Detailed Meteorological Data Research Articles

Wintertime Simulations of a Boreal Lake with the Canadian Small Lake Model

Abstract A one-dimensional mixed layer dynamic lake model is enhanced with snow and ice physics for an examination of processes governing ice cover and phenology in a small boreal lake. The complete snowpack physics module of the Canadian Land Surface Scheme along with a new snow-ice parameterization have been added to the Canadian Small Lake Model, and detailed meteorological and temperature profile data have been acquired for the forcing and evaluation of two wintertime simulations. During the first winter, simulated ice-on and ice-off biases were −3 and −5 days, respectively. In the second winter simulation, ice-on bias was larger, likely due to the absence of a frazil ice scheme in the model, and simulated ice-off was 6 days late, evidently due to insufficient convective mixing beneath the ice in the weeks leading up to ice-off. Ice cover was simulated about 25% too thin between January and March for this year, though late January simulated snow and snow-ice amounts were close to observed. The impact of snow-ice production on simulated ice cover and phenology was found to be dramatic for this lake. In the absence of this process, January snow was more than twice as deep as observed and March ice thickness was less than one-third of that observed. Without snow-ice production, a reasonable simulation of ice cover could only be restored if 62% of snowfall was removed ad hoc (e.g., through blowing snow redistribution)—an excessive amount for a small, sheltered boreal lake.

Exposure, Contemporaneousness and the Effect of Droughts on Children's Cognitive Development

In this paper, we combine a comprehensive Indonesian household survey with detailed meteorological data to explore what can be learned about the effect of drought on the long term cognitive development of Indonesian children living in rural areas. We face a common problem of latent exposure with observable contemporaneousness. The problem is compounded by plausible endogeneity and likely confounding. To estimate the effects of drought on Indonesian children's scores in a fluid intelligence test, we consider a battery of different identification assumptions which vary in credibility and power. Our most powerful assumptions point identify the effect of contemporaneousness, however they have debatable credibility. Our most credible assumptions, on the other hand, convey little information about the effect of contemporaneousness. In between these two extreme, we consider a range of middle-of-the-way assumptions which partially identify the effect of contemporaneousness. Specifically, we characterise some of the assumptions required to establish the sign of the effect of contemporaneousness. Our results reveal differential effects of drought across sexes, however we find at least two competing explanations which would explain these difference: natural selection, on the one hand, and family dis-investing on girls in the fact of hardship, on the other.

The assessment of health impacts and external costs of natural gas-fired power plant of Qom.

The external health damage costs of the combined cycle natural gas-fired power plant of Qom were investigated via the simplified impact pathway approach. Emitted particulate matter (PM10) and gaseous pollutants (NO x , CO, and SO2) from the power plant stack were measured The health effects and related costs were estimated by QUERI model from AirPacts according to the emissions, source and stack parameters, pollutant depletion velocities, exposure-response functions, local and regional population density, and detailed meteorological data. The results showed that the main health effect was assigned to the nitrate as restricted activity days (RAD) with 25,240days/year. For all pollutants, the maximum health damage costs were related to the long-term mortality (49%), restricted activity days (27%), and chronic bronchitis (21%). The annual health damage costs were approximately 4.76 million US$, with the cost being 0.096 US per kWh of generating electricity. Although the health damage costs of gas-fired power plant were lower than those of other heavy fuels, it seems essential to consider the health and environmental damages and focus on the emission control strategies, particularly in site selection for the new power plants and expanding the current ones.

Relative Contributions of Land Use and Climate Change to Water Supply Variations over Yellow River Source Area in Tibetan Plateau during the Past Three Decades.

There is increasing evidence of environmental change impacts on ecosystem processes and services, yet poor understanding of the relative contributions of land use and climate change to ecosystem services variations. Based on detailed meteorological, hydrological records and satellite data over the Yellow River Source Area (YRSA) in Tibetan Plateau from 1980s to 2008, together with a water-yield module of Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and also a Residual Trends (RESTREND) method, we assessed the water supply variations in YRSA during the past three decades and disentangled the relative contributions of land use and climate change. Results show that water supply significantly decreased from 1980 to 2005 and then increased from 2005 to 2008. The quantity slightly decreased from 283.01mm in 1980 to 276.95mm in 1995, 270.12mm in 2000 and 267.97mm in 2005, and it then rebounded slightly to 275.26mm in 2008. The water supply variation ranged from 283.01mm to 267.97mm. Climate change contributed dominantly to water supply decrease from 1980 to 1995, which accounts for approximately 64% of the decrease. During 1995 to 2000, land use contributed more and about 58% to the water supply decrease as the intense human activities. From 2000 to 2005, climate change became a positive contribution to the water supply as the increased precipitation, but the land use still contributed negatively. From 2005 to 2008, both climate and land use have positive impacts, but land use contributed about 61% to the water supply increase. The implementation of the Three Rivers Source Area Ecological Protection Project has greatly improved the vegetation coverage conditions and the water retention ability during this period. We recommend that the implementation of ecological projects, grazing policies and artificial improvement of degraded grassland would help to conserve the water retention ability and increase water supply.

