[Characteristics and the impact factors of acid rain in Fuzhou and Xiamen 1992-2012].

PubMed

Zheng, Qiu-Ping; Wang, Hong; Chen, Bin-Bin; Sui, Ping; Lin, Wen

2014-10-01

Based on the observed acid rain data, synoptic situations and mass concentrations of atmospheric pollutants data from 1992 to 2012, the temporal variation characteristics and the impact factors of acid rain were analyzed in Fuzhou and Xiamen. The results showed that acid rain and non-acid rain accounted for 38.1% and 61.9% respectively in Fuzhou, 40.6% and 59.4% respectively in Xiamen. The annual average pH was 4.1-5.5 in Fuzhou. Acid rain pollution alleviated after 2007 in Fuzhou, and alleviated after 2006 in Xiamen. Acid rain was more serious in winter and spring than in summer and autumn. Precipitation intensity could affect the acidity of rain. Acid rain was observed more serious in southeast, southwest, west and northwest wind in Fuzhou, and more serious in northeast, southwest, west and northwest wind in Xiamen. Acid rain was most severe under the condition of transformed surface cold high, while most light under the conditions of typhoon (intertropical convergence zone) and outside of typhoon (intertropical convergence zone). There was a negative correlation between the mass concentrations of atmospheric pollutants, such as SO2, NO2, PM10, and the pH of rain in Fuzhou.

Comparing the impact of time displaced and biased precipitation estimates for online updated urban runoff models.

PubMed

Borup, Morten; Grum, Morten; Mikkelsen, Peter Steen

2013-01-01

When an online runoff model is updated from system measurements, the requirements of the precipitation input change. Using rain gauge data as precipitation input there will be a displacement between the time when the rain hits the gauge and the time where the rain hits the actual catchment, due to the time it takes for the rain cell to travel from the rain gauge to the catchment. Since this time displacement is not present for system measurements the data assimilation scheme might already have updated the model to include the impact from the particular rain cell when the rain data is forced upon the model, which therefore will end up including the same rain twice in the model run. This paper compares forecast accuracy of updated models when using time displaced rain input to that of rain input with constant biases. This is done using a simple time-area model and historic rain series that are either displaced in time or affected with a bias. The results show that for a 10 minute forecast, time displacements of 5 and 10 minutes compare to biases of 60 and 100%, respectively, independent of the catchments time of concentration.

A comparative assessment of R. M. Young and tipping bucket rain gauges

NASA Technical Reports Server (NTRS)

Goldhirsh, Julius; Gebo, Norman E.

1992-01-01

Rain rates as derived from standard tipping bucket rain gauges have variable integration times corresponding to the interval between bucket tips. For example, the integration time for the Weathertronics rain gauge is given by delta(T) = 15.24/R (min), where R is the rain rate expressed in mm/h and delta(T) is the time between tips expressed in minutes. It is apparent that a rain rate of 1 mm/h has an integration time in excess of 15 minutes. Rain rates larger than 15.24 mm/h will have integration times smaller than 1 minute. The integration time is dictated by the time it takes to fill a small tipping bucket where each tip gives rise to 0.254 mm of rainfall. Hence, a uniform rain rate of 1 mm/h over a 15 minute period will give rise to the same rain rate as 0 mm/h rainfall over the first 14 minutes and 15 mm/h between 14 to 15 minutes from the reference tip. Hence, the rain intensity fluctuations may not be captured with the tipping bucket rain gauge for highly variable rates encompassing lower and higher values over a given integration time. The objective of this effort is to provide an assessment of the features of the R. M. Young capacitive gauge and to compare these features with those of the standard tipping bucket rain gauge. A number of rain rate-time series derived from measurements with approximately co-located gauges are examined.

Rain pH estimation based on the particulate matter pollutants and wet deposition study.

PubMed

Singh, Shweta; Elumalai, Suresh Pandian; Pal, Asim Kumar

2016-09-01

In forecasting of rain pH, the changes caused by particulate matter (PM) are generally neglected. In regions of high PM concentration like Dhanbad, the role of PM in deciding the rain pH becomes important. Present work takes into account theoretical prediction of rain pH by two methods. First method considers only acid causing gases (ACG) like CO2, SO2 and NOx in pH estimation, whereas, second method additionally accounts for effect of PM (ACG-PM). In order to predict the rain pH, site specific deposited dust that represents local PM was studied experimentally for its impact on pH of neutral water. After incorporation of PM correction factor, it was found that, rain pH values estimated were more representative of the observed ones. Fractional bias (FB) for the ACG-PM method reduced to values of the order of 10(-2) from those with order of 10(-1) for the ACG method. The study confirms neutralization of rain acidity by PM. On account of this, rain pH was found in the slightly acidic to near neutral range, despite of the high sulfate flux found in rain water. Although, the safer range of rain pH blurs the severity of acid rain from the picture, yet huge flux of acidic and other ions get transferred to water bodies, soil and ultimately to the ground water system. Simple use of rain pH for rain water quality fails to address the issues of its increased ionic composition due to the interfering pollutants and thus undermines severity of pollutants transferred from air to rain water and then to water bodies and soil. Copyright © 2016 Elsevier B.V. All rights reserved.

40 CFR 72.69 - Issuance and effective date of acid rain permits.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

40 CFR 72.69 - Issuance and effective date of acid rain permits.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

40 CFR 72.69 - Issuance and effective date of acid rain permits.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

40 CFR 72.69 - Issuance and effective date of acid rain permits.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

40 CFR 72.69 - Issuance and effective date of acid rain permits.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

Comparison of Imerg Half Hourly Final GPM data with Rain Gauge for Riyadh City, Kingdom of Saudi Arabia

NASA Astrophysics Data System (ADS)

Tekeli, E.; Dönmez, S.

2016-12-01

Being launched in 1997 with the main goal of measuring moderate to heavy rainfall, TRMM enabled invaluable service to remote sensing and hydrology community with data more than 17 years. Based on TRMM experience, GPM was launched in 2014. GPM with increased radar sensitivity and higher spatial resolutions, is expected to enable better light rain and snowfall detection. In here, light rainfall detection capacity of IMERG Half hourly final GPM (IFHH) product is investigated for Riyadh City in Kingdom of Saudi Arabia. A tipping bucket rain gauge located on the roof of King Saud University Civil Engineering Department provided rainfall measurements in 10 minute intervals from 22 November 2014 till 11 Jun 2015. Obtained rain gauge data indicated 72 light rain (rain rate [rr] ≤2.5mm/h) 5 medium rain (2.5mm/hPreliminary results indicate that IFHH overestimate most of the light rain. For the medium and heavy rain rates, IFHH showed under estimations. As one of the major goals of GPM is accurate light rain detection, similar studies should be continued and databases should be formed.

A Robust, Microwave Rain Gauge

NASA Astrophysics Data System (ADS)

Mansheim, T. J.; Niemeier, J. J.; Kruger, A.

2008-12-01

Researchers at The University of Iowa have developed an all-electronic rain gauge that uses microwave sensors operating at either 10 GHz or 23 GHz, and measures the Doppler shift caused by falling raindrops. It is straightforward to interface these sensors with conventional data loggers, or integrate them into a wireless sensor network. A disadvantage of these microwave rain gauges is that they consume significant power when they are operating. However, this may be partially negated by using data loggers' or sensors networks' sleep-wake-sleep mechanism. Advantages of the microwave rain gauges are that one can make them very robust, they cannot clog, they don't have mechanical parts that wear out, and they don't have to be perfectly level. Prototype microwave rain gauges were collocated with tipping-bucket rain gauges, and data were collected for two seasons. At higher rain rates, microwave rain gauge measurements compare well with tipping-bucket measurements. At lower rain rates, the microwave rain gauges provide more detailed information than tipping buckets, which quantize measurement typically in 1 tip per 0.01 inch, or 1 tip per mm of rainfall.

Millimeter wave propagation modeling of inhomogeneous rain media for satellite communications systems

NASA Technical Reports Server (NTRS)

Persinger, R. R.; Stutzman, W. L.

1978-01-01

A theoretical propagation model that represents the scattering properties of an inhomogeneous rain often found on a satellite communications link is presented. The model includes the scattering effects of an arbitrary distribution of particle type (rain or ice), particle shape, particle size, and particle orientation within a given rain cell. An associated rain propagation prediction program predicts attenuation, isolation and phase shift as a function of ground rain rate. A frequency independent synthetic storm algorithm is presented that models nonuniform rain rates present on a satellite link. Antenna effects are included along with a discussion of rain reciprocity. The model is verified using the latest available multiple frequency data from the CTS and COMSTAR satellites. The data covers a wide range of frequencies, elevation angles, and ground site locations.

Evaluation of Turf-Grass and Prairie-Vegetated Rain Gardens in a Clay and Sand Soil, Madison, Wisconsin, Water Years 2004-08

USGS Publications Warehouse

Selbig, William R.; Balster, Nicholas

2010-01-01

The U.S. Geological Survey, in cooperation with a consortium of 19 cities, towns, and villages in Dane County, Wis., undertook a study to compare the capability of rain gardens with different vegetative species and soil types to infiltrate stormwater runoff from the roof of an adjacent structure. Two rain gardens, one planted with turf grass and the other with native prairie species, were constructed side-by-side in 2003 at two locations with different dominant soil types, either sand or clay. Each rain garden was sized to a ratio of approximately 5:1 contributing area to receiving area and to a depth of 0.5 foot. Each rain garden, regardless of vegetation or soil type, was capable of storing and infiltrating most of the runoff over the 5-year study period. Both rain gardens in sand, as well as the prairie rain garden in clay, retained and infiltrated 100 percent of all precipitation and snowmelt events during water years 2004-07. The turf rain garden in clay occasionally had runoff exceed its confining boundaries, but was still able to retain 96 percent of all precipitation and snowmelt events during the same time period. Precipitation intensity and number of antecedent dry days were important variables that influenced when the storage capacity of underlying soils would become saturated, which resulted in pooled water in the rain gardens. Because the rooftop area that drained runoff to each rain garden was approximately five times larger than the area of the rain garden itself, evapotranspiration was a small percentage of the annual water budget. For example, during water year 2005, the maximum evapotranspiration of total influent volume ranged from 21 percent for the turf rain garden in clay to 25 percent for the turf rain garden in sand, and the minimum ranged from 12 percent for the prairie rain garden in clay to 19 percent for the prairie rain garden in sand. Little to no runoff left each rain garden as effluent and a small percentage of runoff returned to the atmosphere through evapotranspiration; therefore, the remainder was considered recharge. During water year 2005, recharge was 81 to 75 percent of total influent volume for the prairie- and turf-rain gardens in sand and 87 to 78 percent for the prairie- and turf-rain gardens in clay, respectively. Maximum recharge volumes ranged from 90 to 94 percent of the total influent volume in the turf and prairie rain gardens in sand and occurred during water year 2004. Maximum recharge in the turf and prairie rain gardens in clay ranged from 89 percent during water year 2007 to 98 percent during water year 2004. Median infiltration rates were an order of magnitude greater for rain gardens planted in sand than for those in clay, regardless of vegetation type. Under similar soil conditions, rain gardens planted with turf grass had lower median infiltration rates than those planted with prairie species. Median infiltration rates were 0.28 and 0.88 inches per hour in the turf and prairie rain gardens in clay, respectively, and 2.5 and 4.2 inches per hour in the turf and prairie rain gardens in sand, respectively. In general, infiltration rates were greater during spring (April and May) and summer (June through August) months. Of the six observed exceedences of the storage capacity of the turf rain garden in clay between April-November during 2004-07, five were predicted by use of a combination of the normalized surface storage volume, the median infiltration rate, and an estimate of specific yield for soils under the rain garden to a depth equal to the uppermost limiting layer. By use of the same criteria, in water year 2008, when the contributing drainage area to the prairie rain garden in clay was doubled, all four observed exceedences of the total storage capacity were predicted. The accuracy of the predictions of when the total storage capacity of the rain gardens would be exceeded indicates that by applying measurements of the appropriate soil properties to rain g

Direct effect of acid rain on leaf chlorophyll content of terrestrial plants in China.

PubMed

Du, Enzai; Dong, Dan; Zeng, Xuetong; Sun, Zhengzhong; Jiang, Xiaofei; de Vries, Wim

2017-12-15

Anthropogenic emissions of acid precursors in China have resulted in widespread acid rain since the 1980s. Although efforts have been made to assess the indirect, soil mediated ecological effects of acid rain, a systematic assessment of the direct foliage injury by acid rain across terrestrial plants is lacking. Leaf chlorophyll content is an important indicator of direct foliage damage and strongly related to plant productivity. We synthesized data from published literature on experiments of simulated acid rain, by directly exposing plants to acid solutions with varying pH levels, to assess the direct effect of acid rain on leaf chlorophyll content across 67 terrestrial plants in China. Our results indicate that acid rain substantially reduces leaf chlorophyll content by 6.71% per pH unit across the recorded plant species. The direct reduction of leaf chlorophyll content due to acid rain exposure showed no significant difference across calcicole, ubiquist or calcifuge species, implying that soil acidity preference does not influence the sensitivity to leaf injury by acid rain. On average, the direct effects of acid rain on leaf chlorophyll on trees, shrubs and herbs were comparable. The effects, however varied across functional groups and economic use types. Specifically, leaf chlorophyll content of deciduous species was more sensitive to acid rain in comparison to evergreen species. Moreover, vegetables and fruit trees were more sensitive to acid rain than other economically used plants. Our findings imply a potential production reduction and economic loss due to the direct foliage damage by acid rain. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparisons of Rain Estimates from Ground Radar and Satellite Over Mountainous Regions

NASA Technical Reports Server (NTRS)

Lin, Xin; Kidd, Chris; Tao, Jing; Barros, Ana

2016-01-01

A high-resolution rainfall product merging surface radar and an enhanced gauge network is used as a reference to examine two operational surface radar rainfall products over mountain areas. The two operational rainfall products include radar-only and conventional-gauge-corrected radar rainfall products. Statistics of rain occurrence and rain amount including their geographical, seasonal, and diurnal variations are examined using 3-year data. It is found that the three surface radar rainfall products in general agree well with one another over mountainous regions in terms of horizontal mean distributions of rain occurrence and rain amount. Frequency of rain occurrence and fraction of rain amount also indicate similar distribution patterns as a function of rain intensity. The diurnal signals of precipitation over mountain ridges are well captured and joint distributions of coincident raining samples indicate reasonable correlations during both summer and winter. Factors including undetected low-level precipitation, limited availability of gauges for correcting the Z-R relationship over the mountains, and radar beam blocking by mountains are clearly noticed in the two conventional radar rainfall products. Both radar-only and conventional-gauge-corrected radar rainfall products underestimate the rain occurrence and fraction of rain amount at intermediate and heavy rain intensities. Comparison of PR and TMI against a surface radar-only rainfall product indicates that the PR performs equally well with the high-resolution radar-only rainfall product over complex terrains at intermediate and heavy rain intensities during the summer and winter. TMI, on the other hand, requires improvement to retrieve wintertime precipitation over mountain areas.

Scattering by Artificial Wind and Rain Roughened Water Surfaces at Oblique Incidences

NASA Technical Reports Server (NTRS)

Craeye, C.; Sobieski, P. W.; Bliven, L. F.

1997-01-01

Rain affects wind retrievals from scatterometric measurements of the sea surface. To depict the additional roughness caused by rain on a wind driven surface, we use a ring-wave spectral model. This enables us to analyse the rain effect on K(u) band scatterometric observations from two laboratory experiments. Calculations based on the small perturbation method provide good simulation of scattering measurements for the rain-only case, whereas for combined wind and rain cases, the boundary perturbation method is appropriate.

Influence of simulated acidic rain on bacterial speck of tomato. [Lycopersicon esculentum Mill var. 'Chico III', Pseudomonas tomato

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bisessar, S.; Palmer, K.T.; Kuja, A.L.

Ambient rain in southern Ontario has a volume-weighted average pH of approximately 4.2. Tomato (Lycopersicon esculentum Mill var. 'Chico III') seedlings were exposed to simulated acidic rain in specially designed chambers. The inoculum of Pseudomonas tomato (Okabe) Alstatt, causal agent of bacterial speck, was sprayed on plants before or after exposure to acidic rain of pH 2.5, 3.5, and 4.5, as well as on plants not exposed to the simulated acidic rain. Speck symptoms (small, dark, brown spots with yellow halos) were found on all inoculated plants. Exposure of plants to simulted acidic rain inhibited speck development, but the inhibitionmore » was greater on plants exposed to acidic rain after inoculation. Spot necrosis, a typical response to acid rain, occurred on up to 15 to 20% of the leaf area on all tomato plants treated with acidic rain at pH 2.5. Plants alos showed a decrease in growth (height and fresh and dry weights) with an increase in rain acidity. Leaves injured by simulated acidic rain and examined histopathologically displayed cellular malformations including hyperplasia and hypertrophy. Pseudomonas tomato failed to grow on acidified King B medium or Difco nutrient broth adjusted to pH 3.5 or lower.« less

Rainfall estimation over oceans from scanning multichannel microwave radiometer and special sensor microwave/imager microwave data

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Dalu, G.; Liberti, G. L.; Nucciarone, J. J.; Suhasini, R.

1991-01-01

The brightness temperature (T sub b) measured at 37 GHz shows fairly strong emission from rain, and only slight effects caused by scattering by ice above the rain clouds. At frequencies below 37 GHz, were the fov is larger and the volume extinction coefficient is weaker, it is found that the observations do not yield appreciable additional information about rain. At 85 GHz (fov = 15 km), where the volume extinction is considerably larger, direct information about rain below the clouds is usually masked. Based on the above ideas, 37 GHz observations with a 30 km fov from SMMR and SSM/I are selected to develop an empirical method for the estimation of rain rate. In this method, the statistics of the observed T sub b's at 37 GHz in a rain storm are related to the rain rate statistics in that storm. The underestimation of rain rate, arising from the inability of the radiometer to respond sensitively to rain rate above a given threshold, is rectified in this technique with the aid of two parameters that depend on the total water vapor content in the atmosphere. The retrieved rain rates compare favorably with radar observations and monthly mean global maps of rain derived from this technique over the oceans.

Rainfall estimation over oceans from SMMR and SSM/I microwave data

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Dalu, G.; Liberti, G. L.; Nucciarone, J. J.; Suhasini, R.

1992-01-01

The brightness temperature (T sub b) measured at 37 GHz shows fairly strong emission from rain, and only slight effects caused by scattering by ice above the rain clouds. At frequencies below 37 GHz, where the FOV is larger and the volume extinction coefficient is weaker, it is found that the observations do not yield appreciable additional information about rain. At 85 GHz (FOV = 15 km), where the volume extinction is considerably larger, direct information about rain below the clouds is usually masked. Based on the above idea, 37 GHz observations with a 30 km FOV from SMMR and SSM/I are selected to develop an empirical method for the estimation of rain rate. In this method, the statistics of the observed T sub b's at 37 GHz in a rain storm are related to the rain rate statistics in that storm. The underestimation of rain rate, arising from the inability of the radiometer to respond sensitively to rain rate above a given threshold is rectified in this technique with the aid of two parameters that depend on the total water vapor content in the atmosphere. The retrieved rain rates compare favorably with radar observations and monthly mean global maps of rain derived from this technique over the oceans.

A TRMM Rainfall Estimation Method Applicable to Land Areas

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Iacovazzi, R.; Weinman, J.; Dalu, G.

1999-01-01

Methods developed to estimate rain rate on a footprint scale over land with the satellite-borne multispectral dual-polarization Special Sensor Microwave Imager (SSM/1) radiometer have met with limited success. Variability of surface emissivity on land and beam filling are commonly cited as the weaknesses of these methods. On the contrary, we contend a more significant reason for this lack of success is that the information content of spectral and polarization measurements of the SSM/I is limited. because of significant redundancy. As a result, the complex nature and vertical distribution C, of frozen and melting ice particles of different densities, sizes, and shapes cannot resolved satisfactorily. Extinction in the microwave region due to these complex particles can mask the extinction due to rain drops. Because of these reasons, theoretical models that attempt to retrieve rain rate do not succeed on a footprint scale. To illustrate the weakness of these models, as an example we can consider the brightness temperature measurement made by the radiometer in the 85 GHz channel (T85). Models indicate that T85 should be inversely related to the rain rate, because of scattering. However, rain rate derived from 15-minute rain gauges on land indicate that this is not true in a majority of footprints. This is also supported by the ship-borne radar observations of rain in the Tropical Oceans and Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA-COARE) region over the ocean. Based on these observations. we infer that theoretical models that attempt to retrieve rain rate do not succeed on a footprint scale. We do not follow the above path of rain retrieval on a footprint scale. Instead, we depend on the limited ability of the microwave radiometer to detect the presence of rain. This capability is useful to determine the rain area in a mesoscale region. We find in a given rain event that this rain area is closely related to the mesoscale-average rain rate. Based on this observation, in this study we have developed a method to estimate the mesoscale-average rain rate over land utilizing microwave radiometer data. Because of the high degree of geographic and seasonal variability in the nature and intensity of rain, this method requires some tuning with 15-minute rain gauge data on land. After tuning the method, it can be applied to an independent set of rain events that are close in time and space. We find that the mesoscale rain rates retrieved over the period of a month on land with this method shows a correlation of about 0.85 with respect to the surface rain-gauge observations. This mesoscale-average rain rate estimation method can be useful to extend the spatial and temporal coverage of the rainfall data provided by the Precipitation Radar on board the Tropical Rainfall Measuring Mission (TRMM) satellite.

Acid Rain: A Teacher's Guide. Activities for Grades 4 to 12.

ERIC Educational Resources Information Center

National Wildlife Federation, Washington, DC.

This guide on acid rain for elementary and secondary students is divided into three study areas: (1) What Causes Acid Rain; (2) What Problems Acid Rain Has Created; (3) How You and Your Students Can Help Combat Acid Rain. Each section presents background information and a series of lessons pertaining to the section topic. Activities include…

Acid Rain. Activities for Grades 4 to 12. A Teacher's Guide.

ERIC Educational Resources Information Center

Wood, David; Bryant, Jeannette

This teacher's guide on acid rain is divided into three study areas to explain: (1) what causes acid rain; (2) what problems acid rain has created; and (3) what teachers and students can do to help combat acid rain. Instructions for activities within the study areas include suggested grade levels, objectives, materials needed, and directions for…

Rain Rate Statistics in Southern New Mexico

NASA Technical Reports Server (NTRS)

Paulic, Frank J., Jr.; Horan, Stephen

1997-01-01

The methodology used in determining empirical rain-rate distributions for Southern New Mexico in the vicinity of White Sands APT site is discussed. The hardware and the software developed to extract rain rate from the rain accumulation data collected at White Sands APT site are described. The accuracy of Crane's Global Model for rain rate predictions is analyzed.

Application of Statistical Methods of Rain Rate Estimation to Data From The TRMM Precipitation Radar

NASA Technical Reports Server (NTRS)

Meneghini, R.; Jones, J. A.; Iguchi, T.; Okamoto, K.; Liao, L.; Busalacchi, Antonio J. (Technical Monitor)

2000-01-01

The TRMM Precipitation Radar is well suited to statistical methods in that the measurements over any given region are sparsely sampled in time. Moreover, the instantaneous rain rate estimates are often of limited accuracy at high rain rates because of attenuation effects and at light rain rates because of receiver sensitivity. For the estimation of the time-averaged rain characteristics over an area both errors are relevant. By enlarging the space-time region over which the data are collected, the sampling error can be reduced. However. the bias and distortion of the estimated rain distribution generally will remain if estimates at the high and low rain rates are not corrected. In this paper we use the TRMM PR data to investigate the behavior of 2 statistical methods the purpose of which is to estimate the rain rate over large space-time domains. Examination of large-scale rain characteristics provides a useful starting point. The high correlation between the mean and standard deviation of rain rate implies that the conditional distribution of this quantity can be approximated by a one-parameter distribution. This property is used to explore the behavior of the area-time-integral (ATI) methods where fractional area above a threshold is related to the mean rain rate. In the usual application of the ATI method a correlation is established between these quantities. However, if a particular form of the rain rate distribution is assumed and if the ratio of the mean to standard deviation is known, then not only the mean but the full distribution can be extracted from a measurement of fractional area above a threshold. The second method is an extension of this idea where the distribution is estimated from data over a range of rain rates chosen in an intermediate range where the effects of attenuation and poor sensitivity can be neglected. The advantage of estimating the distribution itself rather than the mean value is that it yields the fraction of rain contributed by the light and heavy rain rates. This is useful in estimating the fraction of rainfall contributed by the rain rates that go undetected by the radar. The results at high rain rates provide a cross-check on the usual attenuation correction methods that are applied at the highest resolution of the instrument.

Soak Up the Rain

EPA Pesticide Factsheets

Soak Up the Rain promotes green infrastructure practices such as rain barrels, rain gardens, permeable pavements and green roofs to reduce stormwater runoff and prevent water pollution while bringing about a broad range of community benefits.

Detecting Sulfuric and Nitric Acid Rain Stresses on Quercus glauca through Hyperspectral Responses

PubMed Central

Wang, Shanqian; Zhang, Xiuying; Ma, Yuandan; Li, Xinhui; Zhang, Xiaomin; Liu, Lei

2018-01-01

Acid rain, which has become one of the most severe global environmental issues, is detrimental to plant growth. However, effective methods for monitoring plant responses to acid rain stress are currently lacking. The hyperspectral technique provides a cost-effective and nondestructive way to diagnose acid rain stresses. Taking a widely distributed species (Quercus glauca) in Southern China as an example, this study aims to monitor the hyperspectral responses of Q. glauca to simulated sulfuric acid rain (SAR) and nitric acid rain (NAR). A total of 15 periods of leaf hyperspectral data under four pH levels of SAR and NAR were obtained during the experiment. The results showed that hyperspectral information could be used to distinguish plant responses under acid rain stress. An index (green peak area index, GPAI) was proposed to indicate acid rain stresses, based on the significantly variations in the region of 500–660 nm. Light acid rain (pH 4.5 SAR and NAR) promoted Q. glauca growth relative to the control groups (pH 5.6 SAR and NAR); moderate acid rain (pH 3.0 SAR) firstly promoted and then inhibited plant growth, while pH 3.0 NAR showed mild inhibitory effects during the experiment; and heavy acid rain (pH 2.0) significantly inhibited plant growth. Compared with NAR, SAR induced more serious damages to Q. glauca. These results could help monitor acid rain stress on plants on a regional scale using remote sensing techniques. PMID:29522488

Detecting Sulfuric and Nitric Acid Rain Stresses on Quercus glauca through Hyperspectral Responses.

PubMed

Wang, Shanqian; Zhang, Xiuying; Ma, Yuandan; Li, Xinhui; Cheng, Min; Zhang, Xiaomin; Liu, Lei

2018-03-09

Acid rain, which has become one of the most severe global environmental issues, is detrimental to plant growth. However, effective methods for monitoring plant responses to acid rain stress are currently lacking. The hyperspectral technique provides a cost-effective and nondestructive way to diagnose acid rain stresses. Taking a widely distributed species ( Quercus glauca ) in Southern China as an example, this study aims to monitor the hyperspectral responses of Q. glauca to simulated sulfuric acid rain (SAR) and nitric acid rain (NAR). A total of 15 periods of leaf hyperspectral data under four pH levels of SAR and NAR were obtained during the experiment. The results showed that hyperspectral information could be used to distinguish plant responses under acid rain stress. An index (green peak area index, GPAI) was proposed to indicate acid rain stresses, based on the significantly variations in the region of 500-660 nm. Light acid rain (pH 4.5 SAR and NAR) promoted Q. glauca growth relative to the control groups (pH 5.6 SAR and NAR); moderate acid rain (pH 3.0 SAR) firstly promoted and then inhibited plant growth, while pH 3.0 NAR showed mild inhibitory effects during the experiment; and heavy acid rain (pH 2.0) significantly inhibited plant growth. Compared with NAR, SAR induced more serious damages to Q. glauca . These results could help monitor acid rain stress on plants on a regional scale using remote sensing techniques.

[Effects of simulated acid rain on water physiological characteristics of Myrica rubra seedlings].

PubMed

Yaho, Zhao-bin; Jiang, Hong; Yu, Shu-quan; Lu, Mei-juan

2011-08-01

Taking the seedlings of typical subtropical economic tree species Myrica rubra in Zhejiang Province as test materials, a pot experiment was conducted to study their water physiological characteristics under effects of simulated acid rain (pH 2.5 and pH 4.0), with water (pH 5.6) as the control. Season, year, and acid rain all had significant effects on the photosynthetic rate (Pn). Among the treatments, the Pn had a greater difference in summer than in spring and autumn, and was higher in treatment acid rain (pH 4.0). Season, year, acid rain, and the interactions of season and year and of the three factors had significant effects on the stomata conductance (Gs), and also, the Gs had a greater difference among the treatments in summer than in spring and autumn. Acid rain had inhibitory effect on Gs. Season, year, acid rain, and the interactions of season and year and of season and acid rain affected the transpiration rate (Tr) significantly. Same as Pn and Gs, the Tr had a greater difference among the treatments in summer than in spring and autumn. Acid rain (pH 2.5) had the strongest inhibitory effect on Tr. Acid rain and the interactions of season and year and of season and acid rain had significant effects on the water use efficiency (WUE), and acid rain (pH 2.5) had definitely positive effect on the WUE.

Comparison of Instantaneous Frequency Scaling from Rain Attenuation and Optical Disdrometer Measurements at K/Q bands

NASA Technical Reports Server (NTRS)

Nessel, James; Zemba, Michael; Luini, Lorenzo; Riva, Carlo

2015-01-01

Rain attenuation is strongly dependent on the rain rate, but also on the rain drop size distribution (DSD). Typically, models utilize an average drop size distribution, such as those developed by Laws and Parsons, or Marshall and Palmer. However, individual rain events may possess drop size distributions which could be significantly different from the average and will impact, for example, fade mitigation techniques which utilize channel performance estimates from a signal at a different frequency. Therefore, a good understanding of the characteristics and variability of the raindrop size distribution is extremely important in predicting rain attenuation and instantaneous frequency scaling parameters on an event-toevent basis. Since June 2014, NASA Glenn Research Center (GRC) and the Politecnico di Milano (POLIMI) have measured the attenuation due to rain in Milan, Italy, on the 20/40 GHz beacon signal broadcast from the Alphasat TDP#5 Aldo Paraboni Q/V-band Payload. Concomitant with these measurements are the measurements of drop size distribution and rain rate utilizing a Thies Clima laser precipitation monitor (disdrometer). In this paper, we discuss the comparison of the predicted rain attenuation at 20 and 40 GHz derived from the drop size distribution data with the measured rain attenuation. The results are compared on statistical and real-time bases. We will investigate the performance of the rain attenuation model, instantaneous frequency scaling, and the distribution of the scaling factor. Further, seasonal rain characteristics will be analysed.

9-year distributions of rain intensities measured in Prague and their utilization in telecommunications

NASA Astrophysics Data System (ADS)

Kvicera, V.; Grabner, M.

2012-04-01

Experimental research in the Department of Frequency Engineering of the Czech Metrology Institute (CMI) in Prague, the Czech Republic, is focused on stability of received signals on terrestrial radio and optical communication paths. Hydrometeors (rain, snow, fog, hails) can cause serious attenuation of electromagnetic waves in the frequency bands above 10 GHz and the availability performances of terrestrial radio communication systems are seriously affected by heavy hydrometeors events. The rain intensity data is usually used for the calculations of attenuation due to rain on terrestrial radio links in accordance with either the relevant ITU-R Recommendation or other methods. Therefore, our experimental research is also focused on our own meteorological measurements in the vicinity of experimental radio and optical paths. The heated tipping-bucket rain gauge with the collector area of 500 cm2 and the rain amount per tip of 0.1 mm is used at CMI for the measurements of intensities of hydrometeors. The time of tips is recorded with uncertainty of 1 second. Hydrometeors intensity data obtained from January 2003 to December 2011 (9 years of observation) was statistically processed over the individual years. All the recorded individual hydrometeor events were compared with the concurrent meteorological conditions and were carefully categorized according to the types of individual hydrometeors, i.e. rain, rain with snow, rain with hails, snow, fog, fog with rain, fog with snow, and fog with rain and snow. The obtained cumulative distributions (CDs) of intensities of individual hydrometeors over 9 years of observation will be presented and compared with the CD of intensities of all hydrometeors together. The rain amounts were examined too. The obtained rain amounts for individual years and the average rain amounts for individual months over the 9-year period will be given. The obtained CD of average 1-minute rain intensities for the average year over the 9-year period of observation was used for the calculations of CDs of attenuation due to rain on terrestrial radio paths in accordance with the relevant recommendation of the ITU-R. The examples of the calculated CDs of attenuation due to rain will be presented for radio communication links with different path lengths working in different frequency bands. The obtained CDs can be used for the assessment of availability performances of terrestrial radio communication links in the climatic region where the rain intensities were measured. The examples will be given. Ministry of Education, Youth and Sports of the Czech Republic under the Project No. OC09076 supported the described work.

EFFECTS OF SIMULATED ACIDIC RAIN APPLIED ALONE AND IN COMBINATION WITH AMBIENT RAIN ON GROWTH AND YIELD OF FIELD-GROWN SNAP BEAN

EPA Science Inventory

Field-grown snap bean plants were treated with simulated acidic rain applied either alone or in combination with ambient rain and the effects on growth and yield were determined. In plots where ambient rain was excluded, a retractable canopy was activated to shield the crop. Four...

Discussions on the Design of the Pool Landscape in the Rain Garden Construction

NASA Astrophysics Data System (ADS)

Zou, Shuzhen; Zhu, Yirong; Wei, Chaojun; Tao, Biaohong

2018-03-01

With rapid urbanization, the environmental problems are becoming increasingly prominent and diversified ecological landscape designs consequently appear with the rain garden landscape design as a typical. Based on the introduction to rain garden ecological functions and in combination with domestic and international rain garden landscape design cases, this paper discussed the rain garden pool landscape design.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, Yun; Gong, Daoyi; Leung, Ruby

Long-term daily precipitation data from NCDC are used to investigate the changes of light rain events from 1973-2009 over North America, Europe and Asia. Results reveal that the trend of light rain events presents a remarkably diverse feature in different regions, while an overall decrease trend can be found over the continents in northern hemisphere. In North America, most of stations show a decrease trend for light rain on the annual basis but a decrease trend can also be found for moderate and heavy rain. The opposite trends are observed over the stations in Europe and the trend of lightmore » rain is not significant when averaged for all the stations. In Asia, especially East Asia, the light rain days show an overwhelming decrease trend with high spatial coherency. Meanwhile the moderate and heavy rain events (> 10 mm/day) have increased, suggesting a remarkable shift of precipitation from light to heavy rain in East Asia. While both the warming at a global scale and increased atmospheric aerosols due to air pollution at a regional scale (e.g. East Asia) may have affected the light rain changes, it remains a challenging task to quantitatively detect and separate the cause of light rain changes in different regions.« less

Effects of wind and rain on thermal responses of humans in a mildly cold environment.

PubMed

Yamane, Motoi; Oida, Yukio; Ohnishi, Norikazu; Matsumoto, Takaaki; Kitagawa, Kaoru

2010-05-01

The purpose of the present study was to clarify the effects of wind and rain on peripheral heat loss by non-exercising minimally clothed humans in a mildly cold environment. Seven healthy young male subjects wearing only shorts rested in a standing position for 20 min at an ambient temperature of 15 degrees C under three conditions: without exposure to wind or rain (CON), with exposure to wind (3 m/s) (WIND) and with exposure to wind (3 m/s) and rain (40 mm/h) (WIND + RAIN). Mean heat loss measured using a heat flux transducer was significantly greater in the subjects exposed to WIND + RAIN compared to those exposed to CON and WIND conditions (p < 0.01). Metabolic heat production was significantly greater under WIND + RAIN than under CON and WIND (p < 0.01). Decrease in heat storage was significantly larger at WIND + RAIN compared with CON and WIND (p < 0.01). Mean skin temperature was significantly lower under WIND + RAIN than under CON and WIND conditions (p < 0.01). These results indicate that peripheral heat loss significantly increases when humans are exposed to wind and rain for a short period (20 min) under a mildly cold condition.

Comparisons of Instantaneous TRMM Ground Validation and Satellite Rain Rate Estimates at Different Spatial Scales

NASA Technical Reports Server (NTRS)

Wolff, David B.; Fisher, Brad L.

2007-01-01

This study provides a comprehensive inter-comparison of instantaneous rain rates observed by the two rain sensors aboard the TRMM satellite with ground data from two regional sites established for long-term ground validation: Kwajalein Atoll and Melbourne, Florida. The satellite rain algorithms utilize remote observations of precipitation collected by the TRMM microwave imager (TMI) and the Precipitation Radar (PR) aboard the TRMM satellite. Three standard Level I1 rain products are generated from operational applications of the TMI, PR and Combined (COM) rain algorithms using rain information collected from the TMI and the PR along the orbital track of the TRMM satellite. In the first part of the study, 0.25 x 0.25 instantaneous rain rates obtained from the TRMM 3668 product were analyzed and compared to instantaneous GV rain rates gridded at a scale of 0.5deg x 0.5. In the second part of the study, TMI, PR, COM and GV rain rates were spatio-temporally matched and averaged at the scale of TMI footprint (- 150 sq km). This study covered a six-year period 1999-2004 and consisted of over 50,000 footprints for each GV site. In the first analysis our results showed that all of the respective rain rate estimates agree well, with some exceptions. The more salient differences were associated with heavy rain events in which one or more of the algorithms failed to properly retrieve these extreme events. Also, it appears that there is a preferred mode of precipitation for TMI rain rates at or near 2 mm/hr over the ocean. This mode was noted over ocean areas of Kwajalein and Melbourne and has been observed in TRMM tropical-global ocean areas as well.

Large-scale modeling of rain fields from a rain cell deterministic model

NASA Astrophysics Data System (ADS)

FéRal, Laurent; Sauvageot, Henri; Castanet, Laurent; Lemorton, JoëL.; Cornet, FréDéRic; Leconte, Katia

2006-04-01

A methodology to simulate two-dimensional rain rate fields at large scale (1000 × 1000 km2, the scale of a satellite telecommunication beam or a terrestrial fixed broadband wireless access network) is proposed. It relies on a rain rate field cellular decomposition. At small scale (˜20 × 20 km2), the rain field is split up into its macroscopic components, the rain cells, described by the Hybrid Cell (HYCELL) cellular model. At midscale (˜150 × 150 km2), the rain field results from the conglomeration of rain cells modeled by HYCELL. To account for the rain cell spatial distribution at midscale, the latter is modeled by a doubly aggregative isotropic random walk, the optimal parameterization of which is derived from radar observations at midscale. The extension of the simulation area from the midscale to the large scale (1000 × 1000 km2) requires the modeling of the weather frontal area. The latter is first modeled by a Gaussian field with anisotropic covariance function. The Gaussian field is then turned into a binary field, giving the large-scale locations over which it is raining. This transformation requires the definition of the rain occupation rate over large-scale areas. Its probability distribution is determined from observations by the French operational radar network ARAMIS. The coupling with the rain field modeling at midscale is immediate whenever the large-scale field is split up into midscale subareas. The rain field thus generated accounts for the local CDF at each point, defining a structure spatially correlated at small scale, midscale, and large scale. It is then suggested that this approach be used by system designers to evaluate diversity gain, terrestrial path attenuation, or slant path attenuation for different azimuth and elevation angle directions.

SSM/I Rain Retrievals Within a Unified All-Weather Ocean Algorithm

NASA Technical Reports Server (NTRS)

Wentz, Frank J.; Spencer, Roy W.

1996-01-01

A new method for the physical retrieval of rain rates from satellite microwave radiometers is presented and compared to two other rainfall climatologies derived from satellites. The method is part of a unified ocean parameter retrieval algorithm that is based on the fundamental principles of radiative transfer. The algorithm simultaneously finds near-surface wind speed W, columnar water vapor V, columnar cloud liquid water L, rain rate R, and effective radiating temperature T(sub U) for the upwelling radiation. The performance of the algorithm in the absence of rain is discussed in Wentz, and this paper focuses on the rain component of the algorithm. A particular strength of the unified algorithm is its ability to 'orthogonalize' the retrievals so that there is minimum cross-talk between the retrieved parameters. For example, comparisons of the retrieved water vapor with radiosonde observations show that there is very little correlation between the water vapor retrieval error and rain rate. For rain rates from 1 to 15 mm/h, the rms difference between the retrieved water vapor and the radiosonde value is 5 mm. A novel feature of the rain retrieval method is a beamfilling correction that is based upon the ratio of the retrieved liquid water absorption coefficients at 37 GHz and 19.35 GHz. This ratio decreases by about 40% when heavy and light rain co-exist within the SSM/I footprint as compared to the case of uniform rain. This correction has the effect of increasing the rain rate when the spectral ratio of the absorption coefficients is small. Even with this beamfilling correction, tropical rainfall is still unrealistically low when the freezing level in the tropics (approx. 5 km) is used to specify the rain layer thickness. We restore realism by reducing the assumed averaged tropical rain layer thickness to 3 km, thereby accounting for the existence of warm rain processes in which the rain layer does not extend to the freezing level. Global rain rates are produced for the 1991 through 1994 period from observations taken by microwave radiometers (SSM/I) that are aboard two polar-orbiting satellites. We find that approximately 6% of the SSM/I observations detect measurable rain rates (R greater than 0.2 mm/h). Zonal averages of the rain rates show the peak at the intertropical convergence zone (ITCZ) is quite narrow in meridional extent and varies from about 7 mm/day in the winter to a maximum 11 mm/day in the summer. Very low precipitation rates (less than 0.3 mm/day) are observed in those areas of subsidence influenced by the large semipermanent anticyclones. In general, these features are similar to those reported in previously published rain climatologies. However, significant differences do exists between our rain rates and those produced by Spencer. These differences seem to be related to non-precipitating cloud water.

