS, and RADIAN programs.

The western region of Bay of Bengal (BoB) is of high importance because of its variability in Western Boundary Current (WBC) pattern, numerous eddy genesis and biogeochemical activities. The WBC is northward in pre–Indian Summer Monsoon (ISM) season and southward in post–ISM season with the presence of anticyclonic and cyclonic gyres respectively. During ISM, the western BoB is dominated by various cyclonic and anticyclonic eddies with discontinuous WBC. The seasonally reversing wind pattern also favors the variation in the circulation pattern of the bay. The mechanism of eddy genesis in the western BoB and their characteristics specially during ISM, when the WBC is discontinuous, is not studied well. Our study uses the Regional Ocean Modeling System (ROMS) to investigate the role of coastal Kelvin wave, which originated from the equatorial wave guide, and local wind on the mesoscale eddies in the western BoB. To better understand the forcing mechanism involved, river influx and modified wind fields are incorporated in the experiments. The simulated Kelvin wave propagation is consistent with the satellite altimetry observations. Two upwelling and two downwelling Coastal Kelvin Wave (CKW) signals are identified. First upwelling signal (UCKW1) exists from January to April whereas the second signal (UCKW2) appears in September. Two downwelling signals are seen from May to August (DCKW1) and October to December (DCKW2), respectively. Depth of 20°C isotherm (D20) shows good correlation with the remote forcing signals as well as surface wind variability. The CKW signals during pre– and post–ISM (UCKW1 and DCKW2 respectively) are dominant. The reversing weaker signals (DCKW1 and UCKW2) contribute to the WBC discontinuity during ISM. Reduction in wind fields results in weak WBC during pre– and post–ISM. Increase in wind field results in strengthening of the weaker CKW modes rather than strengthening the WBC. Average surface eddy kinetic energy along with eddy intensity, radius and lifetime are sensitive to the change in wind field. The eddies are seen to propagate clockwise (anticlockwise) in general due to decrease (increase) in wind field. The study indicates that the CKWs and the local wind have significant impact on seasonally reversing WBC, eddy genesis and their characteristics in the western BoB.

Changing irrigation water demand (IWD) and supply (IWS) patterns (size and time) under increased climate variability and socio-economic development is significantly effecting the water and food production in the densely populated South Asia (SA). Considering food security paradigm of SA, where rice and wheat are major staple and water-intensive crops, this study aims to investigate the linkages in IWD by crops and IWS by sources (surface and groundwater) using integrated climate and socio-economic projections. The novel aspect of this study is to explore IWD and IWS pattern shifts during critical crop growth stages (CW’s), which is previously less studied with no remarkable research evidence for IGB region. Quantification of shifts in IWD and IWS patterns in future is crucial for long-term integrated water resources and agricultural planning. For this, LPJmL crop-water model is forced with an ensemble of eight state of the art downscaled GCM at 5 arc-min resolution. To assess the combined impacts of climate and socio-economic changes, RCP-SSP framework is used. Our statistical analysis results show that IWD is higher in vegetative stage (CW1) than the reproductive stage (CW2) during both Rabi and Kharif cropping seasons. Water demand is decreasing in future for wheat while increasing for rice. IWS is decreasing substantially from surface while increasing largely from groundwater resources during Rabi. Though, IWS during kharif season is increasing largely from both surface and groundwater resources. There is mismatch in demand and supply as evident from the results suggesting 10 days early wheat planting reduces IWD by 8.0% in F1, 18.7% in F2 and 28.4% in F3 during CW1 with a decrease of 7%, 30 % and 62.56% during F1, F2 and F3 in CW2. Increased IWS with larger contribution from groundwater resources is projected for both crops in future. Water gap between demand and supply during both CW’s in future is increasing for Rabi and Kharif suggesting 10 days early planting of wheat while 20 days delay in kharif planting. Estimation of IWS by sources helped in assessing shifts in percent (%) dependency of water supply from different sources. Moreover, Spatio-temporal mismatch between water demand and supply help exploring geospatially driven water gap trends consequently, highlighting water stress hotspots during CW’s in future.

