Cloud and surface properties and the solar radiation budget derived from satellite data over the Arctic Ocean: Comparisons with surface measurements and in situ aircraft data

Thesis (Ph.D.) University of Alaska Fairbanks, 2000Use of satellite data to study the surface and cloud properties and the solar radiation budget (SRB) is very important for improving our understanding of cloud and sea-ice albedo feedback in the Arctic. Based on an accurate and comprehensive Radiative Transfer Model (RTM), algorithms were developed for using the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) data for the discrimination of cloud from snow/ice surfaces, retrieval of snow surface properties and surface albedo, and retrieval of cloud optical depth (tau) and effective droplet size ( re). Through the improved estimation of solar reflectance in AVHRR channel 3 (3.75 mum) and atmospheric anisotropic correction, a threshold function was found and used for developing an automatic cloud discrimination algorithm over snow/ice surfaces. Thin cirrus was discriminated using the brightness temperature difference between AVHRR channels 4 and 5 and brightness temperature in channel 4. Retrieval of snow grain size and mass-fraction of soot from AVHRR is difficult because of the effects of aerosol in channel 1 and the strong water vapor absorption in channel 2. Retrieval of surface albedo is more promising, but, with the melt of snow/ice, different narrow-to-broadband conversion relations should be used to derive broadband albedo. AVHRR channels 2, 3 and 4 are used to retrieve tau, r e and cloud top temperature simultaneously. Validation of these algorithms with in-situ aircraft measurements by the NCAR C-130 and the NASA ER-2 and with surface measurements obtained during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment indicates that the retrieved re is close to the "true" value of re, but the retrieved tau tends to be overestimated. Uncertainties of cloud retrievals with regard to cloud cover fraction, vertical inhomogeneity, multi-layer stratification and cloud phase were examined. Inter comparison of different satellite data demonstrates that NOAA-14 AVHRR data for SHEBA is overestimated by 10--20% using the calibration by Rao and Chen (1996). Finally, seasonal variation of surface albedo, cloud properties and SRB over SHEBA was derived based on 1 or 2 AVHRR overpasses per day from April to August, 1998

Quantization of Noncommutative Scalar Solitons at finite θ\theta

We start by discussing the classical noncommutative (NC) Q-ball solutions near the commutative limit, then generalize the virial relation. Next we quantize the NC Q-ball canonically. At very small theta quantum correction to the energy of the Q-balls is calculated through summation of the phase shift. UV/IR mixing terms are found in the quantum corrections which cannot be renormalized away. The same method is generalized to the NC GMS soliton for the smooth enough solution. UV/IR mixing is also found in the energy correction and UV divergence is shown to be absent. In this paper only (2+1) dimensional scalar field theory is discussed.Comment: 14 pages, no figure

Continuous Spin Representations of the Poincar\'e and Super-Poincar\'e Groups

We construct Wigner's continuous spin representations of the Poincar\'e algebra for massless particles in higher dimensions. The states are labeled both by the length of a space-like translation vector and the Dynkin indices of the {\it short little group} $SO(d-3)$, where $d$ is the space-time dimension. Continuous spin representations are in one-to-one correspondence with representations of the short little group. We also demonstrate how combinations of the bosonic and fermionic representations form supermultiplets of the super-Poincar\'e algebra. If the light-cone translations are nilpotent, these representations become finite dimensional, but contain zero or negative norm states, and their supersymmetry algebra contains a central charge in four dimensions.Comment: 19 page

Carbon-Coated FeP Nanoparticles Anchored on Carbon Nanotube Networks as Anode for Long-Life Sodium-Ion Storage

A novel electrode design strategy of carbon-coated FeP particles anchored on a conducting carbon nanotube network (CNT@FePC) is designed to achieve a superior sodium ion storage. Such a unique structure demonstrated excellent long-life cycling stability (a 95% capacity retention for more than 1200 cycles at 3 A g-1) and rate capability (delivered 272 mAh g-1 at 8 A g-1)