Rain attenuation studies from radiometric and rain DSD measurements at two tropical locations

NASA Astrophysics Data System (ADS)

Halder, Tuhina; Adhikari, Arpita; Maitra, Animesh

2018-05-01

Efficient use of satellite communication in tropical regions demands proper characterization of rain attenuation, particularly, in view of the available popular propagation models which are mostly based on temperate climatic data. Thus rain attenuations at frequencies 22.234, 23.834 and 31.4/30 GHz over two tropical locations Kolkata (22.57°N, 88.36°E, India) and Belem (1.45°S, 48.49° W, Brazil), have been estimated for the year 2010 and 2011, respectively. The estimation has been done utilizing ground-based disdrometer observations and radiometric measurements over Earth-space path. The results show that rain attenuation estimations from radiometric data are reliable only at low rain rates (<30 mm/h). However, the rain attenuation estimations from disdrometer measurements show good agreement with the ITU-R model, even at high rain rates (upto100 mm/h). Despite having significant variability in terms of drop size distribution (DSD), the attenuation values calculated from DSD data (disdrometer measurements) at Kolkata and Belem differ a little for the rain rates below 30 mm/h. However, the attenuation values, obtained from radiometric measurements at the two places, show significant deviations ranging from 0.54 dB to 3.2 dB up to a rain rate of 30 mm/h, on account of different rain heights, mean atmospheric temperatures and climatology of the two locations.

Performance analysis of rain attenuation on earth-to-satellite microwave links design in Libya

NASA Astrophysics Data System (ADS)

Rafiqul Islam, Md; Hussein Budalal, Asma Ali; Habaebi, Mohamed H.; Badron, Khairayu; Fadzil Ismail, Ahmad

2017-11-01

Performances of earth-to-satellite microwave links operating in Ku, Ka, and V-bands are degraded by the environment and strongly attenuated by rain. Rain attenuation is the most significant consideration and challenge to design a reliable earth-to-satellite microwave links for these frequency bands. Hence, it is essential for satellite link designer to take into account rain fade margin accurately before system implementation. Rain rate is the main measured parameter to predict of rain attenuation. Rainfall statistical data measured and recorded in Libya for the period of 30 years are collected from 5 locations. The prediction methods require one minute integration time rain intensity. Therefore, collected data were analyzed and processed to convert into one-minute rain rate cumulative distribution in Libya. The model proposed by ITU-R is used to predict and investigate rain fade based on converted 1-minute rain rate data. Rain fade predicted at two locations are used for performance analysis in terms of link spectral efficiency and throughput. V-band downlink shows that 99.99% availability is possible in all the Southern part stations in Libya at 0.29 bps/Hz spectral efficiency and 20.74 Mbps throughput when 72 MHz transponder band width is used which is not feasible in Northern part. Results of this paper will be a very useful resource to design highly reliable earth-to-satellite communication links in Libya.

Characterization of tropical precipitation using drop size distribution and rain rate-radar reflectivity relation

NASA Astrophysics Data System (ADS)

Das, Saurabh; Maitra, Animesh

2018-04-01

Characterization of precipitation is important for proper interpretation of rain information from remotely sensed data. Rain attenuation and radar reflectivity (Z) depend directly on the drop size distribution (DSD). The relation between radar reflectivity/rain attenuation and rain rate (R) varies widely depending upon the origin, topography, and drop evolution mechanism and needs further understanding of the precipitation characteristics. The present work utilizes 2 years of concurrent measurements of DSD using a ground-based disdrometer at five diverse climatic conditions in Indian subcontinent and explores the possibility of rain classification based on microphysical characteristics of precipitation. It is observed that both gamma and lognormal distributions are performing almost similar for Indian region with a marginally better performance by one model than other depending upon the locations. It has also been found that shape-slope relationship of gamma distribution can be a good indicator of rain type. The Z-R relation, Z = ARb, is found to vary widely for different precipitation systems, with convective rain that has higher values of A than the stratiform rain for two locations, whereas the reverse is observed for the rest of the three locations. Further, the results indicate that the majority of rainfall (>50%) in Indian region is due to the convective rain although the occurrence time of convective rain is low (<10%).

Acid Rain: A Teaching Focus for the Intermediate Grades.

ERIC Educational Resources Information Center

Adams, Renee B.; Adams, Neil D.

1992-01-01

The study of acid rain provides ample opportunities for active, interdisciplinary learning. This article describes 12 hands-on activities designed to expand students' understanding of acid rain. Background information on acid rain is included. (LB)

Life in Tropical Rain Forests.

ERIC Educational Resources Information Center

NatureScope, 1989

1989-01-01

Discusses the diversity of rain forest life, the adaptations of rain forest plants and animals, and ways these organisms interact. Includes activities on canopy critters with a copyable sheet, rain forest revue, design a plant, and jungle sleuths. (RT)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanpied, G.D.

Trees of seedling apple (Malus domesticas borkh.) received 2.5 cm of artificial rain at pH 3.3 or 4.2, each with 0.4 or 1.4 mg Ca/liter of rain water during 7-hour periods. In the early summer period (June 19-July 10) artificial rain reduced Ca in apple leaves, but there were no significant differences due to pH or Ca concentration in the rain. Ca losses during rain treatment appeared to be recovered during 1 week holding periods after treatment. In the autumn period (September 25-October 16) the reduction in leaf Ca was greatest wih low pH, low Ca rain and least withmore » high pH, high Ca rain, which increased Ca in the leaves. K in the leaves was reduced more than Ca, but was not affected by pH or Ca in the rain during either period of observation.« less

A rain pixel recovery algorithm for videos with highly dynamic scenes.

PubMed

Jie Chen; Lap-Pui Chau

2014-03-01

Rain removal is a very useful and important technique in applications such as security surveillance and movie editing. Several rain removal algorithms have been proposed these years, where photometric, chromatic, and probabilistic properties of the rain have been exploited to detect and remove the rainy effect. Current methods generally work well with light rain and relatively static scenes, when dealing with heavier rainfall in dynamic scenes, these methods give very poor visual results. The proposed algorithm is based on motion segmentation of dynamic scene. After applying photometric and chromatic constraints for rain detection, rain removal filters are applied on pixels such that their dynamic property as well as motion occlusion clue are considered; both spatial and temporal informations are then adaptively exploited during rain pixel recovery. Results show that the proposed algorithm has a much better performance for rainy scenes with large motion than existing algorithms.

Effect of rain on Ku-band scatterometer wind measurements

NASA Technical Reports Server (NTRS)

Spencer, Michael; Shimada, Masanobu

1991-01-01

The impact of precipitation on scatterometer wind measurements is investigated. A model is developed which includes the effects of rain attenuation, rain backscatter, and storm horizontal structure. Rain attenuation is found to be the dominant error source at low radar incidence angles and high wind speeds. Volume backscatter from the rain-loaded atmosphere, however, is found to dominate for high incidence angles and low wind speeds.

Rain Splash Dispersal of Gibberella zeae Within Wheat Canopies in Ohio.

PubMed

Paul, P A; El-Allaf, S M; Lipps, P E; Madden, L V

2004-12-01

ABSTRACT Rain splash dispersal of Gibberella zeae, causal agent of Fusarium head blight of wheat, was investigated in field studies in Ohio between 2001 and 2003. Samplers placed at 0, 30, and 100 cm above the soil surface were used to collect rain splash in wheat fields with maize residue on the surface and fields with G. zeae-infested maize kernels. Rain splash was collected during separate rain episodes throughout the wheat-growing seasons. Aliquots of splashed rain were transferred to petri dishes containing Komada's selective medium, and G. zeae was identified based on colony and spore morphology. Dispersed spores were measured in CFU/ml. Intensity of splashed rain was highest at 100 cm and ranged from 0.2 to 10.2 mm h(-1), depending on incident rain intensity and sampler height. Spores were recovered from splash samples at all heights in both locations for all sampled rain events. Both macroconidia and ascospores were found based on microscopic examination of random samples of splashed rain. Spore density and spore flux density per rain episode ranged from 0.4 to 40.9 CFU cm(-2) and 0.4 to 84.8 CFU cm(-2) h(-1), respectively. Spore flux density was higher in fields with G. zeae-infested maize kernels than in fields with maize debris, and generally was higher at 0 and 30 cm than at 100 cm at both locations. However, on average, spore flux density was only 30% lower at 100 cm (height of wheat spikes) than at the other heights. The log of spore flux density was linearly related to the log of splashed rain intensity and the log of incident rain intensity. The regression slopes were not significantly affected by year, location, height, and their interactions, but the intercepts were significantly affected by both sampler height and location. Thus, our results show that spores of G. zeae were consistently splash dispersed to spike heights within wheat canopies, and splashed rain intensity and spore flux density could be predicted based on incident rain intensity in order to estimate inoculum dispersal within the wheat canopy.

Pollen selection under acid rain stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Y.

To investigate whether acid rain stress induces pollen selection in nature, three different approaches were used, based on the assumption that the response of pollen grains to acid rain is controlled by an acid sensitive gene product. Germination of pollen from homozygous and heterozygous individuals under acid rain stress was examined to detect any differences in rate of germination between populations of homogeneous and heterogeneous pollen grains. In vitro and in vivo bulked segregant analysis using RAPDs was used to search for differences in DNA constitution between the survivors of acid rain stressed and non-acid rain stressed pollen populations inmore » vitro and between the progenies of acid rain stressed and non-acid rain stressed populations during pollination, respectively. No evidence for the pollen selection under acid rain stress was obtained in any of the test systems. Inhibition of protein synthesis using cycloheximide led to significant reduction of tube elongation at 4 hr and had no effect on pollen germination at any time interval tested. Total proteins extracted from control and acid rain stressed pollen grain populations exhibited no differences. The reduction of corn pollen germination in vitro under acid rain stress was mainly due to pollen rupture. The present data indicates the reduction of pollen germination and tube growth under acid rain stress may be a physiological response rather than a genetic response. A simple, nontoxic, and effective method to separate germinated from ungerminated pollen grains has been developed using pollen from corn (Zea mays, L. cv. Pioneer 3747). The separated germinated pollen grains retained viability and continued tube growth when placed in culture medium.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golubev, A.; Balashov, Y.; Mavrin, S.

Washout coefficient Λ is widely used as a parameter in washout models. These models describes overall HTO washout with rain by a first-order kinetic equation, while washout coefficient Λ depends on the type of rain event and rain intensity and empirical parameters a, b. The washout coefficient is a macroscopic parameter and we have considered in this paper its relationship with a microscopic rate K of HTO isotopic exchange in atmospheric humidity and drops of rainwater. We have shown that the empirical parameters a, b can be represented through the rain event characteristics using the relationships of molecular impact rate,more » rain intensity and specific rain water content while washout coefficient Λ can be represented through the exchange rate K, rain intensity, raindrop diameter and terminal raindrop velocity.« less

What You Can Do to Soak Up the Rain

EPA Pesticide Factsheets

Take steps around your home and community to reduce stormwater runoff. Use rain barrels, disconnect/redirect downspouts, plant trees and rain gardens, use drywells and permeable pavers, and plant green roofs. Take action to soak up the rain.

Lessons from the Rain Forest.

ERIC Educational Resources Information Center

Phillips, Shelley

2002-01-01

Presents a first-grade art project after students learned about the rain forest and heard the story, "The Great Kapok Tree: A Tale of the Amazon Rain Forest" (Lynn Cherry). Explains that the students created pictures of the rain forest. (CMK)

Wind scatterometry with improved ambiguity selection and rain modeling

NASA Astrophysics Data System (ADS)

Draper, David Willis

Although generally accurate, the quality of SeaWinds on QuikSCAT scatterometer ocean vector winds is compromised by certain natural phenomena and retrieval algorithm limitations. This dissertation addresses three main contributors to scatterometer estimate error: poor ambiguity selection, estimate uncertainty at low wind speeds, and rain corruption. A quality assurance (QA) analysis performed on SeaWinds data suggests that about 5% of SeaWinds data contain ambiguity selection errors and that scatterometer estimation error is correlated with low wind speeds and rain events. Ambiguity selection errors are partly due to the "nudging" step (initialization from outside data). A sophisticated new non-nudging ambiguity selection approach produces generally more consistent wind than the nudging method in moderate wind conditions. The non-nudging method selects 93% of the same ambiguities as the nudged data, validating both techniques, and indicating that ambiguity selection can be accomplished without nudging. Variability at low wind speeds is analyzed using tower-mounted scatterometer data. According to theory, below a threshold wind speed, the wind fails to generate the surface roughness necessary for wind measurement. A simple analysis suggests the existence of the threshold in much of the tower-mounted scatterometer data. However, the backscatter does not "go to zero" beneath the threshold in an uncontrolled environment as theory suggests, but rather has a mean drop and higher variability below the threshold. Rain is the largest weather-related contributor to scatterometer error, affecting approximately 4% to 10% of SeaWinds data. A simple model formed via comparison of co-located TRMM PR and SeaWinds measurements characterizes the average effect of rain on SeaWinds backscatter. The model is generally accurate to within 3 dB over the tropics. The rain/wind backscatter model is used to simultaneously retrieve wind and rain from SeaWinds measurements. The simultaneous wind/rain (SWR) estimation procedure can improve wind estimates during rain, while providing a scatterometer-based rain rate estimate. SWR also affords improved rain flagging for low to moderate rain rates. QuikSCAT-retrieved rain rates correlate well with TRMM PR instantaneous measurements and TMI monthly rain averages. SeaWinds rain measurements can be used to supplement data from other rain-measuring instruments, filling spatial and temporal gaps in coverage.

Climatology of contribution-weighted tropical rain rates based on TRMM 3B42

NASA Astrophysics Data System (ADS)

Venugopal, V.; Wallace, J. M.

2016-10-01

The climatology of annual mean tropical rain rate is investigated based on merged Tropical Rainfall Measuring Mission (TRMM) 3B42 data. At 0.25° × 0.25° spatial resolution, and 3-hourly temporal resolution, half the rain is concentrated within only ˜1% of the area of the tropics at any given instant. When plotted as a function of logarithm of rain rate, the cumulative contribution of rate-ranked rain occurrences to the annual mean rainfall in each grid box is S shaped and its derivative, the contribution-weighted rain rate spectrum, is Gaussian shaped. The 50% intercept of the cumulative contribution R50 is almost equivalent to the contribution-weighted mean logarithmic rain rate RL¯ based on all significant rain occurrences. The spatial patterns of R50 and RL¯ are similar to those obtained by mapping the fraction of the annual accumulation explained by rain occurrences with rates above various specified thresholds. The geographical distribution of R50 confirms the existence of patterns noted in prior analyses based on TRMM precipitation radar data and reveals several previously unnoticed features.

Effects of melting layer on Ku-band signal depolarization

NASA Astrophysics Data System (ADS)

Sarkar, Thumree; Das, Saurabh; Maitra, Animesh

2014-09-01

Propagation effects on Ku-band over an earth-space path is carried out at Kolkata, India, a tropical location, by receiving a Ku-band signal with horizontal plane polarization transmitted from the geostationary satellite NSS-6 (at 95°E). The amplitude of co-polar attenuation has been monitored along with the measurements of rain rate, rain drop size distribution and height profile of rain rate. The cross-polar enhancement of the signal is also monitored by receiving the same signal in orthogonal direction with another identical receiver. The experimental observations are used to study the effect of melting layer on both co-polar attenuation and cross-polar enhancement for the rain events observed during 2012-2013. Melting layer is indicated by the bright band signature in vertical profile of rain rate. The ground based drop size measurements indicate that the stratiform rain has more number of small drops whereas convective rain composed of large rain drops. The results indicate that the depolarization due to melting layer is more dominant compared to that due to the drop deformation mechanism at low rain rates.

The Effect of Rain on Air-Water Gas Exchange

NASA Technical Reports Server (NTRS)

Ho, David T.; Bliven, Larry F.; Wanninkhof, Rik; Schlosser, Peter

1997-01-01

The relationship between gas transfer velocity and rain rate was investigated at NASA's Rain-Sea Interaction Facility (RSIF) using several SF, evasion experiments. During each experiment, a water tank below the rain simulator was supersaturated with SF6, a synthetic gas, and the gas transfer velocities were calculated from the measured decrease in SF6 concentration with time. The results from experiments with IS different rain rates (7 to 10 mm/h) and 1 of 2 drop sizes (2.8 or 4.2 mm diameter) confirm a significant and systematic enhancement of air-water gas exchange by rainfall. The gas transfer velocities derived from our experiment were related to the kinetic energy flux calculated from the rain rate and drop size. The relationship obtained for mono-dropsize rain at the RSIF was extrapolated to natural rain using the kinetic energy flux of natural rain calculated from the Marshall-Palmer raindrop size distribution. Results of laboratory experiments at RSIF were compared to field observations made during a tropical rainstorm in Miami, Florida and show good agreement between laboratory and field data.

Development of a large-scale, outdoor, ground-based test capability for evaluating the effect of rain on airfoil lift

NASA Technical Reports Server (NTRS)

Bezos, Gaudy M.; Campbell, Bryan A.

1993-01-01

A large-scale, outdoor, ground-based test capability for acquiring aerodynamic data in a simulated rain environment was developed at the Langley Aircraft Landing Dynamics Facility (ALDF) to assess the effect of heavy rain on airfoil performance. The ALDF test carriage was modified to transport a 10-ft-chord NACA 64210 wing section along a 3000-ft track at full-scale aircraft approach speeds. An overhead rain simulation system was constructed along a 525-ft section of the track with the capability of producing simulated rain fields of 2, 10, 30, and 40 in/hr. The facility modifications, the aerodynamic testing and rain simulation capability, the design and calibration of the rain simulation system, and the operational procedures developed to minimize the effect of wind on the simulated rain field and aerodynamic data are described in detail. The data acquisition and reduction processes are also presented along with sample force data illustrating the environmental effects on data accuracy and repeatability for the 'rain-off' test condition.

USGS Tracks Acid Rain

USGS Publications Warehouse

Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

1995-01-01

The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

Dust Rains Deliver Diverse Assemblages of Microorganisms to the Eastern Mediterranean

PubMed Central

Itani, Ghida Nouhad; Smith, Colin Andrew

2016-01-01

Dust rains may be particularly effective at delivering microorganisms, yet their biodiversities have been seldom examined. During 2011 and 2012 in Beirut, Lebanon, 16 of 21 collected rainfalls appeared dusty. Trajectory modelling of air mass origins was consistent with North African sources and at least one Southwest Asian source. As much as ~4 g particulate matter, ~20 μg DNA, and 50 million colony forming units were found deposited per square meter during rainfalls each lasting less than one day. Sequencing of 93 bacteria and 25 fungi cultured from rain samples revealed diverse bacterial phyla, both Gram positive and negative, and Ascomycota fungi. Denaturing Gradient Gel Electrophoresis of amplified 16S rDNA of 13 rains revealed distinct and diverse assemblages of bacteria. Dust rain 16S libraries yielded 131 sequences matching, in decreasing order of abundance, Betaproteobacteria, Alphaproteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, Cyanobacteria, Epsilonproteobacteria, Gammaproteobacteria, and Deltaproteobacteria. Clean rain 16S libraries yielded 33 sequences matching only Betaproteobacteria family Oxalobacteraceae. Microbial composition varied between dust rains, and more diverse and different microbes were found in dust rains than clean rains. These results show that dust rains deliver diverse communities of microorganisms that may be complex products of revived desert soil species and fertilized cloud species. PMID:26939571

Response of soybean seed germination to cadmium and acid rain.

PubMed

Liu, Ting Ting; Wu, Peng; Wang, Li Hong; Zhou, Qing

2011-12-01

Cadmium (Cd) pollution and acid rain are the main environmental issues, and they often occur in the same agricultural region. Nevertheless, up to now, little information on the combined pollution of Cd(2+) and acid rain action on crops were presented. Here, we investigated the combined effect of Cd(2+) and acid rain on the seed germination of soybean. The results indicated that the single treatment with the low level of Cd(2+) (0.18, 1.0, 3.0 mg L(-1)) or acid rain (pH ≥3.0) could not affect the seed germination of soybean, which was resulted in the increased activities of peroxidase and catalase. The single treatment with the high concentration of Cd(2+) (>6 mg L(-1)) or acid rain at pH 2.5 decreased the activities of peroxidase and catalase, damaged the cell membrane and then decreased the seed germination of soybean. Meanwhile, the same toxic effect was observed in the combined treatment with Cd(2+) and acid rain, and the combined treatment had more toxic effect than the single treatment with Cd(2+) or acid rain. Thus, the combined pollution of Cd(2+) and acid rain had more potential threat to the seed germination of soybean than the single pollution of Cd(2+) or acid rain.

The role of rain in dispersal of the primary inoculum of Plasmopara viticola.

PubMed

Rossi, Vittorio; Caffi, Tito

2012-02-01

Although primary infection of grapevines by Plasmopara viticola requires splash dispersal of inoculum from soil to leaves, little is known about the role of rain in primary inoculum dispersal. Distribution of rain splashes from soil to grapevine canopy was evaluated over 20 rain periods (0.2 to 64.2 mm of rain) with splash samplers placed within the canopy. Samplers at 40, 80, and 140 cm above the soil caught 4.4, 0.03, and 0.003 drops/cm(2) of sampler area, respectively. Drops caught at 40 and 80 cm (1.5 cm in diameter) were larger than drops at 140 cm (1.3 cm). Leaf coverage by splashed drops, total drop number, and drop size increased with an increase in the maximum intensity of rain (mm/h) during any rain period. Any rainfall led to infection in potted grapevines placed outside on leaf litter containing oospores, if the litter contained germinated oospores at the time of rain; infection severity was unrelated to rain amount or intensity. Results from vineyards also indicate that any rain can carry P. viticola inoculum from soil to leaves and should be considered a splash event in disease prediction systems. Sampling for early disease detection should focus on the lower canopy, where the probability of splash impact is greatest.

Dust Rains Deliver Diverse Assemblages of Microorganisms to the Eastern Mediterranean

NASA Astrophysics Data System (ADS)

Itani, Ghida Nouhad; Smith, Colin Andrew

2016-03-01

Dust rains may be particularly effective at delivering microorganisms, yet their biodiversities have been seldom examined. During 2011 and 2012 in Beirut, Lebanon, 16 of 21 collected rainfalls appeared dusty. Trajectory modelling of air mass origins was consistent with North African sources and at least one Southwest Asian source. As much as ~4 g particulate matter, ~20 μg DNA, and 50 million colony forming units were found deposited per square meter during rainfalls each lasting less than one day. Sequencing of 93 bacteria and 25 fungi cultured from rain samples revealed diverse bacterial phyla, both Gram positive and negative, and Ascomycota fungi. Denaturing Gradient Gel Electrophoresis of amplified 16S rDNA of 13 rains revealed distinct and diverse assemblages of bacteria. Dust rain 16S libraries yielded 131 sequences matching, in decreasing order of abundance, Betaproteobacteria, Alphaproteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, Cyanobacteria, Epsilonproteobacteria, Gammaproteobacteria, and Deltaproteobacteria. Clean rain 16S libraries yielded 33 sequences matching only Betaproteobacteria family Oxalobacteraceae. Microbial composition varied between dust rains, and more diverse and different microbes were found in dust rains than clean rains. These results show that dust rains deliver diverse communities of microorganisms that may be complex products of revived desert soil species and fertilized cloud species.

Data driven analysis of rain events: feature extraction, clustering, microphysical /macro physical relationship

NASA Astrophysics Data System (ADS)

Djallel Dilmi, Mohamed; Mallet, Cécile; Barthes, Laurent; Chazottes, Aymeric

2017-04-01

The study of rain time series records is mainly carried out using rainfall rate or rain accumulation parameters estimated on a fixed integration time (typically 1 min, 1 hour or 1 day). In this study we used the concept of rain event. In fact, the discrete and intermittent natures of rain processes make the definition of some features inadequate when defined on a fixed duration. Long integration times (hour, day) lead to mix rainy and clear air periods in the same sample. Small integration time (seconds, minutes) will lead to noisy data with a great sensibility to detector characteristics. The analysis on the whole rain event instead of individual short duration samples of a fixed duration allows to clarify relationships between features, in particular between macro physical and microphysical ones. This approach allows suppressing the intra-event variability partly due to measurement uncertainties and allows focusing on physical processes. An algorithm based on Genetic Algorithm (GA) and Self Organising Maps (SOM) is developed to obtain a parsimonious characterisation of rain events using a minimal set of variables. The use of self-organizing map (SOM) is justified by the fact that it allows to map a high dimensional data space in a two-dimensional space while preserving as much as possible the initial space topology in an unsupervised way. The obtained SOM allows providing the dependencies between variables and consequently removing redundant variables leading to a minimal subset of only five features (the event duration, the rain rate peak, the rain event depth, the event rain rate standard deviation and the absolute rain rate variation of order 0.5). To confirm relevance of the five selected features the corresponding SOM is analyzed. This analysis shows clearly the existence of relationships between features. It also shows the independence of the inter-event time (IETp) feature or the weak dependence of the Dry percentage in event (Dd%e) feature. This confirms that a rain time series can be considered by an alternation of independent rain event and no rain period. The five selected feature are used to perform a hierarchical clustering of the events. The well-known division between stratiform and convective events appears clearly. This classification into two classes is then refined in 5 fairly homogeneous subclasses. The data driven analysis performed on whole rain events instead of fixed length samples allows identifying strong relationships between macrophysics (based on rain rate) and microphysics (based on raindrops) features. We show that among the 5 identified subclasses some of them have specific microphysics characteristics. Obtaining information on microphysical characteristics of rainfall events from rain gauges measurement suggests many implications in development of the quantitative precipitation estimation (QPE), for the improvement of rain rate retrieval algorithm in remote sensing context.

Have Tropical Cyclones Been Feeding More Extreme Rainfall?

NASA Technical Reports Server (NTRS)

Lau, K.-M.; Zhou, Y. P.; Wu, H.-T.

2008-01-01

We have conducted a study of the relationship between tropical cyclone (TC) and extreme rain events using GPCP and TRMM rainfall data, and storm track data for July through November (JASON) in the North Atlantic (NAT) and the western North Pacific (WNP). Extreme rain events are defined in terms of percentile rainrate, and TC-rain by rainfall associated with a named TC. Results show that climatologically, 8% of rain events and 17% of the total rain amount in NAT are accounted by TCs, compared to 9% of rain events and 21% of rain amount in WNP. The fractional contribution of accumulated TC-rain to total rain, Omega, increases nearly linearly as a function of rainrate. Extending the analyses using GPCP pentad data for 1979-2005, and for the post-SSM/I period (1988-2005), we find that while there is no significant trend in the total JASON rainfall over NAT or WNP, there is a positive significant trend in heavy rain over both basins for the 1979-2005 period, but not for the post-SSM/I period. Trend analyses of Omega for both periods indicate that TCs have been feeding increasingly more to rainfall extremes in NAT, where the expansion of the warm pool area can explain slight more than 50% of the change in observed trend in total TC rainfall. In WNP, trend signals for Omega are mixed, and the long-term relationship between TC rain and warm pool areas are strongly influenced by interannual and interdecadal variability.

Visualization of soil-moisture change in response to precipitation within two rain gardens in Ohio

USGS Publications Warehouse

Dumouchelle, Denise H.; Darner, Robert A.

2014-01-01

Stormwater runoff in urban areas is increasingly being managed by means of a variety of treaments that reduce or delay runoff and promote more natural infiltration. One such treatment is a rain garden, which is built to detain runoff and allow for water infiltration and uptake by plants.Water flow into or out of a rain garden can be readily monitored with a variety of tools; however, observing the movement of water within the rain garden is less straightforward. Soil-moisture probes in combination with an automated interpolation procedure were used to document the infiltration of water into two rain gardens in Ohio. Animations show changes in soil moisture in the rain gardens during two precipitation events. At both sites, the animations demonstrate underutilization of the rain gardens.

Rain rate duration statistics derived from the Mid-Atlantic coast rain gauge network

NASA Technical Reports Server (NTRS)

Goldhirsh, Julius

1993-01-01

A rain gauge network comprised of 10 tipping bucket rain gauges located in the Mid-Atlantic coast of the United States has been in continuous operation since June 1, 1986. Rain rate distributions and estimated slant path fade distributions at 20 GHz and 30 GHz covering the first five year period were derived from the gauge network measurements, and these results were described by Goldhirsh. In this effort, rain rate time duration statistics are presented. The rain duration statistics are of interest for better understanding the physical nature of precipitation and to present a data base which may be used by modelers to convert to slant path fade duration statistics. Such statistics are important for better assessing optimal coding procedures over defined bandwidths.

Spread of acid rain over India

NASA Astrophysics Data System (ADS)

Khemani, L. T.; Momin, G. A.; Rao, P. S. Prakasa; Safai, P. D.; Singh, G.; Kapoor, R. K.

Rain water and aerosol samples were collected at a few locations representative of urban and non-urban regions in India. Also, rain water samples were collected in and around a coal-fired power plant. All the rain water and aerosol samples were analyzed for major chemical components along with pH. The rain water at all the places of measurement, except near the industrial sources, has been found to be alkaline and was characterized by the presence of excess cations, particularly by Ca 2+. The acid rain near the industrial sources was associated with excess anions, especially SO 42-. The atmospheric aerosols at all the places of measurement were found rich with basic components, suggesting that the alkaline soil dust and fly ash are responsible at present for preventing the spread of acid rain in India.

CR@BaSO4: an acid rain-indicating material.

PubMed

Gao, Hong-Wen; Xu, Xin-Hui

2011-12-28

The CR@BaSO(4) hybrid was synthesized, characterized and used as an acid rain-indicating (ARI) material. A painted ARI umbrella was discolored after exposure to simulated acid rain of pH 5 or less and returned to the initial color after the rain stopped. Such a functionalized material may make acid rain visual to remind people in real-time. This journal is © The Royal Society of Chemistry 2011

Rain, Snow, and Spring Runoff Revisited.

ERIC Educational Resources Information Center

Bohren, Craig F.

1995-01-01

Explores the theory behind the correlation between warm rain, rapid snowmelt, and the subsequent runoff using the concepts of enthalpy, thermal transfer, and energy transfer. Concludes that rapid runoff is not a consequence of rain per se but of the high humidities associated with the rain. (JRH)

The Effects of Rain Garden Size on Performance

EPA Science Inventory

The presentation discusses the effect of rain garden size on the hydrologic and pollutant removal performance of rain garden systems. The slides will summarize data from both the full-scale rain garden project associated with the permeable pavement parking lot as well as the pilo...

Comparisons of Instantaneous TRMM Ground Validation and Satellite Rain Rate Estimates at Different Spatial Scales

NASA Technical Reports Server (NTRS)

Wolff, David B.; Fisher, Brad L.

2007-01-01

This study provides a comprehensive inter-comparison of instantaneous rain estimates from the two rain sensors aboard the TRMM satellite with ground data from thee designated Ground Validation Sites: Kwajalein Atoll, Melbourne, Florida and Houston, Texas. The satellite rain retrievals utilize rain observations collected by the TRMM microwave imager (TMI) and the Precipitation Radar (PR) aboard the TRMM satellite. Three standard instantaneous rain products are the generated from the rain information retrieved from the satellite using the TMI, PR and Combined (COM) rain algorithms. The validation data set used in this study was obtained from instantaneous rain rates inferred from ground radars at each GV site. The first comparison used 0.5(sup 0) x 0.5(sup 0) gridded data obtained from the TRMM 3668 product, and similarly gridded GV data obtained from ground-based radars. The comparisons were made at the same spatial and temporal scales in order to eliminate sampling biases in our comparisons. An additional comparison was made by averaging rain rates for the PR, COM and GV estimates within each TMI footprint (approx. 150 square kilometers). For this analysis, unconditional mean rain rates from PR, COM and GV estimates were calculated within each TMI footprint that was observed within 100 km from the respective GV site (and also observed by the PR). This analysis used all the available matching data from the period 1999-2004, representing a sample size of over 50,000 footprints for each site. In the first analysis our results showed that all of the respective rain rate estimates agree well, with some exceptions. The more salient differences were associated with heavy rain events in which one or more of the algorithms failed to properly retrieve these extreme events. Also, it appears that there is a preferred mode of precipitation for TMI rain rates at or near 2 mm per hour over the ocean. This mode was noted over ocean areas of Melbourne, Florida and Kwajalein, Republic of the Marshall Islands, and is shown to exist in TRMM tropical-global ocean areas as well. Further research by algorithm developers is needed to explain or justify the seemingly errant observed probability distributions.

[Influence of simulated acid rain on nitrogen and phosphorus contents and their stoichiome-tric ratios of tea organs in a red soil region, China].

PubMed

Zhang, Yu Fei; Fang, Xiang Min; Chen, Fu Sheng; Zong, Ying Ying; Gu, Han Jiao; Hu, Xiao Fei

2017-04-18

A 25-year-old tea plantation in a typical red soil region was selected for an in situ simulated acid rain experiment treated by pH 4.5, 3.5, 2.5 and water (control, CK). Roots with different functions, leaves and twigs with different ages were collected to measure nitrogen (N) and phosphorus (P) contents in the third year after simulated acid rain treatment. The N/P and acid rain sensitivity coefficient of tea plant organs were also calculated. The results indicated that with the increase of acid rain intensity, the soil pH, NO 3 - -N and available P decreased, while the absorption root N content increased. Compared with the control, the N content in absorption root was increased by 32.9% under the treatment of pH 2.5. The P content in storage root significantly decreased with enhanced acid rain intensity, and the acid rain treatment significantly enhanced N/P of absorption root. Young and mature leaf N, P contents were not sensitive to different intensities of acid rain, but the mature leaf N/P was significantly increased under pH 3.5 treatment compared with the control. The effects of acid rain treatments differed with tea twig ages. Compared with the control, low intensity acid treatment (pH 4.5) significantly increased young twig N content and N/P, while no signi-ficant differences in old twig N content and N/P were observed among four acid rain treatments. Acid rain sensitivity coefficients of absorption root, young leaf and twig N contents were higher than that of storage root, old leaf and twig, respectively. And the storage root and leaf P had higher acid rain sensitivity coefficient than other tea organs. In sum, tea organs N content was sensitive to acid rain treatment, and moderate acid rain could increase young organ N content and N/P, and change the cycle and balance of N and P in tea plantation.

Detecting Trends in Tropical Rainfall Characteristics, 1979-2003

NASA Technical Reports Server (NTRS)

Lau, K. M.; Wu, H. T.

2006-01-01

From analyses of blended space-based and ground-based global rainfall data, we found increasing trends in the occurrence of extreme heavy and light rain events, coupled to a decreasing trend in moderate rain events in the tropics during 1979-2003. The trends are consistent with a shift in the large-scale circulation associated with a) a relatively uniform increase in warm rain over the tropical oceans, b) enhanced ice-phase rain over the near-equatorial oceans, and c) reduced mixed-phase rain over the tropical ocean and land regions. Due to the large compensation among different rain categories, the total tropical rainfall trend remained undetectable.

Development of one-minute rain-rate and rain-attenuation contour maps for satellite propagation system planning in a subtropical country: South Africa

NASA Astrophysics Data System (ADS)

Ojo, J. S.; Owolawi, P. A.

2014-10-01

Millimeter and microwave system design at higher frequencies require as input a 1-min rain-rate cumulative distribution function for estimating the level of degradation that can be encountered at such frequency bands. Owing to the lack of 1-min rain-rate data in South Africa and the availability of 5-min and hourly rainfall data, we have used rain-rate conversion models and the refined Moupfouma model to convert the available data into 1-min rain-rate statistics. The attenuation caused by these rain rates was predicted using the International Telecommunication Union (ITU) recommendations model. The Kriging interpolation method was used to draw contour maps over different percentages of time for spatial interpolation of rain-rate values into a regular grid in order to obtain a highly consistent and predictable inter-gauge rain-rate variation over South Africa. The present results will be useful for system designers of modern broadband wireless access (BWA) and high-density cell-based Ku/Ka, Q/V band satellite systems, over the desired area of coverage in order to determine the appropriate effective isotropically radiated power (EIRP) and receiver characteristics of this region.

The Study of Rain Specific Attenuation for the Prediction of Satellite Propagation in Malaysia

NASA Astrophysics Data System (ADS)

Mandeep, J. S.; Ng, Y. Y.; Abdullah, H.; Abdullah, M.

2010-06-01

Specific attenuation is the fundamental quantity in the calculation of rain attenuation for terrestrial path and slant paths representing as rain attenuation per unit distance (dB/km). Specific attenuation is an important element in developing the predicted rain attenuation model. This paper deals with the empirical determination of the power law coefficients which allow calculating the specific attenuation in dB/km from the knowledge of the rain rate in mm/h. The main purpose of the paper is to obtain the coefficients of k and α of power law relationship between specific attenuation. Three years (from 1st January 2006 until 31st December 2008) rain gauge and beacon data taken from USM, Nibong Tebal have been used to do the empirical procedure analysis of rain specific attenuation. The data presented are semi-empirical in nature. A year-to-year variation of the coefficients has been indicated and the empirical measured data was compared with ITU-R provided regression coefficient. The result indicated that the USM empirical measured data was significantly vary from ITU-R predicted value. Hence, ITU-R recommendation for regression coefficients of rain specific attenuation is not suitable for predicting rain attenuation at Malaysia.

Effects of sulfuric, nitric, and mixed acid rain on Chinese fir sapling growth in Southern China.

PubMed

Liu, Xin; Fu, Zhiyuan; Zhang, Bo; Zhai, Lu; Meng, Miaojing; Lin, Jie; Zhuang, Jiayao; Wang, G Geoff; Zhang, Jinchi

2018-09-30

The influence of acid rain on plant growth includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in root growth. In addition, the concentration of NO 3 - in acid rain increases along with the rapid growth of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 1:0, 5:1, 1:1, 1:5 and 0:1, on Chinese fir sapling growth from March 2015 to April 2016. Results showed that Chinese fir sapling height growth rate (HGR) and basal diameter growth rate (DGR) decreased as acid rain pH decreased, and also decreased as the percentage of NO 3 - increased in acid rain. Acid rain pH significantly decreased the Chlorophyll a (Chla) and Chlorophyll b (Chlb) content, and Chla and Chlb contents with acid rain S/N 1:5 were significantly lower than those with S/N 1:0 at pH 2.5. The chlorophyll fluorescence parameters, maximal efficiency of Photosystem II photochemistry (Fv/Fm) and non-photochemical quenching coefficient (NPQ), with most acid rain treatments were significantly lower than those with CK treatments. Root activities first increased and then decreased as acid rain pH decreased, when acid rain S/N ratios were 1:1, 1:5 and 0:1. Redundancy discriminant analysis (RDA) showed that the Chinese fir DGR and HGR had positive correlations with Chla, Chlb, Fv/Fm ratio, root activity, catalase and superoxide dismutase activities in roots under the stress of acid rain with different pH and S/N ratios. The structural equation modelling (SEM) results showed that acid rain NO 3 - concentration and pH had stronger direct effects on Chinese fir sapling HGR and DGR, and the direct effects of acid rain NO 3 - concentration and pH on HGR were lower than those on DGR. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect the sustainable development of monoculture Chinese fir plantations in southern China. Copyright © 2018. Published by Elsevier Inc.

40 CFR 72.85 - Permit reopenings.

Code of Federal Regulations, 2013 CFR

2013-07-01

... REGULATION Permit Revisions § 72.85 Permit reopenings. (a) The permitting authority shall reopen an Acid Rain permit for cause whenever: (1) Any additional requirement under the Acid Rain Program becomes applicable... revoked to assure compliance with Acid Rain Program requirements. (b) In reopening an Acid Rain permit for...

40 CFR 72.85 - Permit reopenings.

Code of Federal Regulations, 2014 CFR

2014-07-01

... REGULATION Permit Revisions § 72.85 Permit reopenings. (a) The permitting authority shall reopen an Acid Rain permit for cause whenever: (1) Any additional requirement under the Acid Rain Program becomes applicable... revoked to assure compliance with Acid Rain Program requirements. (b) In reopening an Acid Rain permit for...

40 CFR 72.85 - Permit reopenings.

Code of Federal Regulations, 2012 CFR

2012-07-01

... REGULATION Permit Revisions § 72.85 Permit reopenings. (a) The permitting authority shall reopen an Acid Rain permit for cause whenever: (1) Any additional requirement under the Acid Rain Program becomes applicable... revoked to assure compliance with Acid Rain Program requirements. (b) In reopening an Acid Rain permit for...