Downslope and gusty winds in the lee of the Santa Ynez Mountains (SYM) greatly influence the Santa Barbara (SB) coast in California. These winds, known as ‘Sundowners’ due to their typical peak after sunset, are characterized by northerly cross-mountain flow and strong stability at mountaintop level. The National Weather Service (NWS) defines a Sundowner when sustained cross-mountain winds greater or equal to 30 mph or gusts greater or equal to 35 mph are observed at surface stations located downwind of the SYM. In addition to gale-force winds, temperatures above 100°F and relative humidity below 15% are not uncommon during sundowners, and the marine layer influences the spatial extent to which these strong winds may reach. These conditions have led to turbulence which effects aviation at the local airport and the rapid spread of multiple destructive wildfires in the region, including the Jesusita Fire (2009), Sherpa Fire (2016), and Thomas Fire (2017).

Reservoirs are a globally important source of methane (CH4) to the atmosphere, but measuring CH4 emission rates from reservoirs is difficult due to the spatial and temporal variability in emissions via the emission pathways of ebullition (bubbling) and diffusion. The dominant source of CH4 in reservoirs is production by methanogens in the reservoir sediment, a process that has been widely shown to have a positive correlation with temperature. However, oxidation of CH4 to carbon dioxide by methanotrophs, an important sink for CH4 within lakes, also scales with temperature. Understanding the relationship between reservoir CH4 emission (i.e. production – consumption) and temperature is made more complex by this dual feedback. This study presents results from multiple in-situ monitoring efforts at a small eutrophic reservoir in the Midwest US that look at how CH4 emissions vary with temperature across space and time. Using data sets from eddy covariance monitoring as well as inverted funnels, we found strong log relationships between daily average CH4 fluxes and daily average sediment temperature, with R2 values of 0.58, 0.45, and 0.7 for the eddy covariance data, the inverted funnel deployed at the 1.3-m site (“shallow”), and the inverted funnel deployed at the 8-m site (“deep”), respectively. The Q10 values for the shallow and deep site were 32 and 20, respectively, indicating a stronger dependence on temperature at the shallow site. However, both the shallow and deep sites had similar emission rates, scaling with relative maximum sediment temperature at each respective site. Sediment temperature was also found to be the second most important variable input to the artificial neural network used for gap-filling the eddy covariance CH4 fluxes (after wind speed). Improving our understanding of the temperature – methane emission feedback in freshwaters will enhance our ability to predict future global methane emissions.

Modern bedrock streams and rivers emerged in the Midwestern United States in response to glacial outwash floods ~19,000 years ago and continued to adjust to new drainage patterns over the landscape formed by Wisconsin glaciation events. The Illinois River and corresponding tributaries form a fascinating landscape with canyons carved 50-200 m deep into the St. Peter Sandstone. These geomorphic features are preserved and open to visitors as Starved Rock State Park in Central Illinois. Free access to the state parks and close proximity to the large Chicago metropolitan area result in frequent visitation to this natural attraction. Recently, the rates of natural stream incision appear to be overprinted by direct human influences on the landscape. The St. Peter Sandstone is a weakly cemented, extremely friable quartz arenite, making it susceptible to human disturbance and rapid natural erosion. This study explores how quickly present day changes occur along bedrock surfaces using photogrammetric Structure-from-Motion (SfM). Repeat photographic data were collected once per month from two sites within the park where canyon walls contained human carvings that served as reference features to align photos and monitor change. Photos were merged in Agisoft PhotoScan Pro to construct 3D point clouds and imported into CloudCompare to measure changes to rock surfaces between monthly visits. The photogrammetric SfM analysis detected measurable change on a centimeter to millimeter scale. Changes along footpaths were observed when visitor traffic was high. During winter months when visitor traffic decreased, rainfall and snowmelt runoff primarily caused mobilization and removal of loose sediments covering bedrock surfaces. Bedrock thin sections from each site were studied to assess the influence of cement on erosion rates. Lower cement concentrations were observed at the outcrop site with the greatest measured surface change. Changes detected with SfM analyses demonstrate that human interactions can influence erosion processes in a short time. While both natural and human caused changes occurred on bedrock surfaces, precipitation created greater measurable differences.