Meteorological Modeling Using the WRF-ARW Model for Grand Bay Intensive Studies of Atmospheric Mercury

Measurements at the Grand Bay National Estuarine Research Reserve support a range of research activities aimed at improving the understanding of the atmospheric fate and transport of mercury. Routine monitoring was enhanced by two intensive measurement periods conducted at the site in summer 2010 and spring 2011. Detailed meteorological data are required to properly represent the weather conditions, to determine the transport and dispersion of plumes and to understand the wet and dry deposition of mercury. To describe the mesoscale features that might influence future plume calculations for mercury episodes during the Grand Bay Intensive campaigns, fine-resolution meteorological simulations using the Weather Research and Forecasting (WRF) model were conducted with various initialization and nudging configurations. The WRF simulations with nudging generated reasonable results in comparison with conventional observations in the region and measurements obtained at the Grand Bay site, including surface and sounding data. The grid nudging, together with observational nudging, had a positive effect on wind prediction. However, the nudging of mass fields (temperature and moisture) led to overestimates of precipitation, which may introduce significant inaccuracies if the data were to be used for subsequent atmospheric mercury modeling. The regional flow prediction was also influenced by the reanalysis data used to initialize the WRF simulations. Even with observational nudging, the summer case simulation results in the fine resolution domain inherited features of the reanalysis data, resulting in different regional wind patterns. By contrast, the spring intensive period showed less influence from the reanalysis data.

Evaluating the PAS-SIM model using a passive air sampler calibration study for pesticides.

The main objective of this study was to evaluate the performance of a model for simulating the uptake of various pesticides on passive air samplers (PAS). From 2006-2007 a series of PAS using XAD-resin were deployed at Egbert, a rural agricultural site in southern Ontario, Canada, to measure the uptake of pesticides for time periods ranging from two months to one year. A continuous increase in sequestered amounts was observed for most pesticides, except for trifluralin and pendimethalin, which could conceivably be subject to substantial degradation inside the sampler. Continuous low-volume active air samples taken during the same period, along with data on weather conditions, allowed for the simulation of the uptake of the pesticides using the model (PAS-SIM). The modelled accumulation of pesticides on the PAS over the deployment period was in good agreement with the experimental data in most cases (i.e., within a factor of two) providing insight into the uptake kinetics of this type of sampler in the field. Passive sampling rates (PSR, m(3) d(-1)) were determined from the empirical data generated for this study using three different methods and compared with the PSRs generated by the model. Overall, the PAS-SIM model, which is capable of accounting for the influence of temperature and wind variations on PSRs, provided reasonable results that range between the three empirical approaches employed and well-established literature values. Further evaluation and application of the PAS-SIM model to explore the potential spatial and temporal variability in PAS uptake kinetics is warranted, particularly for established monitoring sites where detailed meteorological data are more likely to be available.

Massachusetts Wind Turbine Acoustics Research Project—Goals and preliminary results

The Commonwealth of Massachusetts (USA) has 43 operating wind turbine projects of 100 kW or more. At several of these projects, noise complaints have been made to state authorities. The Massachusetts Clean Energy Center, which provides funding for early stage analysis and development of wind power projects, and the Massachusetts Department of Environmental Protection, which regulates noise, launched the project to increase understanding of (1) wind turbine acoustic impacts, taking into account variables such as wind turbine size, technology, wind speed, topography and distance, and (2) the generation, propagation, and measurement of sound around wind turbine projects, to inform policy-makers on how pre- and post-construction wind turbine noise studies should be conducted. This study involved the collection of detailed sound and meteorological data at five locations. The resulting database and interim reports contain information on infrasound and audible frequencies, including amplitude modulation, tonality, and level. Analyses will include how the effects of wind shear and other variables may affect these parameters. Preliminary findings reflect the effects of meteorological conditions on wind turbine sound generation and propagation.