40 CFR 72.85 - Permit reopenings.

Code of Federal Regulations, 2011 CFR

2011-07-01

... REGULATION Permit Revisions § 72.85 Permit reopenings. (a) The permitting authority shall reopen an Acid Rain permit for cause whenever: (1) Any additional requirement under the Acid Rain Program becomes applicable... revoked to assure compliance with Acid Rain Program requirements. (b) In reopening an Acid Rain permit for...

40 CFR 72.85 - Permit reopenings.

Code of Federal Regulations, 2010 CFR

2010-07-01

... REGULATION Permit Revisions § 72.85 Permit reopenings. (a) The permitting authority shall reopen an Acid Rain permit for cause whenever: (1) Any additional requirement under the Acid Rain Program becomes applicable... revoked to assure compliance with Acid Rain Program requirements. (b) In reopening an Acid Rain permit for...

Variation of rain intensity and drop size distribution with General Weather Patterns (GWL)

NASA Astrophysics Data System (ADS)

Ghada, Wael; Buras, Allan; Lüpke, Marvin; Menzel, Annette

2017-04-01

Short-duration rainfall extremes may cause flash floods in certain catchments (e.g. cities or fast responding watersheds) and pose a great risk to affected communities. In order to predict their occurrence under future climate change scenarios, their link to atmospheric circulation patterns needs to be well understood. We used a comprehensive data set of meteorological data (temperature, rain gauge precipitation) and precipitation spectra measured by a disdrometer (OTT PARSIVEL) between October 2008 and June 2010 at Freising, southern Germany. For the 21 months of the study period, we integrated the disdrometer spectra over intervals of 10 minutes to correspond to the temporal resolution of the weather station data and discarded measurements with air temperatures below 0°C. Daily General Weather Patterns ("Großwetterlagen", GWL) were downloaded from the website of the German Meteorological Service. Out of the 29 GWL, 14 were included in the analysis for which we had at least 12 rain events during our study period. For the definition of a rain event, we tested different lengths of minimum inter-event times and chose 30 min as a good compromise between number and length of resulting events; rain events started when more than 0.001 mm/h (sensitivity of the disdrometer) were recorded. The length of the rain events ranged between 10 min and 28 h (median 130 min) with the maximum rain intensity recorded being 134 mm/h on 24-07-2009. Seasonal differences were identified for rain event average intensities and maximum intensities per event. The influence of GWL on rain properties such as rain intensity and drop size distribution per time step and per event was investigated based on the above mentioned rain event definition. Pairwise Wilcoxon-tests revealed that higher rain intensity and larger drops were associated with the GWL "Low over the British Isles" (TB), whereas low rain intensities and less drops per interval were associated with the GWL "High over Central Europe" (HM). "Trough over Central Europe" (TRM) was linked to smaller drops and "High Scandinavia-Iceland, Trough C. Europe" (HNFZ) had fewer drops per time step when compared to other GWL types. We also investigated the intra-event behavior regarding fluctuations in rain intensity, rain drop counts, and drop size distribution with time. When combined with predictions of circulation patterns, our analysis provides a detailed insight into the characteristics of rain events under different future climate scenarios, but definitively an extended measurement period and more measurement locations are needed for validation.

Effective application of optical sensing technology for sustainable liquid level sensing and rainfall measurement

NASA Astrophysics Data System (ADS)

Afzal, Muhammad Hassan Bin

2015-05-01

Rainfall measurement is performed on regular basis to facilitate effectively the weather stations and local inhabitants. Different types of rain gauges are available with different measuring principle for rainfall measurement. In this research work, a novel optical rain sensor is designed, which precisely calculate the rainfall level according to rainfall intensity. This proposed optical rain sensor model introduced in this paper, which is basically designed for remote sensing of rainfall and it designated as R-ORMS (Remote Optical Rainfall Measurement sensor). This sensor is combination of some improved method of tipping bucket rain gauge and most of the optical hydreon rain sensor's principle. This optical sensor can detect the starting time and ending time of rain, rain intensity and rainfall level. An infrared beam from Light Emitting Diode (LED) through powerful convex lens can accurately determines the diameter of each rain drops by total internal reflection principle. Calculations of these accumulative results determine the rain intensity and rainfall level. Accurate rainfall level is determined by internal optical LED based sensor which is embedded in bucket wall. This internal sensor is also following the total internal reflection (TIR) principle and the Fresnel's law. This is an entirely novel design of optical sensing principle based rain sensor and also suitable for remote sensing rainfall level. The performance of this proposed sensor has been comprehensively compared with other sensors with similar attributes and it showed better and sustainable result. Future related works have been proposed at the end of this paper, to provide improved and enhanced performance of proposed novel rain sensor.

Application of a Threshold Method to Airborne-Spaceborne Attenuating-Wavelength Radars for the Estimation of Space-Time Rain-Rate Statistics.

NASA Astrophysics Data System (ADS)

Meneghini, Robert

1998-09-01

A method is proposed for estimating the area-average rain-rate distribution from attenuating-wavelength spaceborne or airborne radar data. Because highly attenuated radar returns yield unreliable estimates of the rain rate, these are eliminated by means of a proxy variable, Q, derived from the apparent radar reflectivity factors and a power law relating the attenuation coefficient and the reflectivity factor. In determining the probability distribution function of areawide rain rates, the elimination of attenuated measurements at high rain rates and the loss of data at light rain rates, because of low signal-to-noise ratios, leads to truncation of the distribution at the low and high ends. To estimate it over all rain rates, a lognormal distribution is assumed, the parameters of which are obtained from a nonlinear least squares fit to the truncated distribution. Implementation of this type of threshold method depends on the method used in estimating the high-resolution rain-rate estimates (e.g., either the standard Z-R or the Hitschfeld-Bordan estimate) and on the type of rain-rate estimate (either point or path averaged). To test the method, measured drop size distributions are used to characterize the rain along the radar beam. Comparisons with the standard single-threshold method or with the sample mean, taken over the high-resolution estimates, show that the present method usually provides more accurate determinations of the area-averaged rain rate if the values of the threshold parameter, QT, are chosen in the range from 0.2 to 0.4.

A Method to Retrieve Rainfall Rate Over Land from TRMM Microwave Imager Observations

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Lau, William K. M. (Technical Monitor)

2002-01-01

Over tropical land regions, rain rate maxima in mesoscale convective systems revealed by the Precipitation Radar (PR) flown on the Tropical Rainfall Measuring Mission (TRMM) satellite are found to correspond to thunderstorms, i.e., Cbs. These Cbs are reflected as minima in the 85 GHz brightness temperature, T85, observed by the TRMM Microwave Imager (TMI) radiometer. Because the magnitude of TMI observations do not discriminate satisfactorily convective and stratiform rain, we developed here a different TMI discrimination method. In this method, two types of Cbs, strong and weak, are inferred from the Laplacian of T85 at minima. Then, to retrieve rain rate, where T85 is less than 270 K, a weak (background) rain rate is deduced using T85 observations. Furthermore, over a circular area of 10 km radius centered at the location of each T85 minimum, an additional Cb component of rain rate is added to the background rain rate. This Cb component of rain rate is estimated with the help of (T19-T37) and T85 observations. Initially, our algorithm is calibrated with the PR rain rate measurements from 20 MCS rain events. After calibration, this method is applied to TMI data taken from several tropical land regions. With the help of the PR observations, we show that the spatial distribution and intensity of rain rate over land estimated from our algorithm are better than those given by the current TMI-Version-5 Algorithm. For this reason, our algorithm may be used to improve the current state of rain retrievals on land.

40 CFR 72.63 - Administrative record.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.63 Administrative record. (a... Rain permit or denial of an Acid Rain permit. The administrative record will contain: (1) The permit... permit or denial of a draft permit; (7) The Acid Rain permit; and (8) Any response to public comments...

Acid Rain: What We Must Do.

ERIC Educational Resources Information Center

Gorham, Eville

1983-01-01

Addresses questions about the nature, source, and history of acid rain. In addition, discusses the questions: Why is acid rain a problem? Is acid rain getting worse? What is the threat of further problems? Concludes that it is time to act on the problem and recommends an appropriate course of action. (JN)

40 CFR 72.50 - General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... REGULATION Acid Rain Permit Contents § 72.50 General. (a) Each Acid Rain permit (including any draft or proposed Acid Rain permit) will contain the following elements in a format prescribed by the Administrator: (1) All elements required for a complete Acid Rain permit application under § 72.31 of this part, as...

40 CFR 76.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 17 2013-07-01 2013-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

40 CFR 76.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

40 CFR 72.63 - Administrative record.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.63 Administrative record. (a... Rain permit or denial of an Acid Rain permit. The administrative record will contain: (1) The permit... permit or denial of a draft permit; (7) The Acid Rain permit; and (8) Any response to public comments...

40 CFR 72.50 - General.

Code of Federal Regulations, 2014 CFR

2014-07-01

... REGULATION Acid Rain Permit Contents § 72.50 General. (a) Each Acid Rain permit (including any draft or proposed Acid Rain permit) will contain the following elements in a format prescribed by the Administrator: (1) All elements required for a complete Acid Rain permit application under § 72.31 of this part, as...

40 CFR 76.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 17 2014-07-01 2014-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

40 CFR 72.50 - General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... REGULATION Acid Rain Permit Contents § 72.50 General. (a) Each Acid Rain permit (including any draft or proposed Acid Rain permit) will contain the following elements in a format prescribed by the Administrator: (1) All elements required for a complete Acid Rain permit application under § 72.31 of this part, as...

40 CFR 72.63 - Administrative record.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.63 Administrative record. (a... Rain permit or denial of an Acid Rain permit. The administrative record will contain: (1) The permit... permit or denial of a draft permit; (7) The Acid Rain permit; and (8) Any response to public comments...

40 CFR 72.50 - General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... REGULATION Acid Rain Permit Contents § 72.50 General. (a) Each Acid Rain permit (including any draft or proposed Acid Rain permit) will contain the following elements in a format prescribed by the Administrator: (1) All elements required for a complete Acid Rain permit application under § 72.31 of this part, as...

40 CFR 72.50 - General.

Code of Federal Regulations, 2012 CFR

2012-07-01

... REGULATION Acid Rain Permit Contents § 72.50 General. (a) Each Acid Rain permit (including any draft or proposed Acid Rain permit) will contain the following elements in a format prescribed by the Administrator: (1) All elements required for a complete Acid Rain permit application under § 72.31 of this part, as...

40 CFR 76.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

40 CFR 72.63 - Administrative record.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.63 Administrative record. (a... Rain permit or denial of an Acid Rain permit. The administrative record will contain: (1) The permit... permit or denial of a draft permit; (7) The Acid Rain permit; and (8) Any response to public comments...

40 CFR 76.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

40 CFR 72.63 - Administrative record.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.63 Administrative record. (a... Rain permit or denial of an Acid Rain permit. The administrative record will contain: (1) The permit... permit or denial of a draft permit; (7) The Acid Rain permit; and (8) Any response to public comments...

The mixing of rain with near-surface water

Treesearch

Dennis F. Houk

1976-01-01

Rain experiments were run with various temperature differences between the warm rain and the cool receiving water. The rain intensities were uniform and the raindrop sizes were usually uniform (2.2 mm, 3.6 mm, and 5.5 mm diameter drops). Two drop size distributions were also used.

Carbon speciation at the air-sea interface during rain

NASA Astrophysics Data System (ADS)

McGillis, Wade; Hsueh, Diana; Takeshita, Yui; Donham, Emily; Markowitz, Michele; Turk, Daniela; Martz, Todd; Price, Nicole; Langdon, Chris; Najjar, Raymond; Herrmann, Maria; Sutton, Adrienne; Loose, Brice; Paine, Julia; Zappa, Christopher

2015-04-01

This investigation demonstrates the surface ocean dilution during rain events on the ocean and quantifies the lowering of surface pCO2 affecting the air-sea exchange of carbon dioxide. Surface salinity was measured during rain events in Puerto Rico, the Florida Keys, East Coast USA, Panama, and the Palmyra Atoll. End-member analysis is used to determine the subsequent surface ocean carbonate speciation. Surface ocean carbonate chemistry was measured during rain events to verify any approximations made. The physical processes during rain (cold, fresh water intrusion and buoyancy, surface waves and shear, microscale mixing) are described. The role of rain on surface mixing, biogeochemistry, and air-sea gas exchange will be discussed.

The area-time-integral technique to estimate convective rain volumes over areas applied to satellite data - A preliminary investigation

NASA Technical Reports Server (NTRS)

Doneaud, Andre A.; Miller, James R., Jr.; Johnson, L. Ronald; Vonder Haar, Thomas H.; Laybe, Patrick

1987-01-01

The use of the area-time-integral (ATI) technique, based only on satellite data, to estimate convective rain volume over a moving target is examined. The technique is based on the correlation between the radar echo area coverage integrated over the lifetime of the storm and the radar estimated rain volume. The processing of the GOES and radar data collected in 1981 is described. The radar and satellite parameters for six convective clusters from storm events occurring on June 12 and July 2, 1981 are analyzed and compared in terms of time steps and cluster lifetimes. Rain volume is calculated by first using the regression analysis to generate the regression equation used to obtain the ATI; the ATI versus rain volume relation is then employed to compute rain volume. The data reveal that the ATI technique using satellite data is applicable to the calculation of rain volume.

Acid rain stimulation of Lake Michigan phytoplankton growth

USGS Publications Warehouse

Manny, Bruce A.; Fahnenstiel, G.L.; Gardner, W.S.

1987-01-01

Three laboratory experiments demonstrated that additions of rainwater to epilimnetic lake water collected in southeastern Lake Michigan stimulated chlorophyll a production more than did additions of reagent-grade water during incubations of 12 to 20 d. Chlorophyll a production did not begin until 3–5 d after the rain and lake water were mixed. The stimulation caused by additions of rain acidified to pH 3.0 was greater than that caused by additions of untreated rain (pH 4.0–4.5). Our results support the following hypotheses: (1) Acid rain stimulates the growth of phytoplankton in lake water; (2) phosphorus in rain appears to be the factor causing this stimulation. We conclude that acid rain may accelerate the growth of epilimnetic phytoplankton in Lake Michigan (and other similar lakes) during stratification when other sources of bioavailable phosphorus to the epilimnion are limited

Automatic single-image-based rain streaks removal via image decomposition.

PubMed

Kang, Li-Wei; Lin, Chia-Wen; Fu, Yu-Hsiang

2012-04-01

Rain removal from a video is a challenging problem and has been recently investigated extensively. Nevertheless, the problem of rain removal from a single image was rarely studied in the literature, where no temporal information among successive images can be exploited, making the problem very challenging. In this paper, we propose a single-image-based rain removal framework via properly formulating rain removal as an image decomposition problem based on morphological component analysis. Instead of directly applying a conventional image decomposition technique, the proposed method first decomposes an image into the low- and high-frequency (HF) parts using a bilateral filter. The HF part is then decomposed into a "rain component" and a "nonrain component" by performing dictionary learning and sparse coding. As a result, the rain component can be successfully removed from the image while preserving most original image details. Experimental results demonstrate the efficacy of the proposed algorithm.

The potential influence of rain on airfoil performance

NASA Technical Reports Server (NTRS)

Dunham, R. Earl, Jr.

1987-01-01

The potential influence of heavy rain on airfoil performance is discussed. Experimental methods for evaluating rain effects are reviewed. Important scaling considerations for extrapolating model data are presented. It is shown that considerable additional effort, both analytical and experimental, is necessary to understand the degree of hazard associated with flight operations in rain.

High Impact Weather Associated with a Predecessor Rain Event Over Misawa Air Base

DTIC Science & Technology

2012-03-01

1  1.  Tropical Storms and Predecessor Rain Events...34  B.  MISAWA STORM EVENT ..........................................................................45  C.  NAGASAKI...through 1200 UTC 24 September 2011 (green line), shaded rain events PRE( STORM ) on left(right) with max 24 h rain period shaded in red (After http

No Rain, No Gain

ERIC Educational Resources Information Center

Perna, Mark C.

2005-01-01

Marketing is like the rain. Some people are quickly aware of it, while others take repeated and consistent drops for quite an extended period of time before they take action. Building on the marketing principles discussed in previous issues, the next key principle to smart marketing is the "Rain Effect." The Rain Effect is the use of consistent…

Create a Rain Forest in the Gym.

ERIC Educational Resources Information Center

Kane, Karen

1995-01-01

Describes a creative interdisciplinary program for K-3 students that involves setting up a rain forest in the gymnasium to teach students gymnastic skills in the context of the Amazon rain forest. The paper describes how to set up the rain forest and teach a variety of classes. Rainforest resources are included. (SM)

40 CFR 76.9 - Permit application and compliance plans.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.9 Permit application and... complete Acid Rain permit application (or, if the unit is covered by an Acid Rain permit, a complete permit... specify one or more other Acid Rain compliance options for NOX in accordance with the requirements of this...

76 FR 71559 - Acid Rain Program: Notice of Annual Adjustment Factors for Excess Emissions Penalty

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-18

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9494-6] Acid Rain Program: Notice of Annual Adjustment... annual adjustment factors for excess emissions penalty. SUMMARY: The Acid Rain Program under title IV of... emissions for sources that do not meet their annual Acid Rain emissions limitations. This notice states the...

78 FR 64496 - Acid Rain Program: Notice of Annual Adjustment Factors for Excess Emissions Penalty

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-29

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9902-14-OAR] Acid Rain Program: Notice of Annual Adjustment... annual adjustment factors for excess emissions penalty. SUMMARY: The Acid Rain Program under title IV of... emissions for sources that do not meet their annual Acid Rain emissions limitations. This notice states the...

Acid Rain Study Guide.

ERIC Educational Resources Information Center

Hunger, Carolyn; And Others

Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

40 CFR 76.9 - Permit application and compliance plans.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.9 Permit application and... complete Acid Rain permit application (or, if the unit is covered by an Acid Rain permit, a complete permit... specify one or more other Acid Rain compliance options for NOX in accordance with the requirements of this...

40 CFR 76.9 - Permit application and compliance plans.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.9 Permit application and... complete Acid Rain permit application (or, if the unit is covered by an Acid Rain permit, a complete permit... or specify one or more other Acid Rain compliance options for NOX in accordance with the requirements...

40 CFR 76.9 - Permit application and compliance plans.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.9 Permit application and... complete Acid Rain permit application (or, if the unit is covered by an Acid Rain permit, a complete permit... specify one or more other Acid Rain compliance options for NOX in accordance with the requirements of this...

The Acid Rain Reader.

ERIC Educational Resources Information Center

Stubbs, Harriett S.; And Others

A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

40 CFR 76.9 - Permit application and compliance plans.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.9 Permit application and... complete Acid Rain permit application (or, if the unit is covered by an Acid Rain permit, a complete permit... or specify one or more other Acid Rain compliance options for NOX in accordance with the requirements...

SULFURIC ACID RAIN EFFECTS ON CROP YIELD AND FOLIAR INJURY

EPA Science Inventory

A study was undertaken to determine the relative sensitivity of major U.S. crops to sulfuric acid rain. Plants were grown under controlled environmental conditions and exposed to simulated acid rain of three sulfuric acid concentrations (pH 3.0, 3.5, 4.0) or to a control rain (pH...

Dual-polarization characteristics of the radar ocean return in the presence of rain

NASA Technical Reports Server (NTRS)

Meneghini, R.; Kumagai, H.; Kozu, T.

1992-01-01

Experimental data are presented on the polarimetric and dual-wavelength characteristics of the ocean surface in the presence of rain. To explain a portion of the variability observed in scatter plots under rain conditions, a storm model is used that incorporates measured drop size distributions. The fairly large variability indicates that effects of drop size distribution and the presence of partially melted particles can introduce a significant error in the estimate of attenuation. This effect is especially significant in the case of a 10-GHz radar under high rain rates. A surface reference method at this frequency will tend to overestimate the rain attenuation unless melting layer attenuation is properly taken into account. Observations of the cross-polarization return in stratiform rain over an ocean surface show three distinct components. Two of these correspond to aspherical, nonaligned particles in the melting layer seen in the direct and mirror-image returns. The remaining part depends both on the off-nadir depolarization by the surface and on the rain medium. A possible mechanism for this latter effect is the bistatic scattering from the rain to the surface.

Rain Volume Estimation over Areas Using Satellite and Radar Data

NASA Technical Reports Server (NTRS)

Doneaud, A. A.; Miller, J. R., Jr.; Johnson, L. R.; Vonderhaar, T. H.; Laybe, P.

1984-01-01

The application of satellite data to a recently developed radar technique used to estimate convective rain volumes over areas on a dry environment (the northern Great Plains) is discussed. The area time integral technique (ATI) provides a means of estimating total rain volumes over fixed and floating target areas of the order of 1,000 to 100,000 km(2) for clusters lasting 40 min. The basis of the method is the existence of a strong correlation between the area coverage integrated over the lifetime of the storm (ATI) and the rain volume. One key element in this technique is that it does not require the consideration of the structure of the radar intensities inside the area coverage to generate rain volumes, but only considers the rain event per se. This fact might reduce or eliminate some sources of error in applying the technique to satellite data. The second key element is that the ATI once determined can be converted to total rain volume by using a constant factor (average rain rate) for a given locale.

Effects and mechanism of acid rain on plant chloroplast ATP synthase.

PubMed

Sun, Jingwen; Hu, Huiqing; Li, Yueli; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2016-09-01

Acid rain can directly or indirectly affect plant physiological functions, especially photosynthesis. The enzyme ATP synthase is the key in photosynthetic energy conversion, and thus, it affects plant photosynthesis. To clarify the mechanism by which acid rain affects photosynthesis, we studied the effects of acid rain on plant growth, photosynthesis, chloroplast ATP synthase activity and gene expression, chloroplast ultrastructure, intracellular H(+) level, and water content of rice seedlings. Acid rain at pH 4.5 remained the chloroplast structure unchanged but increased the expression of six chloroplast ATP synthase subunits, promoted chloroplast ATP synthase activity, and increased photosynthesis and plant growth. Acid rain at pH 4.0 or less decreased leaf water content, destroyed chloroplast structure, inhibited the expression of six chloroplast ATP synthase subunits, decreased chloroplast ATP synthase activity, and reduced photosynthesis and plant growth. In conclusion, acid rain affected the chloroplast ultrastructure, chloroplast ATPase transcription and activity, and P n by changing the acidity in the cells, and thus influencing the plant growth and development. Finally, the effects of simulated acid rain on the test indices were found to be dose-dependent.

Geochemical and stable isotope characteristics of urban heavy rain in the downtown of Tokyo, Japan

NASA Astrophysics Data System (ADS)

Uchiyama, Ryunosuke; Okochi, Hiroshi; Ogata, Hiroko; Katsumi, Naoya; Asai, Daisuke; Nakano, Takanori

2017-09-01

In order to make clear the impact of air pollution on the formation of sudden and locally-distributed heavy rain in urban area (hereafter Urban Heavy Rain: UHR), we analyzed inorganic ion concentration and stable isotope ratio of water (δD and δ18O) in rainwater. Rainwater samples were collected in Shinjuku, which is a representative downtown of Tokyo, Japan, during four years from October 2012 to December 2015. The concentration and wet deposition fluxes of acidic components (H+, NH4+, NO3-, and nss-SO42 -) in UHR were especially higher than those in other types of rain events, i.e. normal rain, typhoon heavy rain, and frontal heavy rain. UHR had distinctly lower stable isotope ratios than those in other urban rains with same rainfall amount and summer precipitation systems. There was a high negative correlation between δ18O and the distances from the sampling point to the formation area of UHR within 10 km, while there were high positive correlations between δ18O and the concentration of acidic components in UHR. These findings indicate that UHR could effectively scavenge acidic substances within cloud and suggest the use of stable isotope ratios as tracers of an urban heavy rain's water and in-cloud scavenging process.

Study on the relationship between meteorological conditions and acid rain in mid-eastern Fujian.

PubMed

Lin, C C; Liu, J X; Cai, Y Y; Li, B L; Wang, Z L; Chen, B B

2009-08-01

Based on the acid rain observation data and the contemporaneous historical synoptic charts of Mid-Eastern Fujian during the period of 1991 to 2003, we analyzed the distribution characteristics of acid rain in different seasons, weather types, precipitation grades and wind directions. The results showed that the acid pollution in Mid-Eastern Fujian was still serious. In winter, the precipitation pH value was 4.79, and the acid rain frequency was 60.62% which was twice higher than that in summer. The pH value of warm shear-type precipitation at 850 hPa was 4.79. Nearly half of these precipitations had the problems of acid rain pollution. The acid rain frequency of the inverted trough type was only 26.11% which was the lowest one in all types. There was no marked difference of the acid rain distribution characteristics between ahead-of-trough and behind-the-trough. The precipitation pH values of the five grades were lower than 5.30 and the acid rain frequency changed as an inverted U shape with the increasing of the rainfall. The pH values of precipitations in the eight wind directions were generally below 5.20, and the acid rain frequencies were about 40%.

Pollen resistance to water in 80 angiosperm species: flower structures protect rain-susceptible pollen.

PubMed

Mao, Yun-Yun; Huang, Shuang-Quan

2009-08-01

Flowers exhibit adaptive responses to biotic and abiotic factors. It remains unclear whether pollen susceptibility to rain damage plays a role in the evolution of floral form. We investigated flower performance in rain and compared pollen longevity in dry conditions, pure water and solutions with different sucrose concentrations in 80 flowering species from 46 families with diverse floral shapes and pollination modes. A pollen viability test showed that pollen longevity in all studied species was greatly reduced by wetting. We found that pollen of species with complete protection by flower structures was susceptible to water damage and a high proportion of resistant pollen occurred in unprotected species. Flowers whose structures expose pollen to rain may also reduce rain damage through temporal patterns of pollen presentation. This prediction was supported by our direct measurement of pollen presentation duration on rainy days. Our observations showed that variation in pollen performance in water was associated with differences in floral forms. Water-resistant pollen and extended pollen presentation duration were favored by selection via rain contact in species in which pollen was not protected from rain. These findings support the functional hypothesis that flower structures protect susceptible pollen from rain, demonstrating that rain acts as a force shaping floral form.

Micro-Physical characterisation of Convective & Stratiform Rainfall at Tropics

NASA Astrophysics Data System (ADS)

Sreekanth, T. S.

Large Micro-Physical characterisation of Convective & Stratiform Rainfall at Tropics begin{center} begin{center} Sreekanth T S*, Suby Symon*, G. Mohan Kumar (1) , and V Sasi Kumar (2) *Centre for Earth Science Studies, Akkulam, Thiruvananthapuram (1) D-330, Swathi Nagar, West Fort, Thiruvananthapuram 695023 (2) 32. NCC Nagar, Peroorkada, Thiruvananthapuram ABSTRACT Micro-physical parameters of rainfall such as rain drop size & fall speed distribution, mass weighted mean diameter, Total no. of rain drops, Normalisation parameters for rain intensity, maximum & minimum drop diameter from different rain intensity ranges, from both stratiform and convective rain events were analysed. Convective -Stratiform classification was done by the method followed by Testud et al (2001) and as an additional information electrical behaviour of clouds from Atmospheric Electric Field Mill was also used. Events which cannot be included in both types are termed as 'mixed precipitation' and identified separately. For the three years 2011, 2012 & 2013, rain events from both convective & stratiform origin are identified from three seasons viz Pre-Monsoon (March-May), Monsoon (June-September) and Post-Monsoon (October-December). Micro-physical characterisation was done for each rain events and analysed. Ground based and radar observations were made and classification of stratiform and convective rainfall was done by the method followed by Testud et al (2001). Radar bright band and non bright band analysis was done for confimation of stratifom and convective rain respectievely. Atmospheric electric field data from electric field mill is also used for confirmation of convection during convective events. Statistical analyses revealed that the standard deviation of rain drop size in higher rain rates are higher than in lower rain rates. Normalised drop size distribution is ploted for selected events from both forms. Inter relations between various precipitation parameters were analysed in three seasons.

Combined effects of lanthanum (III) chloride and acid rain on photosynthetic parameters in rice.

PubMed

Wang, Lihong; Wang, Wen; Zhou, Qing; Huang, Xiaohua

2014-10-01

Rare earth elements (REEs) pollution and acid rain are environmental issues, and their deleterious effects on plants attract worldwide attention. These two issues exist simultaneously in many regions, especially in some rice-growing areas. However, little is known about the combined effects of REEs and acid rain on plants. Here, the combined effects of lanthanum chloride (LaCl3), one type of REE salt, and acid rain on photosynthesis in rice were investigated. We showed that the combined treatment of 81.6 μM LaCl3 and acid rain at pH 4.5 increased net photosynthetic rate (Pn), stomatic conductance (Gs), intercellular CO2 concentration (Ci), Hill reaction activity (HRA), apparent quantum yield (AQY) and carboxylation efficiency (CE) in rice. The combined treatment of 81.6 μM LaCl3 and acid rain at pH 3.5 began to behave toxic effects on photosynthesis (decreasing Pn, Gs, HRA, AQY and CE, and increasing Ci), and the maximally toxic effects were observed in the combined treatment of 2449.0 μM LaCl3 and acid rain at pH 2.5. Moreover, the combined effects of LaCl3 and acid rain on photosynthesis in rice depended on the growth stage of rice, with the maximal effects occurring at the booting stage. Furthermore, the combined treatment of high-concentration LaCl3 and low-pH acid rain had more serious effects on photosynthesis in rice than LaCl3 or acid rain treatment alone. Finally, the combined effect of LaCl3 and acid rain on Pn in rice resulted from the changes in stomatic (Gs, Ci) and non-stomatic (HRA, AQY and CE) factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Implications of Warm Rain in Shallow Cumulus and Congestus Clouds for Large-Scale Circulations

NASA Astrophysics Data System (ADS)

Nuijens, Louise; Emanuel, Kerry; Masunaga, Hirohiko; L'Ecuyer, Tristan

2017-11-01

Space-borne observations reveal that 20-40% of marine convective clouds below the freezing level produce rain. In this paper we speculate what the prevalence of warm rain might imply for convection and large-scale circulations over tropical oceans. We present results using a two-column radiative-convective model of hydrostatic, nonlinear flow on a non-rotating sphere, with parameterized convection and radiation, and review ongoing efforts in high-resolution modeling and observations of warm rain. The model experiments investigate the response of convection and circulation to sea surface temperature (SST) gradients between the columns and to changes in a parameter that controls the conversion of cloud condensate to rain. Convection over the cold ocean collapses to a shallow mode with tops near 850 hPa, but a congestus mode with tops near 600 hPa can develop at small SST differences when warm rain formation is more efficient. Here, interactive radiation and the response of the circulation are crucial: along with congestus a deeper moist layer develops, which leads to less low-level radiative cooling, a smaller buoyancy gradient between the columns, and therefore a weaker circulation and less subsidence over the cold ocean. The congestus mode is accompanied with more surface precipitation in the subsiding column and less surface precipitation in the deep convecting column. For the shallow mode over colder oceans, circulations also weaken with more efficient warm rain formation, but only marginally. Here, more warm rain reduces convective tops and the boundary layer depth—similar to Large-Eddy Simulation (LES) studies—which reduces the integrated buoyancy gradient. Elucidating the impact of warm rain can benefit from large-domain high-resolution simulations and observations. Parameterizations of warm rain may be constrained through collocated cloud and rain profiling from ground, and concurrent changes in convection and rain in subsiding and convecting branches of circulations may be revealed from a collocation of space-borne sensors, including the Global Precipitation Measurement (GPM) and upcoming Aeolus missions.

Combined effects of simulated acid rain and lanthanum chloride on chloroplast structure and functional elements in rice.

PubMed

Hu, Huiqing; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2016-05-01

Acid rain and rare earth element (REE) pollution exist simultaneously in many agricultural regions. However, how REE pollution and acid rain affect plant growth in combination remains largely unknown. In this study, the combined effects of simulated acid rain and lanthanum chloride (LaCl3) on chloroplast morphology, chloroplast ultrastructure, functional element contents, chlorophyll content, and the net photosynthetic rate (P n) in rice (Oryza sativa) were investigated by simulating acid rain and rare earth pollution. Under the combined treatment of simulated acid rain at pH 4.5 and 0.08 mM LaCl3, the chloroplast membrane was smooth, proteins on this membrane were uniform, chloroplast structure was integrated, and the thylakoids were orderly arranged, and simulated acid rain and LaCl3 exhibited a mild antagonistic effect; the Mg, Ca, Mn contents, the chlorophyll content, and the P n increased under this combined treatment, with a synergistic effect of simulated acid rain and LaCl3. Under other combined treatments of simulated acid rain and LaCl3, the chloroplast membrane surface was uneven, a clear "hole" was observed on the surface of chloroplasts, and the thylakoids were dissolved and loose; and the P n and contents of functional elements (P, Mg, K, Ca, Mn, Fe, Ni, Cu, Zn and Mo) and chlorophyll decreased. Under these combined treatments, simulated acid rain and LaCl3 exhibited a synergistic effect. Based on the above results, a model of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis was established in order to reveal the combined effects on plant photosynthesis, especially on the photosynthetic organelle-chloroplast. Our results would provide some references for further understanding the mechanism of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis.

Comparative effects of simulated acid rain of different ratios of SO42- to NO3- on fine root in subtropical plantation of China.

PubMed

Liu, Xin; Zhao, Wenrui; Meng, Miaojing; Fu, Zhiyuan; Xu, Linhao; Zha, Yan; Yue, Jianmin; Zhang, Shuifeng; Zhang, Jinchi

2018-03-15

The influence of acid rain on forest trees includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in fine-root growth. In addition, the concentration of NO 3 - in acid rain increases with the rapidly growing of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 5:1 (S), 1:1 (SN) and 1:5 (N), on fine-root growth from March 2015 to February 2016. Results showed that fine roots were more sensitive to the effects of acid rain than soils in the short-term. Both soil pH and fine root biomass (FRB) significantly decreased as acid rain pH decreased, and also decreased with the percentage of NO 3 - increased in acid rain. Acid rain pH significantly influenced soil total carbon and available potassium in summer. Higher acidity level (pH=2.5), especially of the N treatments, had the strongest inhibitory impact on soil microbial activity after summer. The structural equation modelling results showed that acid rain S/N ratio and pH had stronger direct effects on FRB than indirect effects via changed soil and fine root properties. Fine-root element contents and antioxidant enzymes activities were significantly affected by acid rain S/N ratio and pH during most seasons. Fine-root Al ion content, Ca/Al, Mg/Al ratios and catalase activity were used as better indicators than soil parameters for evaluating the effects of different acid rain S/N ratios and pH on forests. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect fine-root growth in subtropical forests of China. Copyright © 2017. Published by Elsevier B.V.

Humid tropical rain forest has expanded into eucalypt forest and savanna over the last 50 years

PubMed Central

Tng, David Y P; Murphy, Brett P; Weber, Ellen; Sanders, Gregor; Williamson, Grant J; Kemp, Jeanette; Bowman, David M J S

2012-01-01

Tropical rain forest expansion and savanna woody vegetation thickening appear to be a global trend, but there remains uncertainty about whether there is a common set of global drivers. Using geographic information techniques, we analyzed aerial photography of five areas in the humid tropics of northeastern Queensland, Australia, taken in the 1950s and 2008, to determine if changes in rain forest extent match those reported for the Australian monsoon tropics using similar techniques. Mapping of the 1950s aerial photography showed that of the combined study area (64,430 ha), 63% was classified as eucalypt forests/woodland and 37% as rain forest. Our mapping revealed that although most boundaries remained stable, there was a net increase of 732 ha of the original rain forest area over the study period, and negligible conversion of rain forest to eucalypt forest/woodland. Statistical modeling, controlling for spatial autocorrelation, indicated distance from preexisting rain forest as the strongest determinant of rain forest expansion. Margin extension had a mean rate across the five sites of 0.6 m per decade. Expansion was greater in tall open forest types but also occurred in shorter, more flammable woodland vegetation types. No correlations were detected with other local variables (aspect, elevation, geology, topography, drainage). Using a geographically weighted mean rate of rain forest margin extension across the whole region, we predict that over 25% of tall open forest (a forest type of high conservation significance) would still remain after 2000 years of rain forest expansion. This slow replacement is due to the convoluted nature of the rain forest boundary and the irregular shape of the tall open forest patches. Our analyses point to the increased concentration of atmospheric CO2 as the most likely global driver of indiscriminate rain forest expansion occurring in northeastern Australia, by increasing tree growth and thereby overriding the effects of fire disturbance. PMID:22408724

Particle transport patterns of short-distance soil erosion by wind-driven rain, rain and wind

NASA Astrophysics Data System (ADS)

Marzen, Miriam; Iserloh, Thomas; de Lima, João L. M. P.; Ries, Johannes B.

2015-04-01

Short distance erosion of soil surface material is one of the big question marks in soil erosion studies. The exact measurement of short-distance transported soil particles, prior to the occurrence of overland flow, is a challenge to soil erosion science due to the particular requirements of the experimental setup and test procedure. To approach a quantification of amount and distance of each type of transport, we applied an especially developed multiple-gutter system installed inside the Trier Portable Wind and Rainfall Simulator (PWRS). We measured the amount and travel distance of soil particles detached and transported by raindrops (splash), wind-driven rain (splash-saltation and splash-drift) and wind (saltation). The test setup included three different erosion agents (rain/ wind-driven rain/ wind), two substrates (sandy/ loamy), three surface structures (grain roughness/ rills lengthwise/ rills transversal) and three slope angles (0°/+7°/-7°). The results present detailed transport patterns of the three erosion agents under the varying soil and surface conditions up to a distance of 1.6 m. Under the applied rain intensity and wind velocity, wind-driven rain splash generates the highest erosion. The erodibility and travel distance of the two substrates depend on the erosion agent. The total erosion is slightly higher for the slope angle -7° (downslope), but for wind-driven rain splash, the inclination is not a relevant factor. The effect of surface structures (rills) changes with traveling distance. The wind driven rain splash generates a much higher amount of erosion and a further travel distance of the particles due to the combined action of wind and rain. The wind-driven rain factor appears to be much more significant than the other factors. The study highlights the effects of different erosion agents and surface parameters on short-distance particle transport and the powerful impact of wind-driven rain on soil erosion.

Long-term effects of the rain exposure shortly after the atomic bombings in Hiroshima and Nagasaki.

PubMed

Sakata, Ritsu; Grant, Eric J; Furukawa, Kyoji; Misumi, Munechika; Cullings, Harry; Ozasa, Kotaro; Shore, Roy E

2014-12-01

The "black rain" that fell after the atomic bombings of Hiroshima and Nagasaki has been generally believed to contain radioactive materials. During 1949-1961 the Atomic Bomb Casualty Commission conducted surveys that included a query about exposure to the rain that fell a short time after the bombings. This article presents the first report of those data in relation to possible adverse health outcomes. This study looked at Life Span Study subjects who were in either city at the time of bombing and had an estimated direct radiation dose from the bombs (n = 86,609). The mortality data from 1950-2005 and cancer incidence data from 1958-2005 were used. Excess relative risks (ERRs) of subjects who were exposed to rain compared to those who reported no rain exposure were calculated using a Poisson regression model. In Hiroshima 11,661 subjects (20%) reported that they were exposed to rain, while in Nagasaki only 733 subjects (2.6%) reported rain exposure. To avoid outcome dependent biases (i.e., recall of exposure after a health outcome has already occurred), the primary analyses were based on events that occurred during 1962-2005. No significant risks due to rain exposure were observed for death due to all causes, all solid cancer or leukemia in Hiroshima. In Nagasaki there was no significantly elevated rain exposure-associated risks for 1962-2005, however, for 1950-2005 there was a weak association for all-cause mortality (ERR = 0.08; 95% confidence interval 0.00006, 0.17; P = 0.05). For incidence of solid cancer and leukemia, no significantly elevated rain exposure risks were observed in either city. These results failed to show deleterious health effects from rain exposure. While these data represent the most extensive set of systematically collected data on rain exposure of the atomic bomb survivors, they are limited by substantial uncertainties regarding exposures and missing individual data, so cautious interpretation is advised.

TRMM-observed summer warm rain over the tropical and subtropical Pacific Ocean: Characteristics and regional differences

NASA Astrophysics Data System (ADS)

Qin, Fang; Fu, Yunfei

2016-06-01

Based on the merged measurements from the TRMM Precipitation Radar and Visible and Infrared Scanner, refined characteristics (intensity, frequency, vertical structure, and diurnal variation) and regional differences of the warm rain over the tropical and subtropical Pacific Ocean (40ffiS-40ffiN, 120ffiE-70ffiW) in boreal summer are investigated for the period 1998-2012. The results reveal that three warm rain types (phased, pure, and mixed) exist over these regions. The phased warm rain, which occurs during the developing or declining stage of precipitation weather systems, is located over the central to western Intertropical Convergence Zone, South Pacific Convergence Zone, and Northwest Pacific. Its occurrence frequency peaks at midnight and minimizes during daytime with a 5.5-km maximum echo top. The frequency of this warm rain type is about 2.2%, and it contributes to 40% of the regional total rainfall. The pure warm rain is characterized by typical stable precipitation with an echo top lower than 4 km, and mostly occurs in Southeast Pacific. Although its frequency is less than 1.3%, this type of warm rain accounts for 95% of the regional total rainfall. Its occurrence peaks before dawn and it usually disappears in the afternoon. For the mixed warm rain, some may develop into deep convective precipitation, while most are similar to those of the pure type. The mixed warm rain is mainly located over the ocean east of Hawaii. Its frequency is 1.2%, but this type of warm rain could contribute to 80% of the regional total rainfall. The results also uncover that the mixed and pure types occur over the regions where SST ranges from 295 to 299 K, accompanied by relatively strong downdrafts at 500 hPa. Both the mixed and pure warm rains happen in a more unstable atmosphere, compared with the phased warm rain.