In the northern Hikurangi margin, aseismic slip events known as slow slip events (SSEs) occur approximately every 18-24 months with a long duration (weeks to months), and have been shown to cause 1 to 3 cm of horizontal surface displacement onshore and 1.5 to 5.4 cm of vertical displacement (uplift) offshore. The discovery of SSEs has expanded our scientific understanding of slip behavior at subduction zones to encompass behaviors beyond earthquake-producing (fast) slip events. Using converted phase seismic signals from local earthquakes in addition to direct P and S arrivals allows us to further analyze the properties of the plate interface along the subduction zone, including its composition, ­topography and heterogeneity. It has been hypothesized that these properties play a role in the process of slow slip, therefore our investigation of converted waves focuses on the area offshore the east coast of the North Island of New Zealand, where dozens of SSEs have been observed in the past twenty years. We examine an earthquake catalog comprised of local slab earthquakes occurring recorded on ocean-bottom seismometers (OBSs) from the one-year-long Hikurangi Ocean Bottom Investigation of Tremor and Slow Slip (HOBITSS) experiment as well as New Zealand’s permanent GeoNet on-land seismic network. Preliminary findings indicate strong secondary arrivals on the vertical component of the land stations which are likely Sp conversions from the plate interface. We aim to identify conversions from the plate interface on the OBSs from the HOBITSS experiment, as these data will help us resolve a part of the plate interface that was not investigated in previous converted wave studies. We will conduct a systematic search for phase-converted arrivals from the plate interface, initially focusing primarily on Sp conversions by examining the vertical component seismograms.

Total column measurements of CO2 (XCO2) have been proposed as a possible way to estimate emissions from large urban regions. Using calculations from the Weather Research and Forecasting (WRF) model with a 1km emissions field, we investigate the viability of both real and proposed observing systems consisting of surface and/or column measurements for constraining emission sources of various types and sizes in the San Francisco Bay Area. We find that column observations are best suited for assessing enhancements downwind of very large emissions sources. For smaller sources (such as highways), in situ surface monitors are required to provide sufficient sensitivity. We explore methods for estimating emissions from the real and simulated observations.

At regional scales, electrical resistivity illuminates Earth processes involving fluid evolution and transport, temperature contrasts, and fault characteristics and behavior. It also clarifies continental terrane assembly and event sequencing through electronic mineral markers. Magnetotellurics (MT) is sensitive over such scales, but faces high property contrasts, small signals, 3-D complexity, discontinuous fields, and ill-posed inversion. So-called wideband (~0.003 – 500 s wave period) MT recording constrains crustal structure, and high fidelity through its central dead band is routinely achieved now via distant remote referencing, continuous streaming, and outlier removal. To resolve across the upper mantle, long period data must be of high quality through 10,000 s. Electronics modifications now permit good quality MT data over polar ice-covered regions, and non plane wave outliers appear largely avoidable. Regularized 3D non-linear inversion using simulation equations that recognize a spatially discontinuous electric field has become common practice and lends essential credibility to interpretations. However, resistivity model non-uniqueness is seldom tested enough, and assuming isotropic resistivity can lead to artifacts. Fluids interpreted to cause low resistivity in ductile deep crust should be at lithostatic pressures and have compositions compatible with ambient temperature and metamorphic grade. Vertical current channeling enhances resolution of large-scale fault zones connecting deep and shallow structures. Stabilized terranes can exhibit strong, quasi-linear conductors marking belts of graphite or sulfides deposited in sediment-starved foredeeps or rift margin basins, with a particular concentration in the Proterozoic corresponding to atmospheric oxygenation events. An exciting recent avenue is estimating H2O content of nominally anhydrous minerals (NAMs) in the upper mantle, which strongly affects electrical conductivity but not seismic velocity. The large bandwidth of MT data affords a broad-scale, unified view of Earth processes from mantle level sources through crustal storage and evolution to near-surface deposition. Support has been from U.S. Dept of Energy contract DE-0006732 and National Science Foundation grant OPP-1443532, and numerous prior.