Harmonizing Multiple Methods for Reconstructing Historical Potential and Reference Evapotranspiration

AbstractPotential evapotranspiration (PET) and reference evapotranspiration (RET) data are usually critical components of hydrologic analysis. Many different equations are available to estimate PET and RET. Most of these equations, such as the Priestley-Taylor and Penman- Monteith methods, rely on detailed meteorological data collected at ground-based weather stations. Few weather stations collect enough data to estimate PET or RET using one of the more complex evapotranspiration equations. Currently, satellite data integrated with ground meteorological data are used with one of these evapotranspiration equations to accurately estimate PET and RET. However, earlier than the last few decades, historical reconstructions of PET and RET needed for many hydrologic analyses are limited by the paucity of satellite data and of some types of ground data. Air temperature stands out as the most generally available meteorological ground data type over the last century. Temperature-based approaches used with readily a...

Performance evaluation of artificial neural networks in estimating reference evapotranspiration with minimal meteorological data

Detailed meteorological data required for the equation of FAO-56 Penman-Monteith (P-M) method that was adopted by Food and Agriculture Organization (FAO) as a standard method in estimating reference evapotranspiration (ETo) are not often available, especially in developing countries. The Hargreaves equation (HG) has been successfully used in some locations to estimate ETo where sufficient data were not available to use the P-M method. This paper investigates the potential of two Artificial Neural Network (ANN) architectures, the multilayer perceptron architecture, in which a backpropagation algorithm (BPANN) is used, and the cascade correlation architecture (CCANN), in which Kalman’s learning rule is embedded in modeling the daily ETo with minimal meteorological data. An overview of the features of ANNs and traditional methods such as P-M and HG is presented, and the advantages and limitations of each method are discussed. Daily meteorological data from three automatic weather stations located in Greece were used to optimize and test the different models. The exponent value of the HG equation was locally optimized, and an adjusted HGadj equation was used. The comparisons were based on error statistical techniques using P-M daily ETo values as reference. According to the results obtained, it was found that taking into account only the mean, maximum and minimum air temperatures, the selected ANN models markedly improved the daily ETo estimates and provided unbiased predictions and systematically better accuracy compared with the HGadj equation. The results also show that the CCANN model performed better than the BPANN model at all stations.

First Glacier Inventory and Recent Changes in Glacier Area in the Monte San Lorenzo Region (47°S), Southern Patagonian Andes, South America

We present the first glacier inventory of the Monte San Lorenzo region (47°35′S, 72°18′W) in the southern Patagonian Andes of Chile and Argentina. This region contains the largest and easternmost glaciers at these latitudes in South America. The inventory was developed using a combination of ASTER and Landsat ETM + scenes from 2005 and 2008, respectively, and a semi-automatic band ratio approach to map glacier ice. Manual corrections were applied to include debris-covered ice and ice in cast shadows. We inventoried 213 glaciers that cover a 2005/2008 total area of ca. 207 km2 and lie between 520 m and 3700 m in elevation. Landsat TM images acquired in 1985 and 2000 were subsequently used to assess changes in glacierized area over the 1985–2008 interval. Based on all available information, we determined an 18.6% reduction in the total glacier area since 1985. Glaciers smaller than 1 km2 have shown highly variable (0–100%) relative areal reduction, whereas the formation and growth of proglacial lakes promoted rapid recession of the larger valley glaciers, which concentrate the major ice losses, representing ca. 32% of the total glacier area reduction. Glacier fragmentation has occurred for 50% of the ice bodies larger than 1 km2. These results agree with the generalized pattern of glacier retreat observed throughout the Patagonian Andes, but the lack of detailed meteorological and glaciological data in the area preclude a more refined analysis of the climate-glacier relationships and processes explaining the recent glacier trends.

OSL and radiocarbon dating on late Quaternary lacustrine sediments from Tengger Desert in China and its implication for palaeolake highstands

Based on the detailed meteorological data in the Tengger Desert, this paper aims to clarify the characteristics of windblown sand and to show the dynamical environment in the Tengger desert. Results of data analysis indicate that both the wind direction and the sand-drift intensity exhibit obvious spatial and temporal variations. The prevailing wind directions for the desert are NW and SE, depending on the regional landform and season. The mean annual wind speed in the hinterland of the desert is greater than its periphery. The mean annual drift potential (DP) is 358.72 VU in Shapotou region on the southern margin of the desert, indicating the intermediate wind environment of the desert.

Characteristics of wind-blown sand and near-surface wind regime in the Tengger Desert, China

Abstract Based on the detailed meteorological data in the Tengger Desert, this paper aims to clarify the characteristics of windblown sand and to show the dynamical environment in the Tengger desert. Results of data analysis indicate that both the wind direction and the sand-drift intensity exhibit obvious spatial and temporal variations. The prevailing wind directions for the desert are NW and SE, depending on the regional landform and season. The mean annual wind speed in the hinterland of the desert is greater than its periphery. The mean annual drift potential (DP) is 358.72 VU in Shapotou region on the southern margin of the desert, indicating the intermediate wind environment of the desert.

