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There are two models for the surface layer in the convective boundary layer (CBL). First is the standard Monin–Obukhov similarity theory, and second is the McNaughton–Laubach model (Laubach and McNaughton 2009, Boundary-Layer Meteorology 133:219–252; hereafter MNL model) developed based on the complex dynamical system approach to address characteristics of the unstable surface layer. The fundamental difference between the Monin–Obukhov similarity theory and the MNL model is the use of local and non-local parameters for analyzing surface-layer spectra in the CBL. However, there is a need to check applicability of this new model at various flow conditions before the model could be extensively used. Subsequently, applicability of the MNL model is tested in comparison to the standard model using CBL observations from three different regions with increasing terrain complexity (i.e. over flat-terrain, onslope, and ridge-top sites). The MNL model is tested by estimating and using the non-local scaling parameters to collapse the power spectra of velocity and temperature on the frequency–amplitude scale under the generalized hypothesis that convective surface layer depends on non-local outer variables. We find that the u and v spectra for all sites indicate run-to-run similarity of each spectra with MNL scaling irrespective of the height limiting role of local buoyancy on the shape of the spectra. Similarly, w spectra from all sites indicate transitions between the surface friction layer and the outer layer are governed by flow in the entire CBL. The temperature spectra collapse using (zϵo)2/3H0-2 as amplitude scaling and kzi1/2z1/2 as wavenumber scaling, is a new observation within the surface friction layer, where the streamwise wavenumber is k, measurement height is z, CBL height is zi, the dissipation rate of turbulence energy in the outer CBL is ϵo, and the surface heat flux is H0. These observations corroborate well with the MNL model conjecture that the convective temperature spectra do not depend only on local stability, and CBL parameters affect spectra when a subset of local factors remains constant.

To directly access the dynamics of electron distribution near the Fermi-surface after plasmon excitation, pump-probe spectroscopy was performed by pumping plasmons on noble-metal films and probing the interband transition. Spectral change in the interband transitions is sensitive to the electron distribution near the Fermi-surface, because it involves the d valence-band to the conduction band transitions and should reflect the k-space distribution dynamics of electrons. For the continuous-wave pump and probe experiment, the plasmon modulation spectra are found to differ from both the current modulation and temperature difference spectra, possibly reflecting signatures of the plasmon wave function. For the femtosecond-pulse pump and probe experiment, the transient spectra agree well with the known spectra upon the excitation of the respective electrons resulting from plasmon relaxation, probably because the lifetime of plasmons is shorter than the pulse duration.

The depletion of the ozone layer creates a gate for non‐visible spectra to impact the Earth's surface and interfere with fruit and vegetable growth and developments by affecting their morphology and physiology. The potential contribution of visible light to photosynthetic activity has received significant attention, particularly blue and red/far‐red light in the visible spectrum. However, plants are also inevitably exposed to relatively high doses of non‐visible spectra, including ultraviolet (UV) and infrared (IR) radiation. This review examines the literature on the impact of such non‐visible spectra on fruit and vegetable growth and development. The accumulation of radiation‐absorbing compounds is a primary mechanism of acclimation to changing radiation levels. Anthocyanins are compounds that exhibit high sensitivity to UV and IR radiation as well as temperature variations, playing a crucial protective role against detrimental radiation in plants. Current research helps to elucidate the involvement of low and high temperatures in the control of UVB‐induced anthocyanin accumulation. Different UV radiation types have been shown to affect fruit and vegetable growth and pigment content differentially. Recent studies have also revealed that IR radiation increases anthocyanin content. Furthermore, specific non‐visible spectra mitigate the inhibitory effect of high and low temperature stress on anthocyanin accumulation in fruits and vegetables. These findings have important implications for the horticultural industry, as they suggest that the application of specific of non‐visible light spectra could be a promising approach to increasing the nutritional value and marketability of fruits and vegetables.

Ice internal temperature and basal geothermal heat flux (GHF) are analyzed along a study line in northwestern Greenland. The temperatures were obtained from a previously reported inversion of airborne microwave brightness-temperature spectra. The temperatures vary slowly through the upper ice sheet and more rapidly near the base increasing from ~259 K near Camp Century to values near the melting point near NorthGRIP. The flow-law rate factor is computed from temperature data and analytic expressions. The rate factor increases from ~1 × 10−8 to 8 × 10−8 kPa−3 a−1 along the line. A laminar flow model combined with the depth-dependent rate factor is used to estimate horizontal velocity. The modeled surface velocities are about a factor of 10 less than interferometric synthetic aperture radar (InSAR) surface velocities. The laminar velocities are fitted to the InSAR velocities through a factor of 8 enhancement of the rate factor for the lower 25% of the column. GHF values retrieved from the brightness temperature spectra increase from ~55 to 84 mW m−2 from Camp Century to NorthGRIP. A strain heating correction improves agreement with other geophysical datasets near Camp Century and NEEM but differ by ~15 mW m−2 in the central portion of the profile.