Understanding the near-surface roughness is paramount for the evolution of surface features and its contribution to the ice sheet dynamics. In regions experiencing the transition from dry snow to melt conditions, the surface becomes rough which along with liquid water content influences the radar backscatter. Such surfaces are driven by wind resulting in the formation of features oriented at different azimuth directions, ranging from ripples to dunes. Different scales of roughness also induce depolarisation in the radar signal, thereby making it difficult to infer the effective contribution of densification process on total backscatter. Here, we present a physical understanding of a wind-induced snow surface having anisotropic roughness from the modelled radar backscatter. As part of the approach, we propose to model the horizontal component of roughness (autocorrelation length) as a function of azimuth direction in the surface scattering model, i.e. Integral Equation Model. We performed our experiments for strongly anisotropic (a < 0.2), weakly anisotropic (a > 0.7), and isotropic (a = 1) surfaces, where a is the anisotropy, tuned for C-band frequency. Also, the minima of backscatter intensity varied over entire range of azimuth angles at a particular incidence angle is derived for retrieving the most dominant wind direction. From our analysis, significant azimuth modulation occurs in the radar backscatter at low incidence angles. Moreover, we found that the most dominant wind direction at 30-deg incidence angle changes from a strongly anisotropic surface (i.e. 0-deg) to a weakly anisotropic surface (i.e. 90-deg), however it remains unaltered for 45-deg and 60-deg incidence angles (i.e. 90-deg). Our modelled results are in strong agreement with wind scatterometer data of ice sheets and further show the potential of 30-deg incidence angle for tracking the changes in wind flow pattern based on directionality of roughness. In this regard, we foresee the importance of azimuth modulation for understanding the properties and orientation of surface features in the ice sheets, with particular application to wind flow. As a future scope, we plan to apply our model on radar images for the retrieval of wind directions and compare the directionality of roughness with the katabatic wind flow patterns and AWS measurements.

Solar-induced chlorophyll fluorescence (SIF) offers a promising method to remotely monitor photosynthesis at the canopy and regional scale. However, in order to interpret satellite SIF measurements in a biological context, there needs to be a better understanding of the diurnal dynamics of SIF and photosynthesis under variable stress conditions. Photons absorbed by a leaf can enter photochemistry, be actively dissipated via non-photochemical quenching (NPQ), or be re-emitted as chlorophyll fluorescence. Therefore, having better understanding of NPQ should improve interpretation of SIF. At the canopy scale, we captured diurnal dynamics of SIF and GPP. We then coupled leaf-level measurements of chlorophyll fluorescence, NPQ and photosynthesis and plant water status with canopy-level SIF and GPP to explore the mechanisms controlling diurnal dynamics of fluorescence vs. photosynthesis in a rain-fed maize field situated in upstate New York.

This study presents the novel application of tidal gravimetric data in the determination of phase-velocity dispersion curves of Rayleigh surface waves. Tidal gravimeters are capable to detect surface waves of periods even up to 500−600 s, while a typical broad-band seismic sensor can detect them up to the periods of 200−300 s due to its mechanical limitation. The capability of using tidal gravimeters as long period seismometers has already been analyzed since the late ’90s. These researches were mainly focused on the comparison of the power spectral density of noise level of gravimeters and seismometers and the analysis of normal modes of the largest earthquakes recorded by gravimeters. The first steps in the calculation of group velocity dispersion curves of Rayleigh surface waves were carried out lately. The Wiener deconvolution technique was used to calculate the phase-velocity dispersion curve by a two-stations method, from two pre-processed traces recorded in two different stations, located at the same great circle that the epicentre. The Incorporated Research Institutions for Seismology (IRIS) database were searched in terms of availability of at least 1 Hz data recorded by a co-located broad-band seismometer and tidal gravimeter. Additionally, the IRIS database provides the information about the transfer function of instruments, what is necessary in the two-stations method. Only, three sites met the above conditions: Black Forest, Membach and Rochfort, all located in Western and Central Europe. The compatibility of gravimetric and seismic data in the period range of 20-100 s are shown. Tidal gravimeters, because of their higher sensitivity, can better detect weaker earthquakes, which results in a higher number of recordings. However, to explore all advantages of gravimetric recordings of earthquakes, especially up to the periods of 500-600 s, above analysis must be applied to tidal gravimeters with higher inter-station distances and evaluated transfer functions. This work was done in the research project No. 2017/27/B/ST10/01600 financed from the funds of the Polish National Science Centre.