Rain attenuation statistics over millimeter wave bands in South Korea

NASA Astrophysics Data System (ADS)

Shrestha, Sujan; Choi, Dong-You

2017-01-01

Rain induced degradations are significant for terrestrial microwave links operating at frequencies higher than 10 GHz. Paper presents analyses done on rain attenuation and rainfall data for three years between 2013 till 2015, in 3.2 km experimental link of 38 GHz and 0.1 km link at 75 GHz. The less link distance is maintained for 75 GHz operating frequency in order to have better recording of propagation effect as such attenuation induced by rain. OTT Parsivel is used for collection of rain rate database which show rain rate of about 50 mm/h and attenuation values of 20.89 and 28.55 dB are obtained at 0.01% of the time for vertical polarization under 38 and 75 GHz respectively. Prediction models, namely, ITU-R P. 530-16, Da Silva Mello, Moupfouma, Abdulrahman, Lin and differential equation approach are analyzed. This studies help to identify most suitable rain attenuation model for higher microwave bands. While applying ITU-R P. 530-16, the relative error margin of about 3%, 38% and 42% along with 80, 70, 61% were obtained in 0.1%, 0.01% and 0.001% of the time for vertical polarization under 38 and 75 GHz respectively. Interestingly, ITU-R P. 530-16 shows relatively closer estimation to measured rain attenuation at 75 GHz with relatively less error probabilities and additionally, Abdulrahman and ITU-R P. 530-16 results in better estimation to the measured rain attenuation at 38 GHz link. The performance of prominent rain attenuation models are judged with different error matrices as recommended by ITU-R P. 311-15. Furthermore, the efficacy of frequency scaling technique of rain attenuation between links distribution are also discussed. This study shall be useful for making good considerations in rain attenuation predictions for terrestrial link operating at higher frequencies.

A TRMM Microwave Radiometer Rain Rate Estimation Method with Convective and Stratiform Discrimination

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Iacovazzi, R., Jr.; Weinman, J. A.; Dalu, G.

1999-01-01

Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) radiometer brightness temperature data in the 85 GHz channel (T85) reveal distinct local minima (T85min) in a regional map containing a Mesoscale Convective System (MCS). This is because of relatively small footprint size (approximately 5.5 km) and strong extinction properties in this channel of the TMI. A map of surface rain rate for that region, deduced from simultaneous measurements made by the Precipitation Radar (PR) on board the TRMM satellite, reveals that these T85(sub min), produced by scattering, correspond to local PR rain maxima. Utilizing the PR rain rate map as a guide, we infer empirically from TMI data the presence of three different kinds of thunderstorms or Cbs. These Cbs are classified as young, mature, and decaying types, and are assumed to have a scale of about 20 km on the average. Two parameters are used to classify these three kinds of Cbs based on the T85 data: a) the magnitude of scattering depression deduced from local T85(sub min) and b) the mean horizontal gradient of T85 around such minima. Knowing the category of a given Cb, we can estimate the rain rate associated with it. Such estimation is done with the help of relationships linking T85min to rain rate in each Cb type. Similarly, a weak background rain rate in all the areas where T85 is less than 260 K is deduced with another relationship linking T85 to rain rate. In our rain retrieval model, this background rain constitutes stratiform rain where the Cbs are absent. Initially, these relationships are optimized or tuned utilizing the PR and TMI data of a few MCS events. After such tuning, the model is applied to independent MCS cases. The areal distribution of light (1-10 mm/hr), moderate (10-20 mm/hr), and intense (>= 20 mm/hr) rain rates are retrieved satisfactorily. Accuracy in the estimates of the light, moderate, and intense rain areas and the mean rain rates associated with such areas in these independent MCS cases is on the average about 15 %. Taking advantage of this ability of our retrieval method, one could derive the latent heat input into the atmosphere over the 760 km wide swath of the TMI radiometer in the tropics.

TMI Rain Rate Estimation Over Land and Ocean Utilizing Convective and Stratiform Discrimination

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Iacovazzi, R., Jr.; Weinman, J. A.; Dalu, G.

1999-01-01

Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) radiometer brightness temperature data in the 85 GHz channel (T85) reveal distinct local minima in a regional map containing a Mesoscale Convective System (MCS). This is because of relatively small footprint size (approximately 5.5 km) and strong extinction properties in this channel of the TMI. A map of rain rate for that region, deduced from simultaneous measurements made by the Precipitation Radar (PR) on board the TRMM satellite, reveals that these T85 minima, produced by scattering, correspond to local PR rain maxima. Utilizing the PR rain rate map as a guide, we infer from TMI data the presence of three different kinds of thunderstorms or Cbs. They are young, mature, and decaying Cbs that have a scale of about 20 km on the average. Two parameters enable us to infer these three kinds of Cbs objectively: a) the magnitude of scattering depression deduced from local T85 minima and b) the mean horizontal gradient of T85 around such minima. Knowing the category of a given Cb, we can estimate the rain rate associated with it. Such estimation is done with the help of relationships linking T85 minimum to rain rate in each Cb type. Similarly, a weak background rain rate in all the areas where T85 is less than 260 K is deduced with another relationship linking T85 to rain rate. In our rain retrieval model, this background rain constitutes the stratiform rain where the Cbs are absent. Initially, these relationships are optimized or tuned utilizing the PR and TMI data of a few MCS events. After such tuning, the model is applied to independent MCS cases. The areal distribution of light (1-10 mm/hr), moderate (10-20 mm/hr), and intense (> 20 mm/hr) rain rates are retrieved satisfactorally. Accuracy in the estimates of the light, moderate and intense rain areas and the mean rain rates associated with such areas in these independent MCS cases is on the average about 15%. Taking advantage of this ability of our retrieval method, one could derive the latent heat input into the atmosphere over the 760 km wide swath of the TMI radiometer in the tropics.

Study of rain attenuation in Ka band for satellite communication in South Korea

NASA Astrophysics Data System (ADS)

Shrestha, Sujan; Choi, Dong-You

2016-10-01

The important factor to be considered in the link budget estimation for satellite communication systems, operating at frequencies above 10 GHz is the rain attenuation. Scattering and absorption are the main concern for system designers at these frequency bands. This has resulted in the need for suitable prediction models that can best provide estimates of attenuation due to rain with available information of rain attenuation data. Researchers have developed models that can be used to estimate 1-min rainfall attenuation distribution for earth space link but there is still some confusion with regard to choosing the right model to predict attenuation for the location of interest. In this context, the existing prediction models need to be tested against the measured results. This paper presents studies on rain attenuation at 19.8 GHz, which specifies the performance parameters for Ka-Band under earth space communication system. It presents the experimental result of rain rates and rain-induced attenuation in 19.8 and 20.73 GHz for vertical and circular polarization respectively. The received signal data for rain attenuation and rain rate were collected at 10 s intervals over a three year periods from 2013 to 2015. The data highlights the impact of clear air variation and rain fade loss. Rain rate data was measured through OTT Parsivel. During the observation period, rain rates of about 50 mm/h and attenuation values of 11.6 dB for 0.01% of the time were noted. The experimental link was set up at Korea Radio Promotion Association, Mokdong, Seoul. Out of several models, this paper present discussion and comparison of ITU-R P.618-12, Unified Method, Dissanayake Allnutt and Haidara (DAH), Simple Attenuation (SAM), Crane Global and Ramachandran and Kumar models. The relative error margin of 27.51, 89.84,72.46% and 67.24, 130.84, 166.48% are obtained for 0.1%, 0.01% and 0.001% of the time for 19.8 and 20.73 GHz under vertical and circular polarization respectively from ITU-R P. 618-12 method which has been analyzed in the further section of this article. In order to obtain the better approximation of rain induced attenuation, the suitable method is proposed for earth space link whose efficiency have been compared with prominent rain attenuation models. The method provides useful information for system engineers and researchers in making a decision over the choice of suitable rain attenuation prediction method for earth space communication operating in the South Korea region.

Understanding Acid Rain

ERIC Educational Resources Information Center

Damonte, Kathleen

2004-01-01

The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

77 FR 39404 - Safety Zone; Wicomico Community Fireworks Rain Date, Great Wicomico River, Mila, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-03

...-AA00 Safety Zone; Wicomico Community Fireworks Rain Date, Great Wicomico River, Mila, VA AGENCY: Coast... zone on the Great Wicomico River in the vicinity of Mila, VA in support of the Wicomico Community Rain... as follows: Sec. 165.T05-0425 Safety Zone; Wicomico Community Fireworks Rain Date, Great Wicomico...

Rain erosion considerations for launch vehicle insulation systems

NASA Technical Reports Server (NTRS)

Daniels, D. J.; Sieker, W. D.

1977-01-01

In recent years the Delta launch vehicle has incorporated the capability to be launched through rain. This capability was developed to eliminate a design constraint which could result in a costly launch delay. This paper presents the methodology developed to implement rain erosion protection for the insulated exterior vehicle surfaces. The effect of the interaction between insulation material rain erosion resistance, rainstorm models, surface geometry and trajectory variations is examined. It is concluded that rain erosion can significantly impact the performance of launch vehicle insulation systems and should be considered in their design.

Vibration (?) spikes during natural rain events

NASA Technical Reports Server (NTRS)

Short, David A.

1994-01-01

Limited analysis of optical rain gauge (ORG) data from shipboard and ground based sensors has shown the existence of spikes, possibly attributable to sensor vibration, while rain is occurring. An extreme example of this behavior was noted aboard the PRC#5 on the evening of December 24, 1992 as the ship began repositioning during a rain event in the TOGA/COARE IFA. The spikes are readily evident in the one-second resolution data, but may be indistinguishable from natural rain rate fluctuations in subsampled or averaged data. Such spikes result in increased rainfall totals.

Sources of sulphur in rain collected below a wheat canopy.

PubMed

Raybould, C C; Unsworth, M H; Gregory, P J

1977-05-12

Vegetation plays an important role in the cycle of sulphur between the atmosphere and the soil. We have measured the quantity of sulphur in rain collected below a maturing wheat canopy. This sulphur has three sources: first, the atmosphere, from which falling rain gains SO2 and sulphate; second, leaf surfaces, from which rain washes sulphur which was previously deposited by turbulent transfer ('dry deposition'), and third, leaf tissue, from which rain leaches sulphur. We have now deduced from field and laboratory measurements that leaching supplied nearly 90% of the sulphur gained by rain as it fell through the wheat canopy. Only a small fraction of sulphur which had been dry-deposited on the surface of leaves could be washed off.

Rain measurements from space using a modified Seasat-type radar altimeter

NASA Technical Reports Server (NTRS)

Goldhirsh, J.; Walsh, E. J.

1982-01-01

The incorporation in the 13.5 GHz Seasat-type radar altimeter of a mode to measure rain rate is investigated. Specifically, an algorithm is developed relating the echo power at the various range bins, to the rain rate taking into consideration Mie scattering and path attenuation. The dependence of the algorithm on rain drop size distribution and nonuniform rain structure are examined and associated uncertainties defined. A technique for obtaining drop size distribution through the measurements of power at the top of the raincell and power difference through the cell also is investigated together with an associated error analysis. A description of the minor hardware modifications to the basic Seasat design is given for implementing the rain measurements.

Rain-rate data base development and rain-rate climate analysis

NASA Technical Reports Server (NTRS)

Crane, Robert K.

1993-01-01

The single-year rain-rate distribution data available within the archives of Consultative Committee for International Radio (CCIR) Study Group 5 were compiled into a data base for use in rain-rate climate modeling and for the preparation of predictions of attenuation statistics. The four year set of tip-time sequences provided by J. Goldhirsh for locations near Wallops Island were processed to compile monthly and annual distributions of rain rate and of event durations for intervals above and below preset thresholds. A four-year data set of tropical rain-rate tip-time sequences were acquired from the NASA TRMM program for 30 gauges near Darwin, Australia. They were also processed for inclusion in the CCIR data base and the expanded data base for monthly observations at the University of Oklahoma. The empirical rain-rate distributions (edfs) accepted for inclusion in the CCIR data base were used to estimate parameters for several rain-rate distribution models: the lognormal model, the Crane two-component model, and the three parameter model proposed by Moupfuma. The intent of this segment of the study is to obtain a limited set of parameters that can be mapped globally for use in rain attenuation predictions. If the form of the distribution can be established, then perhaps available climatological data can be used to estimate the parameters rather than requiring years of rain-rate observations to set the parameters. The two-component model provided the best fit to the Wallops Island data but the Moupfuma model provided the best fit to the Darwin data.

Effects of acidic precipitation on host-parasite interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shriner, D.S.

1974-01-01

During the past decade, the average acidity of rain and snow increased by 1-2 pH units in many parts of Europe and North America. Little is known of the effects of acid rain resulting from dissolution of sulfur dioxide on biological systems. The effects of simulated sulfuric acid rain on four host-pathogen system were studied. Plants were exposed in greenhouse and field to simulated rain of pH 3.2 or pH 6.0 in amounts and intervals common to weather patterns of the eastern United States. Simulated acid rain resulted in: (1) an 86% inhibition in telia production of Cronartium fusiforme onmore » willow oak (Quercus phellos); (2) a 66% inhibition in the production of root-knot nematodes (Meloidogyne hapla) on field grown kidney beans (Phaseolus vulgaris Red Kidney); (3) a 20% decrease in the severity of Uromyces phaseoli infection of field grown kidney beans; and (4) either stimulated or inhibited development of halo blight on kidney bean (caused by Pseudomonas phaseolicola) depending upon the segment of the disease cycle in which the stress occurred: (a) simulated acid rain before inoculation stimulated disease development; (b) suspension of inoculum in acid rain decreased inoculum potential; and (c) acid rain after infection inhibited disease development. Results suggest that the pH of rain is a new environmental parameter of concern to plant pathologists.« less

Rainfall measurement from opportunistic use of earth-space link in Ku Band

NASA Astrophysics Data System (ADS)

Barthès, L.; Mallet, C.

2013-02-01

The present study deals with the development of a low cost microwave device devoted to measure average rain rate observed along earth - satellite links. The principle is to use rain atmospheric attenuation along Earth - space links in Ku-band to deduce the path averaged rain rate. These links are characterized by a path length of a few km through the troposphere. Ground based power measurements are carried out by receiving TV channels from different geostationary satellites in Ku-band. The major difficulty in this study is to retrieve rain characteristics among many fluctuations of the received signal which are due to atmospheric scintillations, changes in the composition of the atmosphere (water vapour concentration, cloud water content) or satellite features (variation of the emitted power, satellite motions). In order to perform a feasibility study of such a device, a measurement campaign has been performed for five months near Paris. This paper proposes an algorithm based on an artificial neural network to identify drought and rainy periods and to suppress the variability of the received signal due to no-rain effects. Taking into account the height of the rain layer, rain attenuation is then inverted to obtain path averaged rain rate. Obtained rainfall rates are compared with co-located rain gauges and radar measurements on the whole experiment period, then the most significant rainy events are analyzed.

The effect of simulated acid rain on the stabilization of cadmium in contaminated agricultural soils treated with stabilizing agents.

PubMed

Zhu, Hao; Wu, Chunfa; Wang, Jun; Zhang, Xumei

2018-04-16

Stabilization technology is one of widely used remediation technologies for cadmium (Cd)-contaminated agricultural soils, but stabilized Cd in soil may be activated again when external conditions such as acid rain occurred. Therefore, it is necessary to study the effect of acid rain on the performance of different stabilizing agents on Cd-polluted agriculture soils. In this study, Cd-contaminated soils were treated with mono-calcium phosphate (MCP), mono-ammonium phosphate (MAP), and artificial zeolite (AZ) respectively and incubated 3 months. These treatments were followed by two types of simulated acid rain (sulfuric acid rain and mixed acid rain) with three levels of acidity (pH = 3.0, 4.0, and 5.6). The chemical forms of Cd in the soils were determined by Tessier's sequential extraction procedure, and the leaching toxicities of Cd in the soils were assessed by toxicity characteristic leaching procedure (TCLP). The results show that the three stabilizing agents could decrease the mobility of Cd in soil to some degree with or without simulated acid rain (SAR) treatment. The stabilization performances followed the order of AZ < MAP < MCP. Acid rain soaking promoted the activation of Cd in stabilized soil, and both anion composition and pH of acid rain were two important factors that influenced the stabilization effect of Cd.

Daily rainfall statistics of TRMM and CMORPH: A case for trans-boundary Gandak River basin

NASA Astrophysics Data System (ADS)

Kumar, Brijesh; Patra, Kanhu Charan; Lakshmi, Venkat

2016-07-01

Satellite precipitation products offer an opportunity to evaluate extreme events (flood and drought) for areas where rainfall data are not available or rain gauge stations are sparse. In this study, daily precipitation amount and frequency of TRMM 3B42V.7 and CMORPH products have been validated against daily rain gauge precipitation for the monsoon months (June-September or JJAS) from 2005-2010 in the trans-boundary Gandak River basin. The analysis shows that the both TRMM and CMORPH can detect rain and no-rain events, but they fail to capture the intensity of rainfall. The detection of precipitation amount is strongly dependent on the topography. In the plains areas, TRMM product is capable of capturing high-intensity rain events but in the hilly regions, it underestimates the amount of high-intensity rain events. On the other hand, CMORPH entirely fails to capture the high-intensity rain events but does well with low-intensity rain events in both hilly regions as well as the plain region. The continuous variable verification method shows better agreement of TRMM rainfall products with rain gauge data. TRMM fares better in the prediction of probability of occurrence of high-intensity rainfall events, but it underestimates intensity at high altitudes. This implies that TRMM precipitation estimates can be used for flood-related studies only after bias adjustment for the topography.

When It Rains, It Pours

ERIC Educational Resources Information Center

Mills, Linda

2012-01-01

"It's raining, it's pouring, the old man is snoring!" "The itsy, bitsy spider crawled up the waterspout, down came the rain and washed the spider out. Out came the sun and dried up all the rain, and the itsy, bitsy spider went up the spout again." What do children's nursery rhymes have to do with the school library? The author begins by telling a…

Effect of rain-shelter cultivation of Vitis vinifera cv. Cabernet Gernischet on the phenolic profile of berry skins and the incidence of grape diseases.

PubMed

Meng, Jiang-Fei; Ning, Peng-Fei; Xu, Teng-Fei; Zhang, Zhen-Wen

2012-12-27

Rain-shelter cultivation is an effective cultural method to prevent rainfall damage during grape harvest and widely applied in the Chinese rainy regions. In this study we investigated the effect of rain-shelter cultivation on grape diseases and phenolic composition in the skins of Vitis vinifera cv. Cabernet Gernischet grape berries through the comparison with open-field cultivation at two vintages (2010 and 2011). The results showed that rain-shelter cultivation reduced the incidence of grape diseases significantly and delayed the maturation of Cabernet Gernischet fruits. With regards to most of the phenolic compounds identified in this study, their content in grape samples under rain-shelter cultivation was decreased compared to those under open-field cultivation. However, rain-shelter cultivation stimulated the accumulation of dihydroquercetin-3-O-rhamnoside in grape skins during grape maturation. These were related with micrometeorological alterations in vineyards by using plastic covering under rain-shelter cultivation. It suggests the rain-shelter cultivation makes possible the cultivation of "Cabernet Gernischet" grapes in an organic production system, for providing a decrease in the incidence of diseases and the dependence on chemical pesticides in the grape and wine industry.

Comparing Satellite Rainfall Estimates with Rain-Gauge Data: Optimal Strategies Suggested by a Spectral Model

NASA Technical Reports Server (NTRS)

Bell, Thomas L.; Kundu, Prasun K.; Lau, William K. M. (Technical Monitor)

2002-01-01

Validation of satellite remote-sensing methods for estimating rainfall against rain-gauge data is attractive because of the direct nature of the rain-gauge measurements. Comparisons of satellite estimates to rain-gauge data are difficult, however, because of the extreme variability of rain and the fact that satellites view large areas over a short time while rain gauges monitor small areas continuously. In this paper, a statistical model of rainfall variability developed for studies of sampling error in averages of satellite data is used to examine the impact of spatial and temporal averaging of satellite and gauge data on intercomparison results. The model parameters were derived from radar observations of rain, but the model appears to capture many of the characteristics of rain-gauge data as well. The model predicts that many months of data from areas containing a few gauges are required to validate satellite estimates over the areas, and that the areas should be of the order of several hundred km in diameter. Over gauge arrays of sufficiently high density, the optimal areas and averaging times are reduced. The possibility of using time-weighted averages of gauge data is explored.

Rain attenuation measurements: Variability and data quality assessment

NASA Technical Reports Server (NTRS)

Crane, Robert K.

1989-01-01

Year to year variations in the cumulative distributions of rain rate or rain attenuation are evident in any of the published measurements for a single propagation path that span a period of several years of observation. These variations must be described by models for the prediction of rain attenuation statistics. Now that a large measurement data base has been assembled by the International Radio Consultative Committee, the information needed to assess variability is available. On the basis of 252 sample cumulative distribution functions for the occurrence of attenuation by rain, the expected year to year variation in attenuation at a fixed probability level in the 0.1 to 0.001 percent of a year range is estimated to be 27 percent. The expected deviation from an attenuation model prediction for a single year of observations is estimated to exceed 33 percent when any of the available global rain climate model are employed to estimate the rain rate statistics. The probability distribution for the variation in attenuation or rain rate at a fixed fraction of a year is lognormal. The lognormal behavior of the variate was used to compile the statistics for variability.

Pyrite oxidation under simulated acid rain weathering conditions.

PubMed

Zheng, Kai; Li, Heping; Wang, Luying; Wen, Xiaoying; Liu, Qingyou

2017-09-01

We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.

The role of calcium in improving photosynthesis and related physiological and biochemical attributes of spring wheat subjected to simulated acid rain.

PubMed

Dolatabadian, Aria; Sanavy, Seyed Ali Mohammad Modarres; Gholamhoseini, Majid; Joghan, Aydin Khodaei; Majdi, Mohammad; Kashkooli, Arman Beyraghdar

2013-04-01

The response of photosynthesis parameters, catalase, superoxide dismutase and peroxidase activity, malondialdehyde, proline, chlorophyll, yield and yield components to foliar application of calcium and simulated acid rain in wheat were investigated. Foliar treatment of calcium led to significant increases in the photosynthesis rate, transpiration rate, stomatal conductance, proline, chlorophyll, yield and yield components in plants subjected to acid rain. Antioxidant enzyme activity and lipid peroxidation in the wheat leaves decreased because of calcium foliar application. Calcium hindered degradation of the rubisco subunits under acid rain treatment compared with water-treated plants. Results suggest that acid rain induces the production of free radicals resulting in lipid peroxidation of the cell membrane so that significant increase in antioxidant enzyme activity was observed. In addition, photosynthetic parameters i.e. photosynthesis rate, transpiration rate and stomatal conductance were drastically suppressed by acid rain. The cellular damage caused by free radicals might be reduced or prevented by a protective metabolism including antioxidative enzymes and calcium. We report that foliar application of calcium before acid rain may ameliorate the adverse effects of acid rain in wheat plants.

Phosphorus limits Eucalyptus grandis seedling growth in an unburnt rain forest soil

PubMed Central

Tng, David Y. P.; Janos, David P.; Jordan, Gregory J.; Weber, Ellen; Bowman, David M. J. S.

2014-01-01

Although rain forest is characterized as pyrophobic, pyrophilic giant eucalypts grow as rain forest emergents in both temperate and tropical Australia. In temperate Australia, such eucalypts depend on extensive, infrequent fires to produce conditions suitable for seedling growth. Little is known, however, about constraints on seedlings of tropical giant eucalypts. We tested whether seedlings of Eucalyptus grandis experience edaphic constraints similar to their temperate counterparts. We hypothesized that phosphorous addition would alleviate edaphic constraints. We grew seedlings in a factorial experiment combining fumigation (to simulate nutrient release and soil pasteurization by fire), soil type (E. grandis forest versus rain forest soil) and phosphorus addition as factors. We found that phosphorus was the principal factor limiting E. grandis seedling survival and growth in rain forest soil, and that fumigation enhanced survival of seedlings in both E. grandis forest and rain forest soil. We conclude that similar to edaphic constraints on temperate giant eucalypts, mineral nutrient and biotic attributes of a tropical rain forest soil may hamper E. grandis seedling establishment. In rain forest soil, E. grandis seedlings benefited from conditions akin to a fire-generated ashbed (i.e., an “ashbed effect”). PMID:25339968

Presenting the Rain-Sea Interaction Facility

NASA Technical Reports Server (NTRS)

Bliven, Larry F.; Elfouhaily, Tonas M.

1993-01-01

The new Rain-Sea Interaction Facility (RSIF) was established at GSFC/WFF and the first finds are presented. The unique feature of this laboratory is the ability to systematically study microwave scattering from a water surface roughened by artificial rain, for which the droplets are at terminal velocity. The fundamental instruments and systems (e.g., the rain simulator, scatterometers, and surface elevation probes) were installed and evaluated during these first experiments - so the majority of the data were obtained with the rain simulator at 1 m above the water tank. From these initial experiments, three new models were proposed: the square-root function for NCS vs. R, the log Gaussian model for ring-wave elevation frequency spectrum, and the Erland probability density distribution for back scattered power. Rain rate is the main input for these models, although the coefficients may be dependent upon other factors (drop-size distribution, fall velocity, radar configuration, etc.). The facility is functional and we foresee collaborative studies with investigators who are engaged in measuring and modeling rain-sea interaction processes.

Theoretical Analysis of Rain Attenuation Probability

NASA Astrophysics Data System (ADS)

Roy, Surendra Kr.; Jha, Santosh Kr.; Jha, Lallan

2007-07-01

Satellite communication technologies are now highly developed and high quality, distance-independent services have expanded over a very wide area. As for the system design of the Hokkaido integrated telecommunications(HIT) network, it must first overcome outages of satellite links due to rain attenuation in ka frequency bands. In this paper theoretical analysis of rain attenuation probability on a slant path has been made. The formula proposed is based Weibull distribution and incorporates recent ITU-R recommendations concerning the necessary rain rates and rain heights inputs. The error behaviour of the model was tested with the loading rain attenuation prediction model recommended by ITU-R for large number of experiments at different probability levels. The novel slant path rain attenuastion prediction model compared to the ITU-R one exhibits a similar behaviour at low time percentages and a better root-mean-square error performance for probability levels above 0.02%. The set of presented models exhibits the advantage of implementation with little complexity and is considered useful for educational and back of the envelope computations.

Effects and mechanisms of the combined pollution of lanthanum and acid rain on the root phenotype of soybean seedlings.

PubMed

Sun, Zhaoguo; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2013-09-01

Rare earth pollution and acid rain pollution are both important environmental issues worldwide. In regions which simultaneously occur, the combined pollution of rare earth and acid rain becomes a new environmental issue, and the relevant research is rarely reported. Accordingly, we investigated the combined effects and mechanisms of lanthanum ion (La(3+)) and acid rain on the root phenotype of soybean seedlings. The combined pollution of low-concentration La(3+) and acid rain exerted deleterious effects on the phenotype and growth of roots, which were aggravated by the combined pollution of high-concentration La(3+) and acid rain. The deleterious effects of the combined pollution were stronger than those of single La(3+) or acid rain pollution. These stronger deleterious effects on the root phenotype and growth of roots were due to the increased disturbance of absorption and utilization of mineral nutrients in roots. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characteristics and transport of organochlorine pesticides in urban environment: air, dust, rain, canopy throughfall, and runoff.

PubMed

Zhang, Wei; Ye, Youbin; Hu, Dan; Ou, Langbo; Wang, Xuejun

2010-11-01

Characteristics and transport of organochlorine pesticides (OCPs) in urban multiple environments, including air, dust, rain, canopy throughfall, and runoff water, are explored in this study. Hexachlorocyclohexanes (HCHs) dominated in both air and rain water, and dichlorodiphenyltrichloroethane (DDT) related substances showed a higher affinity to dust. Relatively high concentrations of DDT and dichlorodiphenyldichloroethylene (DDE) in air, rain and dust imply that technical DDT in the environment has been degrading, and there may be unknown local or regional emission sources that contain DDTs in the study area. Source identification showed that DDTs in Beijing urban environments with a fresh signature may originate from the atmospheric transport from remote areas. The ratio of α-/γ-HCH in dust, rain, canopy throughfall and runoff were close to 1, indicating the possible use of lindane. OCPs in runoff were transported from various sources including rain, dust, and canopy throughfall. In runoff, DDTs and hexachlorobenzene (HCB) were mainly transported from dust, and HCHs were mainly from rain and canopy throughfall.

TRMM Observations of Polarization Difference in 85 GHz: Information About Hydrometeors and Rain Rate

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Einaudi, Franco (Technical Monitor)

2000-01-01

Observations made by the Precipitation Radar (PR) and the Microwave Imager (TMI) radiometer on board the Tropical Rainfall Measuring Mission (TRMM) satellite help us to show the significance of the 85 GHz polarization difference, PD85, measured by TMI. Rain type, convective or stratiform, deduced from the PR allows us to infer that PD85 is generally positive in stratiform rain clouds, while PD85 can be markedly negative in deep convective rain clouds. Furthermore, PD85 increases in a gross manner as stratiform rain rate increases. On the contrary, in a crude fashion PD85 decreases as convective rain rate increases. From the observations of TMI and PR, we find that PD85 is a weak indicator of rain rate. Utilizing information from existing polarimetric radar studies, we infer that negative values of PD85 are likely associated with vertically-oriented small oblate or wet hail that are found in deep convective updrafts.

Occurrence of acid rain in Baton Rouge, Louisiana, Summer 1981. The role of the catalytic converter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, J.W.; Ghane, H.

1982-01-01

Between June and October 1981, acid rain falling in Baton Rouge, LA was studied. The acidity of the rain ranged for pH 3.9 to pH 5.8. Preliminary data showed that rain associated with thermal cumulo nimbus tended to be more acidic, but rain associated with active cold fronts were less acid. This may relate to dispersion and dilution of the acid aerosols by the cold front. It is proposed that exhaust from automobiles fitted with catalytic converters is a substantial contributor to the acid rain problem, and that their net value to the abatement of pollution must be questioned, particularlymore » in regions of the country where smog is not a problem. (JMT)« less

An experimental study of microwave scattering from rain- and wind-roughened seas

NASA Technical Reports Server (NTRS)

Bliven, L. F.; Giovanangeli, J.-P.

1993-01-01

This paper investigates radar cross-section (RCS) characteristics of rain- and wind-roughened sea-surfaces. We conducted experiments in laboratory wind-wave tanks using artificial rain. The study includes light rain rates, light wind speeds, and combinations of these. A 36 Ghz scatterometer was operated at 30 deg incidence angle and with vertical polarization. RCS data were obtained not only with the scatterometer pointing up-wind but also as a function of azimuthal angle. We use a scatterometer rain and wind model SRWM-1, which relates the total average RCS in storms to the sum of the average RCS due to rain plus the average RCS due to wind. Implications of the study for operational monitoring of wind in rainy oceanic areas by satellite-borne instruments is discussed.

Constructed Rain Garden Systems for Stormwater Quality Control under Tropical Climates

NASA Astrophysics Data System (ADS)

Mohd Sidek, Lariyah; Elyza Muha, Norshafa; Noor, Nur Asmaliza Md; Basri, Hidayah

2013-06-01

Malaysia has taken an integrated approach to manage storm water that is increasingly becoming a problem in big cities. Rain gardens are recommended as green technology for a new storm water management in Malaysia. The approach is applied in urban planning and design that integrates the total water cycle management into the development process areas. Rain gardens have been effective in reducing peak discharge and consistently reduce the number of storm water pollutants. This paper will examine some of guidelines, laboratory studies and field monitoring that shows great potential and benefit of rain garden. The preliminary results for rain garden performance were reported in this paper. The findings from this research will open avenues for researchers to advance the knowledge in rain garden systems to achieve the sustainable development in Malaysia.

Fatigue loading history reconstruction based on the rain-flow technique

NASA Technical Reports Server (NTRS)

Khosrovaneh, A. K.; Dowling, N. E.

1989-01-01

Methods are considered for reducing a non-random fatigue loading history to a concise description and then for reconstructing a time history similar to the original. In particular, three methods of reconstruction based on a rain-flow cycle counting matrix are presented. A rain-flow matrix consists of the numbers of cycles at various peak and valley combinations. Two methods are based on a two dimensional rain-flow matrix, and the third on a three dimensional rain-flow matrix. Histories reconstructed by any of these methods produce a rain-flow matrix identical to that of the original history, and as a result the resulting time history is expected to produce a fatigue life similar to that for the original. The procedures described allow lengthy loading histories to be stored in compact form.

Communications Link Characterization Experiment (CLCE) technical data report, volume 2

NASA Technical Reports Server (NTRS)

1977-01-01

The results are presented of the long term rain rate statistical analysis and the investigation of determining the worst month statistical from the measured attenuation data caused by precipitation. The rain rate statistics cover a period of 11 months from July of 1974 to May of 1975 for measurements taken at the NASA, Rosman station. The rain rate statistical analysis is a continuation of the analysis of the rain rate data accumulated for the ATS-6 Millimeter Wave Progation Experiment. The statistical characteristics of the rain rate data through December of 1974 is also presented for the above experiment.

Validation of Rain Rate Retrievals for the Airborne Hurricane Imaging Radiometer (HIRAD)

NASA Technical Reports Server (NTRS)

Jacob, Maria Marta; Salemirad, Matin; Jones, W. Linwood; Biswas, Sayak; Cecil, Daniel

2015-01-01

The NASA Hurricane and Severe Storm Sentinel (HS3) mission is an aircraft field measurements program using NASA's unmanned Global Hawk aircraft system for remote sensing and in situ observations of Atlantic and Caribbean Sea hurricanes. One of the principal microwave instruments is the Hurricane Imaging Radiometer (HIRAD), which measures surface wind speeds and rain rates. For validation of the HIRAD wind speed measurement in hurricanes, there exists a comprehensive set of comparisons with the Stepped Frequency Microwave Radiometer (SFMR) with in situ GPS dropwindsondes [1]. However, for rain rate measurements, there are only indirect correlations with rain imagery from other HS3 remote sensors (e.g., the dual-frequency Ka- & Ku-band doppler radar, HIWRAP), which is only qualitative in nature. However, this paper presents results from an unplanned rain rate measurement validation opportunity that occurred in 2013, when HIRAD flew over an intense tropical squall line that was simultaneously observed by the Tampa NEXRAD meteorological radar (Fig. 1). During this experiment, Global Hawk flying at an altitude of 18 km made 3 passes over the rapidly propagating thunderstorm, while the TAMPA NEXRAD perform volume scans on a 5-minute interval. Using the well-documented NEXRAD Z-R relationship, 2D images of rain rate (mm/hr) were obtained at two altitudes (3 km & 6 km), which serve as surface truth for the HIRAD rain rate retrievals. A preliminary comparison of HIRAD rain rate retrievals (image) for the first pass and the corresponding closest NEXRAD rain image is presented in Fig. 2 & 3. This paper describes the HIRAD instrument, which 1D synthetic-aperture thinned array radiometer (STAR) developed by NASA Marshall Space Flight Center [2]. The rain rate retrieval algorithm, developed by Amarin et al. [3], is based on the maximum likelihood estimation (MLE) technique, which compares the observed Tb's at the HIRAD operating frequencies of 4, 5, 6 and 6.6 GHz with corresponding theoretical Tb values from a forward radiative transfer model (RTM). The optimum solution is the integrated rain rate that minimizes the difference between RTM and observed values. Because the excess Tb from rain comes from the direct upwelling and the indirect reflected downwelling paths through the atmosphere, there are several assumptions made for the 2D rain distribution in the antenna incident plane (crosstrack to flight direction). The opportunity to knowing 2D rain surface truth from NEXRAD at two different altitudes will enable a comprehensive evaluation to be preformed and reported in this paper.

A new method for automated dynamic calibration of tipping-bucket rain gauges

USGS Publications Warehouse

Humphrey, M.D.; Istok, J.D.; Lee, J.Y.; Hevesi, J.A.; Flint, A.L.

1997-01-01

Existing methods for dynamic calibration of tipping-bucket rain gauges (TBRs) can be time consuming and labor intensive. A new automated dynamic calibration system has been developed to calibrate TBRs with minimal effort. The system consists of a programmable pump, datalogger, digital balance, and computer. Calibration is performed in two steps: 1) pump calibration and 2) rain gauge calibration. Pump calibration ensures precise control of water flow rates delivered to the rain gauge funnel; rain gauge calibration ensures precise conversion of bucket tip times to actual rainfall rates. Calibration of the pump and one rain gauge for 10 selected pump rates typically requires about 8 h. Data files generated during rain gauge calibration are used to compute rainfall intensities and amounts from a record of bucket tip times collected in the field. The system was tested using 5 types of commercial TBRs (15.2-, 20.3-, and 30.5-cm diameters; 0.1-, 0.2-, and 1.0-mm resolutions) and using 14 TBRs of a single type (20.3-cm diameter; 0.1-mm resolution). Ten pump rates ranging from 3 to 154 mL min-1 were used to calibrate the TBRs and represented rainfall rates between 6 and 254 mm h-1 depending on the rain gauge diameter. All pump calibration results were very linear with R2 values greater than 0.99. All rain gauges exhibited large nonlinear underestimation errors (between 5% and 29%) that decreased with increasing rain gauge resolution and increased with increasing rainfall rate, especially for rates greater than 50 mm h-1. Calibration curves of bucket tip time against the reciprocal of the true pump rate for all rain gauges also were linear with R2 values of 0.99. Calibration data for the 14 rain gauges of the same type were very similar, as indicated by slope values that were within 14% of each other and ranged from about 367 to 417 s mm h-1. The developed system can calibrate TBRs efficiently, accurately, and virtually unattended and could be modified for use with other rain gauge designs. The system is now in routine use to calibrate TBRs in a large rainfall collection network at Yucca Mountain, Nevada.

Compilation and Analysis of 20 and 30 GHz Rain Fade Events at the ACTS NASA Ground Station: Statistics and Model Assessment

NASA Technical Reports Server (NTRS)

Manning, Robert M.

1996-01-01

The purpose of the propagation studies within the ACTS Project Office is to acquire 20 and 30 GHz rain fade statistics using the ACTS beacon links received at the NGS (NASA Ground Station) in Cleveland. Other than the raw, statistically unprocessed rain fade events that occur in real time, relevant rain fade statistics derived from such events are the cumulative rain fade statistics as well as fade duration statistics (beyond given fade thresholds) over monthly and yearly time intervals. Concurrent with the data logging exercise, monthly maximum rainfall levels recorded at the US Weather Service at Hopkins Airport are appended to the database to facilitate comparison of observed fade statistics with those predicted by the ACTS Rain Attenuation Model. Also, the raw fade data will be in a format, complete with documentation, for use by other investigators who require realistic fade event evolution in time for simulation purposes or further analysis for comparisons with other rain fade prediction models, etc. The raw time series data from the 20 and 30 GHz beacon signals is purged of non relevant data intervals where no rain fading has occurred. All other data intervals which contain rain fade events are archived with the accompanying time stamps. The definition of just what constitutes a rain fade event will be discussed later. The archived data serves two purposes. First, all rain fade event data is recombined into a contiguous data series every month and every year; this will represent an uninterrupted record of the actual (i.e., not statistically processed) temporal evolution of rain fade at 20 and 30 GHz at the location of the NGS. The second purpose of the data in such a format is to enable a statistical analysis of prevailing propagation parameters such as cumulative distributions of attenuation on a monthly and yearly basis as well as fade duration probabilities below given fade thresholds, also on a monthly and yearly basis. In addition, various subsidiary statistics such as attenuation rate probabilities are derived. The purged raw rain fade data as well as the results of the analyzed data will be made available for use by parties in the private sector upon their request. The process which will be followed in this dissemination is outlined in this paper.

