Statistical data fusion of multi-sensor AOD over the Continental United States

This article illustrates two techniques for merging daily aerosol optical depth (AOD) measurements from satellite and ground-based data sources to achieve optimal data quality and spatial coverage. The first technique is a traditional Universal Kriging (UK) approach employed to predict AOD from multi-sensor aerosol products that are aggregated on a reference grid with AERONET as ground truth. The second technique is spatial statistical data fusion (SSDF); a method designed for massive satellite data interpolation. Traditional kriging has computational complexity O(N³), making it impractical for large datasets. Our version of UK accommodates massive data inputs by performing kriging locally, while SSDF accommodates massive data inputs by modelling their covariance structure with a low-rank linear model. In this study, we use aerosol data products from two satellite instruments: the moderate resolution imaging spectrometer and the geostationary operational environmental satellite, covering the Continental United States.     

Temperature of interstellar warm ionized medium

This investigation on the temperature of the interstellar warm ionized medium (WIM) is characterized by the number and energy balance of the constituents of the WIM complex plasma viz. H plasma (electrons/ions/neutral atoms) and graphite dust, having a size distribution, characterized by the MRN (Mathis, Rumpl and Nordsieck) power law. Ionization of neutral atoms, electron–ion recombination, photoemission of electrons from and accretion on the dust and cooling through electron collisional excitation, followed by radiative decay of atoms has been included in the analysis. An appropriate expression for the rate of emission and mean energy of photoelectrons emitted from the surface of positively charged dust particles has been used which takes into account the dependence of absorption efficiency on wavelength of the radiation, radius of the particle and spectral irradiance distribution. The results of the parametric analysis have been displayed graphically. It is seen that the consensus values of temperature, surface potential on the dust particles and electron/ion/neutral atom densities, characteristic of interstellar warm ionized medium can be explained on the basis of plausible combinations of the dust particle density n _d and the parameter f _ex α _ex , where f _ex is the fraction of the energy of the neutral gas atoms which gets irradiated, α _ex n _e n _n is the number of the neutral atoms, which get excited per unit volume per unit time and n _e (n _n ) correspond to the density of electrons (neutral atoms).     

Indian summer monsoon forcing on the deglacial polar cold reversals

The deglacial transition from the last glacial maximum at \(\sim \)20 kiloyears before present (ka) to the Holocene (11.7 ka to Present) was interrupted by millennial-scale cold reversals, viz., Antarctic Cold Reversal (\(\sim \)14.5–12.8 ka) and Greenland Younger Dryas (\(\sim \)12.8–11.8 ka) which had different timings and extent of cooling in each hemisphere. The cause of this synchronously initiated, but different hemispheric cooling during these cold reversals (Antarctic Cold Reversal \(\sim \)3\(^{\circ }\hbox {C}\) and Younger Dryas \(\sim \)10\(^{\circ }\hbox {C}\)) is elusive because \(\hbox {CO}_{2}\), the fundamental forcing for deglaciation, and Atlantic meridional overturning circulation, the driver of antiphased bipolar climate response, both fail to explain this asymmetry. We use centennial-resolution records of the local surface water \(\delta ^{18}\hbox {O}\) of the Eastern Arabian Sea, which constitutes a proxy for the precipitation associated with the Indian Summer Monsoon, and other tropical precipitation records to deduce the role of tropical forcing in the polar cold reversals. We hypothesize a mechanism for tropical forcing, via the Indian Summer Monsoons, of the polar cold reversals by migration of the Inter-Tropical Convergence Zone and the associated cross-equatorial heat transport.     

尼泊尔Koshi Tappu野生动物保护区中村落人类与野生动物冲突（英文）

人类与野生动物的冲突一直是尼泊尔许多地区（包括尼泊尔东部）面临的最棘手的问题之一。本研究评估了尼泊尔Sunsari区Koshi Tappu野生动物保护区Paschim Kusaha村的人类与野生动物冲突状况。通过问卷调查和正式/非正式访谈,从不同家庭的47名受访者中收集数据。结果显示,破坏力最大的野生动物为野象、野猪和野水牛,袭击最多的农作物为水稻（63.83%）、玉米（19.15%）和马铃薯（17.02%）。人类与野生动物之间的大部分相遇发生在夜间（黄昏后和黎明前）,有记录显示夜间相遇占总相遇次数的78.72%。当地居民受到的主要负面影响包括财产损失、动物骚扰以及野生动物对农田的破坏等。尽管保护区和周边地区的人类死亡率记录令人不安（在过去5年中有22人死亡）,但仍有70%的受访者对野生动物保护持积极态度。建议提高对野生动物行为的认识以及保护,设立容易获得补偿的计划和项目,以尽量减少该地区的人类与野生动物的冲突。     

Dissolution kinetics and topographic relaxation on celestite (0 0 1) surfaces: The effect of solution saturation state studied using Atomic Force Microscopy

Dissolution of celestite (0 0 1) was studied by atomic force microscopy as a function of solution undersaturation. In solutions near saturation with respect to celestite, dissolution of the mineral took place exclusively by removal of ions from existing step edges. The onset of etch pit nucleation was observed at a critical saturation state of . Below this saturation state, dissolution took place both at existing step edges and via the creation of new steps surrounding the etch pits. The dissolution rates of celestite exhibited a non-linear dependence on saturation state. Basic crystal dissolution/growth models were inadequate to describe the non-linearity, but a model that incorporates a critical undersaturation provided an improved fit to data collected at high undersaturation. A simple model for dissolution at low undersaturation also fit the rate data well, but in light of the conditions necessary to produce new step edges, the rate coefficient in this model is poorly constrained due to the effects of sample surface history. Consideration of the process of topographic relaxation, consisting of changes in the surface microtopography (i.e., step density) resulting from changes in solution conditions, led to predicted relaxation times on the order of days for the celestite-water interface.     

Methodology for assessing the usability of earth observation-based data for disaster management

The year 2010 through 2011 witnessed a number of disasters such as floods in Pakistan and Eastern Europe and earthquakes in Chile, China and Haiti. In response, earth observation (EO) data, geographic information science (GIS) technologies and services were used to provide information before, during and after the disaster occurred. However, use of EO for disaster management still faces a number of challenges due to the lack of common established standards for producing disaster products, the lack of coordination between a large number of suppliers leading to a large collection of datasets on websites of coordinating agencies and the lack of an established framework for monitoring and authenticating the level of quality and reliability of the products delivered to the targeted users. Assessing the quality of such products is a challenge to any potential user of such datasets. The methodology presented here integrates the role of EO expert and targeted end-user into one model where the first phase involves the expert and the second phase the end-user. The expert handles the technical and expertise aspect of EO data by rating the level of conformance of a product to the parameters of a ??quality information template?? (QIT), and the end-user explores various rated datasets and sets preferences for decision-making based on this QIT. The end-user has the possibility of accessing the product through an interactive web platform. The preferences set are used for weighing and ranking for the combination of the potential datasets and the task to be performed.