Contrary to Monin–Obukhov similarity theory, near-surface atmospheric turbulence depends not only on local motions but also on larger-scale motions associated with the full atmospheric boundary layer (ABL), where they themselves evolve in character with thermal stratification. After reviewing our current knowledge of ABL motions, we present wavelet velocity and air temperature spectra for both eddy-surface-layer (ESL) flows above rough surfaces and roughness-sublayer (RSL) flows above vegetation canopies, both flows characterizing turbulence over two scales of land roughness. Spectra are extended to the production scale to identify the influence of ABL-scale motions following the thermal stratification. Contrary to turbulence in the ESL, RSL turbulence appears weakly enhanced by ABL-scale motions in near-neutral regimes. With increasing influence of buoyancy, ABL-scale motions play a larger role in ESL and RSL flows, dominating the locally produced turbulence in free convection, while acting to decouple local from the large-scale motions in the stable regime. The behaviour of ESL and RSL spectra with stability variations support the view of, (1) canopy-scale eddies dominating the canopy turbulence over the larger ABL-scale motions in windy conditions, (2) ABL-scale motions known as very-large-scale motions (VLSMs) influencing the ESL horizontal velocity turbulence in windy conditions, and (3) the progressive transitioning of ABL-scale motions from VLSMs to thermals with instability in ESL flows. The direct contribution of ABL-scale motions to near-surface momentum and heat turbulent fluxes appears small. Finally, near-surface velocity spectra are well-approximated as a linear superposition of individual spectra associated to the main eddies populating the flow.

Simultaneous development of well impedance matching and strong loss capability has become a mainstream method for achieving outstanding electromagnetic microwave absorption (EMWA) performances over wide temperature range. However, it is difficult to pursue both due to the mutual restraint of relationship between impedance matching and loss capability about temperature. Here, we propose a flexible regulation engineering of titanium nitride (TiN) nanofibrous membranes (NMs, TNMs), which could be distributed uniformly in the polydimethylsiloxane (PDMS) matrix and contributed to the formation of abundant local conductive networks, generating the local conductive loss and enhancing the loss ability of EMWs. Moreover, when the TNMs are used as functional units and dispersed in the matrix, the corresponding composites exhibit an outstanding anti-reflection effect on microwaves. As hoped, under the precondition of good impedance matching, local conductive loss and polarization loss together improve the loss capacity at room temperature, and polarization loss can compensate the local conductive loss to acquire effective dielectric response at elevated temperature. Benefiting from the reasonably synergistic loss ability caused by flexible regulation engineering, the corresponding composites exhibit the perfect EMWA performances in a wide temperature range from 298 to 573 K. This work not only elaborates the ponderable insights of independent membrane in the composition-structure-function connection, but also provides a feasible tactic for resolving coexistence of well impedance matching and strong loss capability issues in wide temperature spectrum.

Ambient concentrations of ice-forming particles measured during ship expeditions are collected and summarised with the aim of determining the spatial distribution and variability in ice nuclei in oceanic regions. The presented data from literature and previously unpublished data from over 23 months of ship-based measurements stretch from the Arctic to the Southern Ocean and include a circumnavigation of Antarctica. In comparison to continental observations, ship-based measurements of ambient ice nuclei show 1 to 2 orders of magnitude lower mean concentrations. To quantify the geographical variability in oceanic areas, the concentration range of potential ice nuclei in different climate zones is analysed by meridionally dividing the expedition tracks into tropical, temperate and polar climate zones. We find that concentrations of ice nuclei in these meridional zones follow temperature spectra with similar slopes but vary in absolute concentration. Typically, the frequency with which specific concentrations of ice nuclei are observed at a certain temperature follows a log-normal distribution. A consequence of the log-normal distribution is that the mean concentration is higher than the most frequently measured concentration. Finally, the potential contribution of ship exhaust to the measured ice nuclei concentration on board research vessels is analysed as function of temperature. We find a sharp onset of the influence at approximately −36 ∘C but none at warmer temperatures that could bias ship-based measurements.