Raman spectroscopy is a promising analytical technique for in situ characterization of the icy mineral context on the surfaces of Ocean Worlds. This technique is highly sensitive to the molecular environment of ice and non-ice constituents, whereby non-destructive measurements can be conducted without any specific sample preparation. However, the application of Raman spectroscopy for space exploration remains in its infancy. Potential in situ Ocean Worlds mission concepts seek a quantitative assessment of the icy mineralogical context of samples that would be further analyzed for organic content and possible traces of biosignatures, which could be satisfied with a Raman spectrometer. To begin assessing this possibility, the current study aims to evaluate how well a laboratory Raman instrument can quantify non-ice constituents in icy materials. Here, we focused on the binary H2O-Na2SO4 system because it is relevant to Europa, the materials that form upon freezing are well-understood, and the freezing behavior is predictable and devoid of metastable and/or glassy phases that could confound the analyses. We find that the sulfate-to-water peak area ratio shows a strong linear correlation with the salt concentration in the starting solution. Local heterogeneities in mineralogical abundances that likely developed during freezing of the solutions tend to degrade data precision and correspondingly increase the uncertainty of the estimated concentration from measurements conducted on frozen solutions. Future studies are needed to investigate other systems, include multiple components, and develop modeling approaches to account for textural and mineralogical variability in icy materials. Part of this work has been conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Copyright 2021. All rights reserved.

In 2012, Aquatec launched an equipment award scheme for postgraduate students and early career scientists. Successful recipients with limited budgets gain free access to high quality subsea instrumentation for a laboratory or ‘eld campaign of up to three months, plus a travel grant to allow them to present their work at a conference. So far there have been 11 successful awardees who have applied from or deployed instruments in 13 countries spanning ’ve continents, in *umes, lakes, rivers, and coastal seas. In this paper, we present an overview of the most successful award projects. We also evaluate the impact of the scheme on the award recipients’ chosen project work and how it in*uenced their future career. The evaluation draws on analysis of the recipient study reports and the use of questionnaires and interviews. The scheme has also suffered the occasional setback. We attempt to identify some of the potential pitfalls of such a program, and highlight the key factors that lead not only to the best student experience, but also a positive outcome for the awarding company

Ultra-high pressure (UHP) metamorphism of the Tso Morari coesite-eclogite during burial in NW Himalaya has been intensively studied over the past several decades. However, amphibolite-facies metamorphism and accompanying metasomatism occurring at lower-crustal depths in the Tso Morari terrane are less well-constrained. In this study, we characterize the eclogite amphibolization and related metasomatic fluids by systematically sampling and analyzing the eclogites at the core of an eclogite boudin and the amphiblolized eclogite (amphibolite) at the rim. Integrated techniques including modal mineralogy, mineral chemistry, whole-rock geochemistry, Mössbauer spectroscopy, and thermodynamic modelling are used to constrain the fluid-induced eclogite amphibolization and associated fluid behaviors. Petrographic observations show that infiltration of an external fluid caused complete amphibolite-facies overprinting of the eclogites at the boudin rim. This is recorded petrographically as increased modal proportions of amphibole, biotite, epidote, plagioclase, and calcite in the amphibolites. The infiltrating fluid caused increased K2O and CO2 concentrations and higher bulk-rock Fe3+/ΣFe ratio for the amphibolites, as well as increased LILE (e.g., K, Rb, Cs, Sr, Ba) and ratios of Ba/Rb and Cs/Rb. Phase equilibria modelling using P–T–M(H2O) pseudosections on the amphibolite and the surrounding gneiss indicate that the fluid infiltration occurred at 9.0–12.5 kbar and ~608 °C with >2.6–3.1 mol % H2O infiltration. The abrupt increase of bulk-rock Fe3+/ΣFe ratio from 0.192 to 0.395 near the boudin rim indicate that this phase of fluid most likely derived from the mixing of dehydrated host orthogneiss and/or metasediments during uplift at the amphibolite-facies zone in the subduction channel. This study also demonstrates the need for using careful petrographic observations and geochemical analysis in parallel with thermodynamic modelling to achieve realistic results.