Evaluation of Improvements to the TRMM Microwave Rain Algorithm

NASA Technical Reports Server (NTRS)

Yang, Song; Olson, Williams S.; Smith, Eric A.; Kummerow, Christian

2002-01-01

Improvements made to the Version 5 TRMM passive microwave rain retrieval algorithm (2A-12) are evaluated using independent data. Surface rain rate estimates from the Version 5 TRMM TMI (2A-12), PR (2A-25) and TMI/PR Combined (2B-31) algorithms and ground-based radar estimates for selected coincident subset datasets in 1998 over Melbourne and Kwajalein show varying degrees of agreement. The surface rain rates are then classified into convective and stratiform rain types over ocean, land, and coastal areas for more detailed comparisons to the ground radar measurements. These comparisons lead to a better understanding of the relative performances of the current TRMM rain algorithms. For example, at Melbourne more than 80% of the radar-derived rainfall is classified as convective rain. Convective rain from the TRMM rain algorithms is less than that from ground radar measurements, while TRMM stratiform rain is much greater. Rain area coverage from 2A-12 is also in reasonable agreement with ground radar measurements, with about 25% more over ocean and 25% less over land and coastal areas. Retrieved rain rates from the improved (Version 6) 2A-12 algorithm will be compared to 2A-25, 2B-31, and ground-based radar measurements to evaluate the impact of improvements to 2A-12 in Version 6. An important improvement to the Version 6 2A-12 algorithm is the retrieval of Q1/Q2 (latent heating/drying) profiles in addition to the surface rain rate and hydrometeor profiles. In order to ascertain the credibility of the new products, retrieved Q1/Q2 profiles are compared to independent ground-based estimates. Analyses of dual-Doppler radar data in conjunction with coincident rawinsonde data yield estimates of the vertical distributions of diabatic heating/drying at high horizontal resolution for selected cases over the Kwajalein and LBA field sites. The estimated vertical heating/drying structures appear to be reasonable. Comparisons of Q1/Q2 profiles from Version 6 2A-12 and the ground-based estimates are in progress. Retrieved Q1/Q2 structures will also be compared to MM5 hurricane simulations for selected cases. The results of these intercomparisons will be presented at the conference.

Millimeter wave satellite communication studies. Results of the 1981 propagation modeling effort

NASA Technical Reports Server (NTRS)

Stutzman, W. L.; Tsolakis, A.; Dishman, W. K.

1982-01-01

Theoretical modeling associated with rain effects on millimeter wave propagation is detailed. Three areas of work are discussed. A simple model for prediction of rain attenuation is developed and evaluated. A method for computing scattering from single rain drops is presented. A complete multiple scattering model is described which permits accurate calculation of the effects on dual polarized signals passing through rain.

Urban dew and rain in Paris, France: Occurrence and physico-chemical characteristics

NASA Astrophysics Data System (ADS)

Beysens, D.; Mongruel, A.; Acker, K.

2017-06-01

This paper summarizes one year (April 2011 to March 2012) measurements on planar condensing surfaces of dew and rain events and related physico-chemical characteristics in the urban environment of Paris (city center). Yearly collected water was 3.48 mm for dew (63 events) and 593 mm for rain (146 events). The latter value compares well with rain data (547 mm and 107 events) collected within 12 km at Paris-Orly airport. An estimation of dew yield based on meteo data gives 2.35 mm and 74 events, to be compared with 17.11 mm and 196 events at Paris-Orly. These differences highlight the large reduction in dew events and dew yields in an urban area as compared to a close rural-like area. This reduction is not due to a sky view reduction but to heat island that increases air temperature and decreases relative humidity. Analysis of dew (34) and rain (77) samples were done concerning pH, electrical conductivity (EC), major anions and cations as well as selected trace metals and other minor ions. Mean pH values are found similar for both, dew (6.5) and rain (6.1), rain being slightly more acidic than dew. The mean dew total ionic content (TIC 1.8 meq/l) and EC value (124 μS/cm) are about four times that of rain (0.45 meq/l; 35 μS/cm), meaning that total dissolved solids in dew is nearly four times that in rain. Sulfate and nitrate are the most acidifying components, calcium the most neutralizing constituent with ratio of mean total acidity/total alkalinity comparable for dew and rain ( 0.9). Sulfate and nitrate have mainly anthropogenic sources, whereas chloride and magnesium are mostly connected with marine air masses. Dew is a considerable factor of wet deposition of pollutants; dew and rain ion concentrations, however, meet the WHO requirements for drinking water.

Cooling time of porous asphalt pavement affecting compaction process due to various raining condition

NASA Astrophysics Data System (ADS)

Hashim, W.; Noor, M. N. M.; Shaffie, E.; Rahman, Z. A.; Arshad, A. K.

2018-04-01

While bright sunshine and warm temperatures make for the best paving weather, construction projects can get a bit rough in adverse weather conditions. In this case, porous asphalt is used on paving. Light sprinkles can usually be handled without any serious problems. Moderate rainfall events, on the other hand, will generally require the paving project to be postponed. Steady downpours will cool the porous asphalt mix and make proper compaction extremely difficult to obtain. For the viability of the project, contractors will always wait until the sky clears up. According to the JKR Specification 4(Clause 4.2.6.4), it clearly states that no pavement work should be done during rain. The rain is a cold medium where it will actually cools down everything that make contact with the water. Whereas, the mix porous asphalt (PA) is a hot medium. When these two elements combined, the surface and the PA will harden at a stage where it will not be well compacted. This will cause problems in the future. The test is conducted by pouring water onto the pavement(through raining simulation).Since the rain intensity can be determined by the size of the rain drops, the difference in the shower hole size is good enough to create different rain intensities to predict the PA cooling rate when it makes contact with water. These two variables will work as a comparison in this study between raining and no rain condition. As a result, whenever the water make a contact with the PA, the rates of cooling drops 98% from the normal rates of cooling of PA (without rain)giving the Time Available for Compaction (TAC) to be less than 60 seconds. This study may be a knowledge on how the rates of cooling work if the PA make contact with water. It can also be used as future reference on the study of cooling rates of porous pavement during raining condition.

Effect of rain gauge density over the accuracy of rainfall: a case study over Bangalore, India.

PubMed

Mishra, Anoop Kumar

2013-12-01

Rainfall is an extremely variable parameter in both space and time. Rain gauge density is very crucial in order to quantify the rainfall amount over a region. The level of rainfall accuracy is highly dependent on density and distribution of rain gauge stations over a region. Indian Space Research Organisation (ISRO) have installed a number of Automatic Weather Station (AWS) rain gauges over Indian region to study rainfall. In this paper, the effect of rain gauge density over daily accumulated rainfall is analyzed using ISRO AWS gauge observations. A region of 50 km × 50 km box over southern part of Indian region (Bangalore) with good density of rain gauges is identified for this purpose. Rain gauge numbers are varied from 1-8 in 50 km box to study the variation in the daily accumulated rainfall. Rainfall rates from the neighbouring stations are also compared in this study. Change in the rainfall as a function of gauge spacing is studied. Use of gauge calibrated satellite observations to fill the gauge station value is also studied. It is found that correlation coefficients (CC) decrease from 82% to 21% as gauge spacing increases from 5 km to 40 km while root mean square error (RMSE) increases from 8.29 mm to 51.27 mm with increase in gauge spacing from 5 km to 40 km. Considering 8 rain gauges as a standard representative of rainfall over the region, absolute error increases from 15% to 64% as gauge numbers are decreased from 7 to 1. Small errors are reported while considering 4 to 7 rain gauges to represent 50 km area. However, reduction to 3 or less rain gauges resulted in significant error. It is also observed that use of gauge calibrated satellite observations significantly improved the rainfall estimation over the region with very few rain gauge observations.

Validation of TRMM Precipitation Radar Through Comparison of its Multi-Year Measurements to Ground-Based Radar

NASA Technical Reports Server (NTRS)

Liao, Liang; Meneghini, Robert

2010-01-01

A procedure to accurately resample spaceborne and ground-based radar data is described, and then applied to the measurements taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and the ground-based Weather Surveillance Radar-1988 Doppler (WSR-88D or WSR) for the validation of the PR measurements and estimates. Through comparisons with the well-calibrated, non-attenuated WSR at Melbourne, Florida for the period 1998-2007, the calibration of the Precipitation Radar (PR) aboard the TRMM satellite is checked using measurements near the storm top. Analysis of the results indicates that the PR, after taking into account differences in radar reflectivity factors between the PR and WSR, has a small positive bias of 0.8 dB relative to the WSR, implying a soundness of the PR calibration in view of the uncertainties involved in the comparisons. Comparisons between the PR and WSR reflectivities are also made near the surface for evaluation of the attenuation-correction procedures used in the PR algorithms. It is found that the PR attenuation is accurately corrected in stratiform rain but is underestimated in convective rain, particularly in heavy rain. Tests of the PR estimates of rainfall rate are conducted through comparisons in the overlap area between the TRMM overpass and WSR scan. Analyses of the data are made both on a conditional basis, in which the instantaneous rain rates are compared only at those pixels where both the PR and WSR detect rain, and an unconditional basis, in which the area-averaged rain rates are estimated independently for the PR and WSR. Results of the conditional rain comparisons show that the PR-derived rain is about 9% greater and 19% less than the WSR estimates for stratiform and convective storms, respectively. Overall, the PR tends to underestimate the conditional mean rain rate by 8% for all rain categories, a finding that conforms to the results of the area-averaged rain (unconditional) comparisons.

Non-Drug Pain Relief: Imagery

MedlinePlus

... the pain as a thunderstorm with lightning and thunder that rains on your body. Imagine how the ... rain and thunderclouds away. Instead of rain and thunder, you have sunshine and warmth. The air smells ...

Application of a Threshold Method to the TRMM Radar for the Estimation of Space-Time Rain Rate Statistics

NASA Technical Reports Server (NTRS)

Meneghini, Robert; Jones, Jeffrey A.

1997-01-01

One of the TRMM radar products of interest is the monthly-averaged rain rates over 5 x 5 degree cells. Clearly, the most directly way of calculating these and similar statistics is to compute them from the individual estimates made over the instantaneous field of view of the Instrument (4.3 km horizontal resolution). An alternative approach is the use of a threshold method. It has been established that over sufficiently large regions the fractional area above a rain rate threshold and the area-average rain rate are well correlated for particular choices of the threshold [e.g., Kedem et al., 19901]. A straightforward application of this method to the TRMM data would consist of the conversion of the individual reflectivity factors to rain rates followed by a calculation of the fraction of these that exceed a particular threshold. Previous results indicate that for thresholds near or at 5 mm/h, the correlation between this fractional area and the area-average rain rate is high. There are several drawbacks to this approach, however. At the TRMM radar frequency of 13.8 GHz the signal suffers attenuation so that the negative bias of the high resolution rain rate estimates will increase as the path attenuation increases. To establish a quantitative relationship between fractional area and area-average rain rate, an independent means of calculating the area-average rain rate is needed such as an array of rain gauges. This type of calibration procedure, however, is difficult for a spaceborne radar such as TRMM. To estimate a statistic other than the mean of the distribution requires, in general, a different choice of threshold and a different set of tuning parameters.

Relating Convective and Stratiform Rain to Latent Heating

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Lang, Stephen; Zeng, Xiping; Shige, Shoichi; Takayabu, Yukari

2010-01-01

The relationship among surface rainfall, its intensity, and its associated stratiform amount is established by examining observed precipitation data from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). The results show that for moderate-high stratiform fractions, rain probabilities are strongly skewed toward light rain intensities. For convective-type rain, the peak probability of occurrence shifts to higher intensities but is still significantly skewed toward weaker rain rates. The main differences between the distributions for oceanic and continental rain are for heavily convective rain. The peak occurrence, as well as the tail of the distribution containing the extreme events, is shifted to higher intensities for continental rain. For rainy areas sampled at 0.58 horizontal resolution, the occurrence of conditional rain rates over 100 mm/day is significantly higher over land. Distributions of rain intensity versus stratiform fraction for simulated precipitation data obtained from cloud-resolving model (CRM) simulations are quite similar to those from the satellite, providing a basis for mapping simulated cloud quantities to the satellite observations. An improved convective-stratiform heating (CSH) algorithm is developed based on two sources of information: gridded rainfall quantities (i.e., the conditional intensity and the stratiform fraction) observed from the TRMM PR and synthetic cloud process data (i.e., latent heating, eddy heat flux convergence, and radiative heating/cooling) obtained from CRM simulations of convective cloud systems. The new CSH algorithm-derived heating has a noticeably different heating structure over both ocean and land regions compared to the previous CSH algorithm. Major differences between the new and old algorithms include a significant increase in the amount of low- and midlevel heating, a downward emphasis in the level of maximum cloud heating by about 1 km, and a larger variance between land and ocean in the new CSH algorithm.

Advanced communications technology satellite high burst rate link evaluation terminal power control and rain fade software test plan, version 1.0

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.

1993-01-01

The Power Control and Rain Fade Software was developed at the NASA Lewis Research Center to support the Advanced Communications Technology Satellite High Burst Rate Link Evaluation Terminal (ACTS HBR-LET). The HBR-LET is an experimenters terminal to communicate with the ACTS for various experiments by government, university, and industry agencies. The Power Control and Rain Fade Software is one segment of the Control and Performance Monitor (C&PM) Software system of the HBR-LET. The Power Control and Rain Fade Software automatically controls the LET uplink power to compensate for signal fades. Besides power augmentation, the C&PM Software system is also responsible for instrument control during HBR-LET experiments, control of the Intermediate Frequency Switch Matrix on board the ACTS to yield a desired path through the spacecraft payload, and data display. The Power Control and Rain Fade Software User's Guide, Version 1.0 outlines the commands and procedures to install and operate the Power Control and Rain Fade Software. The Power Control and Rain Fade Software Maintenance Manual, Version 1.0 is a programmer's guide to the Power Control and Rain Fade Software. This manual details the current implementation of the software from a technical perspective. Included is an overview of the Power Control and Rain Fade Software, computer algorithms, format representations, and computer hardware configuration. The Power Control and Rain Fade Test Plan provides a step-by-step procedure to verify the operation of the software using a predetermined signal fade event. The Test Plan also provides a means to demonstrate the capability of the software.

Intra-event isotope and raindrop size data of tropical rain reveal effects concealed by event averaged data

NASA Astrophysics Data System (ADS)

Managave, S. R.; Jani, R. A.; Narayana Rao, T.; Sunilkumar, K.; Satheeshkumar, S.; Ramesh, R.

2016-08-01

Evaporation of rain is known to contribute water vapor, a potent greenhouse gas, to the atmosphere. Stable oxygen and hydrogen isotopic compositions (δ18O and, δD, respectively) of precipitation, usually measured/presented as values integrated over rain events or monthly mean values, are important tools for detecting evaporation effects. The slope ~8 of the linear relationship between such time-averaged values of δD and δ18O (called the meteoric water line) is widely accepted as a proof of condensation under isotopic equilibrium and absence of evaporation of rain during atmospheric fall. Here, through a simultaneous investigation of the isotopic and drop size distributions of seventeen rain events sampled on an intra-event scale at Gadanki (13.5°N, 79.2°E), southern India, we demonstrate that the evaporation effects, not evident in the time-averaged data, are significantly manifested in the sub-samples of individual rain events. We detect this through (1) slopes significantly less than 8 for the δD-δ18O relation on intra-event scale and (2) significant positive correlations between deuterium excess ( d-excess = δD - 8*δ18O; lower values in rain indicate evaporation) and the mass-weighted mean diameter of the raindrops ( D m ). An estimated ~44 % of rain is influenced by evaporation. This study also reveals a signature of isotopic equilibration of rain with the cloud base vapor, the processes important for modeling isotopic composition of precipitation. d-excess values of rain are modified by the post-condensation processes and the present approach offers a way to identify the d-excess values least affected by such processes. Isotope-enabled global circulation models could be improved by incorporating intra-event isotopic data and raindrop size dependent isotopic effects.

Photosynthesis and oxidative stress in the restinga plant species Eugenia uniflora L. exposed to simulated acid rain and iron ore dust deposition: potential use in environmental risk assessment.

PubMed

Neves, Natália Rust; Oliva, Marco Antonio; da Cruz Centeno, Danilo; Costa, Alan Carlos; Ribas, Rogério Ferreira; Pereira, Eduardo Gusmão

2009-06-01

The Brazilian sandy coastal plain named restinga is frequently subjected to particulate and gaseous emissions from iron ore factories. These gases may come into contact with atmospheric moisture and produce acid rain. The effects of the acid rain on vegetation, combined with iron excess in the soil, can lead to the disappearance of sensitive species and decrease restinga biodiversity. The effects of iron ore dust deposition and simulated acid rain on photosynthesis and on antioxidant enzymes were investigated in Eugenia uniflora, a representative shrub species of the restinga. This study aimed to determine the possible utility of this species in environmental risk assessment. After the application of iron ore dust as iron solid particulate matter (SPM(Fe)) and simulated acid rain (pH 3.1), the 18-month old plants displayed brown spots and necrosis, typical symptoms of iron toxicity and injuries caused by acid rain, respectively. The acidity of the rain intensified leaf iron accumulation, which reached phytotoxic levels, mainly in plants exposed to iron ore dust. These plants showed the lowest values for net photosynthesis, stomatal conductance, transpiration, chlorophyll a content and electron transport rate through photosystem II (PSII). Catalase and superoxide dismutase activities were decreased by simulated acid rain. Peroxidase activity and membrane injury increased following exposure to acid rain and simultaneous SPM(Fe) application. Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses. This species could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories. Non-invasive evaluations of visual injuries, photosynthesis and chlorophyll a fluorescence, as well as invasive biochemical analysis could be used as markers.

Combined effects of lanthanum ion and acid rain on growth, photosynthesis and chloroplast ultrastructure in soybean seedlings.

PubMed

Wen, Kejia; Liang, Chanjuan; Wang, Lihong; Hu, Gang; Zhou, Qing

2011-07-01

Rare earth elements (REEs) have been accumulated in the agricultural environment. Acid rain is a serious environmental issue. In the present work, the effects of lanthanum ion (La(3+)) and acid rain on the growth, photosynthesis and chloroplast ultrastructure in soybean seedlings were investigated using the gas exchange measurements system, chlorophyll fluorometer, transmission electron microscopy and some biochemical techniques. It was found that although the growth and photosynthesis of soybean seedlings treated with the low concentration of La(3+) was improved, the growth and photosynthesis of soybean seedlings were obviously inhibited in the combined treatment with the low concentration of La(3+) and acid rain. At the same time, the chloroplast ultrastructure in the cell of soybean seedlings was destroyed. Under the combined treatment with the high concentration of La(3+) and acid rain, the chloroplast ultrastructure in the cell of soybean seedlings was seriously destroyed, and the growth and of photosynthesis were greatly decreased compared with those of the control, the single treatment with the high concentration of La(3+) and the single treatment with acid rain, respectively. The degree of decrease and destruction on chloroplast ultrastructure depended on the increases in the concentration of La(3+) and acid rain (H(+)). In conclusion, the combined pollution of La(3+) and acid rain obviously destroyed the chloroplast ultrastructure of cell and aggravated the harmful effect of the single La(3+) and acid rain on soybean seedlings. As a new combined pollutant, the harmful effect of REEs ions and acid rain on plant should be paid attention to. Copyright © 2011 Elsevier Ltd. All rights reserved.

Rain-Shelter Cultivation Modifies Carbon Allocation in the Polyphenolic and Volatile Metabolism of Vitis vinifera L. Chardonnay Grapes.

PubMed

Gao, Yuan; Li, Xiao-Xi; Han, Mei-Mei; Yang, Xiao-Fan; Li, Zheng; Wang, Jun; Pan, Qiu-Hong

2016-01-01

This study investigated the effect of rain-shelter cultivation on the biosynthesis of flavonoids and volatiles in grapes, with an aim of determining whether rain-shelter application could help to improve the sensory attributes and quality of grapes. Vitis vinifera L. Chardonnay grapes, grown in the Huaizhuo basin region of northern China, were selected within two consecutive years. A rain-shelter roof was constructed using a colorless polyethylene (PE) film with a light transmittance of 80%. Results showed that rain-shelter treatment did not affect the accumulation of soluble solids during grape maturation. However, the allocation of assimilated carbon in phenolic and volatile biosynthetic pathways varied significantly, leading to alterations in polyphenolic and volatile profiles. The rain-shelter cultivation enhanced the concentration of flavan-3-ols via the flavonoid-3'5'-hydroxylase (F3'5'H) pathway, but reduced the level of flavonols and flavan-3-ols via the flavonoid-3'-hydroxylase (F3'H) pathway. In addition, the rain-shelter cultivation significantly enhanced the synthesis of fatty acid-derived volatiles, isoprene-derived terpenoids and amino acid-derived branched-chain aliphatics, but led to a decrease in the accumulation of isoprene-derived norisoprenoids and amino acid-derived benzenoids. Principal component analysis revealed some key compounds that differentiated the grapes cultivated under open-field and rain-shelter conditions. Moreover, the effect of the rain-shelter application on the accumulation of these compounds appeared to be vintage dependent. The alteration of their profiles caused by the rain-shelter treatment was significant in the vintage that received higher rainfall, which usually took place in the first rapid growth and veraison phases.

Rain-Shelter Cultivation Modifies Carbon Allocation in the Polyphenolic and Volatile Metabolism of Vitis vinifera L. Chardonnay Grapes

PubMed Central

Han, Mei-Mei; Yang, Xiao-Fan; Li, Zheng; Wang, Jun; Pan, Qiu-Hong

2016-01-01

This study investigated the effect of rain-shelter cultivation on the biosynthesis of flavonoids and volatiles in grapes, with an aim of determining whether rain-shelter application could help to improve the sensory attributes and quality of grapes. Vitis vinifera L. Chardonnay grapes, grown in the Huaizhuo basin region of northern China, were selected within two consecutive years. A rain-shelter roof was constructed using a colorless polyethylene (PE) film with a light transmittance of 80%. Results showed that rain-shelter treatment did not affect the accumulation of soluble solids during grape maturation. However, the allocation of assimilated carbon in phenolic and volatile biosynthetic pathways varied significantly, leading to alterations in polyphenolic and volatile profiles. The rain-shelter cultivation enhanced the concentration of flavan-3-ols via the flavonoid-3’5’-hydroxylase (F3’5’H) pathway, but reduced the level of flavonols and flavan-3-ols via the flavonoid-3’-hydroxylase (F3’H) pathway. In addition, the rain-shelter cultivation significantly enhanced the synthesis of fatty acid-derived volatiles, isoprene-derived terpenoids and amino acid-derived branched-chain aliphatics, but led to a decrease in the accumulation of isoprene-derived norisoprenoids and amino acid-derived benzenoids. Principal component analysis revealed some key compounds that differentiated the grapes cultivated under open-field and rain-shelter conditions. Moreover, the effect of the rain-shelter application on the accumulation of these compounds appeared to be vintage dependent. The alteration of their profiles caused by the rain-shelter treatment was significant in the vintage that received higher rainfall, which usually took place in the first rapid growth and veraison phases. PMID:27218245

Satellite Sampling and Retrieval Errors in Regional Monthly Rain Estimates from TMI AMSR-E, SSM/I, AMSU-B and the TRMM PR

NASA Technical Reports Server (NTRS)

Fisher, Brad; Wolff, David B.

2010-01-01

Passive and active microwave rain sensors onboard earth-orbiting satellites estimate monthly rainfall from the instantaneous rain statistics collected during satellite overpasses. It is well known that climate-scale rain estimates from meteorological satellites incur sampling errors resulting from the process of discrete temporal sampling and statistical averaging. Sampling and retrieval errors ultimately become entangled in the estimation of the mean monthly rain rate. The sampling component of the error budget effectively introduces statistical noise into climate-scale rain estimates that obscure the error component associated with the instantaneous rain retrieval. Estimating the accuracy of the retrievals on monthly scales therefore necessitates a decomposition of the total error budget into sampling and retrieval error quantities. This paper presents results from a statistical evaluation of the sampling and retrieval errors for five different space-borne rain sensors on board nine orbiting satellites. Using an error decomposition methodology developed by one of the authors, sampling and retrieval errors were estimated at 0.25 resolution within 150 km of ground-based weather radars located at Kwajalein, Marshall Islands and Melbourne, Florida. Error and bias statistics were calculated according to the land, ocean and coast classifications of the surface terrain mask developed for the Goddard Profiling (GPROF) rain algorithm. Variations in the comparative error statistics are attributed to various factors related to differences in the swath geometry of each rain sensor, the orbital and instrument characteristics of the satellite and the regional climatology. The most significant result from this study found that each of the satellites incurred negative longterm oceanic retrieval biases of 10 to 30%.

Scale Dependence of Statistics of Spatially Averaged Rain Rate Seen in TOGA COARE Comparison with Predictions from a Stochastic Model

NASA Technical Reports Server (NTRS)

Kundu, Prasun K.; Bell, T. L.; Lau, William K. M. (Technical Monitor)

2002-01-01

A characteristic feature of rainfall statistics is that they in general depend on the space and time scales over which rain data are averaged. As a part of an earlier effort to determine the sampling error of satellite rain averages, a space-time model of rainfall statistics was developed to describe the statistics of gridded rain observed in GATE. The model allows one to compute the second moment statistics of space- and time-averaged rain rate which can be fitted to satellite or rain gauge data to determine the four model parameters appearing in the precipitation spectrum - an overall strength parameter, a characteristic length separating the long and short wavelength regimes and a characteristic relaxation time for decay of the autocorrelation of the instantaneous local rain rate and a certain 'fractal' power law exponent. For area-averaged instantaneous rain rate, this exponent governs the power law dependence of these statistics on the averaging length scale $L$ predicted by the model in the limit of small $L$. In particular, the variance of rain rate averaged over an $L \\times L$ area exhibits a power law singularity as $L \\rightarrow 0$. In the present work the model is used to investigate how the statistics of area-averaged rain rate over the tropical Western Pacific measured with ship borne radar during TOGA COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmospheric Response Experiment) and gridded on a 2 km grid depends on the size of the spatial averaging scale. Good agreement is found between the data and predictions from the model over a wide range of averaging length scales.

Acid Rain: The Silent Environmental Threat.

ERIC Educational Resources Information Center

Zmud, Mia

1992-01-01

Describes the silent environmental threat posed by acid rain. Caused mainly by manmade pollutants, acid rain damages water and trees, decreases visibility, corrodes monuments, and threatens public health. The article includes guidelines for action. (SM)

Distribution of rain height over subtropical region: Durban, South Africa for satellite communication systems

NASA Astrophysics Data System (ADS)

Olurotimi, E. O.; Sokoya, O.; Ojo, J. S.; Owolawi, P. A.

2018-03-01

Rain height is one of the significant parameters for prediction of rain attenuation for Earth-space telecommunication links, especially those operating at frequencies above 10 GHz. This study examines Three-parameter Dagum distribution of the rain height over Durban, South Africa. 5-year data were used to study the monthly, seasonal, and annual variations using the parameters estimated by the maximum likelihood of the distribution. The performance estimation of the distribution was determined using the statistical goodness of fit. Three-parameter Dagum distribution shows an appropriate distribution for the modeling of rain height over Durban with the Root Mean Square Error of 0.26. Also, the shape and scale parameters for the distribution show a wide variation. The probability exceedance of time for 0.01% indicates the high probability of rain attenuation at higher frequencies.

Rain water chemistry in Ankara, Turkey

NASA Astrophysics Data System (ADS)

Tuncel, Semra G.; Ungör, Sevgi

Samples of rain water were collected in Ankara for the period between September 1989 and May 1990, by using wet-only sampler. Concentrations of major cations (H +, Na + K + Ca 2+ and NH 4+) and major anions (Cl -, NO 3- and SO 42-) were determined for the first time in Turkey. The rain water was not acidic owing to high concentrations of alkaline soil particles in the atmosphere. However, the concentrations of acid forming ions, such as SO 4- and N03, were higher than the concentrations expected in a typical urban atmosphere. Most of the SO 4- in rain water was in the form of CaSO 4. Rain-aerosol coupling were examined by simultaneous sampling of aerosols with rain. The ions most efficiently scavenged from the atmosphere were found to be SO 42- and Ca 2+.

A numerical study of the acid rain in northern Taiwan in winter season

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Ching-Sen; Deng, Zen-Sing

1996-12-31

Two-thirds of the land mass of Taiwan island is covered by mountains. In winter precipitation could occur in northern Taiwan when the prevailing wind was from northeastern direction. In northern Taiwan the acid rain (pH value less than 5.0) in winter time could contribute about 30 rain in the whole year. A three-dimensional numerical model with terrain following coordinated system was used to simulate the precipitation system and the characteristics of acid rain. A smooth terrain was assumed in the model. A mean sounding was used to initialize the numerical model when acid rain occurred in northern Taiwan during wintermore » time from 1991 to 1993. Investigations of the effect of pollutions from abroad on the acid rain in northern Taiwan in winter are considered for the future.« less

Heavy rain effects

NASA Technical Reports Server (NTRS)

Dunham, R. Earl, Jr.

1994-01-01

This paper summarizes the current state of knowledge of the effect of heavy rain on airplane performance. Although the effects of heavy rain on airplane systems and engines are generally known, only recently has the potential aerodynamic effect of heavy rain been recognized. In 1977 the United States Federal Aviation Administration (FAA) conducted a study of 25 aircraft accidents and incidents which occurred between 1964 and 1976 in which low-altitude wind shear could have been a contributing factor. Of the 25 cases (23 approach or landing and 2 take-off) in the study, ten cases had occurred in a rain environment, and in five cases these were classified as intense or heavy rain encounters. These results led to the reconsideration of high-intensity, short-duration rainfall as a potential weather-related aircraft safety hazard, particularly in the take-off and/or approach phases of flight.

Environmental fog/rain visual display system for aircraft simulators

NASA Technical Reports Server (NTRS)

Chase, W. D. (Inventor)

1982-01-01

An environmental fog/rain visual display system for aircraft simulators is described. The electronic elements of the system include a real time digital computer, a caligraphic color display which simulates landing lights of selective intensity, and a color television camera for producing a moving color display of the airport runway as depicted on a model terrain board. The mechanical simulation elements of the system include an environmental chamber which can produce natural fog, nonhomogeneous fog, rain and fog combined, or rain only. A pilot looking through the aircraft wind screen will look through the fog and/or rain generated in the environmental chamber onto a viewing screen with the simulated color image of the airport runway thereon, and observe a very real simulation of actual conditions of a runway as it would appear through actual fog and/or rain.

A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. 1: Theoretical development and application to yearly predictions for selected cities in the United States

NASA Technical Reports Server (NTRS)

Manning, Robert M.

1986-01-01

A rain attenuation prediction model is described for use in calculating satellite communication link availability for any specific location in the world that is characterized by an extended record of rainfall. Such a formalism is necessary for the accurate assessment of such availability predictions in the case of the small user-terminal concept of the Advanced Communication Technology Satellite (ACTS) Project. The model employs the theory of extreme value statistics to generate the necessary statistical rainrate parameters from rain data in the form compiled by the National Weather Service. These location dependent rain statistics are then applied to a rain attenuation model to obtain a yearly prediction of the occurrence of attenuation on any satellite link at that location. The predictions of this model are compared to those of the Crane Two-Component Rain Model and some empirical data and found to be very good. The model is then used to calculate rain attenuation statistics at 59 locations in the United States (including Alaska and Hawaii) for the 20 GHz downlinks and 30 GHz uplinks of the proposed ACTS system. The flexibility of this modeling formalism is such that it allows a complete and unified treatment of the temporal aspects of rain attenuation that leads to the design of an optimum stochastic power control algorithm, the purpose of which is to efficiently counter such rain fades on a satellite link.

Alterations in cytosol free calcium in horseradish roots simultaneously exposed to lanthanum(III) and acid rain.

PubMed

Zhang, Xuanbo; Wang, Lihong; Zhou, Anhua; Zhou, Qing; Huang, Xiaohua

2016-04-01

The extensive use of rare earth elements (REEs) has increased their environmental levels. REE pollution concomitant with acid rain in many agricultural regions can affect crop growth. Cytosol free calcium ions (Ca(2+)) play an important role in almost all cellular activities. However, no data have been reported regarding the role of cytosol free Ca(2+) in plant roots simultaneously exposed to REE and acid rain. In this study, the effects of exposures to lanthanum(III) and acid rain, independently and in combination, on cytosol free Ca(2+) levels, root activity, metal contents, biomass, cytosol pH and La contents in horseradish roots were investigated. The simultaneous exposures to La(III) and acid rain increased or decreased the cytosol free Ca(2+) levels, depending on the concentration of La(III), and these effects were more evident than independent exposure to La(III) or acid rain. In combined exposures, cytosol free Ca(2+) played an important role in the regulation of root activity, metal contents and biomass. These roles were closely related to La(III) dose, acid rain strength and treatment mode (independent exposure or simultaneous exposure). A low concentration of La(III) (20 mg L(-1)) could alleviate the adverse effects on the roots caused by acid rain, and the combined exposures at higher concentrations of La(III) and acid rain had synergic effects on the roots. Copyright © 2015 Elsevier Inc. All rights reserved.

Response of plasma membrane H+-ATPase in rice (Oryza sativa) seedlings to simulated acid rain.

PubMed

Liang, Chanjuan; Ge, Yuqing; Su, Lei; Bu, Jinjin

2015-01-01

Understanding the adaptation of plants to acid rain is important to find feasible approaches to alleviate such damage to plants. We studied effects of acid rain on plasma membrane H(+)-ATPase activity and transcription, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate during stress and recovery periods. Simulated acid rain at pH 5.5 did not affect plasma membrane H(+)-ATPase activity, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate. Plasma membrane H(+)-ATPase activity and transcription in leaves treated with acid rain at pH 3.5 was increased to maintain ion homeostasis by transporting excessive H(+) out of cells. Then intracellular H(+) was close to the control after a 5-day recovery, alleviating damage on membrane and sustaining photosynthetic efficiency and growth. Simulated acid rain at pH 2.5 inhibited plasma membrane H(+)-ATPase activity by decreasing the expression of H(+)-ATPase at transcription level, resulting in membrane damage and abnormal intracellular H(+), and reduction in photosynthetic efficiency and relative growth rate. After a 5-day recovery, all parameters in leaves treated with pH 2.5 acid rain show alleviated damage, implying that the increased plasma membrane H(+)-ATPase activity and its high expression were involved in repairing process in acid rain-stressed plants. Our study suggests that plasma membrane H(+)-ATPase can play a role in adaptation to acid rain for rice seedlings.

Single-image-based Rain Detection and Removal via CNN

NASA Astrophysics Data System (ADS)

Chen, Tianyi; Fu, Chengzhou

2018-04-01

The quality of the image is degraded by rain streaks, which have negative impact when we extract image features for many visual tasks, such as feature extraction for classification and recognition, tracking, surveillance and autonomous navigation. Hence, it is necessary to detect and remove rain streaks from single images, which is a challenging problem since we have no spatial-temporal information of rain streaks compared to the dynamic video stream. Inspired by the priori that the rain streaks have almost the same feature, such as the direction or the thickness, although they are in different types of real-world images. The paper aims at proposing an effective convolutional neural network (CNN) to detect and remove rain streaks from single image. Two models of synthesized rainy image, linear additive composite model (LACM model) and screen blend model (SCM model), are considered in this paper. The main idea is that it is easier for our CNN network to find the mapping between the rainy image and rain streaks than between the rainy image and clean image. The reason is that rain streaks have fixed features, but clean images have various features. The experiments show that the designed CNN network outperforms state-of-the-art approaches on both synthesized and real-world images, which indicates the effectiveness of our proposed framework.

Combined effects of lead and acid rain on photosynthesis in soybean seedlings.

PubMed

Hu, Huiqing; Wang, Lihong; Liao, Chenyu; Fan, Caixia; Zhou, Qing; Huang, Xiaohua

2014-10-01

To explore how lead (Pb) and acid rain simultaneously affect plants, the combined effects of Pb and acid rain on the chlorophyll content, chlorophyll fluorescence reaction, Hill reaction rate, and Mg(2+)-ATPase activity in soybean seedlings were investigated. The results indicated that, when soybean seedlings were treated with Pb or acid rain alone, the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, and maximal photochemical efficiency (F(v)/F(m)) were decreased, while the initial fluorescence (F 0) and maximum quantum yield (Y) were increased, compared with those of the control. The combined treatment with Pb and acid rain decreased the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, F(v)/F(m), and Y and increased F 0 in soybean seedlings. Under the combined treatment with Pb and acid rain, the two factors showed additive effects on the chlorophyll content in soybean seedlings and exhibited antagonistic effects on the Hill reaction rate. Under the combined treatment with high-concentration Pb and acid rain, the two factors exhibited synergistic effects on the Mg(2+)-ATPase activity, F 0, F v/F m, as well as Y. In summary, the inhibition of the photosynthetic process is an important physiological basis for the simultaneous actions of Pb and acid rain in soybean seedlings.

A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. Part 2: Theoretical development of a dynamic model and application to rain fade durations and tolerable control delays for fade countermeasures

NASA Technical Reports Server (NTRS)

Manning, Robert M.

1987-01-01

A dynamic rain attenuation prediction model is developed for use in obtaining the temporal characteristics, on time scales of minutes or hours, of satellite communication link availability. Analagous to the associated static rain attenuation model, which yields yearly attenuation predictions, this dynamic model is applicable at any location in the world that is characterized by the static rain attenuation statistics peculiar to the geometry of the satellite link and the rain statistics of the location. Such statistics are calculated by employing the formalism of Part I of this report. In fact, the dynamic model presented here is an extension of the static model and reduces to the static model in the appropriate limit. By assuming that rain attenuation is dynamically described by a first-order stochastic differential equation in time and that this random attenuation process is a Markov process, an expression for the associated transition probability is obtained by solving the related forward Kolmogorov equation. This transition probability is then used to obtain such temporal rain attenuation statistics as attenuation durations and allowable attenuation margins versus control system delay.

Average BER and outage probability of the ground-to-train OWC link in turbulence with rain

NASA Astrophysics Data System (ADS)

Zhang, Yixin; Yang, Yanqiu; Hu, Beibei; Yu, Lin; Hu, Zheng-Da

2017-09-01

The bit-error rate (BER) and outage probability of optical wireless communication (OWC) link for the ground-to-train of the curved track in turbulence with rain is evaluated. Considering the re-modulation effects of raining fluctuation on optical signal modulated by turbulence, we set up the models of average BER and outage probability in the present of pointing errors, based on the double inverse Gaussian (IG) statistical distribution model. The numerical results indicate that, for the same covered track length, the larger curvature radius increases the outage probability and average BER. The performance of the OWC link in turbulence with rain is limited mainly by the rain rate and pointing errors which are induced by the beam wander and train vibration. The effect of the rain rate on the performance of the link is more severe than the atmospheric turbulence, but the fluctuation owing to the atmospheric turbulence affects the laser beam propagation more greatly than the skewness of the rain distribution. Besides, the turbulence-induced beam wander has a more significant impact on the system in heavier rain. We can choose the size of transmitting and receiving apertures and improve the shockproof performance of the tracks to optimize the communication performance of the system.

A cloud model-radiative model combination for determining microwave TB-rain rate relations

NASA Technical Reports Server (NTRS)

Szejwach, Gerard; Adler, Robert F.; Jobard, Esabelle; Mack, Robert A.

1986-01-01

The development of a cloud model-radiative transfer model combination for computing average brightness temperature, T(B), is discussed. The cloud model and radiative transfer model used in this study are described. The relations between rain rate, cloud and rain water, cloud and precipitation ice, and upwelling radiance are investigated. The effects of the rain rate relations on T(B) under different climatological conditions are examined. The model-derived T(B) results are compared to the 92 and 183 GHz aircraft observations of Hakkarinen and Adler (1984, 1986) and the radar-estimated rain rate of Hakkarinen and Adler (1986); good correlation between the data is detected.

Nature in the Classroom: Acid Rain.

ERIC Educational Resources Information Center

Doyle, Charles

1982-01-01

As a lesson topic, acid rain is defined, its chemistry given, and its development since the 1950s described. The worldwide effects of acid rain are discussed along with the available technology for controlling the problem. (CM)

Effects of acid rain on grapevines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forsline, P.L.; Musselman, R.C.; Dee, R.J.

1983-01-01

Mature vineyard-growing Concord grapevines were sprayed with simulated acid rain solutions ranging from pH 2.5 to 5.5 both as acute treatments at anthesis and chronically throughout the season in 1980 and 1981. In 1981, 8 additional varieties were also treated with simulated acid rain solutions at pH 2.75 and 3.25. With Concord in 1981, few foliar lesions on leaves were visible at pH 2.75. In contrast, many leaf lesions with decreased fruit soluble solids were observed at pH 2.5 in 1980. The relationship between acid-rain and oxidant stipple, chlorosis, and soluble solids in the absence of acid rain leaf lesionsmore » at pH>2.5 remains unclear. Acute sprays (pH2.75) at anthesis reduced pollen germination in four grape cultivars. However, fruit set was reduced in only one of these. Grape yields were not influenced by acid rain treatments. There was no evidence that acid-rain at ambient pH levels had negative effects on grape production or fruit quality.« less

A modified ATI technique for nowcasting convective rain volumes over areas. [area-time integrals

NASA Technical Reports Server (NTRS)

Makarau, Amos; Johnson, L. Ronald; Doneaud, Andre A.