Identification of Cassava MicroRNAs under Abiotic Stress

Edwardsiella ictaluri (E. ictaluri) is one of the main bacterial pathogens in catfish which has caused serious economic loss to yellow catfish (Pelteobagrus fulvidraco) in China. In our previous work, we demonstrated that CypA was up-regulated at the early stage of E. ictaluri infection in yellow catfish and displayed strong chemotactic activity for leukocytes in vitro. However, the effect of CypA on E. ictaluri is unknown in vivo. Therefore, two homozygous transgenic zebrafish lines expressing yellow catfish CypA (TG-CypA-1 and TG-CypA-2) were generated. After challenged with E. ictaluri at a dose of 1.0 x 10(4) CFU per adult fish, both two transgenic lines exhibited a higher resistance to bacterial infection than the wildtype zebrafish. Herein, CypA gene in E. ictalurichallenged yellow catfish was screened for presence of polymorphisms by sequencing and six single nucleotide polymorphisms (SNPs) were identified. SNP association analysis revealed that 528T/C SNP in the first intron was significantly different in disease-susceptible and-resistant groups, which was confirmed in two independent populations of yellow catfish. Moreover, the relative expression of CypA in the resistant group (CC genotype in 528T/C SNP) was significantly higher than that in the susceptible group (TT genotype in 528T/C SNP) in different immune organs of yellow catfish including spleen, head kidney, body kidney and liver. Our results reveal the potential function of CypA in host defense to bacterial infection and suggest the SNP marker in CypA gene associated with the resistance to E. ictaluri may facilitate the selective breeding of disease-resistant yellow catfish in the future

A Note on the Non-Commutative Wess-Zumino Model

We show that the noncommutative Wess-Zumino (NCWZ) Lagrangian with permutation terms in the interaction parts is renormalizable at one-loop level by only a wave function renormalization. When the non-commutativity vanishes, the logarithmic divergence of the wave function renormalization of the NCWZ theory is the same as that of the commutative one. Next the algebras of noncommutative field theories (NCFT's) are studied. From Neother currents, the field representation for the generators of NCFT's is extracted. Then based on this representation, the commutation relations between the generators are calculated for NCFT's. The symmetry properties of NCFT's inferred from these commutation relations are discussed and compared with those of the commutative ones.Comment: 10 pages with no figure

Impact of Stratosphere on Cold Air Outbreak: Observed Evidence by CrIS on SNPP and Its Comparison with Models

A cold air outbreak (CAO) is an extreme weather phenomenon that has significant social and economic impacts over a large region of the midlatitudes. However, the dynamical mechanism of the occurrence and evolution of CAO events, particularly the role of the stratosphere, is not well understood. Through an analysis of one extreme CAO episode that occurred on 27–31 January 2019 across much of the US Midwest, this study examined its thermodynamic structure and the impact of stratospheric downward transport using the single-field-view (SFOV) satellite products (with a spatial resolution of ~14 km at nadir) from the Cross-track Infrared Sounder (CrIS) onboard Suomi National Polar-Orbiting Partnership (SNPP) in conjunction with MERRA-2 and ERA-5 reanalysis products. It is found that along the path of cold air transport, particularly near the coldest surface center, there exists a large enhancement of O3, deep tropopause folding, significant downward transport of stratospheric dry air, and a warm center above the tropopause. The upper warm center can be observed directly using the brightness temperature (BT) of CrIS stratospheric sounding channels. While similar large-scale patterns of temperature (T), relative humidity (RH), and ozone (O3) are captured from CrIS, MERRA-2, and ERA-5 products, it is found that, in the regions impacted by CAO, MERRA-2 has a thicker dry layer under the tropopause (with the difference of RH up to ~10%) and the total column ozone (TCO) from ERA-5 has a relatively large positive bias of 2.8 ± 2.8% compared to that measured by Ozone Mapping and Profiler Suite (OMPS). This study provides some observational evidence from CrIS that confirm the impact of the stratosphere on CAO through downward transport and demonstrates the value of the SFOV retrieval products for CAO dynamic transport study and model evaluation

Design and implementation of LPWA-based air quality monitoring system

Increasing attention has been paid to air quality monitoring with a rapid development in industry and transportation applications in the modern society. However, the existing air quality monitoring systems cannot provide satisfactory spatial and temporal resolutions of the air quality information with low costs in real time. In this paper, we propose a new method to implement the air quality monitoring system based on state-of-the-art Internet-of-Things (IoT) techniques. In this system, portable sensors collect the air quality information timely, which is transmitted through a low power wide area network. All air quality data are processed and analyzed in the IoT cloud. The completed air quality monitoring system, including both hardware and software, is developed and deployed successfully in urban environments. Experimental results show that the proposed system is reliable in sensing the air quality, which helps reveal the change patterns of air quality to some extent