scholarly journals Results of research on pollen fall-out in the atmospheric ground layer

2015 ◽  
Vol 42 (2) ◽  
pp. 183-191
Author(s):  
Stefania Tyczyńska
Keyword(s):  
Ground Layer ◽  
Atmospheric Layer ◽  
Lower Atmospheric Layer

The paper covers results of observations on the distribution of tree and herbaseous plants' pollen in the lower atmospheric layer at various heights in the three-year period 1966-1968. On the basis of the material obtained a calendar of pollen appearance was prepared.

Symbiotic Relationship between Meiyu Rainfall and the Morphology of Meiyu Front

2021 ◽  
Author(s):  
Xiaokang Wang ◽  
Renjun Zhou ◽  
Yi Deng ◽  
Chunguang Cui ◽  
Yang Hu ◽  
...  
Keyword(s):  
Convective Instability ◽  
Extreme Rainfall ◽  
Heavy Precipitation ◽  
Precipitation Event ◽  
Symbiotic Relationship ◽  
Atmospheric Layer ◽  
Band Shape ◽  
Meiyu Front ◽  
Rain Band ◽  
Lower Atmospheric Layer

Abstract Observational evidences from a heavy precipitation event of the 2020 extreme Meiyu season are presented here to reveal a symbiotic relationship between Meiyu rainfall and the morphology of Meiyu front. The two influence each other through dynamical and thermodynamic feedbacks and evolve in a coherent way to generate cyclic behaviors. Specifically, an intense and band-shaped Meiyu front leads to symmetrical instability in the lower atmospheric layer and convective instability in the middle atmospheric layer, forming a rain band along the front. The Meiyu front and its associated instability subsequently weakens as a result of rainfall and the front is bent by the process of tilting frontolysis. Deep convective instability in the middle and lower layers develops in the warm-humid prefrontal area, and triggers isolated heavy rainfall replacing the original rain band south of the bent front. This warm sector precipitation then strengthens the front through tilting and diabatic heating frontogenesis. A stronger front recovers its initial band shape and the associated rainfall also resumes the form of rain band along the front. Analyses of potential energy associated with instability, water vapor convergence, and cross-frontal circulation are carried out to illustrate key processes of this Meiyu front-rainfall cycle. The implications of this symbiotic relationship for simulating and predicting extreme rainfall associated with Meiyu fronts are presented.

Sensitivity of ground layer vegetation diversity descriptors in indicating forest naturalness

2006 ◽  
Vol 7 (2) ◽  
pp. 199-209 ◽  
Author(s):  
T. Standovár ◽  
P. Ódor ◽  
R. Aszalós ◽  
L. Gálhidy
Keyword(s):  
Ground Layer ◽  
Vegetation Diversity

scholarly journals Performance of Reconfigurable Antenna Fabricated on Flexible and Nonflexible Materials for Band Switching Applications

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2553
Author(s):  
B. R. Sanjeeva Reddy ◽  
Naresh K. Darimireddy ◽  
Chan-Wang Park ◽  
Abdellah Chehri
Keyword(s):  
Relative Permittivity ◽  
Ground Layer ◽  
Reconfigurable Antenna ◽  
Textile Antenna

In this article, a novel frequency slot-based switchable antenna fabricated on flexible and nonflexible materials is presented for suitable reconfigurable radiations of Bluetooth, WiMAX, and upper WLAN applications. Initially, the performance of this structure was simulated using a CSTTM simulator and evaluated experimentally using a nonflexible FR4 structure. The same antenna was implemented on a flexible (jean) substrate with a relative permittivity of 1.7. The proposed textile antenna prototypes were fabricated by optimal dimensions of an E-shaped slot with a variation on the shape of the ground layer, integrated using a crossed T-shaped strip with ON/OFF switchable state operations. The proposed antenna prototype is compact (20 × 20 mm2), providing switchable radiations with tri bands, has frequencies ranged at 2.36–2.5 GHz for Bluetooth, 3.51–3.79 GHz and 5.47–5.98 GHz for the distinct bands of WiMAX and WLAN, respectively, as well as part of UWB operations.

Lack of congruence between terrestrial and epiphytic lichen strata in boreal forests

2021 ◽  
Vol 53 (1) ◽  
pp. 149-158
Author(s):  
Robert J. Smith ◽  
Sarah Jovan ◽  
Susan Will-Wolf
Keyword(s):  
Species Richness ◽  
Boreal Forests ◽  
Environmental Gradients ◽  
Ground Layer ◽  
Global Changes ◽  
Layer Versus ◽  
Epiphytic Lichen ◽  
Incremental Change ◽  
Compositional Gradients ◽  
Environmental Responses

AbstractLichens occupy diverse substrates across tremendous ranges of environmental variation. In boreal forests, lichen communities co-occur in ‘strata’ defined by terrestrial or arboreal substrates, but these strata may or may not be interchangeable as bioindicators. Do co-occurring lichen strata have similar community structures and environmental responses? Could one stratum serve as a proxy for the other? We assessed variation in species richness and community compositions between ground-layer versus epiphyte-layer lichen strata in boreal forests and peatlands of interior Alaska. Species richness was lower and more spatially structured in the ground layer than the epiphyte layer. Richness of strata was not correlated. The most compositionally unique ground-layer communities were species-poor but contained regionally rare species not common in other plots. Variation in community compositions (ordination scores) were not congruent between strata (Procrustes congruence < 0.16 on 0–1 scale); the largest departures from congruence occurred where ground layers were species-poor. The best predictors of ground-layer community compositions were hydrological and topographic, whereas epiphytes were most associated with macroclimate and tree abundances. We conclude that lichens on different substrates ‘move in different circles’: compositional gradients did not agree and the environmental gradients most important to each lichen stratum were not the same. The conditions which strongly influence one vegetation stratum may have little bearing upon another. As global changes modify habitats, an incremental change in environment may lead community trajectories to diverge among lichen strata.

scholarly journals Retrieval of Layer Averaged Relative Humidity Profiles from MHS Observations over Tropical Region

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
R. K. Gangwar ◽  
B. S. Gohil ◽  
A. K. Mathur
Keyword(s):  
Relative Humidity ◽  
Radiative Transfer ◽  
Reanalysis Data ◽  
Tropical Region ◽  
Atmospheric Layer ◽  
Ncep Reanalysis ◽  
Microwave Humidity Sounder ◽  
Using Data ◽  
Profile Errors ◽  
Humidity Profiles

The present paper deals with the retrieval of the atmospheric layer averaged relative humidity profiles using data from the Microwave Humidity Sounder (MHS) onboard the MetOp satellite. The retrieval has been innovatively performed by firstly retrieving humidity for pairs of thick overlapping layers (TOLs) used subsequently to derive humidity for associated thin isolated layer (TIL). A water vapour dependent (WVD) algorithm has been developed and applied to infer the humidity of TOLs. Thus, the retrieved profiles have been finally compared with standard algorithm (NORM). These algorithms have been developed based on radiative transfer simulations and study of sensitivities of MHS channels on humidity of various types of layers (TOL, TIL). The algorithm has been tested with MHS data and validated using concurrent radiosonde as well as NCEP reanalysis data indicating profile errors of ~15% and ~19%, respectively.

Thinning effects on canopy structure and ground layer diversity in a burned mesic oak savanna

2017 ◽  
Vol 144 (2) ◽  
pp. 191-205 ◽  
Author(s):  
Marlin L. Bowles ◽  
Beth A. Lawrence ◽  
Deborah J. Antlitz
Keyword(s):  
Canopy Structure ◽  
Ground Layer ◽  
Oak Savanna
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