1988-01-01

This paper explores the applicability of the area-time-integral (ATI) technique for the estimation of the growth portion only of a convective storm (while the rain volume is computed using the entire life history of the event) and for nowcasting the total rain volume of a convective system at the stage of its maximum development. For these purposes, the ATIs were computed from the digital radar data (for 1981-1982) from the North Dakota Cloud Modification Project, using the maximum echo area (ATIA) no less than 25 dBz, the maximum reflectivity, and the maximum echo height as the end of the growth portion of the convective event. Linear regression analysis demonstrated that correlations between total rain volume or the maximum rain volume versus ATIA were the strongest. The uncertainties obtained were comparable to the uncertainties which typically occur in rain volume estimates obtained from radar data employing Z-R conversion followed by space and time integration. This demonstrates that the total rain volume of a storm can be nowcasted at its maximum stage of development.

Improved Gradation for Rain Garden of Low Impact Development

NASA Astrophysics Data System (ADS)

Lee, Sandra; Chang, Fu-Ming

2016-04-01

With rapid urban and economic development, living standard improves in urban areas but urban ecological environments deteriorate rapidly. Urban waterlogging and flooding have become a serious problem for urban water security. As urbanization continues, sustainability is the key to balance between urban development and healthy environment. Rain garden is recommended to be one of the best ways to reduce urban pollutants. It not only diminishes runoff flooding but also purify water in the urban area. The studies on rain gardens are mainly about how to incorporate rain garden to purify water quality, but lack of researches on runoff control. This project focuses on rain garden under Low Impact Development using indoor laboratory to test and quantify the water holding capacities of two different Taiwan indigenous rain garden plants, Taiwan Cyclosorus and Sour Grass. The results show that the water holding capacity of Sour Grass (10%-37%) is better than that of Taiwan Cyclosorus (6.8%-17.3%). The results could be a helpful reference for Low Impact Development in urban flood prevention and urban planning. Keywords: Low Impact Development; rain garden; indoor laboratory experiments; water holding capacity; porosity

Validating Microwave-Based Satellite Rain Rate Retrievals Over TRMM Ground Validation Sites

NASA Astrophysics Data System (ADS)

Fisher, B. L.; Wolff, D. B.

2008-12-01

Multi-channel, passive microwave instruments are commonly used today to probe the structure of rain systems and to estimate surface rainfall from space. Until the advent of meteorological satellites and the development of remote sensing techniques for measuring precipitation from space, there was no observational system capable of providing accurate estimates of surface precipitation on global scales. Since the early 1970s, microwave measurements from satellites have provided quantitative estimates of surface rainfall by observing the emission and scattering processes due to the existence of clouds and precipitation in the atmosphere. This study assesses the relative performance of microwave precipitation estimates from seven polar-orbiting satellites and the TRMM TMI using four years (2003-2006) of instantaneous radar rain estimates obtained from Tropical Rainfall Measuring Mission (TRMM) Ground Validation (GV) sites at Kwajalein, Republic of the Marshall Islands (KWAJ) and Melbourne, Florida (MELB). The seven polar orbiters include three different sensor types: SSM/I (F13, F14 and F15), AMSU-B (N15, N16 and N17), and AMSR-E. The TMI aboard the TRMM satellite flies in a sun asynchronous orbit between 35 S and 35 N latitudes. The rain information from these satellites are combined and used to generate several multi-satellite rain products, namely the Goddard TRMM Multi-satellite Precipitation Analysis (TMPA), NOAA's CPC Morphing Technique (CMORPH) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN). Instantaneous rain rates derived from each sensor were matched to the GV estimates in time and space at a resolution of 0.25 degrees. The study evaluates the measurement and error characteristics of the various satellite estimates through inter-comparisons with GV radar estimates. The GV rain observations provided an empirical ground-based reference for assessing the relative performance of each sensor and sensor class. Because the relative performance of the rain algorithms depends on the underlying surface terrain, the data for MELB was further stratified into ocean, land and coast categories using a 0.25 terrain mask. Relative to GV, AMSR-E and the TMI exhibited the highest correlation and skill over the full dynamic range of observed rain rates at both validation sites. The AMSU sensors, on the other hand, exhibited the lowest correlation and skill, though all sensors performed reasonably well compared to GV. The general tendency was for the microwave sensors to overestimate rain rates below 1 mm/hr where the sampling was highest and to underestimate the high rain rates above 10 mm/hr where the sampling was lowest. Underestimation of the low rain rate regime is attributed to difficulties of detecting and measuring low rain rates, while overestimation over the oceans was attributed largely to saturation of the brightness temperatures at high rain rates. Overall biases depended on the relative differences in the total rainfall at the extremes and the performance of each sensor at the nominal rain rates.

Acid Rain.

ERIC Educational Resources Information Center

Openshaw, Peter

1987-01-01

Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

Scale Dependence of Spatiotemporal Intermittence of Rain

NASA Technical Reports Server (NTRS)

Kundu, Prasun K.; Siddani, Ravi K.

2011-01-01

It is a common experience that rainfall is intermittent in space and time. This is reflected by the fact that the statistics of area- and/or time-averaged rain rate is described by a mixed distribution with a nonzero probability of having a sharp value zero. In this paper we have explored the dependence of the probability of zero rain on the averaging space and time scales in large multiyear data sets based on radar and rain gauge observations. A stretched exponential fannula fits the observed scale dependence of the zero-rain probability. The proposed formula makes it apparent that the space-time support of the rain field is not quite a set of measure zero as is sometimes supposed. We also give an ex.planation of the observed behavior in tenus of a simple probabilistic model based on the premise that rainfall process has an intrinsic memory.

Experimental investigation of influence of acid rain on leaching and hydraulic characteristics of cement-based solidified/stabilized lead contaminated clay.

PubMed

Du, Yan-Jun; Jiang, Ning-Jun; Shen, Shui-Long; Jin, Fei

2012-07-30

Remediation of contaminated lands in China urban areas is of great concern. Degradation of construction facilities caused by acid rain is a serious environmental pollution issue in China. This paper presents an investigation of the effects of acid rain on leaching and hydraulic properties of cement-based solidified/stabilized lead contaminated soil. Laboratory tests including infiltration test and soaking test are conducted. It is found that the soil hydraulic conductivity decreases with increase in the pore volume of flow of permeant liquids (acid rain and distilled water). The decreasing rate in the case of the acid rain is lower than that in the case of the distilled water. The soaking test results show that pH and the presence of sulfate ions of acid rain have considerable influence on the leached concentrations and leaching rate of calcium. Copyright © 2012 Elsevier B.V. All rights reserved.

Estimating the exceedance probability of rain rate by logistic regression

NASA Technical Reports Server (NTRS)

Chiu, Long S.; Kedem, Benjamin

1990-01-01

Recent studies have shown that the fraction of an area with rain intensity above a fixed threshold is highly correlated with the area-averaged rain rate. To estimate the fractional rainy area, a logistic regression model, which estimates the conditional probability that rain rate over an area exceeds a fixed threshold given the values of related covariates, is developed. The problem of dependency in the data in the estimation procedure is bypassed by the method of partial likelihood. Analyses of simulated scanning multichannel microwave radiometer and observed electrically scanning microwave radiometer data during the Global Atlantic Tropical Experiment period show that the use of logistic regression in pixel classification is superior to multiple regression in predicting whether rain rate at each pixel exceeds a given threshold, even in the presence of noisy data. The potential of the logistic regression technique in satellite rain rate estimation is discussed.

Estimating 1 min rain rate distributions from numerical weather prediction

NASA Astrophysics Data System (ADS)

Paulson, Kevin S.

2017-01-01

Internationally recognized prognostic models of rain fade on terrestrial and Earth-space EHF links rely fundamentally on distributions of 1 min rain rates. Currently, in Rec. ITU-R P.837-6, these distributions are generated using the Salonen-Poiares Baptista method where 1 min rain rate distributions are estimated from long-term average annual accumulations provided by numerical weather prediction (NWP). This paper investigates an alternative to this method based on the distribution of 6 h accumulations available from the same NWPs. Rain rate fields covering the UK, produced by the Nimrod network of radars, are integrated to estimate the accumulations provided by NWP, and these are linked to distributions of fine-scale rain rates. The proposed method makes better use of the available data. It is verified on 15 NWP regions spanning the UK, and the extension to other regions is discussed.

A Stochastic Model of Space-Time Variability of Tropical Rainfall: I. Statistics of Spatial Averages

NASA Technical Reports Server (NTRS)

Kundu, Prasun K.; Bell, Thomas L.; Lau, William K. M. (Technical Monitor)

2002-01-01

Global maps of rainfall are of great importance in connection with modeling of the earth s climate. Comparison between the maps of rainfall predicted by computer-generated climate models with observation provides a sensitive test for these models. To make such a comparison, one typically needs the total precipitation amount over a large area, which could be hundreds of kilometers in size over extended periods of time of order days or months. This presents a difficult problem since rain varies greatly from place to place as well as in time. Remote sensing methods using ground radar or satellites detect rain over a large area by essentially taking a series of snapshots at infrequent intervals and indirectly deriving the average rain intensity within a collection of pixels , usually several kilometers in size. They measure area average of rain at a particular instant. Rain gauges, on the other hand, record rain accumulation continuously in time but only over a very small area tens of centimeters across, say, the size of a dinner plate. They measure only a time average at a single location. In making use of either method one needs to fill in the gaps in the observation - either the gaps in the area covered or the gaps in time of observation. This involves using statistical models to obtain information about the rain that is missed from what is actually detected. This paper investigates such a statistical model and validates it with rain data collected over the tropical Western Pacific from ship borne radars during TOGA COARE (Tropical Oceans Global Atmosphere Coupled Ocean-Atmosphere Response Experiment). The model incorporates a number of commonly observed features of rain. While rain varies rapidly with location and time, the variability diminishes when averaged over larger areas or longer periods of time. Moreover, rain is patchy in nature - at any instant on the average only a certain fraction of the observed pixels contain rain. The fraction of area covered by rain decreases, as the size of a pixel becomes smaller. This means that within what looks like a patch of rainy area in a coarse resolution view with larger pixel size, one finds clusters of rainy and dry patches when viewed on a finer scale. The model makes definite predictions about how these and other related statistics depend on the pixel size. These predictions were found to agree well with data. In a subsequent second part of the work we plan to test the model with rain gauge data collected during the TRMM (Tropical Rainfall Measuring Mission) ground validation campaign.

Isotopic equilibrium between precipitation and water vapor: evidence from continental rains in central Kenya

NASA Astrophysics Data System (ADS)

Soderberg, K.; Gerlein, C.; Kemeny, P. C.; Caylor, K. K.

2013-12-01

An accurate understanding of the relationships between the isotopic composition of liquid water and that of water vapor in the environment can help describe hydrologic processes across many scales. One such relationship is the isotopic equilibrium between falling raindrops and the surrounding vapor. The degree of equilibration is used to model the isotopic composition of precipitation in isotope-enable general circulation models and land-atmosphere exchange models. Although this equilibrium has been a topic of isotope hydrology research for more than four decades, few studies have included vapor measurements to validate modeling efforts. Recent advances in laser technology have allowed for in situ vapor measurements at high temporal resolution (e.g., >1 Hz). Here we present concomitant rain and vapor measurements for a series of 17 rain events during the 'Continental' rainy season (June through August) at Mpala Research Center in central Kenya. Rain samples (n=218) were collected at intervals of 2 to 35 minutes (median of 3 minutes) depending on the rain rate (0.4 to 10.5 mm/hr). The volume-weighted mean rain values for δ18O, δ2H and D-excess (δ2H - 8* δ18O) were 0.1 ‰, 10.7 ‰, and 10.1 ‰. These values are more enriched than the annual weighted means reported for the area (-2.2 ‰, -7.6 ‰, and 11.0 ‰, respectively). Vapor was measured continuously at ~2Hz (DLT-100, Los Gatos Research), with an inverted funnel intake 4m above the ground surface. The mean vapor isotopic composition during the rain events was -10.0 +/- 1.2 ‰ (1 σ) for δ18O and -73.9 +/- 7.0 ‰ for δ2H. The difference between the rain sample isotopic composition and that of liquid in isotopic equilibrium with the corresponding vapor at the ambient temperature was 0.8 +/- 2.2 ‰ for δ18O and 6.2 +/- 7.0 ‰ for δ2H. This disequilibrium was found to correlate with the natural log of rain rate (R2 of 0.26 for δ18O and 0.46 for δ2H), with lower rain rates having larger disequilibrium. There was also a temporal pattern in the disequilibrium for δ18O, with the first five rain events having significantly larger (p < 0.01) disequilibrium (4.4 ‰) than the subsequent rain events (0.6 ‰). The temporal pattern suggests that, in addition to the relationship with rain rate, there is some relationship between rain-vapor equilibrium and larger-scale controls such as vapor source region, precipitation recycling and air mass trajectory.

Patterns of precipitation: Fine-scale rain dynamics in the South of England

NASA Astrophysics Data System (ADS)

Callaghan, Sarah

2010-05-01

The consensus in the climate change community is that one of the (many) effects of climate change will be that the nature of rain events will change, and in all likelihood, they will become more extreme. Currently, most long-term rain rate data sets are hourly (or longer) rain accumulations, so investigating the rain events that occur for less than 0.01% (52.5 minutes) of a year is not possible. Rain datasets do exist with smaller temporal resolution, but these are either not continuous, or simply have not been in operation long enough to investigate any trends in climate change. The Chilbolton Observatory in the south of England is one of the world's most advanced meteorological radar experimental facilities, and is home to the world's largest fully steerable meteorological radar, the Chilbolton Advanced Meteorological Radar (CAMRa). It also hosts a wide range of meteorological and atmospheric sensing instruments, including cameras, lidars, radiometers and a wide selection of different types of rain gauges. The UK atmospheric science, hydrology and Earth Observation communities use the instruments located at Chilbolton to conduct research in weather, flooding and climate. This often involves observations of meteorological phenomena operating below the current resolution of (forecasting and climate) models and work on their effective parameterisation. The Chilbolton datasets contain a continuous drop counting rain gauge time series at 10 seconds integration time, spanning from January 2001 to the present. Though the length of the time series is not sufficient to confidently identify any effects of climate change, the time resolution is sufficient to investigate the differences in the extreme values of rain events over the nine years of the dataset, characterising the inter-annual and seasonal variability. Changes in the occurrence of different rain events have also been investigated by looking at event and inter-event durations to determine if there is any change in the relative number of stratiform and convective events over the time period. Knowledge of the fine scale variability of rain (both in the spatial and temporal domains) is important for the development of accurate models for small-scale forecasting, as well as models for the implementation and operation of rain affected systems, such as microwave radio communications and flood mitigation. As the rain gauge measurements made at Chilbolton will continue for the foreseeable future, these datasets will become increasingly valuable, as they provide a "ground-truth" that can be compared with the results of climate and other models.

Rainfall Stochastic models

NASA Astrophysics Data System (ADS)

Campo, M. A.; Lopez, J. J.; Rebole, J. P.

2012-04-01

This work was carried out in north of Spain. San Sebastian A meteorological station, where there are available precipitation records every ten minutes was selected. Precipitation data covers from October of 1927 to September of 1997. Pulse models describe the temporal process of rainfall as a succession of rainy cells, main storm, whose origins are distributed in time according to a Poisson process and a secondary process that generates a random number of cells of rain within each storm. Among different pulse models, the Bartlett-Lewis was used. On the other hand, alternative renewal processes and Markov chains describe the way in which the process will evolve in the future depending only on the current state. Therefore they are nor dependant on past events. Two basic processes are considered when describing the occurrence of rain: the alternation of wet and dry periods and temporal distribution of rainfall in each rain event, which determines the rainwater collected in each of the intervals that make up the rain. This allows the introduction of alternative renewal processes and Markov chains of three states, where interstorm time is given by either of the two dry states, short or long. Thus, the stochastic model of Markov chains tries to reproduce the basis of pulse models: the succession of storms, each one composed for a series of rain, separated by a short interval of time without theoretical complexity of these. In a first step, we analyzed all variables involved in the sequential process of the rain: rain event duration, event duration of non-rain, average rainfall intensity in rain events, and finally, temporal distribution of rainfall within the rain event. Additionally, for pulse Bartlett-Lewis model calibration, main descriptive statistics were calculated for each month, considering the process of seasonal rainfall in each month. In a second step, both models were calibrated. Finally, synthetic series were simulated with calibration parameters; series were recorded every ten minutes and hourly, aggregated. Preliminary results show adequate simulation of the main features of rain. Main variables are well simulated for time series of ten minutes, also over one hour precipitation time series, which are those that generate higher rainfall hydrologic design. For coarse scales, less than one hour, rainfall durations are not appropriate under the simulation. A hypothesis may be an excessive number of simulated events, which causes further fragmentation of storms, resulting in an excess of rain "short" (less than 1 hour), and therefore also among rain events, compared with the ones that occur in the actual series.

Model studies of the beam-filling error for rain-rate retrieval with microwave radiometers

NASA Technical Reports Server (NTRS)

Ha, Eunho; North, Gerald R.

1995-01-01

Low-frequency (less than 20 GHz) single-channel microwave retrievals of rain rate encounter the problem of beam-filling error. This error stems from the fact that the relationship between microwave brightness temperature and rain rate is nonlinear, coupled with the fact that the field of view is large or comparable to important scales of variability of the rain field. This means that one may not simply insert the area average of the brightness temperature into the formula for rain rate without incurring both bias and random error. The statistical heterogeneity of the rain-rate field in the footprint of the instrument is key to determining the nature of these errors. This paper makes use of a series of random rain-rate fields to study the size of the bias and random error associated with beam filling. A number of examples are analyzed in detail: the binomially distributed field, the gamma, the Gaussian, the mixed gamma, the lognormal, and the mixed lognormal ('mixed' here means there is a finite probability of no rain rate at a point of space-time). Of particular interest are the applicability of a simple error formula due to Chiu and collaborators and a formula that might hold in the large field of view limit. It is found that the simple formula holds for Gaussian rain-rate fields but begins to fail for highly skewed fields such as the mixed lognormal. While not conclusively demonstrated here, it is suggested that the notionof climatologically adjusting the retrievals to remove the beam-filling bias is a reasonable proposition.

Dissolved nutrients and atrazine removal by column-scale monophasic and biphasic rain garden model systems.

PubMed

Yang, Hanbae; McCoy, Edward L; Grewal, Parwinder S; Dick, Warren A

2010-08-01

Rain gardens are bioretention systems that have the potential to reduce peak runoff flow and improve water quality in a natural and aesthetically pleasing manner. We compared hydraulic performance and removal efficiencies of nutrients and atrazine in a monophasic rain garden design versus a biphasic design at a column-scale using simulated runoff. The biphasic rain garden was designed to increase retention time and removal efficiency of runoff pollutants by creating a sequence of water saturated to unsaturated conditions. We also evaluated the effect of C substrate availability on pollutant removal efficiency in the biphasic rain garden. Five simulated runoff events with various concentrations of runoff pollutants (i.e. nitrate, phosphate, and atrazine) were applied to the monophasic and biphasic rain gardens once every 5d. Hydraulic performance was consistent over the five simulated runoff events. Peak flow was reduced by approximately 56% for the monophasic design and 80% for the biphasic design. Both rain garden systems showed excellent removal efficiency of phosphate (89-100%) and atrazine (84-100%). However, significantly (p<0.001) higher removal of nitrate was observed in the biphasic (42-63%) compared to the monophasic rain garden (29-39%). Addition of C substrate in the form of glucose increased removal efficiency of nitrate significantly (p<0.001), achieving up to 87% removal at a treatment C/N ratio of 2.0. This study demonstrates the importance of retention time, environmental conditions (i.e. saturated/unsaturated conditions), and availability of C substrate for bioremediation of pollutants, especially nitrates, in rain gardens. (c) 2010 Elsevier Ltd. All rights reserved.

A satellite observational and numerical study of precipitation characteristics in western North Atlantic tropical cyclones

NASA Technical Reports Server (NTRS)

Rodgers, Edward B.; Chang, Simon W.; Pierce, Harold F.

1994-01-01

Special Sensor Microwave/Imager (SSM/I) observations were used to examine the spatial and temporal changes of the precipitation characteristics of tropical cyclones. SSM/I observations were also combined with the results of a tropical cyclone numerical model to examine the role of inner-core diabatic heating in subsequent intensity changes of tropical cyclones. Included in the SSM/I observations were rainfall characteristics of 18 named western North Atlantic tropical cyclones between 1987 and 1989. The SSM/I rain-rate algorithm that employed the 85-GHz channel provided an analysis of the rain-rate distribution in greater detail. However, the SSM/I algorithm underestimated the rain rates when compared to in situ techniques but appeared to be comparable to the rain rates obtained from other satellite-borne passive microwave radiometers. The analysis of SSM/I observations found that more intense systems had higher rain rates, more latent heat release, and a greater contribution from heavier rain to the total tropical cyclone rainfall. In addition, regions with the heaviest rain rates were found near the center of the most intense tropical cyclones. Observational analysis from SSM/I also revealed that the greatest rain rates in the inner-core regions were found in the right half of fast-moving cyclones, while the heaviest rain rates in slow-moving tropical cyclones were found in the forward half. The combination of SSM/I observations and an interpretation of numerical model simulations revealed that the correlation between changes in the inner core diabetic heating and the subsequent intensity became greater as the tropical cyclones became more intense.

[Relationship between atmospheric particles and rain water chemistry character].

PubMed

Huo, Ming-Qun; Sun, Qian; Xie, Peng; Bai, Yu-Hua; Liu, Zhao-Rong; Li, Ji-Long; Lu, Si-Hua

2009-11-01

Rain and atmospheric particle samples were collected in the rural area of Taian and Shenzhen in 2007, respectively. Rain sampling was carried out during the precipitation process and several samples were got from the beginning of one precipitation to the end. The chemical character changes during precipitation and the changes of concentration of particles before and after rain were studied in this research to understand the contribution of particles on the rain chemical character and the rain-out effect for particles. The volume-weighted mean pH of rainwater in Taian was 5.97 and the total concentration of ions was 1 187.96 microeq x L(-1). The mass concentration of PM10 in Taian was 131.76 microg/m3 and that of PM2.5 was 103.84 microg/m3. The volume-weighted mean pH of rainwater in Shenzhen was 4.72 and the total concentration of ions was 175.89 microeq x L(-1). The mass concentration of PM10 in Shenzhen was 56.66 microg/m3 and that of PM2.5 was 41.52 microg/m3. During precipitation process pH and ion concentration of rain decrease and it is shown the neutralizing effect happens. The difference between rainwater of Taian and Shenzhen is due to cloud water acidity, atmospheric particles character and atmospheric acid-basic gases concentration. The clean-up effect of Na+ and Ca2+ by rain is high and which of NH4+ and NO3- is low. The clean-up effect for mass concentration, ions concentration and element concentration of particles by rain are significant.

Rain Gardens: Stormwater Infiltrating Systems

EPA Science Inventory

The hydrological dynamics and changes in stormwater nutrient concentrations within rain gardens were studied by introducing captured stormwater runoff to rain gardens at EPA’s Urban Water Research Facility in Edison, New Jersey. The runoff used in these experiments was collected...

Learning About Acid Rain: A Teacher's Guide for Grades 6 through 8

EPA Pesticide Factsheets

Find on this page a link to the Acid Rain Teacher's Guide for Students Grades 6-8. This guide contains information, class discussions and experiments teachers can use to teach students about acid rain.

Acid Rain: Activities for Science Teachers.

ERIC Educational Resources Information Center

Johnson, Eric; And Others

1983-01-01

Seven complete secondary/college level acid rain activities are provided. Activities include overview; background information and societal implications; major concepts; student objectives; vocabulary/material lists; procedures; instructional strategies; and questions/discussion and extension suggestions. Activities consider effects of acid rain on…

Development of a low-budget, remote, solar powered, and self-operating rain gauge for spatial rainfall real time data monitoring in pristine and urban areas

NASA Astrophysics Data System (ADS)

Shafiei Shiva, J.; Chandler, D. G.; Nucera, K. J.; Valinski, N.

2016-12-01

Precipitation is one of the main components of the hydrological cycle and simulations and it is generally stated as an average value for the study area. However, due to high spatial variability of precipitation in some situations, more precise local data is required. In order to acquire the precipitation data, interpolation of neighbor gauged precipitation data is used which is the most affordable technique for a watershed scale study. Moreover, novel spatial rain measurements such as Doppler radars and satellite image processing have been widely used in recent studies. Although, due to impediments in the radar data processing and the effect of the local setting on the accuracy of the interpolated data, the local measurement of the precipitation remains as one of the most reliable approaches in attaining rain data. In this regard, development of a low-budget, remote, solar powered, and self-operating rain gauge for spatial rainfall real time data monitoring for pristine and urban areas has been presented in this research. The proposed rain gauge consists of two main parts: (a) hydraulic instruments and (b) electrical devices. The hydraulic instruments will collect the rain fall and store it in a PVC container which is connected to the high sensitivity pressure transducer systems. These electrical devices will transmit the data via cellphone networks which will be available for further analysis in less than one minute, after processing. The above-mentioned real time rain fall data can be employed in the precipitation measurement and the evaporation estimation. Due to the installed solar panel for battery recharging and designed siphon system for draining cumulative rain, this device is considered as a self-operating rain gauge. At this time, more than ten rain gauges are built and installed in the urban area of Syracuse, NY. Furthermore, these data are also useful for calibration and validation of data obtained by other rain gauging devices and estimation techniques. Moreover, remote data communication challenges in urban area are demonstrated and the solution for these problems have been addressed. Finally, the rainfall data obtained from the presented rain gauge has been compared with other measuring systems.

Real-Time Tracking of the Extreme Rainfall of Hurricanes Harvey, Irma, and Maria using UCI CHRS's iRain System

NASA Astrophysics Data System (ADS)

Shearer, E. J.; Nguyen, P.; Ombadi, M.; Palacios, T.; Huynh, P.; Furman, D.; Tran, H.; Braithwaite, D.; Hsu, K. L.; Sorooshian, S.; Logan, W. S.

2017-12-01

During the 2017 hurricane season, three major hurricanes-Harvey, Irma, and Maria-devastated the Atlantic coast of the US and the Caribbean Islands. Harvey set the record for the rainiest storm in continental US history, Irma was the longest-lived powerful hurricane ever observed, and Maria was the costliest storm in Puerto Rican history. The recorded maximum precipitation totals for these storms were 65, 16, and 20 inches respectively. These events provided the Center for Hydrometeorology and Remote Sensing (CHRS) an opportunity to test its global real-time satellite precipitation observation system, iRain, for extreme storm events. The iRain system has been under development through a collaboration between CHRS at the University of California, Irvine (UCI) and UNESCO's International Hydrological Program (IHP). iRain provides near real-time high resolution (0.04°, approx. 4km) global (60°N - 60°S) satellite precipitation data estimated by the PERSIANN-Cloud Classification System (PERSIANN-CCS) algorithm developed by the scientists at CHRS. The user-interactive and web-accessible iRain system allows users to visualize and download real-time global satellite precipitation estimates and track the development and path of the current 50 largest storms globally from data generated by the PERSIANN-CCS algorithm. iRain continuously proves to be an effective tool for measuring real-time precipitation amounts of extreme storms-especially in locations that do not have extensive rain gauge or radar coverage. Such areas include large portions of the world's oceans and over continents such as Africa and Asia. CHRS also created a mobile app version of the system named "iRain UCI", available for iOS and Android devices. During these storms, real-time rainfall data generated by PERSIANN-CCS was consistently comparable to radar and rain gauge data. This presentation evaluates iRain's efficiency as a tool for extreme precipitation monitoring and provides an evaluation of the PERSIANN-CCS real-time rainfall estimates during Hurricanes Harvey, Irma, and Maria in relation to radar and rain gauge data using continuous (correlation, root mean square error, and bias) and categorical (POD and FAR) indices. These results present the relative skill of PERSIANN-CCS real-time data to radar and rain gauge data.

[Spatiotemporal trends and the impact factors of acid rain in Anhui Province].

PubMed

Shi, Chun-E; Qiu, Ming-Yan; Zhang, Ai-Min; Zhang, Hao; Zhang, Su; Wang, Zi-Fa

2010-06-01

The observational data of acid rain at seven stations in Anhui province operated by China Meteorological Administration (CMA), as well as the coal consumptions in Anhui and some surrounding provinces along with satellite measured tropospheric NO2 columns, were used to analyze the spatiotemporal trends of acid rain in Anhui and the potential reasons of the increasing occurrence frequency of acid rain. In addition, the technique of back-trajectory-cluster analysis was used to examine the impacts of transport patterns on the precipitation acidity in Anhui. The occurrence frequency shows the lowest in summer and the highest in autumn, with 3-year average pH < 5.6 during 2006-2008 at all stations, hereinto, pH values are between 5.0 and 4.5 in Hefei, Anqing, Maanshan and Bengbu. In spatial, acid rain were the most severe in southern to middle Anhui and mitigated to north. The distributions of pH were concentrative at Fuyang, Tongling and Huangshan, with more than 75% occurred between 6.00-7.50 (Fuyang), 5.00-6.00 (Tongling) and 5.00-6.50 (Huangshan); quite dispersive at other stations, with the maximum at 4.00-4.50 (Hefei and Anqing), 5.00-5.50 (Maanshan) and 5.50-6.00 (Bengbu). The occurrence frequencies of acid rain increased evidently at all stations comparing with those in the end of 1990s. The results of back-trajectories-cluster analysis show that the acid rain is closely related with the regional-range transport of acid rain precursors at each station. The air-masses from southeast and northeast, especially those passing through Jiangsu and Zhejiang, associated with the highest frequencies of acid rain with pH < 5.0, indicating that the industrial emissions in the economy developed areas of Yangtze Delta play key roles in acid rain in Anhui province. In addition, statistics shows that the occurrence frequency of acid rain in Hefei was highly correlated with the trends of the provincial coal consumptions in Anhui, Jiangsu and Zhejiang, also tropospheric NO2 column content over Anhui province and surrounding areas with all correlation coefficients > 0.7, suggesting the close relationship between the quick increasing acid rain in Hefei and the regional pollutant emissions.

Comprehensive evaluation of multisatellite precipitation estimates over India using gridded rainfall data

NASA Astrophysics Data System (ADS)

Sunilkumar, K.; Narayana Rao, T.; Saikranthi, K.; Purnachandra Rao, M.

2015-09-01

This study presents a comprehensive evaluation of five widely used multisatellite precipitation estimates (MPEs) against 1° × 1° gridded rain gauge data set as ground truth over India. One decade observations are used to assess the performance of various MPEs (Climate Prediction Center (CPC)-South Asia data set, CPC Morphing Technique (CMORPH), Precipitation Estimation From Remotely Sensed Information Using Artificial Neural Networks, Tropical Rainfall Measuring Mission's Multisatellite Precipitation Analysis (TMPA-3B42), and Global Precipitation Climatology Project). All MPEs have high detection skills of rain with larger probability of detection (POD) and smaller "missing" values. However, the detection sensitivity differs from one product (and also one region) to the other. While the CMORPH has the lowest sensitivity of detecting rain, CPC shows highest sensitivity and often overdetects rain, as evidenced by large POD and false alarm ratio and small missing values. All MPEs show higher rain sensitivity over eastern India than western India. These differential sensitivities are found to alter the biases in rain amount differently. All MPEs show similar spatial patterns of seasonal rain bias and root-mean-square error, but their spatial variability across India is complex and pronounced. The MPEs overestimate the rainfall over the dry regions (northwest and southeast India) and severely underestimate over mountainous regions (west coast and northeast India), whereas the bias is relatively small over the core monsoon zone. Higher occurrence of virga rain due to subcloud evaporation and possible missing of small-scale convective events by gauges over the dry regions are the main reasons for the observed overestimation of rain by MPEs. The decomposed components of total bias show that the major part of overestimation is due to false precipitation. The severe underestimation of rain along the west coast is attributed to the predominant occurrence of shallow rain and underestimation of moderate to heavy rain by MPEs. The decomposed components suggest that the missed precipitation and hit bias are the leading error sources for the total bias along the west coast. All evaluation metrics are found to be nearly equal in two contrasting monsoon seasons (southwest and northeast), indicating that the performance of MPEs does not change with the season, at least over southeast India. Among various MPEs, the performance of TMPA is found to be better than others, as it reproduced most of the spatial variability exhibited by the reference.

Effects of rain gardens on the quality of water in the Minneapolis-St. Paul metropolitan area of Minnesota, 2002-04

USGS Publications Warehouse

Tornes, Lan H.

2005-01-01

Site design, including capacity relative to drainage area and soil permeability, is an important consideration in the efficiency of rain-garden operation. Vegetation type likely affects the infiltration capacity, nutrient uptake, and evapotranspiration of a rain garden and probably the resulting water quality. The long-term efficiency of rain gardens is difficult to determine from the results of this study because most are still evolving and maturing in relation to their hydrologic, biologic, and chemical setting. Many resource managers have questioned what long-term maintenance will be needed to keep rain gardens operating effectively. Additional or continued studies could address many of these concerns.

A simple rain attenuation model for earth-space radio links operating at 10-35 GHz

NASA Technical Reports Server (NTRS)

Stutzman, W. L.; Yon, K. M.

1986-01-01

The simple attenuation model has been improved from an earlier version and now includes the effect of wave polarization. The model is for the prediction of rain attenuation statistics on earth-space communication links operating in the 10-35 GHz band. Simple calculations produce attenuation values as a function of average rain rate. These together with rain rate statistics (either measured or predicted) can be used to predict annual rain attenuation statistics. In this paper model predictions are compared to measured data from a data base of 62 experiments performed in the U.S., Europe, and Japan. Comparisons are also made to predictions from other models.

Millimeter wave attenuation prediction using a piecewise uniform rain rate model

NASA Technical Reports Server (NTRS)

Persinger, R. R.; Stutzman, W. L.; Bostian, C. W.; Castle, R. E., Jr.

1980-01-01

A piecewise uniform rain rate distribution model is introduced as a quasi-physical model of real rain along earth-space millimeter wave propagation paths. It permits calculation of the total attenuation from specific attenuation in a simple fashion. The model predications are verified by comparison with direct attenuation measurements for several frequencies, elevation angles, and locations. Also, coupled with the Rice-Holmberg rain rate model, attenuation statistics are predicated from rainfall accumulation data.

Teleconnection, Regime Shift, and Predictability of Climate Extremes: A Case Study for the Russian Heat Wave and Pakistan Flood in Summer 2010

NASA Technical Reports Server (NTRS)

Lau, W. K.; Reale, O.; Kim, K.

2011-01-01

In this talk, we present observational evidence showing that the two major extremes events of the summer of 2010, i.e., the Russian heat wave and the Pakistan flood were physically connected. We find that the Pakistan flood was contributed by a series of unusually heavy rain events over the upper Indus River Basin in July-August. The rainfall regimes shifted from an episodic heavy rain regime in mid-to-late July to a steady heavy rain regime in August. An atmospheric Rossby wave associated with the development of the Russian heat wave was instrumental in spurring the episodic rain events , drawing moisture from the Bay of Bengal and the northern Arabian Sea. The steady rain regime was maintained primarily by monsoon moisture surges from the deep tropics. From experiments with the GEOS-5 forecast system, we assess the predictability of the heavy rain events associated with the Pakistan flood. Preliminary results indicate that there are significantly higher skills in the rainfall forecasts during the episodic heavy rain events in July, compared to the steady rain period in early to mid-August. The change in rainfall predictability may be related to scale interactions between the extratropics and the tropics resulting in a modulation of rainfall predictability by the circulation regimes.

Warm Rain Processes Over the Tropical Oceans and Implications on Climate Change

NASA Technical Reports Server (NTRS)

Lau, William K. M.; Wu, H. T.

2004-01-01

In this talk, we will first show results from TRMM regarding the characteristics of warm rains over the tropical oceans, and the dependence of rate of warm rain production on sea surface temperature. Results lead to the hypothesis that warm rain production efficiency, i.e., autoconversion, may be increased in a warm climate. We use the GEOS-II GCM to test this hypothesis. Our modeling results show that in a climate with increased rate of autoconversion, the total rain amount is increased, with warm rain contributing to a larger portion of the increase. The abundant rainout of warm precipitation at middle to low levels causes a reduction of high cloud cover due to the depletion of water available for ice-phase rain production. As a result, more isolated, but more intense penetrative convection develops. Results also show that increased autoconversion reduces the convective adjustment time scale tends, implying a faster recycling of atmospheric water. Most interestingly, the increased low level heating associated with warm rain leads to more energetic Madden and Julian oscillations in the tropics, with well-defined eastward propagation. While reducing the autoconversion leads to an abundant mix of westward and eastward tropical disturbance on daily to weekly time scales. The causes of the sensitivity of the dynamical regimes to the microphysics parameterization in the GCM will be discussed.

Evaluation of SEVIRI-Derived Rain Rates and Accumulated Rainfall with TRMM-TMI and Rain Gauge Data over West-Africa

NASA Astrophysics Data System (ADS)

Wolters, E. L. A.; Roebeling, R. A.; Stammes, P.; Wang, P.; Ali, A.; Brissebrat, G.

2009-11-01

Clouds are of paramount importance to the hydrological cycle, as they influence the surface energy balance, thereby constraining the amount of energy available for evaporation, and their contribution through precipitation. Especially in regions where water availability is critical, such as in West-Africa, accurate determination of various terms of the hydrological cycle is warranted. At the Royal Netherlands Meteorological Institute (KNMI), an algorithm to retrieve Cloud Physical Properties (CPP) from mainly visible and near-infrared spectral channel radiances from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard Meteosat-8 and -9 has been developed. Recently, this algorithm as been extended with a rain rate retrieval method. Evaluation of this geophysical quantity has been done with rain radar data over the Netherlands. This paper presents the first results of this rain rate retrieval over West-Africa for June 2006. In addition, the added value of the high temporal and spatial resolution of the SEVIRI instrument is shown. Over land, retrievals are compared with rain gauge observations performed during the African Monsoon Multidisciplinary Analyses (AMMA) project and with a kriged dataset of the Comite Inter-Estate pour la Lutte contre la Secheresse au Sahel (CILSS) rain gauge network, whereas rain rate retrievals over ocean are evaluated using Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) data.

Non-linear direct effects of acid rain on leaf photosynthetic rate of terrestrial plants.

PubMed

Dong, Dan; Du, Enzai; Sun, Zhengzhong; Zeng, Xuetong; de Vries, Wim

2017-12-01

Anthropogenic emissions of acid precursors have enhanced global occurrence of acid rain, especially in East Asia. Acid rain directly suppresses leaf function by eroding surface waxes and cuticle and leaching base cations from mesophyll cells, while the simultaneous foliar uptake of nitrates in rainwater may directly benefit leaf photosynthesis and plant growth, suggesting a non-linear direct effect of acid rain. By synthesizing data from literature on acid rain exposure experiments, we assessed the direct effects of acid rain on leaf photosynthesis across 49 terrestrial plants in China. Our results show a non-linear direct effect of acid rain on leaf photosynthetic rate, including a neutral to positive effect above pH 5.0 and a negative effect below that pH level. The acid rain sensitivity of leaf photosynthesis showed no significant difference between herbs and woody species below pH 5.0, but the impacts above that pH level were strongly different, resulting in a significant increase in leaf photosynthetic rate of woody species and an insignificant effect on herbs. Our analysis also indicates a positive effect of the molar ratio of nitric versus sulfuric acid in the acid solution on leaf photosynthetic rate. These findings imply that rainwater acidity and the composition of acids both affect the response of leaf photosynthesis and therefore result in a non-linear direct effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

Acid rain research program. Annual progress report, September 1975--June 1976

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, L.S.; Raynor, G.S.

1976-09-01

The aims of the research program are: (a) to observe the minimum threshold dose of simulated acid rain to produce visual and histological effects on plant foliage, (b) approach threshold limits of simulated sulfate acid rain that affect plant growth and reproduction, and (c) to measure chemical and meteorological parameters of incident rain. Acute leaf injury to several plant species resulted from exposure of foliage to simulated sulfate acid rain of pH level 2.3 to 2.9. Only slight injury occurred at 3.1. Scanning electron micrographs showed that injury to upper leaf surfaces occurred mostly at the base of trichomes (leafmore » hairs) and near stomata. An association of lesion development near vascular tissue was also noted. Histologically, lesions are characterized by an initial collapse of the epidermis with eventual lysis and collapse of more internal leaf tissues on the upper leaf surface of pinto beans which complemented detailed descriptions of visual lesion development after daily exposures to simulated rain. Initial experiments with gametophytes of Pteridium aquilinum show that reproduction of this fern species is very sensitive to solutions of pH 5.2 while vegetative development is not affected at pH levels of 2.2. Initial rain samples from the sequential sampler have been obtained. Initial portions of rain events exhibit a pH near 3.0 in some cases. More complete chemical analyses are anticipated.« less

Using wireless sensor networks to improve understanding of rain-on-snow events across the Sierra Nevada

NASA Astrophysics Data System (ADS)

Maurer, T.; Avanzi, F.; Oroza, C.; Malek, S. A.; Glaser, S. D.; Bales, R. C.; Conklin, M. H.