Ice-nucleating particles (INPs) initiate the primary ice formation in clouds at temperatures above ca. −38 ∘C and have an impact on precipitation formation, cloud optical properties, and cloud persistence. Despite their roles in both weather and climate, INPs are not well characterized, especially in remote regions such as the Arctic. We present results from a ship-based campaign to the European Arctic during May to July 2017. We deployed a filter sampler and a continuous-flow diffusion chamber for offline and online INP analyses, respectively. We also investigated the ice nucleation properties of samples from different environmental compartments, i.e., the sea surface microlayer (SML), the bulk seawater (BSW), and fog water. Concentrations of INPs (NINP) in the air vary between 2 to 3 orders of magnitudes at any particular temperature and are, except for the temperatures above −10 ∘C and below −32 ∘C, lower than in midlatitudes. In these temperature ranges, INP concentrations are the same or even higher than in the midlatitudes. By heating of the filter samples to 95 ∘C for 1 h, we found a significant reduction in ice nucleation activity, i.e., indications that the INPs active at warmer temperatures are biogenic. At colder temperatures the INP population was likely dominated by mineral dust. The SML was found to be enriched in INPs compared to the BSW in almost all samples. The enrichment factor (EF) varied mostly between 1 and 10, but EFs as high as 94.97 were also observed. Filtration of the seawater samples with 0.2 µm syringe filters led to a significant reduction in ice activity, indicating the INPs are larger and/or are associated with particles larger than 0.2 µm. A closure study showed that aerosolization of SML and/or seawater alone cannot explain the observed airborne NINP unless significant enrichment of INP by a factor of 105 takes place during the transfer from the ocean surface to the atmosphere. In the fog water samples with −3.47 ∘C, we observed the highest freezing onset of any sample. A closure study connecting NINP in fog water and the ambient NINP derived from the filter samples shows good agreement of the concentrations in both compartments, which indicates that INPs in the air are likely all activated into fog droplets during fog events. In a case study, we considered a situation during which the ship was located in the marginal sea ice zone and NINP levels in air and the SML were highest in the temperature range above −10 ∘C. Chlorophyll a measurements by satellite remote sensing point towards the waters in the investigated region being biologically active. Similar slopes in the temperature spectra suggested a connection between the INP populations in the SML and the air. Air mass history had no influence on the observed airborne INP population. Therefore, we conclude that during the case study collected airborne INPs originated from a local biogenic probably marine source.

Accurate reference spectroscopic information for the water molecule from the microwave to the near-ultraviolet is of paramount importance in atmospheric research. A semi-empirical potential energy surface for the ground electronic state of H216O has been created by refining almost 4000 experimentally determined energy levels. These states extend into regions with large values of rotational and vibrational excitation. For all states considered in our refinement procedure, which extend to 37 000 cm-1 and J=20 (total angular momentum), the average root-mean-square deviation is approximately 0.05 cm-1. This potential energy surface offers significant improvements when compared to recent models by accurately predicting states possessing high values of J. This feature will offer significant improvements in calculated line positions for high-temperature spectra where transitions between high J states become more prominent.Combining this potential with the latest dipole moment surface for water vapour, a line list has been calculated which extends reliably to 37 000 cm-1. Obtaining reliable results in the ultraviolet is of special importance as it is a challenging spectral region for the water molecule both experimentally and theoretically. Comparisons are made against several experimental sources of cross sections in the near-ultraviolet and discrepancies are observed. In the near-ultraviolet our calculations are in agreement with recent atmospheric retrievals and the upper limit obtained using broadband spectroscopy by p. 194, but they do not support recent suggestions of very strong absorption in this region.

Recently, it has been discussed whether the mesoscale energy spectra in the upper troposphere and lower stratosphere are generated by weakly or strongly nonlinear dynamics. A necessary condition for weak nonlinearity is that the Rossby number Ro ≡ |ζz|/f ≪ 1, where ζz is the vertical vorticity and f is the Coriolis parameter. First, it is shown that Ro can be estimated by integration of the rotational wavenumber energy spectrum Er. Then divergence and rotational energy spectra and their ratio, R ≡ Ed/Er, are calculated from the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) dataset, and it is shown that at least 1000 flight segments are needed to obtain converged results. It is found that R < 1 in the upper troposphere, ruling out the hypothesis that the spectra are produced by inertia–gravity waves with frequencies larger than f. In the lower stratosphere R is slightly larger than unity. An analysis separating between land and ocean data shows that Ed and temperature spectra have somewhat larger magnitude over land compared to ocean in the upper troposphere—a signature of orographically or convectively forced gravity waves. No such effect is seen in the lower stratosphere. At midlatitudes the Rossby number is on the order of unity and at low latitudes it is larger than unity, indicating that strong nonlinearities are prevalent. Also the temperature spectra, when converted into potential energy spectra, have larger magnitude than predicted by the weakly nonlinear wave hypothesis.