ALBERT

Beschreibung: Reducing or stabilizing the stream temperature of ChiChiaWan Creek is a crucial work for Formosan Landlocked Salmon because ChiChiaWan Creek is the only one habitat for this endangered species. Planting trees in the riparian zone would be one of the alternatives. The purpose of this study was to evaluate the effects of several planting strategies on daily maximum stream temperature along the river. The results showed the effective vegetative shading angles should be more than 50° along ChiChiaWan Creek to reduce the direct solar radiation heating effectively. Upstream planting with 70° vegetative shading angle could be the most effective way among all the scenarios. However, this planting strategy could not improve the worst situations in summer because of the large solar elevation angles. The upstream planting in ChiChiaWan Creek was strongly recommended because the canopies could be easier to extend to totally cover the narrow width of river producing the most effective shades. Practicing the upstream planting with 90° vegetative shading angle can increase more than 1 km-long suitable habitats for the endangered Salmon in summer. Alternatively the west-side planting scenario was the second effective way for temperature reduction. Our result provided a useful suggestion for the authorities in charge of saving the Formosan Landlocked Salmon, particularly under the stress of global warming. Copyright © 2011 John Wiley & Sons, Ltd.

Beschreibung: A full kinetic elve model with a wide time range from microseconds to seconds and its spectral range from UV, visible to near-infrared wavelengths is developed. Not only the fast electron-impact emissions N2 1P (B3Πg - A3Σu+), N2 2P(C3Πu - B3Πg), N2 Lyman-Birge-Hopfield (a1Πg - X1Σg+), N2+ 1N (B2Σu+ - X2Σg+) and O2+ 1N (b4Σg− – a4Πu) but also the post-impulse chemiluminescenses, O2 atmospheric band (b1Σg+ – X3Σg−), O(1S – 1D) at 557.7 nm and O(1D – 3P) at 630 nm, are considered in the elve model. We calculate the dominant emissions and possible weak emissions in our elves model to analyze the relative importance of emission intensity, measured by the ISUAL imager with 5 selectable band pass filters (N21P, 762, 630, 557.7, 427.8 nm filter). The modeling emission intensities were well consistent with the measurements by Imager with different filters. This comparison could also be useful in designing the imager filters for future TLE survey missions in Earth orbit.

Beschreibung: ABSTRACT The vector physics of wind-driven rain (WDR) differs from that of wind-free rain, and the interrill soil detachment equations in the Water Erosion Prediction Project (WEPP) model were not originally developed to deal with this phenomenon. This article provides an evaluation of the performance of the interrill component of the WEPP model for WDR events. The interrill delivery rates were measured in the wind tunnel facility of the International Center for Eremology (ICE), Ghent University, Belgium with an experimental setup to study different raindrop impact velocity vectors. Synchronized wind and rain simulations with wind velocities of 6, 10 and 14 m s -1 were applied to a test surface placed on windward and leeward slopes of 7, 15 and 20%. Since both rainfall intensity and raindrop impact velocity varied greatly depending on differences in the horizontal wind velocity under wind-driven rains, the resultant kinetic energy flux (KE r , J m -2  s -1 ) was initially used in place of the WEPP model intensity term in order to incorporate the effect of wind on impact velocity and frequency of raindrops. However, our results showed only minor improvement in the model predictions. For all research data, the model Coefficients of Determination (r 2 ) were 0.63 and 0.71, when using the WEPP and the KE r approaches, respectively. Alternately, integrating the angle of rain incidence into the model by vectorally partitioning normal kinetic energy flux (KE rn , , J m -2  s -1 ) from the KE r greatly improved the model's ability to estimate the interrill sediment delivery rates (r 2  = 0.91). This finding suggested that along with the fall trajectory of wind-driven raindrops with a given frequency, raindrop velocity and direction at the point of impact onto the soil surface provided sufficient physical information to improve WEPP sediment delivery rate predictions under WDR. Copyright © 2012 John Wiley & Sons, Ltd.

Beschreibung: Multilayer covers are widely accepted reclamation designs in the oil sands region of northern Alberta, Canada, with an ultimate goal of revegetating to species characteristic of predisturbance native plant communities. To determine the optimal depth of reclamation material required to reclaim overburden shale from an oil sands mine, an evaluation was made of the long-term performance of six reclamation soil cover depths all placed over overburden. The measured soil water contents from different cover thicknesses at South Bison Hills located at the Syncrude Mine site north of Fort McMurray, Alberta were used to calibrate and validate a dual-porosity model in HYDRUS-1D. The calibrated and validated model was then used to evaluate the influence of cover thickness and climatic variability on plant available water for forest growth. The frequency distributions of actual transpiration (T r ) for six cover treatments with a range of leaf area index (LAI) cases were developed. These T r frequency distributions were then modified by coupling T r and LAI. The modified frequency distributions for annual T r for the six simulated cover thickness highlight the strong non-linearity between the distribution of T r over a long-term (60 year) climate cycle in that incremental increases in cover thickness do not produce proportional increases in T r . The results indicated that, once the cover thickness exceeds 100 cm, there is little incremental increase in the median value of T r over the 60 year climate cycle. This article is protected by copyright. All rights reserved.