2017-12-01

We use data gathered from Wireless Sensor Networks (WSNs) between 2008 and 2017 to investigate the temporal/spatial patterns of rain-on-snow events in three river basins of California's Sierra Nevada. Rain-on-snow transitions occur across a broad elevation range (several hundred meters), both between storms and within a given storm, creating an opportunity to use spatially and temporally dense data to forecast and study them. WSNs collect snow depth; meteorological data; and soil moisture and temperature data across relatively dense sensor clusters. Ten to twelve measurement nodes per cluster are placed across 1-km2 areas in locations representative of snow patterns at larger scales. Combining precipitation and snow data from snow-pillow and climate stations with an estimation of dew-point temperature from WSNs, we determine the frequency, timing, and geographic extent of rain-on-snow events. We compare these results to WSN data to evaluate the impact of rain-on-snow events on snowpack energy balance, density, and depth as well as on soil moisture. Rain-on-snow events are compared to dry warm-weather days to identify the relative importance of rain and radiation as the primary energy input to the snowpack for snowmelt generation. An intercomparison of rain-on-snow events for the WSNs in the Feather, American, and Kings River basins captures the behavior across a 2° latitudinal range of the Sierra Nevada. Rain-on-snow events are potentially a more important streamflow generation mechanism in the lower-elevation Feather River basin. Snowmelt response to rain-on-snow events changes throughout the wet season, with later events resulting in more melt due to snow isothermal conditions, coarser grain size, and more-homogeneous snow stratigraphy. Regardless of snowmelt response, rain-on-snow events tend to result in decreasing snow depth and a corresponding increase in snow density. Our results demonstrate that strategically placed WSNs can provide the necessary data at high temporal resolution to investigate how hydrologic responses evolve in both space and time, data not available from operational networks.

Estimation of Mesoscale Atmospheric Latent Heating Profiles from TRMM Rain Statistics Utilizing a Simple One-Dimensional Model

NASA Technical Reports Server (NTRS)

Iacovazzi, Robert A., Jr.; Prabhakara, C.

2002-01-01

In this study, a model is developed to estimate mesoscale-resolution atmospheric latent heating (ALH) profiles. It utilizes rain statistics deduced from Tropical Rainfall Measuring Mission (TRMM) data, and cloud vertical velocity profiles and regional surface thermodynamic climatologies derived from other available data sources. From several rain events observed over tropical ocean and land, ALH profiles retrieved by this model in convective rain regions reveal strong warming throughout most of the troposphere, while in stratiform rain regions they usually show slight cooling below the freezing level and significant warming above. The mesoscale-average, or total, ALH profiles reveal a dominant stratiform character, because stratiform rain areas are usually much larger than convective rain areas. Sensitivity tests of the model show that total ALH at a given tropospheric level varies by less than +/- 10 % when convective and stratiform rain rates and mesoscale fractional rain areas are perturbed individually by +/- 15 %. This is also found when the non-uniform convective vertical velocity profiles are replaced by one that is uniform. Larger variability of the total ALH profiles arises when climatological ocean- and land-surface temperatures (water vapor mixing ratios) are independently perturbed by +/- 1.0 K (+/- 5%) and +/- 5.0 K (+/- 15%), respectively. At a given tropospheric level, such perturbations can cause a +/- 25% variation of total ALH over ocean, and a factor-of-two sensitivity over land. This sensitivity is reduced substantially if perturbations of surface thermodynamic variables do not change surface relative humidity, or are not extended throughout the entire model evaporation layer. The ALH profiles retrieved in this study agree qualitatively with tropical total diabatic heating profiles deduced in earlier studies. Also, from January and July 1999 ALH-profile climatologies generated separately with TRMM Microwave Imager and Precipitation Radar rain statistics, it is shown that ALH profiles can be retrieved utilizing diverse satellite-derived rain products that offer convective and stratiform discrimination. Therefore, the ALH retrieval model developed in this study can be used to make regional estimates of total diabatic heating profiles in the future Global Precipitation Measurement mission, and to assimilate these profiles into numerical weather forecast and climate models.

Estimation of Mesoscale Atmospheric Latent Heating Profiles from TRMM Rain Statistics Utilizing a Simple One-Dimensional Model

NASA Technical Reports Server (NTRS)

Iacovazzi, Robert A., Jr.; Prabhakara, C.; Lau, William K. M. (Technical Monitor)

2001-01-01

In this study, a model is developed to estimate mesoscale-resolution atmospheric latent heating (ALH) profiles. It utilizes rain statistics deduced from Tropical Rainfall Measuring Mission (TRMM) data, and cloud vertical velocity profiles and regional surface thermodynamic climatologies derived from other available data sources. From several rain events observed over tropical ocean and land, ALH profiles retrieved by this model in convective rain regions reveal strong warming throughout most of the troposphere, while in stratiform rain regions they usually show slight cooling below the freezing level and significant warming above. The mesoscale-average, or total, ALH profiles reveal a dominant stratiform character, because stratiform rain areas are usually much larger than convective rain areas. Sensitivity tests of the model show that total ALH at a given tropospheric level varies by less than +/- 10 % when convective and stratiform rain rates and mesoscale fractional rain areas are perturbed individually by 1 15 %. This is also found when the non-uniform convective vertical velocity profiles are replaced by one that is uniform. Larger variability of the total ALH profiles arises when climatological ocean- and land-surface temperatures (water vapor mixing ratios) are independently perturbed by +/- 1.0 K (+/- 5 %) and +/- 5.0 K (+/- 15 %), respectively. At a given tropospheric level, such perturbations can cause a +/- 25 % variation of total ALH over ocean, and a factor-of-two sensitivity over land. This sensitivity is reduced substantially if perturbations of surface thermodynamic variables do not change surface relative humidity, or are not extended throughout the entire model evaporation layer. The ALH profiles retrieved in this study agree qualitatively with tropical total diabatic heating profiles deduced in earlier studies. Also, from January and July 1999 ALH-profile climatologies generated separately with TRMM Microwave Imager and Precipitation Radar rain statistics, it is shown that ALH profiles can be retrieved utilizing diverse satellite-derived rain products that offer convective and stratiform discrimination. Therefore, the ALH retrieval model developed in this study can be used to make regional estimates of total diabatic heating profiles in the future Global Precipitation Measurement mission, and to assimilate these profiles into numerical weather forecast and climate models.

Flow Dynamics and Nutrient Reduction in Rain Gardens

EPA Science Inventory

The hydrological dynamics and changes in stormwater nutrient concentrations within rain gardens were studied by introducing captured stormwater runoff to rain gardens at EPA’s Urban Water Research Facility in Edison, New Jersey. The runoff used in these experiments was collected...

GREEN INFRASTRUCTURE RESEARCH PROGRAM: Rain Gardens

EPA Science Inventory

the National Risk Management Research Laboratory (NRMRL) rain garden evaluation is part of a larger collection of long-term research that evaluates a variety of stormwater management practices. The U.S. EPA recognizes the potential of rain gardens as a green infrastructure manag...

40 CFR 72.61 - Completeness.

Code of Federal Regulations, 2010 CFR

2010-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.61 Completeness. (a) Determination of Completeness. The Administrator will determine whether the Acid Rain permit application is complete within 60... the Acid Rain permit application is complete under paragraph (a) of this section, the Administrator...

40 CFR 72.61 - Completeness.

Code of Federal Regulations, 2014 CFR

2014-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.61 Completeness. (a) Determination of Completeness. The Administrator will determine whether the Acid Rain permit application is complete within 60... the Acid Rain permit application is complete under paragraph (a) of this section, the Administrator...

40 CFR 72.61 - Completeness.

Code of Federal Regulations, 2013 CFR

2013-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.61 Completeness. (a) Determination of Completeness. The Administrator will determine whether the Acid Rain permit application is complete within 60... the Acid Rain permit application is complete under paragraph (a) of this section, the Administrator...

40 CFR 72.61 - Completeness.

Code of Federal Regulations, 2011 CFR

2011-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.61 Completeness. (a) Determination of Completeness. The Administrator will determine whether the Acid Rain permit application is complete within 60... the Acid Rain permit application is complete under paragraph (a) of this section, the Administrator...

40 CFR 72.61 - Completeness.

Code of Federal Regulations, 2012 CFR

2012-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.61 Completeness. (a) Determination of Completeness. The Administrator will determine whether the Acid Rain permit application is complete within 60... the Acid Rain permit application is complete under paragraph (a) of this section, the Administrator...

Rain Rate from IMERG as a Predictor for Salinity Stratification in the Upper Meter of the Ocean during SPURS-2 Rain Events

NASA Astrophysics Data System (ADS)

Thompson, E. J.; Asher, W.; Drushka, K.; Schanze, J. J.; Jessup, A. T.; Clark, D.

2016-12-01

Rain can produce a lens of fresher and generally colder, less dense water at the ocean surface. These stable surface layers concentrate heat, freshwater, and momentum into a thin layer and reduce the exchange of these properties between the surface layer and deeper water, which can impact regional freshwater storage and air-sea fluxes of heat and moisture. Although in situ observations have shown that fresh lenses are common in the presence of rain, attempts to correlate the magnitude and lifetime of the surface freshening with rain rate using field data have not produced a definitive relationship. The reasons for this are most likely that in situ rain rate measurements represent the freshwater flux to the ocean surface at a single point in space and time, whereas the fresh lens is the result of the integrated rainfall over time and space, convoluted with the evolution of the fresh lens. Therefore, it is possible that integrated, upstream rainfall estimates might provide a better correlate for the presence of fresh lenses than in situ measurements at a point. This hindcast study seeks to determine the utility of NASA GPM IMERG satellite measurements of rain relative to in situ collocated rain measurements in predicting the occurrence and duration of 0-1 m freshwater stabilization of the ocean. Vertical gradients of temperature, salinity, and density between the surface and at most a few meters were measured using towed profilers and underway sampling during the 2016 SPURS-2 experiment conducted in the tropical east Pacific Ocean. Local wind speed was also measured and taken into account. These measurements were used to determine whether local or integrated upstream precipitation metrics could better predict the occurrence of rain-generated lenses of fresher water at the ocean surface and whether the strength and duration of rain events was correlated with the observed lifetime of fresh lenses.

Convective and stratiform rain: Multichannel microwave sensing over oceans

NASA Technical Reports Server (NTRS)

Prabhakara, C.; Nucciarone, J. J.; Dalu, G.

1993-01-01

Measurements made by the Special Sensor Microwave/Imager (SSM/I) radiometer over the oceans, at 19, 37, and 85 GHz in dual polarization, are used to develop a model to classify rain into light-stratiform, moderately convective, and heavy convective types in the mesoscale convective systems (MCS). It is observed that the bulk of the 19- and 37-GHz data are linearly correlated with respect to one another, and generally increase together in brightness as the mean rain rate in the field of view (FOV) of the radiometer increases. However, a significant fraction of the data from these channels departs from this linear relationship, reflecting the nonuniform rain that is convective vs. the relatively light stratiform rain. It is inferred from the SSM/I data, in a MCS, when the slope dT sub 3/dT sub 19 is greater than unity there are optically thin clouds which produce light uniform rain. On the other hand, when dT sub 3/dT sub 19 is close to unity, the rain cells have an open structure and correspond to the convective type of rain. The openings between the cells are apparently a result of the downdrafts and/or entrainment. Relatively low values of 85-GHz brightness temperatures that are present when dT sub 37/dT sub 19 is close to unity support these views and, in addition, leads us to conclude that when the convection is heavy this brightness temperature decreases due to scattering by hydrometeors. On the basis of this explanation of the SSM/I data, an empirical rain retrieval algorithm is developed. Radar backscatter observations over the Atlantic Ocean next to Florida are used to demonstrate the applicability of this method. Three monthly mean maps of rainfall over the oceans from 50 degrees N to 50 degrees S, are presented to illustrate the ability of this method to sense seasonal and interannual variations of rain.

Effects of rare earth and acid rain pollution on plant chloroplast ATP synthase and element contents at different growth stages.

PubMed

Zhang, Fan; Hu, Huiqing; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2018-03-01

Combined rare earth and acid rain pollution has become a new environmental problem, seriously affecting plant survival. The effects of these two kinds of pollutants on plant photosynthesis have been reported, but the micro mechanisms are not very clear. In this research, we studied the effects of lanthanum [La(III), 0.08, 1.20 and 2.40 mM] and acid rain (pH value = 2.5, 3.5 and 4.5) on the ATPase activity and gene transcription level and the functional element contents in rice leaf chloroplasts. The results showed that the combined 0.08 mM La(III) and pH 4.5 acid rain increased the ATPase activity and gene transcription level as well as contents of some functional elements. But other combined treatments of acid rain and La(III) reduced the ATPase activity and gene transcription level as well as functional element contents. The change magnitude of the above indexes at rice booting stage was greater than that in seedling stage or grain filling stage. These results reveal that effects of La(III) and acid rain on ATPase activity and functional element contents in rice leaf chloroplasts are related to the combination of La(III) dose and acid rain intensity and the plant growth stage. In addition, the changes in the ATPase activity were related to ATPase gene transcription level. This study would provide a reference for understanding the microcosmic mechanism of rare earth and acid rain pollution on plant photosynthesis and contribute to evaluate the possible environmental risks associated with combined La(III) and acid rain pollution. The effects of La(III) and acid rain on activity and gene transcription level of rice chloroplast ATPase and contents of functional elements were different at different growth stages. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of simulated acid rain on soil fauna community composition and their ecological niches.

PubMed

Wei, Hui; Liu, Wen; Zhang, Jiaen; Qin, Zhong

2017-01-01

Acid rain is one of the severest environmental issues globally. Relative to other global changes (e.g., warming, elevated atmospheric [CO 2 ], and nitrogen deposition), however, acid rain has received less attention than its due. Soil fauna play important roles in multiple ecological processes, but how soil fauna community responds to acid rain remains less studied. This microcosm experiment was conducted using latosol with simulated acid rain (SAR) manipulations to observe potential changes in soil fauna community under acid rain stress. Four pH levels, i.e., pH 2.5, 3.5, 4.5, and 5.5, and a neutral control of pH 7.0 were set according to the current pH condition and acidification trend of precipitation in southern China. As expected, we observed that the SAR treatments induced changes in soil fauna community composition and their ecological niches in the tested soil; the treatment effects tended to increase as acidity increased. This could be attributable to the environmental stresses (such as acidity, porosity and oxygen supply) induced by the SAR treatments. In addition to direct acidity effect, we propose that potential changes in permeability and movability of water and oxygen in soils induced by acid rain could also give rise to the observed shifts in soil fauna community composition. These are most likely indirect pathways of acid rain to affect belowground community. Moreover, we found that nematodes, the dominating soil fauna group in this study, moved downwards to mitigate the stress of acid rain. This is probably detrimental to soil fauna in the long term, due to the relatively severer soil conditions in the deep than surface soil layer. Our results suggest that acid rain could change soil fauna community and the vertical distribution of soil fauna groups, consequently changing the underground ecosystem functions such as organic matter decomposition and greenhouse gas emissions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rain events decrease boreal peatland net CO2 uptake through reduced light availability.

PubMed

Nijp, Jelmer J; Limpens, Juul; Metselaar, Klaas; Peichl, Matthias; Nilsson, Mats B; van der Zee, Sjoerd E A T M; Berendse, Frank

2015-06-01

Boreal peatlands store large amounts of carbon, reflecting their important role in the global carbon cycle. The short-term exchange and the long-term storage of atmospheric carbon dioxide (CO2 ) in these ecosystems are closely associated with the permanently wet surface conditions and are susceptible to drought. Especially, the single most important peat forming plant genus, Sphagnum, depends heavily on surface wetness for its primary production. Changes in rainfall patterns are expected to affect surface wetness, but how this transient rewetting affects net ecosystem exchange of CO2 (NEE) remains unknown. This study explores how the timing and characteristics of rain events during photosynthetic active periods, that is daytime, affect peatland NEE and whether rain event associated changes in environmental conditions modify this response (e.g. water table, radiation, vapour pressure deficit, temperature). We analysed an 11-year time series of half-hourly eddy covariance and meteorological measurements from Degerö Stormyr, a boreal peatland in northern Sweden. Our results show that daytime rain events systematically decreased the sink strength of peatlands for atmospheric CO2 . The decrease was best explained by rain associated reduction in light, rather than by rain characteristics or drought length. An average daytime growing season rain event reduced net ecosystem CO2 uptake by 0.23-0.54 gC m(-2) . On an annual basis, this reduction of net CO2 uptake corresponds to 24% of the annual net CO2 uptake (NEE) of the study site, equivalent to a 4.4% reduction of gross primary production (GPP) during the growing season. We conclude that reduced light availability associated with rain events is more important in explaining the NEE response to rain events than rain characteristics and changes in water availability. This suggests that peatland CO2 uptake is highly sensitive to changes in cloud cover formation and to altered rainfall regimes, a process hitherto largely ignored. © 2015 John Wiley & Sons Ltd.

Role of tropical cyclones in determining the fate of Bay of Bengal vapor contributed rain δ18O values

NASA Astrophysics Data System (ADS)

Sanyal, Prasanta; Basu, Sayak

2016-04-01

The evaluation of robust future climate prediction is well dependent on the cognition of past and present hydrological systems which could be traced through the oxygen isotopic composition (δ18O) of rain. Compared to Peninsular and Southern India, explanation for the variability in δ18O values of monsoonal rain is sparse for the Eastern India. Analysis (and published records) of Indian summer monsoon (ISM) rain at the entry point of Bay of Bengal (BoB) vapor into the continent showed the gradual depletion of 18O in the ISM rain is determined by the surface run-off and location of cyclone generation in BoB. The timing and density of cyclones control the maxima in amount and minima in δ18O value of ISM rain and possibly also responsible for the long-term (last 10 years) decrease in rain δ18O values (and amount). Large spatial variation and temporally robustness of weak and insignificant amount effect suggested reconsideration of reconstructed past climate records along the track of BoB vapor. The memory effect of atmospheric vapor is found to lower the amount effect.

Multilinear approach to the precipitation-lightning relationship: a case study of summer local electrical storms in the northern part of Spain during 2002-2009 period

NASA Astrophysics Data System (ADS)

Herrero, I.; Ezcurra, A.; Areitio, J.; Diaz-Argandoña, J.; Ibarra-Berastegi, G.; Saenz, J.

2013-11-01

Storms developed under local instability conditions are studied in the Spanish Basque region with the aim of establishing precipitation-lightning relationships. Those situations may produce, in some cases, flash flood. Data used correspond to daily rain depth (mm) and the number of CG flashes in the area. Rain and lightning are found to be weakly correlated on a daily basis, a fact that seems related to the existence of opposite gradients in their geographical distribution. Rain anomalies, defined as the difference between observed and estimated rain depth based on CG flashes, are analysed by PCA method. Results show a first EOF explaining 50% of the variability that linearly relates the rain anomalies observed each day and that confirms their spatial structure. Based on those results, a multilinear expression has been developed to estimate the rain accumulated daily in the network based on the CG flashes registered in the area. Moreover, accumulates and maximum values of rain are found to be strongly correlated, therefore making the multilinear expression a useful tool to estimate maximum precipitation during those kind of storms.

On validation of the rain climatic zone designations for Nigeria

NASA Astrophysics Data System (ADS)

Obiyemi, O. O.; Ibiyemi, T. S.; Ojo, J. S.

2017-07-01

In this paper, validation of rain climatic zone classifications for Nigeria is presented based on global radio-climatic models by the International Telecommunication Union-Radiocommunication (ITU-R) and Crane. Rain rate estimates deduced from several ground-based measurements and those earlier estimated from the precipitation index on the Tropical Rain Measurement Mission (TRMM) were employed for the validation exercise. Although earlier classifications indicated that Nigeria falls into zones P, Q, N, and K for the ITU-R designations, and zones E and H for Crane's climatic zone designations, the results however confirmed that the rain climatic zones across Nigeria can only be classified into four, namely P, Q, M, and N for the ITU-R designations, while the designations by Crane exhibited only three zones, namely E, G, and H. The ITU-R classification was found to be more suitable for planning microwave and millimeter wave links across Nigeria. The research outcomes are vital in boosting the confidence level of system designers in using the ITU-R designations as presented in the map developed for the rain zone designations for estimating the attenuation induced by rain along satellite and terrestrial microwave links over Nigeria.

Acid-rain induced changes in streamwater quality during storms on Catoctin Mountain, Maryland

USGS Publications Warehouse

Rice, Karen C.; Bricker, O.P.

1992-01-01

Catoctin Mountain receives some of the most acidic (lowest pH) rain in the United States. In 1990, the U.S. Geological Survey (USGS), in cooperation with the Maryland Department of the Environment (MDE) and the Maryland Department of Natural Resources (DNR), began a study of the effects of acid rain on the quality of streamwater on the part of Catoctin Mountain within Cunningham Falls State Park, Maryland (fig. 1). Samples of precipitation collected on the mountain by the USGS since 1982 have been analyzed for acidity and concentration of chemical constituents. During 1982-91, the volume-weighted average pH of precipitation was 4.2. (Volume weighting corrects for the effect of acids being washed out of the atmosphere at the beginning of rainfall). The pH value is measured on a logarithmic scale, which means that for each whole number change, the acidity changes by a factor of 10. Thus rain with a pH of 4.2 is more than 10 times as acidic as uncontaminated rain, which has a pH of about 5.6. The acidity of rain during several rainstorms on Catoctin Mountain was more than 100 times more acidic than uncontaminated rain.

A laboratory system for the investigation of rain fade compensation techniques for Ka-band satellites

NASA Technical Reports Server (NTRS)

Svoboda, James S.; Kachmar, Brian A.

1993-01-01

The design and performance of a rain fade simulation/counteraction system on a laboratory simulated 30/20 GHz, time division multiple access (TDMA) satellite communications testbed is evaluated. Severe rain attenuation of electromagnetic radiation at 30/20 GHz occurs due to the carrier wavelength approaching the water droplet size. Rain in the downlink path lowers the signal power present at the receiver, resulting in a higher number of bit errors induced in the digital ground terminal. The laboratory simulation performed at NASA Lewis Research Center uses a programmable PIN diode attenuator to simulate 20 GHz satellite downlink geographic rain fade profiles. A computer based network control system monitors the downlink power and informs the network of any power threshold violations, which then prompts the network to issue commands that temporarily increase the gain of the satellite based traveling wave tube (TWT) amplifier. After the rain subsides, the network returns the TWT to the normal energy conserving power mode. Bit error rate (BER) data taken at the receiving ground terminal serves as a measure of the severity of rain degradation, and also evaluates the extent to which the network can improve the faded channel.

TRMM Gridded Text Products

NASA Technical Reports Server (NTRS)

Stocker, Erich Franz

2007-01-01

NASA's Tropical Rainfall Measuring Mission (TRMM) has many products that contain instantaneous or gridded rain rates often among many other parameters. However, these products because of their completeness can often seem intimidating to users just desiring surface rain rates. For example one of the gridded monthly products contains well over 200 parameters. It is clear that if only rain rates are desired, this many parameters might prove intimidating. In addition, for many good reasons these products are archived and currently distributed in HDF format. This also can be an inhibiting factor in using TRMM rain rates. To provide a simple format and isolate just the rain rates from the many other parameters, the TRMM product created a series of gridded products in ASCII text format. This paper describes the various text rain rate products produced. It provides detailed information about parameters and how they are calculated. It also gives detailed format information. These products are used in a number of applications with the TRMM processing system. The products are produced from the swath instantaneous rain rates and contain information from the three major TRMM instruments: radar, radiometer, and combined. They are simple to use, human readable, and small for downloading.

A Demonstration of Acid Rain and Lake Acidification: Wet Deposition of Sulfur Dioxide.

ERIC Educational Resources Information Center

Goss, Lisa M.

2003-01-01

Introduces a science demonstration on the dissolution of sulfuric oxide emphasizing the concept of acid rain which is an environmental problem. Demonstrates the acidification from acid rain on two lake environments, limestone and granite. Includes safety information. (YDS)

Acid Rain Education and Its Implications for Curricular Development: A Teacher Survey.

ERIC Educational Resources Information Center

Barrow, Lloyd H.; Germann, Paul

1987-01-01

Describes a survey which was designed to obtain information on acid rain education. Reviews results pertaining to instructional time, instructional topics, use of labs from a common resource guide, and preference of materials related to acid rain education. (ML)

The Effects of Rain Garden Size on Hydrologic Performance

EPA Science Inventory

Rain gardens are vegetated depressions designed to accept stormwater runoff. Manuals and guidance documents recommend sizing rain garden cells from 3% to 43% of the associated drainage area, based on factors including soil type, slope, amount of impervious cover in the drainage ...

Analysis of SFMR-Derived and Satellite-Based Rain Rates over the Tropical Western North Pacific

DTIC Science & Technology

2010-03-01

from SFMR are compared to rain rates from the Advanced Microwave Scanning Radiometer–EOS ( ASMR -E) and the Tropical Rainfall Measuring Mission (TRMM...2010 program. Rain rates from SFMR are compared to rain rates from the Advanced Microwave Scanning Radiometer–EOS ( ASMR -E) and the Tropical Rainfall...Figures 10 and 11, except for the ASMR -E and (a) earth-relative flight track and (b) storm-relative flight track for TY Sinlaku on 12 Sep 2008

Comparison in Schemes for Simulating Depositional Growth of Ice Crystal between Theoretical and Laboratory Data

NASA Astrophysics Data System (ADS)

Zhai, Guoqing; Li, Xiaofan

2015-04-01

The Bergeron-Findeisen process has been simulated using the parameterization scheme for the depositional growth of ice crystal with the temperature-dependent theoretically predicted parameters in the past decades. Recently, Westbrook and Heymsfield (2011) calculated these parameters using the laboratory data from Takahashi and Fukuta (1988) and Takahashi et al. (1991) and found significant differences between the two parameter sets. There are two schemes that parameterize the depositional growth of ice crystal: Hsie et al. (1980), Krueger et al. (1995) and Zeng et al. (2008). In this study, we conducted three pairs of sensitivity experiments using three parameterization schemes and the two parameter sets. The pre-summer torrential rainfall event is chosen as the simulated rainfall case in this study. The analysis of root-mean-squared difference and correlation coefficient between the simulation and observation of surface rain rate shows that the experiment with the Krueger scheme and the Takahashi laboratory-derived parameters produces the best rain-rate simulation. The mean simulated rain rates are higher than the mean observational rain rate. The calculations of 5-day and model domain mean rain rates reveal that the three schemes with Takahashi laboratory-derived parameters tend to reduce the mean rain rate. The Krueger scheme together with the Takahashi laboratory-derived parameters generate the closest mean rain rate to the mean observational rain rate. The decrease in the mean rain rate caused by the Takahashi laboratory-derived parameters in the experiment with the Krueger scheme is associated with the reductions in the mean net condensation and the mean hydrometeor loss. These reductions correspond to the suppressed mean infrared radiative cooling due to the enhanced cloud ice and snow in the upper troposphere.

Seasonal Scale Convective-Stratiform Pricipitation Variabilities at Tropics

NASA Astrophysics Data System (ADS)

S, Sreekanth T.

begin{center} Large Seasonal Scale Convective-Stratiform Pricipitation Variabilities at Tropics Sreekanth T S*, Suby Symon*, G. Mohan Kumar (1) and V Sasi Kumar (2) *Centre for Earth Science Studies, Akkulam, Thiruvananthapuram (1) D-330, Swathi Nagar, West Fort, Thiruvananthapuram 695023 (2) 32. NCC Nagar Peroorkada, Thiruvananthapuram ABSTRACT This study investigates the variabilities of convective and stratiform rainfall from 2011 to 2013 at a tropical coastal station in three seasons viz Pre-Monsoon (March-May), Monsoon (June-September) and Post-Monsoon (October-December). Understanding the climatological variability of these two dominant forms of precipitation and their implications in the total rainfall were the main objectives of this investigation. Variabilities in the frequency & duration of events, rain rate & total number of rain drops distribution in different events and the accumulated amount of rain water were analysed. Based on the ground & radar observations from optical & impact disdrometers, Micro Rain Radar and Atmospheric Electric Field Mill, precipitation events were classified into convective and stratiform in three seasons. Classification was done by the method followed by Testud et al (2001) and as an additional information electrical behaviour of clouds from Atmospheric Electric Field Mill is also used. Events which could not be included in both types were termed as 'mixed precipitation' and were included separately. Diurnal variability of the total rainfall in each seasons were also examined. For both convective and stratiform rainfall there exist distinct day-night differences. During nocturnal hours convective rain draged more attention. In all seasons almost 70% of rain duration and 60% of rain events of convective origin were confined to nocturnal hours. But stratiform rain was not affected by diurnal variations greatly because night time occurrences of stratiform duration and events were less than 50%. Also in Monsoon above 35% of rain duration is from mixed precipitation category.

Data-driven clustering of rain events: microphysics information derived from macro-scale observations

NASA Astrophysics Data System (ADS)

Djallel Dilmi, Mohamed; Mallet, Cécile; Barthes, Laurent; Chazottes, Aymeric

2017-04-01

Rain time series records are generally studied using rainfall rate or accumulation parameters, which are estimated for a fixed duration (typically 1 min, 1 h or 1 day). In this study we use the concept of rain events. The aim of the first part of this paper is to establish a parsimonious characterization of rain events, using a minimal set of variables selected among those normally used for the characterization of these events. A methodology is proposed, based on the combined use of a genetic algorithm (GA) and self-organizing maps (SOMs). It can be advantageous to use an SOM, since it allows a high-dimensional data space to be mapped onto a two-dimensional space while preserving, in an unsupervised manner, most of the information contained in the initial space topology. The 2-D maps obtained in this way allow the relationships between variables to be determined and redundant variables to be removed, thus leading to a minimal subset of variables. We verify that such 2-D maps make it possible to determine the characteristics of all events, on the basis of only five features (the event duration, the peak rain rate, the rain event depth, the standard deviation of the rain rate event and the absolute rain rate variation of the order of 0.5). From this minimal subset of variables, hierarchical cluster analyses were carried out. We show that clustering into two classes allows the conventional convective and stratiform classes to be determined, whereas classification into five classes allows this convective-stratiform classification to be further refined. Finally, our study made it possible to reveal the presence of some specific relationships between these five classes and the microphysics of their associated rain events.

Combined acid rain and lanthanum pollution and its potential ecological risk for nitrogen assimilation in soybean seedling roots.

PubMed

Zhang, Fan; Cheng, Mengzhu; Sun, Zhaoguo; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

2017-12-01

Rare earth elements (REEs) are used in various fields, resulting in their accumulation in the environment. This accumulation has affected the survival and distribution of crops in various ways. Acid rain is a serious global environmental problem. The combined effects on crops from these two types of pollution have been reported, but the effects on crop root nitrogen assimilation are rarely known. To explore the impact of combined contamination from these two pollutants on crop nitrogen assimilation, the soybean seedlings were treated with simulated environmental pollution from acid rain and a representative rare earth ion, lanthanum ion (La 3+ ), then the indexes related to plant nitrogen assimilation process in roots were determined. The results showed that combined treatment with pH 4.5 acid rain and 0.08 mM La 3+ promoted nitrogen assimilation synergistically, while the other combined treatments all showed inhibitory effects. Moreover, acid rain aggravated the inhibitory effect of 1.20 or 0.40 mM La 3+ on nitrogen assimilation in soybean seedling roots. Thus, the effects of acid rain and La 3+ on crops depended on the combination levels of acid rain intensity and La 3+ concentration. Acid rain increases the bioavailability of La 3+ , and the combined effects of these two pollutants were more serious than that of either pollutant alone. These results provide new evidence in favor of limiting overuse of REEs in agriculture. This work also provides a new framework for ecological risk assessment of combined acid rain and REEs pollution on soybean crops. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of long-term exposure to simulated acid rain on development, reproduction and acaricide susceptibility of the carmine spider mite, Tetranychus cinnabarinus

PubMed Central

Wang, Jin-Jun; Zhang, Jian-Ping; He, Lin; Zhao, Zhi-Mo

2006-01-01

Development, reproduction and acaricide susceptibility of Tetranychus cinnabarinus (Boisduvals) (Acari: Tetranychidae) were investigated after long-term (about 40 generations) exposure to various levels of acid rain; pH 2.5, 3.0, 4.0, and 5.6. Deionized water (pH 6.8) served as a control. The mites were reared on eggplant leaves at 28°C, 80%RH and a photoperiod of 14:10 (L:D) in the laboratory. The results showed that the duration of the immature stage was significantly affected by acid rain exposure. The shortest duration (8.90 days) was recorded for populations exposed to pH 5.6 acid rain, while the longest duration (9.37 days) occurred after exposure to pH 2.5 acid rain. Compared with the control population, adult longevity was shortened with an increase in acidity. Similarly, the oviposition duration was also shortened by an increase in acidity. Statistically, female fecundity did not differ significantly between pH 5.6, pH 4.0 and control populations, but did differ significantly between the control population and those exposed to pH 2.5 and pH 3.0 acid rain. This suggested that the mite suffered reproductive defects after long-term exposure to acid rain with higher acidity (pH 2.5 and 3.0). The intrinsic rate of increase among different populations was not significantly affected, but the net reproductive rate of populations exposed to pH 2.5 and 3.0 acid rain was significantly less than pH4.0, 5.6, and control populations. Bioassay results showed that after long-term exposure to acid rain, susceptibility of the mites to two acaricides, dichlorvos and fenpropathrin, did not change significantly. PMID:19537978

High Resolution Monthly Oceanic Rainfall Based on Microwave Brightness Temperature Histograms

NASA Astrophysics Data System (ADS)

Shin, D.; Chiu, L. S.

2005-12-01

A statistical emission-based passive microwave retrieval algorithm has been developed by Wilheit, Chang and Chiu (1991) to estimate space/time oceanic rainfall. The algorithm has been applied to Special Sensor Microwave Imager (SSM/I) data taken on board the Defense Meteorological Satellite Program (DMSP) satellites to provide monthly oceanic rainfall over 2.5ox2.5o and 5ox5o latitude-longitude boxes by the Global Precipitation Climatology Project-Polar Satellite Precipitation Data Center (GPCP-PSPDC, URL: http://gpcp-pspdc.gmu.edu/) as part of NASA's contribution to the GPCP. The algorithm has been modified and applied to the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) data to produce a TRMM Level 3 standard product (3A11) over 5ox5o latitude/longitude boxes. In this study, the algorithm code is modified to retrieve rain rates at 2.5ox2.5o and 1ox1o resolutions for TMI. Two months of TMI data have been tested and the results compared with the monthly mean rain rates derived from TRMM Level 2 TMI rain profile algorithm (2A12) and the original 5ox5o data from 3A11. The rainfall pattern is very similar to the monthly average of 2A12, although the intensity is slightly higher. Details in the rain pattern, such as rain shadow due to island blocking, which were not discernible from the low resolution products, are now easily discernible. The spatial average of the higher resolution rain rates are in general slightly higher than lower resolution rain rates, although a Student-t test shows no significant difference. This high resolution product will be useful for the calibration of IR rain estimates for the production of the GPCP merge rain product.

Speciation distribution and mass balance of copper and zinc in urban rain, sediments, and road runoff.

PubMed

Zuo, Xiaojun; Fu, Dafang; Li, He

2012-11-01

Heavy metal pollution in road runoff had caused widespread concern since the last century. However, there are little references on metal speciation in multiple environmental media (e.g., rain, road sediments, and road runoff). Our research targeted the investigation of metal speciation in rain, road sediments, and runoff; the analysis of speciation variation and mass balance of metals among rain, road sediments, and runoff; the selection of main factors by principal component analysis (PCA); and the establishment of equation to evaluate the impact of rain and road sediments to metals in road runoff. Sequential extraction procedure contains five steps for the chemical fractionation of metals. Flame atomic absorption spectrometry (Shimadzu, AA-6800) was used to determine metal speciation concentration, as well as the total and dissolved fractions. The dissolved fractions for both Cu and Zn were dominant in rain. The speciation distribution of Zn was different from that of Cu in road sediments, while speciation distribution of Zn is similar to that of Cu in runoff. The bound to carbonates for both Cu and Zn in road sediments were prone to be dissolved by rain. The levels of Cu and Zn in runoff were not obviously influenced by rain, but significantly influenced by road sediments. The masses for both Cu and Zn among rain, road sediments, and road runoff approximately meet the mass balance equation for all rainfall patterns. Five principal factors were selected for metal regression equation based on PCA, including rainfall, average rainfall intensity, antecedent dry periods, total suspended particles, and temperature. The established regression equations could be used to predict the effect of road runoff on receiving environments.

A Sensitivity Analysis of the Impact of Rain on Regional and Global Sea-Air Fluxes of CO2

PubMed Central

Shutler, J. D.; Land, P. E.; Woolf, D. K.; Quartly, G. D.

2016-01-01

The global oceans are considered a major sink of atmospheric carbon dioxide (CO2). Rain is known to alter the physical and chemical conditions at the sea surface, and thus influence the transfer of CO2 between the ocean and atmosphere. It can influence gas exchange through enhanced gas transfer velocity, the direct export of carbon from the atmosphere to the ocean, by altering the sea skin temperature, and through surface layer dilution. However, to date, very few studies quantifying these effects on global net sea-air fluxes exist. Here, we include terms for the enhanced gas transfer velocity and the direct export of carbon in calculations of the global net sea-air fluxes, using a 7-year time series of monthly global climate quality satellite remote sensing observations, model and in-situ data. The use of a non-linear relationship between the effects of rain and wind significantly reduces the estimated impact of rain-induced surface turbulence on the rate of sea-air gas transfer, when compared to a linear relationship. Nevertheless, globally, the rain enhanced gas transfer and rain induced direct export increase the estimated annual oceanic integrated net sink of CO2 by up to 6%. Regionally, the variations can be larger, with rain increasing the estimated annual net sink in the Pacific Ocean by up to 15% and altering monthly net flux by > ± 50%. Based on these analyses, the impacts of rain should be included in the uncertainty analysis of studies that estimate net sea-air fluxes of CO2 as the rain can have a considerable impact, dependent upon the region and timescale. PMID:27673683

Determination of rain rate from a spaceborne radar using measurements of total attenuation

NASA Technical Reports Server (NTRS)

Meneghini, R.; Eckerman, J.; Atlas, D.

1981-01-01

Studies shows that path-integrated rain rates can be determined by means of a direct measurement of attenuation. For ground based radars this is done by measuring the backscattering cross section of a fixed target in the presence and absence of rain along the radar beam. A ratio of the two measurements yields a factor proportional to the attenuation from which the average rain rate is deduced. The technique is extended to spaceborne radars by choosing the ground as reference target. The technique is also generalized so that both the average and range-profiled rain rates are determined. The accuracies of the resulting estimates are evaluated for a narrow beam radar located on a low earth orbiting satellite.

40 CFR 72.9 - Standard requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.9 Standard requirements. (a) Permit... shall: (i) Submit a complete Acid Rain permit application (including a compliance plan) under this part... information that the permitting authority determines is necessary in order to review an Acid Rain permit...

40 CFR 76.1 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN... Acid Rain emissions limitation or reduction requirement for SO2 under Phase I or Phase II pursuant to... required to meet the Acid Rain emissions reduction requirement for SO2. (c) The provisions of this part...

40 CFR 72.9 - Standard requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.9 Standard requirements. (a) Permit... shall: (i) Submit a complete Acid Rain permit application (including a compliance plan) under this part... information that the permitting authority determines is necessary in order to review an Acid Rain permit...

40 CFR 72.9 - Standard requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.9 Standard requirements. (a) Permit... shall: (i) Submit a complete Acid Rain permit application (including a compliance plan) under this part... information that the permitting authority determines is necessary in order to review an Acid Rain permit...

40 CFR 76.1 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN... Acid Rain emissions limitation or reduction requirement for SO2 under Phase I or Phase II pursuant to... required to meet the Acid Rain emissions reduction requirement for SO2. (c) The provisions of this part...

40 CFR 72.9 - Standard requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.9 Standard requirements. (a) Permit... shall: (i) Submit a complete Acid Rain permit application (including a compliance plan) under this part... information that the permitting authority determines is necessary in order to review an Acid Rain permit...

40 CFR 76.1 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN... Acid Rain emissions limitation or reduction requirement for SO2 under Phase I or Phase II pursuant to... required to meet the Acid Rain emissions reduction requirement for SO2. (c) The provisions of this part...

40 CFR 76.1 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN... Acid Rain emissions limitation or reduction requirement for SO2 under Phase I or Phase II pursuant to... required to meet the Acid Rain emissions reduction requirement for SO2. (c) The provisions of this part...

40 CFR 72.9 - Standard requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.9 Standard requirements. (a) Permit... shall: (i) Submit a complete Acid Rain permit application (including a compliance plan) under this part... information that the permitting authority determines is necessary in order to review an Acid Rain permit...

Acid Rain: What's the Forecast?

ERIC Educational Resources Information Center

Bybee, Rodger

1984-01-01

Discusses various types of acid rain, considered to be a century-old problem. Topics include: wet and dry deposition, effects on a variety of environments, ecosystems subject to detrimental effects, and possible solutions to the problem. A list of recommended resources on acid rain is provided. (BC)

40 CFR 76.1 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN... Acid Rain emissions limitation or reduction requirement for SO2 under Phase I or Phase II pursuant to... required to meet the Acid Rain emissions reduction requirement for SO2. (c) The provisions of this part...