Is Authentication of Regional and Traditional Food Made of Meat Possible?

Authentication of regional and traditional food made of meat poses a significant challenge. It continues to be a very difficult task which requires employment of quite advanced analytical techniques. These products, despite a similar process of manufacturing, differ in taste and aroma. This happens due to the use of special breeds of animals, the application of appropriate feeding regimes as well as the effect of the place and climate. In order to perform correct identification of geographical origin, a good solution is to determine both stable isotopes as well as trace elements. It is essential to collect detailed meteorological and geochemical data and information about farming practices and to compare them with the obtained results. In a majority of cases, the performed identification is confined to species and the determination of the animal breed is very limited. In the case of individual breeds a comparative analysis of SNPs appears to present the highest potential, especially genes affecting the coat color of animals may serve as markers. Experiments confirm that genes responsible for pigmentation underwent mutations in individual breeds. Authentication on the basis of the manufacturing process appears to be easier to realize than tracing geographical origins.

A Comparison of Model Performance between AERMOD and AUSTAL2000

ABSTRACT In this study the performance of the American Meteorological Society and U.S. Environmental Protection Agency Regulatory Model (AERMOD), a Gaussian plume model, is compared in five test cases with the German Dispersion Model according to the Technical Instructions on Air Quality Control (Ausbreitungsmodell gemäβ der Technischen Anleitung zur Reinhaltung der Luft) (AUSTAL2000), a Lagrangian model. The test cases include different source types, rural and urban conditions, flat and complex terrain. The predicted concentrations are analyzed and compared with field data. For evaluation, quantile-quantile plots were used. Further, a performance measure is applied that refers to the upper end of concentration levels because this is the concentration range of utmost importance and interest for regulatory purposes. AERMOD generally predicted concentrations closer to the field observations. AERMOD and AUSTAL2000 performed considerably better when they included the emitting power plant building, indicating that the downwash effect near a source is an important factor. Although AERMOD handled mountainous terrain well, AUSTAL2000 significantly underestimated the concentrations under these conditions. In the urban test case AUSTAL2000 did not perform satisfactorily. This may be because AUSTAL2000, in contrast to AERMOD, does not use any algorithm for nightly turbulence as caused by the urban heat island effect. Both models performed acceptable for a nonbuoyant volume source. AUSTAL2000 had difficulties in stable conditions, resulting in severe underpredictions. This analysis indicates that AERMOD is the stronger model compared with AUSTAL2000 in cases with complex and urban terrain. The reasons for that seem to be AUSTAL2000's simplification of the meteorological input parameters and imprecision because of rounding errors. IMPLICATIONS This study contributes to the understanding of dispersion modeling and demonstrates the advantage of detailed meteorological data. It also helps air quality regulators and planners to identify the most appropriate model to use. It is indicated that AERMOD is more suitable for air quality planning and regulation, when all required meteorological information is available, because its predictions are mostly closer to field observations. Furthermore AUSTAL2000 predicted concentrations that showed a narrow range and triggered far less impacts from the source.

Storm Surge Simulation due to Isewan Typhoon using Detailed Meteorological Re-analysis Data

Re-analysis and reproduction of storm surges and waves due to the Isewan Typhoon were tried using the detailed re-analysis meteorological data that agreed with the meteorologocal observations. In the simulations a coupled model of surge, wave and tide was used. The predictions using the coupled model agreed well with the observed surges, but not for the uncoupled model's predictions that are much smaller than the observations. Predicted waves were comapred with previous estimations since there are no observations. The magnitudes of wave heights were constistent each other.

A comparison of methods for the retrieval of surface reflectance factor from multitemporal SPOT HRV, HRVIR, and HRG multispectral satellite imagery

Absolute atmospheric correction for retrieval of the surface reflectance factor (ρs) is a prerequisite for quantitative remote sensing utilizing multispectral optical satellite data. Areas where changes in land cover are occurring with greatest significance also often lack detailed meteorological data that allow full use of radiative transfer models (RTMs) for reflectance factor retrieval (RFR). This study assessed RFR accuracy of techniques applicable in such circumstances. The historical empirical line method (HELM), four image-based dark-object subtraction (DOS) methods, and the 6S RTM were applied to SPOT imagery datasets covering both the Taita Hills application site in southeast Kenya and the Helsinki metropolitan region control site in Finland. HELM was the only approach that achieved RFR in the visible and near-infrared bands with a RMSE of <0.02ρs and overall relative accuracy of <10%. Further, HELM shortwave infrared (SWIR) performance was significantly better than that of the other techniques and the partially corrected at-satellite reflectance (ρsAT). Although better than the DOS methods, application of 6S using standard atmosphere and aerosol models did not meet the desired RFR accuracy, even with the utilization of horizontal visibility meteorological data.