Beschreibung: We introduce a statistical model to explain the latitudinal dependence of the occurrence rate and energy flux of the ionospheric escaping ions, taking advantage of advances in the spatial coverage and accuracy of FAST observations. We use a weighted piecewise Gaussian function to fit the dependence, because two probability peaks are located in the dayside polar cusp source region and the nightside auroral oval zone source region. The statistical results show that: (1) the Gaussian Mixture Model (GMM) suitably describes the dayside polar cusp upflows, and the dayside and the nightside auroral oval zone upflows. (2) The magnetic latitudes of the ionospheric upflow source regions expand toward the magnetic equator as Kp increases, from 81° MLat (cusp upflows) and 63° MLat (auroral oval upflows) during quiet times to 76° MLat and 61° MLat, respectively. (3) The dayside polar cusp region provides only 3-5% O + upflows among all the source regions, which include the dayside auroral oval zone, dayside polar cusp, nightside auroral oval zone and even the polar cap. However, observations show that more than 70% of upflows occur in the auroral oval zone and that the occurrence probability increases at the altitudes of 3500 - 4200 km, which is considered to be the lower altitude boundary of ion beams. This observed result suggests that soft electron precipitation and transverse wave heating are the most efficient ion energization/acceleration mechanisms at the altitudes of FAST orbit, and that the parallel acceleration caused by field-aligned potential drops become effective above that altitude.

Beschreibung: Using version 2.0 of the TIMED/SABER kinetic temperature data, we have conducted a study on the annual and inter-annual variations of 6.5DWs at 20-110 km, from 52°S-52°N for 2002-2016. First, we obtained global annual variations in the spectral power and amplitudes of 6.5DWs. We found that strong wave amplitudes emerged from 25°S/N-52°S/N, and peaked in the altitudes of the stratosphere, mesosphere and the lower thermosphere. The annual variations in the 6.5DWs are similar in both hemispheres but different at various altitudes. At 40-50 km, the annual maxima emerge mostly in winters. In the MLT, annual peaks occurred twice every half year. At 80-90 km, 6.5DWs appeared mainly in equinoctial seasons and winters. At 100-110 km, 6.5DWs emerged mainly in equinoctial seasons. Second, we continued the study of the inter-annual variations in 6.5DW amplitudes from 2002-2016. Frequency spectra of the monthly mean amplitudes showed that main dynamics in the long-term variations of 6.5DWs were AO and SAO in both hemispheres. In addition, 4-month period signals were noticed in the MLT of the NH. The amplitudes of SAO and AO were obtained using a bandpass filter and were found to increase with altitude, as do the 6.5DW amplitudes. In both hemispheres, the relative importance of SAO and AO changes with altitude. At 40-50 and 100-110 km, AO play a dominant role, while at 80-90 km, they’re weaker than SAO. Our results show that both the annual and inter-annual variations in 6.5DWs are mainly caused by the combined action of SAO and AO.

Beschreibung: [1]  The aerosol products retrieved using the MODIS collection 5.1 Deep Blue algorithm have provided useful information about aerosol properties over bright-reflecting land surfaces, such as desert, semi-arid, and urban regions. However, many components of the C5.1 retrieval algorithm needed to be improved; for example, the use of a static surface database to estimate surface reflectances. This is particularly important over regions of mixed vegetated and non-vegetated surfaces, which may undergo strong seasonal changes in land cover. In order to address this issue, we develop a hybrid approach, which takes advantage of the combination of pre-calculated surface reflectance database and normalized difference vegetation index in determining the surface reflectance for aerosol retrievals. As a result, the spatial coverage of aerosol data generated by the enhanced Deep Blue algorithm has been extended from the arid and semi-arid regions to the entire land areas. In this paper, the changes made in the enhanced Deep Blue algorithm regarding the surface reflectance estimation, aerosol model selection, and cloud screening schemes for producing the MODIS collection 6 aerosol products are discussed. A similar approach has also been applied to the algorithm that generates the SeaWiFS Deep Blue products. Based upon our preliminary results of comparing the enhanced Deep Blue aerosol products with the AERONET measurements, the expected error of the Deep Blue aerosol optical thickness (AOT) is estimated to be better than 0.05 + 20%. Using 10 AERONET sites with long-term time series, 79% of the best-quality Deep Blue AOT values are found to fall within this expected error.

Beschreibung: Hilbert transforms (HT) have first been used to build the essential technique of Grad-Shafranov (GS) reconstruction by Li et al. [2013], where the problem of ill-posedness in GS reconstruction has been thoroughly investigated. In this study, we present an extended Hilbert transform (EHT) over the plane rectangle. In contrast to previous one (HT over the unit circular region), corner singularities are introduced into these new formulae. It's confronted by problems like the integral with both end-point singularities, and the semi-infinite integral with one end-point singularity, as these EHT formulae are used to rebuild the essential technique of GS reconstruction. Two additional mathematic tools are adopted in this study. Firstly, high accuracy quadrature schemes are constructed for those improper integrals based on the double exponential (DE) transformations. Benchmark testing with the analytic solutions on a rectangular boundary has shown the efficiency and robustness of the EHT formulae. Secondly, the data completion or the inverse boundary value problem is solved with the help of a truncated Chebyshev series , which approximates the unknown boundary gradients in very high efficiency under the only assumption that they are Lipschitz continuous on each side of the rectangle. Combining the introduced EHT formulae and the two needed mathematic tools, the essential technique of GS reconstruction is formulated into a linear system of Fredholm equations of the first kind. Then a three-parameter Tikhonov regularization scheme is developed to deal with the ill-posed linear operators appearing in the discretized linear system. This new approach for data completion over the plane rectangle is benchmarked with the analytic solutions. Numerical experiments highlight the efficiency and robustness of the proposed method.