Summer ice in the Arctic is diminishing at an alarming rate. Increase in radiative forcing due to the loss of sea ice is contributing to global warming. Artificially enhancing the sea ice albedo could be a possible lever to restoring and rebuilding the Arctic sea ice. Using reflective hollow glass spheres with low environmental impact, Field et al (2018) reported that such a technology could be promising towards restoring Arctic Sea Ice. Here we present the preliminary climate modeling and impact assessment of such a technology both regionally and globally. We seek to answer the scientific question of whether an enhanced sea ice albedo over the whole of Arctic sea ice provides a large enough perturbation to the climate in the Arctic and if so what is its likely impact over the rest of the globe. The study shows that the climate impact of such a method results in more than 1.5°C cooler temperatures over a large part of the Arctic and about 3°C reduction over regions north of Barents and Kara Seas. We also see notable increases in sea ice thickness (20–50 cm Arctic wide) and (>15–20%) increases in sea ice concentration across large parts of the central Arctic. These preliminary results suggest that such a technology may be a viable instrument for restoring Arctic ice. However, practicality dictates that a localized targeted deployment of the technology may be more desirable. We are extending this work to evaluate targeted deployment of materials in key areas and will present the climate modeling results on efficiency of targeted deployment for at least one such targeted area. Reference: Field, L., Ivanova, D., Bhattacharyya, S., Mlaker, V., Sholtz, A., Decca, R., et al.(2018). Increasing Arctic sea ice albedo using localized reversible geoengineering. Earth’s Future, 6. https://doi.org/10.1029/2018EF000820

We report on the extraction of deep ocean travel time variations from time-lapse cross-correlations between a hydrophone station and a three-component broadband seismometer. The signals we cross-correlate in this study result from repeated activity by the Monowai seamount, one of the most active submarine volcanoes of the Tonga-Kermadec ridge. In particular, we introduce a specific workflow to exploit repetitive hydroacoustic underwater source activity, which we detail to such extent that it serves as an example (or “cookbook”). For this reason, we have made the source code publicly available. The workflow proposed in this study (i) overcomes differences in instrument sensitivity and sample rates, (ii) involves the selection of eligible cross-correlations based on a source activity criterium as well as slowness analysis, and (iii) extracts the travel time variations in distinct frequency bands. In our case, the two frequency bands are 3-6 Hz and 6-12 Hz. We find that the estimated travel time variations in both frequency bands consist of a complex periodic pattern superimposed on a distinct long-term linear trend. This long-term linear trend is decreasing, which we attribute to increasing water temperatures along the propagation path of the hydroacoustic signals.

Current General Circulation Models (GCMs) are struggling to capture the observed diurnal cycle of precipitation. One major problem is that GCMs usually have difficulties to simulate nocturnal deep convections. Nocturnal deep convections are usually decoupled with the land surface and are controlled by other factors aloft, which have not been fully understood. The Plains Elevated Convection at Night (PECAN) is a multi-institutional collaborated field experiment conducted at the central Great Plains during summertime (1 June to 15 July) 2015 on the purpose of improving the understanding and simulation of the processes that initial and maintain deep convections at night. During the 45-day PECAN period there are 31 intensive operational periods (IOP) of nighttime deep convections, each last for one night. The unique part of PECAN experiment is the use of 6 fixed and 4 mobile PECAN Integrated Sounding Arrays (PISA) to take detailed measurements for each IOP. These detailed measurements of thermodynamics, wind and water vapor profiles in high temporal resolution (typically 90-min) allow the observation of the evolution of boundary layer and propagating features. We will report results from the analysis of these PISAs using a constrained variational analysis method to understand the large-scale environment that control the nighttime deep convections at the central Great Plains.