Effects of 10% biofuel substitution on ground level ozone formation in Bangkok, Thailand

The Thai Government's search for alternatives to imported petroleum led to the consideration of mandating 10% biofuel blends (biodiesel and gasohol) by 2012. Concerns over the effects of biofuel combustion on ground level ozone formation in relation to their conventional counterparts need addressing. Ozone formation in Bangkok is explored using a trajectory box model. The model is compared against O 3, NO, and NO 2 time concentration data from air monitoring stations operated by the Thai Pollution Control Department. Four high ozone days in 2006 were selected for modeling. Both the traditional trajectory approach and a citywide average approach were used. The model performs well with both approaches but slightly better with the citywide average. Highly uncertain and missing data are derived within realistic bounds using a genetic algorithm optimization. It was found that 10% biofuel substitution will lead to as much as a 16 ppb peak O 3 increase on these four days compared to a 48 ppb increase due to the predicted vehicle fleet size increase between 2006 and 2012. The approach also suggests that when detailed meteorological data is not available to run three dimensional airshed models, and if the air is stagnant or predominately remains over an urban area during the day, that a simple low cost trajectory analysis of O 3 formation may be applicable.

ChiWI—a road weather index for China

AbstractApplication of Road Weather Information System (RWIS) for China is starting in an international perspective. However, the strong economic development during the last decades in China has caused a dramatic increase in the number of motorized vehicles, which calls for a quick development of RWIS and its application/services to safeguard the rapid development and to improve the safety of transportation. This study focuses on application of a winter index in China to quantify the need of a RWIS in different parts of China. The index is based on a concept related to various relevant weather parameters including ice, fog, snow, and wind. Its use is flexible in the sense that different types of inputs are possible, which is illustrated by a general view of the situation in China using climatological data and a case study using detailed meteorological data in Northern China. The results reveal that there are varying needs for RWIS in large parts of China. Regions with a great need for RWIS lie in the humid middle and northeastern parts of China. Some regions, however, may have a limited need for fully equipped RWIS stations. Such areas are the unpopulated areas in northwest or the dry regions in north. The results indicate that the introduced method provides useful information for China, both in the general view and in the case study. Copyright © 2009 Royal Meteorological Society

Historical Doses to the Public from Routine and Accidental Releases of Tritium - Lawrence Livermore National Laboratory, 1953-2005

Throughout fifty-three years of operations, an estimated 29,300 TBq of tritium have been released to the atmosphere at the Livermore site of Lawrence Livermore National Laboratory; about 75% of this was released accidentally as gaseous tritium in 1965 and 1970. Routine emissions contributed slightly more than 3,700 TBq gaseous tritium and about 2,800 TBq tritiated water vapor to the total. Mean annual doses (with 95% confidence intervals) to the most exposed member of the public were calculated for all years using the same model and the same assumptions. Because time-dependent tritium models require detailed meteorological data that were unavailable for the large releases, ingestion/inhalation dose ratios were derived from experience with UFOTRI. Even with assumptions to assure that doses would not be underestimated, all doses from routine and accidental releases were below the level (3.6 mSv) at which adverse health effects have been documented, and most were below the current regulatory limit of 100 μSv per year from releases to the atmosphere.

Trends in Aphid Occurrence in Spring Barley in 1976-2007

Recently, considerable attention has been paid to climate change effects on nature and abundance of pests affecting agricultural crops. Our study was focused on the trends in aphid abun- dance during the growing seasons in spring barley in 1976-2007. Analysis was conducted based on the records of aphid abundance observations and detailed meteorological data. The first step in the study was to clarify the effects of temperature on aphid occurrence and abun- dance in spring barley. This part of the study was restricted to Dotnuva site, which is a typical area for commercial crop production, in order to reduce the influence of such effects as management, macroclimate, soil and others. A distinct and statistically significant increase in the mean air temperature was noted at the experi- mental site of the Lithuanian Institute of Agriculture in Dotnuva, Kedainiai for the period 1976-2007. A statically significant positive trend was identified for the mean air temperature during April-No- vember. Consequently, during the last decade the occurrence of aphids has also become quite fre- quent.