The Role of Ecologists in Designing Rain Gardens: Enhancing Nitrate removal Performance

EPA Science Inventory

Rain gardens are vegetated surface depressions designed to receive stormwater runoff from roads, roofs, and parking lots. Stormwater infiltration through rain gardens’ sandy soils is intended to have both water quantity and quality benefits, through stream peak flow reduction and...

The role of ecologists in designing rain gardens: Enhancing nitrate removal performance

EPA Science Inventory

Rain gardens are vegetated surface depressions designed to receive stormwater runoff from roads, roofs, and parking lots. Stormwater infiltration through rain gardens’ sandy soils is intended to have both water quantity and quality benefits, through stream peak flow reduction an...

78 FR 29112 - Hiawatha East Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-17

... Forest, 820 Rains Drive, Gladstone, Michigan 49837. Please call ahead at (906) 428-5829 to facilitate..., USDA Forest Service, Hiawatha National Forest, 820 Rains Drive, Gladstone, Michigan 49837; (906) 428... oral comments must be sent to Hiawatha National Forest; Attn: RAC Coordinator; 820 Rains Drive...

Rain garden guidelines for southwest Ohio

EPA Science Inventory

Rain gardens are a unique and practical landscape feature that can enhance the beauty of home gardens. When properly installed, they are one method of limiting the negative effects of rainfall runoff in urban areas. Indeed, rain gardens turn a "negative" into a "positive" by capt...

Observing atmospheric water in storms with the Nimbus 7 scanning multichannel microwave radiometer

NASA Technical Reports Server (NTRS)

Katsaros, K. B.; Lewis, R. M.

1984-01-01

Employing data on integrated atmospheric water vapor, total cloud liquid water and rain rate obtainable from the Nimbus 7 Scanning Multichannel Microwave Radiometer (SMMR), we study the frontal structure of several mid-latitude cyclones over the North Pacific Ocean as they approach the West Coast of North America in the winter of 1979. The fronts, analyzed with all available independent data, are consistently located at the leading edge of the strongest gradient in integrated water vapor. The cloud liquid water content, which unfortunately has received very little in situ verification, has patterns which are consistent with the structure seen in visible and infrared imagery. The rain distribution is also a good indicator of frontal location and rain amounts are generally within a factor of two of what is observed with rain gauges on the coast. Furthermore, the onset of rain on the coast can often be accurately forecast by simple advection of the SMMR observed rain areas.

Rain rate and modeled fade distributions at 20 GHz and 30 GHz derived from five years of network rain gauge measurements

NASA Technical Reports Server (NTRS)

Goldhirsh, Julius; Krichevsky, Vladimir; Gebo, Norman

1992-01-01

Five years of rain rate and modeled slant path attenuation distributions at 20 GHz and 30 GHz derived from a network of 10 tipping bucket rain gages was examined. The rain gage network is located within a grid 70 km north-south and 47 km east-west in the Mid-Atlantic coast of the United States in the vicinity of Wallops Island, Virginia. Distributions were derived from the variable integration time data and from one minute averages. It was demonstrated that for realistic fade margins, the variable integration time results are adequate to estimate slant path attenuations at frequencies above 20 GHz using models which require one minute averages. An accurate empirical formula was developed to convert the variable integration time rain rates to one minute averages. Fade distributions at 20 GHz and 30 GHz were derived employing Crane's Global model because it was demonstrated to exhibit excellent accuracy with measured COMSTAR fades at 28.56 GHz.

On the properties of stochastic intermittency in rainfall processes.

PubMed

Molini, A; La, Barbera P; Lanza, L G

2002-01-01

In this work we propose a mixed approach to deal with the modelling of rainfall events, based on the analysis of geometrical and statistical properties of rain intermittency in time, combined with the predictability power derived from the analysis of no-rain periods distribution and from the binary decomposition of the rain signal. Some recent hypotheses on the nature of rain intermittency are reviewed too. In particular, the internal intermittent structure of a high resolution pluviometric time series covering one decade and recorded at the tipping bucket station of the University of Genova is analysed, by separating the internal intermittency of rainfall events from the inter-arrival process through a simple geometrical filtering procedure. In this way it is possible to associate no-rain intervals with a probability distribution both in virtue of their position within the event and their percentage. From this analysis, an invariant probability distribution for the no-rain periods within the events is obtained at different aggregation levels and its satisfactory agreement with a typical extreme value distribution is shown.

Mesoscale and synoptic scale features of North Pacific weather systems observed with the scanning multichannel microwave radiometer on Nimbus 7

NASA Technical Reports Server (NTRS)

Katsaros, K. B.; Lewis, R. M.

1986-01-01

Employing data on integrated atmospheric water vapor, total cloud liquid water and rain rate obtainable from the Nimbus 7 Scanning Multichannel Microwave Radiometer (SMMR), the frontal structure of several mid-latitude cyclones over the North Pacific Ocean as they approach the West Coast of North America in the winter of 1979. The fronts, analyzed with all available independent data, are consistently located at the leading edge of the strongest gradient in integrated water vapor. The cloud liquid water content, which unfortunately has received very little in situ verification, has patterns which are consistent with the structure seen in visible and infrared imagery. The rain distribution is also a good indicator of frontal location and rain amounts are generally within a factor of two of what is observed with rain gauges on the coast. Furthermore, the onset of rain on the coast can often be accurately forecast by simple advection of the SMMR observed rain areas.

Validation of Rain Rate Retrievals for the Airborne Hurricane Imaging Radiometer (HIRAD)

NASA Technical Reports Server (NTRS)

Jacob, Maria; Salemirad, Matin; Jones, W. Linwood; Biswas, Sayak; Cecil, Daniel

2015-01-01

On board of the NASA's Global Hawk (AV1) aircraft there are two microwave, namely: the passive microwave Hurricane Imaging Radiometer (HIRAD), and the active microwave High-altitude Imaging Wind and Rain Airborne Profiler (HIWRAP). This paper presents results from an unplanned rain rate measurement validation opportunity that occurred in 2013, when the Global Hawk aircraft flew over an intense tropical squall-line that was simultaneously observed, by the Tampa NEXRAD meteorological radar. During this experiment, Global Hawk flying at an altitude of 18 km made 3 passes over the rapidly propagating thunderstorm, while the TAMPA NEXRAD perform volume scans on a 5-minute interval. NEXRAD 2D images of rain rate (mm/hr) were obtained at two altitudes (3 km & 6 km), which serve as surface truth for the HIRAD rain rate retrievals. In this paper, results are presented of the three-way inter-comparison of HIRAD Tb, HIWRAP dbZ and NEXRAD rain rate imagery.

[Combined effects of copper and simulated acid rain on copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa].

PubMed

He, Shan-Ying; Gao, Yong-Jie; Shentu, Jia-Li; Chen, Kun-Bai

2011-02-01

A pot experiment was conducted to study the combined effects of Cu (0-1500 mg x kg(-1)) and simulated acid rain (pH 2.5-5.6) on the copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa. With the increasing concentration of soil Cu, the Cu accumulation in R. acetosa increased, being higher in root than in stem and leaf. The exposure to low pH acid rain promoted the Cu uptake by R. acetosa. With the increase of soil Cu concentration and/or of acid rain acidity, the biomass of R. acetosa decreased, leaf and root MDA contents increased and had good correlation with soil Cu concentration, and the SOD and POD activities in leaf and root displayed a decreasing trend after an initial increase. This study showed that R. acetosa had a strong adaptive ability to Cu and acid rain stress, exhibiting a high application potential in the remediation of Cu-contaminated soil in acid rain areas.

Effects of different CO2 concentration on growth and photosynthetic of rain tree plants (Albizia saman jacq.Merr)

NASA Astrophysics Data System (ADS)

Fathurrahman, F.; Nizam, M. S.; Wan Juliana, W. A.; Doni, Febri; NorLailatul, W. M.; Che Radziah, C. M. Z.

2016-11-01

A preliminary study was conducted to determine the effect of elevated carbon dioxide (CO2) in rain tree growth under controllable growth chamber. The tolerance towards CO2 absorption in the photosynthesis process for the growth of tree rain is still unknown. In this study, rain tree seedlings were incubated for three months in a growth chamber with three different CO2 concentration treatment: GC1 (300 ppm), GC2 (600 ppm) and GC3 (900 ppm) at similar condition of temperature (28°C), humidity (60%) and lighting (1200 lux). The results showed that increased CO2 significantly increase the growth rate and chlorophyll content in rain tree. The results of this study add to the further understanding of how the improvement of the growth and physiological characteristics of rain tree was affected by CO2 enrichment treatment. This research can for used for global warming mitigation in the future.

Prediction of apparent extinction for optical transmission through rain

NASA Astrophysics Data System (ADS)

Vasseur, H.; Gibbins, C. J.

1996-12-01

At optical wavelengths, geometrical optics holds that the extinction efficiency of raindrops is equal to two. This approximation yields a wavelength-independent extinction coefficient that, however, can hardly be used to predict accurately rain extinction measured in optical transmissions. Actually, in addition to the extinct direct incoming light, a significant part of the power scattered by the rain particles reaches the receiver. This leads to a reduced apparent extinction that depends on both rain characteristics and link parameters. A simple method is proposed to evaluate this apparent extinction. It accounts for the additional scattered power that enters the receiver when one considers the forward-scattering pattern of the raindrops as well as the multiple-scattering effects using, respectively, the Fraunhofer diffraction and Twersky theory. It results in a direct analytical formula that enables a quick and accurate estimation of the rain apparent extinction and highlights the influence of the link parameters. Predictions of apparent extinction through rain are found in excellent agreement with measurements in the visible and IR regions.

Interactive effects of cadmium and acid rain on photosynthetic light reaction in soybean seedlings.

PubMed

Sun, Zhaoguo; Wang, Lihong; Chen, Minmin; Wang, Lei; Liang, Chanjuan; Zhou, Qing; Huang, Xiaohua

2012-05-01

Interactive effects of cadmium (Cd(2+)) and acid rain on photosynthetic light reaction in soybean seedlings were investigated under hydroponic conditions. Single treatment with Cd(2+) or acid rain and the combined treatment decreased the content of chlorophyll, Hill reaction rate, the activity of Mg(2+)-ATPase, maximal photochemical efficiency and maximal quantum yield, increased initial fluorescence and damaged the chloroplast structure in soybean seedlings. In the combined treatment, the change in the photosynthetic parameters and the damage of chloroplast structure were stronger than those of any single pollution. Meanwhile, Cd(2+) and acid rain had the interactive effects on the test indices in soybean seedlings. The results indicated that the combined pollution of Cd(2+) and acid rain aggravated the toxic effect of the single pollution of Cd(2+) or acid rain on the photosynthetic parameters due to the serious damage to the chloroplast structure. Copyright © 2011 Elsevier Inc. All rights reserved.

Multidimensional Modeling of Coronal Rain Dynamics

NASA Astrophysics Data System (ADS)

Fang, X.; Xia, C.; Keppens, R.

2013-07-01

We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

Consumer demand for green stormwater management technology in an urban setting: The case of Chicago rain barrels

NASA Astrophysics Data System (ADS)

Ando, Amy W.; Freitas, Luiz P. C.

2011-12-01

Hydrological disruption and water pollution from urbanization can be reduced if households in urban areas adopt decentralized storm water controls. We study a citywide municipal subsidized rain-barrel program in the third biggest city in the United States, Chicago, to explore what factors influence whether households purchase this sort of green storm water management technology in an urban setting. Specifically, we regress census-tract level data on the number of rain barrels adopted in different parts of the city on socioeconomic variables, data on local flood frequency, and features of the housing stock. We find that rain-barrel purchases are not correlated with local levels of flooding, even though city residents were told by program managers that rain barrels could alleviate local flooding. Instead, rain barrels are heavily concentrated in places with high-income attitudinally green populations. We do find more rain barrels were adopted in places close to rain-barrel distribution points and near sites of hydrological information campaigns; thus, policy makers might increase green-technology adoption in areas where they can do the most good by reducing transaction costs and providing education programs to those areas. Finally, our results indicate that owner occupancy is positively correlated with green-technology adoption. Low-rise rental housing may have inefficiently low levels of adoption, such that city managers might want to develop programs to encourage storm water management investments by landlords who do not live in their own properties.

An analytic study of nonsteady two-phase laminar boundary layer around an airfoil

NASA Technical Reports Server (NTRS)

Hsu, Yu-Kao

1989-01-01

Recently, NASA, FAA, and other organizations have focused their attention upon the possible effects of rain on airfoil performance. Rhode carried out early experiments and concluded that the rain impacting the aircraft increased the drag. Bergrum made numerical calculation for the rain effects on airfoils. Luers and Haines did an analytic investigation and found that heavy rain induces severe aerodynamic penalties including both a momentum penalty due to the impact of the rain and a drag and lift penalty due to rain roughening of the airfoil and fuselage. More recently, Hansman and Barsotti performed experiments and declared that performance degradation of an airfoil in heavy rain is due to the effective roughening of the surface by the water layer. Hansman and Craig did further experimental research at low Reynolds number. E. Dunham made a critical review for the potential influence of rain on airfoil performance. Dunham et al. carried out experiments for the transport type airfoil and concluded that there is a reduction of maximum lift capability with increase in drag. There is a scarcity of published literature in analytic research of two-phase boundary layer around an airfoil. Analytic research is being improved. The following assumptions are made: the fluid flow is non-steady, viscous, and incompressible; the airfoil is represented by a two-dimensional flat plate; and there is only a laminar boundary layer throughout the flow region. The boundary layer approximation is solved and discussed.

Coronal rain in magnetic bipolar weak fields

NASA Astrophysics Data System (ADS)

Xia, C.; Keppens, R.; Fang, X.

2017-07-01

Aims: We intend to investigate the underlying physics for the coronal rain phenomenon in a representative bipolar magnetic field, including the formation and the dynamics of coronal rain blobs. Methods: With the MPI-AMRVAC code, we performed three dimensional radiative magnetohydrodynamic (MHD) simulation with strong heating localized on footpoints of magnetic loops after a relaxation to quiet solar atmosphere. Results: Progressive cooling and in-situ condensation starts at the loop top due to radiative thermal instability. The first large-scale condensation on the loop top suffers Rayleigh-Taylor instability and becomes fragmented into smaller blobs. The blobs fall vertically dragging magnetic loops until they reach low-β regions and start to fall along the loops from loop top to loop footpoints. A statistic study of the coronal rain blobs finds that small blobs with masses of less than 1010 g dominate the population. When blobs fall to lower regions along the magnetic loops, they are stretched and develop a non-uniform velocity pattern with an anti-parallel shearing pattern seen to develop along the central axis of the blobs. Synthetic images of simulated coronal rain with Solar Dynamics Observatory Atmospheric Imaging Assembly well resemble real observations presenting dark falling clumps in hot channels and bright rain blobs in a cool channel. We also find density inhomogeneities during a coronal rain "shower", which reflects the observed multi-stranded nature of coronal rain. Movies associated to Figs. 3 and 7 are available at http://www.aanda.org

Atmospheric nitrogen deposition in south-east Scotland: Quantification of the organic nitrogen fraction in wet, dry and bulk deposition

NASA Astrophysics Data System (ADS)

González Benítez, Juan M.; Cape, J. Neil; Heal, Mathew R.; van Dijk, Netty; Díez, Alberto Vidal

Water soluble organic nitrogen (WSON) compounds are ubiquitous in precipitation and in the planetary boundary layer, and therefore are a potential source of bioavailable reactive nitrogen. This paper examines weekly rain data over a period of 22 months from June 2005 to March 2007 collected in 2 types of rain collector (bulk deposition and "dry + wet" deposition) located in a semi-rural area 15 km southwest of Edinburgh, UK (N55°51'44″, W3°12'19″). Bulk deposition collectors are denoted in this paper as "standard rain gauges", and they are the design used in the UK national network for monitoring precipitation composition. "Dry + wet" deposition collectors are flushing rain gauges and they are equipped with a rain detector (conductivity array), a spray nozzle, a 2-way valve and two independent bottles to collect funnel washings (dry deposition) and true wet deposition. On average, for the 27 weekly samples with 3 valid replicates for the 2 types of collectors, dissolved organic nitrogen (DON) represented 23% of the total dissolved nitrogen (TDN) in bulk deposition. Dry deposition of particles and gas on the funnel surface, rather than rain, contributed over half of all N-containing species (inorganic and organic). Some discrepancies were found between bulk rain gauges and flushing rain gauges, for deposition of both TDN and DON, suggesting biological conversion and loss of inorganic N in the flushing samplers.

Comparison of Mosquito Abundance From Biogents Sentinel 2.0 Traps With and Without Rain Covers.

PubMed

Cilek, James E; Weston, Joshua R; Richardson, Alec G

2017-06-01

Biogents Sentinel (BGS) traps have rapidly become a standard for adult Aedes aegypti surveillance. Several investigators have found that trap collections can be damaged easily by heavy dew or rain entering the trap intake port. In addition, water entering the trap may temporarily stop the fan, thus reducing the collection potential of the trap. We evaluated the effectiveness of a rain cover designed to minimize damage to mosquito trap collections from BGS 2.0 traps in a residential backyard in Jacksonville, FL. Rain covers consisted of white fiberglass 51-cm 2 sheets positioned 19, 29, and 39 cm above the air intake of the traps. One BGS trap did not have a rain cover and was used as a control standard for comparison. All traps were baited with the BG-Lure. Generally, traps with rain covers resulted in higher mosquito counts when compared with collections from uncovered traps. Overall mosquito abundance was greater from traps with the rain cover positioned at 29 cm, but this difference was not significantly different when compared with the other cover heights. Covers spaced 29 or 39 cm collected significantly more Culex quinquefasciatus compared with traps at 19 cm and no cover. Species diversity was greatest for BGS traps with the rain cover positioned at 29 cm followed by 39 cm, 19 cm, and no cover; however, differences in diversity among the traps, with or without covers, were not significant.

Rain Garden Research at EPA’s Urban Watershed Research Facility: Promoting Nitrate Removal through Rain Garden Design

EPA Science Inventory

Rain gardens are designed to infiltrate stormwater, capture suspended solids, sorb heavy metals and phosphorus, and transform nutrients through biological processes. Most studies have found a low capacity for stormwater nitrate removal. Research at the Urban Watershed Managemen...

Detail of old rain shed (Building No. 43) showing vertical ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Detail of old rain shed (Building No. 43) showing vertical posts. Note rock foundations of wood tanks once located under the rain shed on the ground at center of photograph. - Hawaii Volcanoes National Park Water Collection System, Hawaii Volcanoes National Park, Volcano, Hawaii County, HI

40 CFR 72.40 - General.

Code of Federal Regulations, 2014 CFR

2014-07-01

... REGULATION Acid Rain Compliance Plan and Compliance Options § 72.40 General. (a) For each affected unit included in an Acid Rain permit application, a complete compliance plan shall: (1) For sulfur dioxide... of the Acid Rain compliance options. (2) For nitrogen oxides emissions, certify that the unit will...

Acid Rain: An Educational Opportunity?

ERIC Educational Resources Information Center

Marion, James I.

1984-01-01

Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…

40 CFR 75.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

An Umbrella for Acid Rain.

ERIC Educational Resources Information Center

Randal, Judith

1979-01-01

The Environmental Protection Agency has awarded several grants to study effects of and possible solutions to the problem of "acid rain"; pollution from atmospheric nitric and sulfuric acids. The research program is administered through North Carolina State University at Raleigh and will focus on biological effects of acid rain. (JMF)

40 CFR 72.40 - General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... REGULATION Acid Rain Compliance Plan and Compliance Options § 72.40 General. (a) For each affected unit included in an Acid Rain permit application, a complete compliance plan shall: (1) For sulfur dioxide... of the Acid Rain compliance options. (2) For nitrogen oxides emissions, certify that the unit will...

40 CFR 75.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

40 CFR 72.40 - General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... REGULATION Acid Rain Compliance Plan and Compliance Options § 72.40 General. (a) For each affected unit included in an Acid Rain permit application, a complete compliance plan shall: (1) For sulfur dioxide... of the Acid Rain compliance options. (2) For nitrogen oxides emissions, certify that the unit will...

40 CFR 75.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 17 2014-07-01 2014-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

40 CFR 72.66 - Public comments.

Code of Federal Regulations, 2013 CFR

2013-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.66 Public comments. (a) General. During the..., if any, to owners and operators of any unit covered by the Acid Rain permit application. (c) Contents...) The environmental effects of acid rain, acid deposition, sulfur dioxide, or nitrogen oxides generally...

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2014 CFR

2014-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

40 CFR 72.40 - General.

Code of Federal Regulations, 2012 CFR

2012-07-01

... REGULATION Acid Rain Compliance Plan and Compliance Options § 72.40 General. (a) For each affected unit included in an Acid Rain permit application, a complete compliance plan shall: (1) For sulfur dioxide... of the Acid Rain compliance options. (2) For nitrogen oxides emissions, certify that the unit will...

40 CFR 72.66 - Public comments.

Code of Federal Regulations, 2012 CFR

2012-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.66 Public comments. (a) General. During the..., if any, to owners and operators of any unit covered by the Acid Rain permit application. (c) Contents...) The environmental effects of acid rain, acid deposition, sulfur dioxide, or nitrogen oxides generally...

40 CFR 72.40 - General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... REGULATION Acid Rain Compliance Plan and Compliance Options § 72.40 General. (a) For each affected unit included in an Acid Rain permit application, a complete compliance plan shall: (1) For sulfur dioxide... of the Acid Rain compliance options. (2) For nitrogen oxides emissions, certify that the unit will...

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2013 CFR

2013-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

40 CFR 72.66 - Public comments.

Code of Federal Regulations, 2010 CFR

2010-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.66 Public comments. (a) General. During the..., if any, to owners and operators of any unit covered by the Acid Rain permit application. (c) Contents...) The environmental effects of acid rain, acid deposition, sulfur dioxide, or nitrogen oxides generally...

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2012 CFR

2012-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2011 CFR

2011-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

40 CFR 75.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

40 CFR 72.66 - Public comments.

Code of Federal Regulations, 2011 CFR

2011-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.66 Public comments. (a) General. During the..., if any, to owners and operators of any unit covered by the Acid Rain permit application. (c) Contents...) The environmental effects of acid rain, acid deposition, sulfur dioxide, or nitrogen oxides generally...

40 CFR 72.66 - Public comments.

Code of Federal Regulations, 2014 CFR

2014-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.66 Public comments. (a) General. During the..., if any, to owners and operators of any unit covered by the Acid Rain permit application. (c) Contents...) The environmental effects of acid rain, acid deposition, sulfur dioxide, or nitrogen oxides generally...

40 CFR 75.3 - General Acid Rain Program provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 17 2013-07-01 2013-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2010 CFR

2010-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

Study of 1-min rain rate integration statistic in South Korea

NASA Astrophysics Data System (ADS)

Shrestha, Sujan; Choi, Dong-You

2017-03-01

The design of millimeter wave communication links and the study of propagation impairments at higher frequencies due to a hydrometeor, particularly rain, require the knowledge of 1-min. rainfall rate data. Signal attenuation in space communication results are due to absorption and scattering of radio wave energy. Radio wave attenuation due to rain depends on the relevance of a 1-min. integration time for the rain rate. However, in practice, securing these data over a wide range of areas is difficult. Long term precipitation data are readily available. However, there is a need for a 1-min. rainfall rate in the rain attenuation prediction models for a better estimation of the attenuation. In this paper, we classify and survey the prominent 1-min. rain rate models. Regression analysis was performed for the study of cumulative rainfall data measured experimentally for a decade in nine different regions in South Korea, with 93 different locations, using the experimental 1-min. rainfall accumulation. To visualize the 1-min. rainfall rate applicable for the whole region for 0.01% of the time, we have considered the variation in the rain rate for 40 stations across South Korea. The Kriging interpolation method was used for spatial interpolation of the rain rate values for 0.01% of the time into a regular grid to obtain a highly consistent and predictable rainfall variation. The rain rate exceeded the 1-min. interval that was measured through the rain gauge compared to the rainfall data estimated using the International Telecommunication Union Radio Communication Sector model (ITU-R P.837-6) along with the empirical methods as Segal, Burgueno et al., Chebil and Rahman, logarithmic, exponential and global coefficients, second and third order polynomial fits, and Model 1 for Icheon regions under the regional and average coefficient set. The ITU-R P. 837-6 exhibits a lower relative error percentage of 3.32% and 12.59% in the 5- and 10-min. to 1-min. conversion, whereas the higher error percentages of 24.64%, 46.44% and 58.46% for the 20-, 30- and 60-min. to 1-min., conversion were obtained in the Icheon region. The available experimental rainfall data were sampled on equiprobable rain-rate values where the application of these models to experimentally obtained data exhibits a variable error rate. This paper aims to provide a better survey of various conversion methods to model a 1-min. rain rate applicable to the South Korea regions with a suitable contour plot at 0.01% of the time.

Enhancing rain garden design to promote nitrate removal: testing a media carbon amendment.

EPA Science Inventory

Rain gardens effectively remove some stressors from stormwater, in particular heavy metals, phosphorus, and oil and grease, but in most cases they show much smaller removal rates of nitrate. This is likely due to the high sand and low organic matter content specified for rain ga...

Rain Garden Research at EPA's Urban Watershed Research Facility

EPA Science Inventory

I have been invited to give a presentation at the 2009 National Erosion Conference in Hartford, CT, on October 27-28, 2009. My presentation discusses the research on sizing of rain gardens that is being conducted using the large, parking lot rain gardens on-site. I discuss the ...

Environmental Education about the Rain Forest.

ERIC Educational Resources Information Center

Berkmuller, Klaus

Designed to help in the development of an educational program about the value of rain forests, this handbook presents a condensation of issues, facts, and concepts. The handbook is divided into three parts. Part one introduces the rain forest ecosystem and provides conceptual background material needed in the determination of problems, the…

40 CFR 72.83 - Administrative permit amendment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.83 Administrative permit amendment. (a) Acid Rain permit... Acid Rain permit, of commencement of operation of qualifying Phase I technology, provided that they are in accordance with § 72.42 of this part; (9) Changes in the date, specified in a new unit's Acid Rain...

40 CFR 72.65 - Public notice of opportunities for public comment.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.65... area where the source covered by the Acid Rain permit application is located or in a State publication... designated representative for the affected source. (3) Identification of each unit covered by the Acid Rain...

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

Acid Rain: The Scientific Challenge.

ERIC Educational Resources Information Center

Godfrey, Paul J.

1991-01-01

Documents the workings and findings of the Massachusetts Acid Rain Monitoring Project, which has pooled the volunteer efforts of more than 1,000 amateur and professional scientists since 1983. Reports on the origins of air pollution, the prediction of acid rain, and its effects on both water life and land resources. (JJK)

40 CFR 72.43 - Phase I reduced utilization plans.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.43 Phase I reduced... any Acid Rain emissions limitation or emissions reduction requirements during Phase I; and (ii) Meets... this section shall include in the Acid Rain permit application for the unit a reduced utilization plan...

40 CFR 76.10 - Alternative emission limitations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.10 Alternative emission limitations. (a... alternative emission limitation on the date that the application for renewal of the source's Acid Rain permit... demonstration period by administrative amendment (under § 72.83 of this chapter) to the Acid Rain permit. (v...

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

40 CFR 72.90 - Annual compliance certification report.

Code of Federal Regulations, 2014 CFR

2014-07-01

... is subject to the Acid Rain emissions limitations, the designated representative of the source at... the source and the affected units at the source in compliance with the Acid Rain Program, whether each... covered by the report in compliance with the requirements of the Acid Rain Program applicable to the unit...

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

40 CFR 96.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2010 CFR

2010-07-01

... unit subject to an Acid Rain Emission limitation who signed and certified any submission that is made.... (b) Monitoring plans. (1) The owner or operator of a unit subject to an Acid Rain emissions... operator of a unit that is not subject to an Acid Rain emissions limitation shall comply with requirements...

40 CFR 72.43 - Phase I reduced utilization plans.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.43 Phase I reduced... any Acid Rain emissions limitation or emissions reduction requirements during Phase I; and (ii) Meets... this section shall include in the Acid Rain permit application for the unit a reduced utilization plan...

40 CFR 97.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2010 CFR

2010-07-01

...)(1). (2) If the NOX authorized account representative for a NOX Budget unit subject to an Acid Rain... or operator of a unit subject to an Acid Rain emissions limitation shall comply with requirements of... to an Acid Rain emissions limitation shall comply with requirements of § 75.62 of this chapter...

40 CFR 72.60 - General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.60 General. (a) Scope. This subpart and parts 74, 76, and 78 of this chapter contain the procedures for federal issuance of Acid Rain permits for Phase I of the Acid Rain Program and Phase II for sources for which the Administrator is the permitting...

40 CFR 72.80 - General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... REGULATION Permit Revisions § 72.80 General. (a) This subpart shall govern revisions to any Acid Rain permit issued by the Administrator and to the Acid Rain portion of any operating permit issued by a State... 71 of this chapter, the provisions of this subpart shall govern revision of any Acid Rain Program...

40 CFR 72.44 - Phase II repowering extensions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.44 Phase II repowering... the requirements of paragraph (a)(1)(i) of this section may include in the unit's Phase II Acid Rain... authority shall issue the Acid Rain portion of the operating permit including: (A) The approved repowering...

40 CFR 72.44 - Phase II repowering extensions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.44 Phase II repowering... the requirements of paragraph (a)(1)(i) of this section may include in the unit's Phase II Acid Rain... authority shall issue the Acid Rain portion of the operating permit including: (A) The approved repowering...

40 CFR 96.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2012 CFR

2012-07-01

... unit subject to an Acid Rain Emission limitation who signed and certified any submission that is made.... (b) Monitoring plans. (1) The owner or operator of a unit subject to an Acid Rain emissions... operator of a unit that is not subject to an Acid Rain emissions limitation shall comply with requirements...

40 CFR 72.43 - Phase I reduced utilization plans.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.43 Phase I reduced... any Acid Rain emissions limitation or emissions reduction requirements during Phase I; and (ii) Meets... this section shall include in the Acid Rain permit application for the unit a reduced utilization plan...

40 CFR 72.90 - Annual compliance certification report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... is subject to the Acid Rain emissions limitations, the designated representative of the source at... the source and the affected units at the source in compliance with the Acid Rain Program, whether each... covered by the report in compliance with the requirements of the Acid Rain Program applicable to the unit...

40 CFR 72.70 - Relationship to title V operating permit program.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.70 Relationship to... operating permit programs and acceptance of State Acid Rain programs, the procedure for including State Acid... of an accepted State program, to issue Phase II Acid Rain permits. (b) Relationship to operating...

40 CFR 74.10 - Roles-EPA and permitting authority.

Code of Federal Regulations, 2013 CFR

2013-07-01

... opt-in provisions of the Acid Rain Program: (1) Calculating the baseline or alternative baseline and... withdrawal conditions prior to withdrawal from the Acid Rain Program as provided under § 74.18; and (5) Approving and disapproving the request to withdraw from the Acid Rain Program. (b) Permitting authority...

40 CFR 72.5 - State authority.

Code of Federal Regulations, 2011 CFR

2011-07-01

... REGULATION Acid Rain Program General Provisions § 72.5 State authority. Consistent with section 116 of the Act, the provisions of the Acid Rain Program shall not be construed in any manner to preclude any... unit or affected source under the Acid Rain Program; provided that such State requirement, if...

40 CFR 96.375 - Petitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is not subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions...

40 CFR 76.10 - Alternative emission limitations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.10 Alternative emission limitations. (a... alternative emission limitation on the date that the application for renewal of the source's Acid Rain permit... demonstration period by administrative amendment (under § 72.83 of this chapter) to the Acid Rain permit. (v...

40 CFR 72.70 - Relationship to title V operating permit program.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.70 Relationship to... operating permit programs and acceptance of State Acid Rain programs, the procedure for including State Acid... of an accepted State program, to issue Phase II Acid Rain permits. (b) Relationship to operating...

40 CFR 72.5 - State authority.

Code of Federal Regulations, 2012 CFR

2012-07-01

... REGULATION Acid Rain Program General Provisions § 72.5 State authority. Consistent with section 116 of the Act, the provisions of the Acid Rain Program shall not be construed in any manner to preclude any... unit or affected source under the Acid Rain Program; provided that such State requirement, if...

40 CFR 74.10 - Roles-EPA and permitting authority.

Code of Federal Regulations, 2012 CFR

2012-07-01

... opt-in provisions of the Acid Rain Program: (1) Calculating the baseline or alternative baseline and... withdrawal conditions prior to withdrawal from the Acid Rain Program as provided under § 74.18; and (5) Approving and disapproving the request to withdraw from the Acid Rain Program. (b) Permitting authority...

Acid Rain, pH & Acidity: A Common Misinterpretation.

ERIC Educational Resources Information Center

Clark, David B.; Thompson, Ronald E.

1989-01-01

Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

40 CFR 72.65 - Public notice of opportunities for public comment.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.65... area where the source covered by the Acid Rain permit application is located or in a State publication... designated representative for the affected source. (3) Identification of each unit covered by the Acid Rain...

40 CFR 72.30 - Requirement to apply.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) PERMITS REGULATION Acid Rain Permit Applications § 72.30 Requirement to apply. (a) Duty to apply. The designated representative of any source with an affected unit shall submit a complete Acid Rain permit... permit that states its Acid Rain program requirements. (b) Deadlines—(1) Phase 1. (i) The designated...

40 CFR 72.30 - Requirement to apply.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) PERMITS REGULATION Acid Rain Permit Applications § 72.30 Requirement to apply. (a) Duty to apply. The designated representative of any source with an affected unit shall submit a complete Acid Rain permit... permit that states its Acid Rain program requirements. (b) Deadlines—(1) Phase 1. (i) The designated...

40 CFR 72.70 - Relationship to title V operating permit program.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.70 Relationship to... operating permit programs and acceptance of State Acid Rain programs, the procedure for including State Acid... of an accepted State program, to issue Phase II Acid Rain permits. (b) Relationship to operating...

40 CFR 97.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2012 CFR

2012-07-01

...)(1). (2) If the NOX authorized account representative for a NOX Budget unit subject to an Acid Rain... or operator of a unit subject to an Acid Rain emissions limitation shall comply with requirements of... to an Acid Rain emissions limitation shall comply with requirements of § 75.62 of this chapter...

40 CFR 72.8 - Retired units exemption.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.8 Retired units exemption. (a) This section... affected unit (except for an opt-in source) that is permanently retired shall be exempt from the Acid Rain... permitting authority otherwise responsible for administering a Phase II Acid Rain permit for the unit. If the...

40 CFR 72.8 - Retired units exemption.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.8 Retired units exemption. (a) This section... affected unit (except for an opt-in source) that is permanently retired shall be exempt from the Acid Rain... permitting authority otherwise responsible for administering a Phase II Acid Rain permit for the unit. If the...

40 CFR 74.43 - Annual compliance certification report.

Code of Federal Regulations, 2010 CFR

2010-07-01

... which an opt-in source is subject to the Acid Rain emissions limitations, the designated representative... compliance with the requirements of the Acid Rain Program applicable to the opt-in source, including: (1) Whether the opt-in source was operated in compliance with applicable Acid Rain emissions limitations...

Acid Rain Students Do Original Research.

ERIC Educational Resources Information Center

Outdoor Communicator, 1984

1984-01-01

At Park Senior High School (Cottage Grove, Minnesota), 46 juniors and seniors planted 384 red pine seedlings in connection with their original research on acid rain, with advice from Dr. Harriet Stubbs, director of the Acid Precipitation Awareness Program (West Saint Paul), which has been developing acid rain teaching materials. (MH)

40 CFR 74.43 - Annual compliance certification report.

Code of Federal Regulations, 2014 CFR

2014-07-01

... which an opt-in source is subject to the Acid Rain emissions limitations, the designated representative... compliance with the requirements of the Acid Rain Program applicable to the opt-in source, including: (1) Whether the opt-in source was operated in compliance with applicable Acid Rain emissions limitations...

40 CFR 74.10 - Roles-EPA and permitting authority.

Code of Federal Regulations, 2011 CFR

2011-07-01

... opt-in provisions of the Acid Rain Program: (1) Calculating the baseline or alternative baseline and... withdrawal conditions prior to withdrawal from the Acid Rain Program as provided under § 74.18; and (5) Approving and disapproving the request to withdraw from the Acid Rain Program. (b) Permitting authority...

40 CFR 72.90 - Annual compliance certification report.

Code of Federal Regulations, 2012 CFR

2012-07-01

... is subject to the Acid Rain emissions limitations, the designated representative of the source at... the source and the affected units at the source in compliance with the Acid Rain Program, whether each... covered by the report in compliance with the requirements of the Acid Rain Program applicable to the unit...

40 CFR 72.60 - General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.60 General. (a) Scope. This subpart and parts 74, 76, and 78 of this chapter contain the procedures for federal issuance of Acid Rain permits for Phase I of the Acid Rain Program and Phase II for sources for which the Administrator is the permitting...

40 CFR 72.44 - Phase II repowering extensions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.44 Phase II repowering... the requirements of paragraph (a)(1)(i) of this section may include in the unit's Phase II Acid Rain... authority shall issue the Acid Rain portion of the operating permit including: (A) The approved repowering...

40 CFR 72.83 - Administrative permit amendment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.83 Administrative permit amendment. (a) Acid Rain permit... Acid Rain permit, of commencement of operation of qualifying Phase I technology, provided that they are in accordance with § 72.42 of this part; (9) Changes in the date, specified in a new unit's Acid Rain...

40 CFR 72.22 - Alternate designated representative.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the term “designated representative” is used under the Acid Rain Program, the term shall be construed...), whenever the term “alternate designated representative” is used under the Acid Rain Program, the term shall... used under the Acid Rain Program, the term shall be construed to include either of the alternate...

40 CFR 72.44 - Phase II repowering extensions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.44 Phase II repowering... the requirements of paragraph (a)(1)(i) of this section may include in the unit's Phase II Acid Rain... authority shall issue the Acid Rain portion of the operating permit including: (A) The approved repowering...

40 CFR 72.65 - Public notice of opportunities for public comment.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.65... area where the source covered by the Acid Rain permit application is located or in a State publication... designated representative for the affected source. (3) Identification of each unit covered by the Acid Rain...

40 CFR 74.43 - Annual compliance certification report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... which an opt-in source is subject to the Acid Rain emissions limitations, the designated representative... compliance with the requirements of the Acid Rain Program applicable to the opt-in source, including: (1) Whether the opt-in source was operated in compliance with applicable Acid Rain emissions limitations...

40 CFR 72.5 - State authority.

Code of Federal Regulations, 2010 CFR

2010-07-01

... REGULATION Acid Rain Program General Provisions § 72.5 State authority. Consistent with section 116 of the Act, the provisions of the Acid Rain Program shall not be construed in any manner to preclude any... unit or affected source under the Acid Rain Program; provided that such State requirement, if...

40 CFR 72.60 - General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.60 General. (a) Scope. This subpart and parts 74, 76, and 78 of this chapter contain the procedures for federal issuance of Acid Rain permits for Phase I of the Acid Rain Program and Phase II for sources for which the Administrator is the permitting...

40 CFR 72.60 - General.

Code of Federal Regulations, 2012 CFR

2012-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.60 General. (a) Scope. This subpart and parts 74, 76, and 78 of this chapter contain the procedures for federal issuance of Acid Rain permits for Phase I of the Acid Rain Program and Phase II for sources for which the Administrator is the permitting...

40 CFR 72.83 - Administrative permit amendment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.83 Administrative permit amendment. (a) Acid Rain permit... Acid Rain permit, of commencement of operation of qualifying Phase I technology, provided that they are in accordance with § 72.42 of this part; (9) Changes in the date, specified in a new unit's Acid Rain...

40 CFR 72.70 - Relationship to title V operating permit program.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.70 Relationship to... operating permit programs and acceptance of State Acid Rain programs, the procedure for including State Acid... of an accepted State program, to issue Phase II Acid Rain permits. (b) Relationship to operating...

40 CFR 96.375 - Petitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is not subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions...

40 CFR 72.83 - Administrative permit amendment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.83 Administrative permit amendment. (a) Acid Rain permit... Acid Rain permit, of commencement of operation of qualifying Phase I technology, provided that they are in accordance with § 72.42 of this part; (9) Changes in the date, specified in a new unit's Acid Rain...

40 CFR 72.80 - General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... REGULATION Permit Revisions § 72.80 General. (a) This subpart shall govern revisions to any Acid Rain permit issued by the Administrator and to the Acid Rain portion of any operating permit issued by a State... 71 of this chapter, the provisions of this subpart shall govern revision of any Acid Rain Program...

40 CFR 72.8 - Retired units exemption.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.8 Retired units exemption. (a) This section... affected unit (except for an opt-in source) that is permanently retired shall be exempt from the Acid Rain... permitting authority otherwise responsible for administering a Phase II Acid Rain permit for the unit. If the...

40 CFR 96.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2013 CFR

2013-07-01

... unit subject to an Acid Rain Emission limitation who signed and certified any submission that is made.... (b) Monitoring plans. (1) The owner or operator of a unit subject to an Acid Rain emissions... operator of a unit that is not subject to an Acid Rain emissions limitation shall comply with requirements...

40 CFR 96.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2011 CFR

2011-07-01

... unit subject to an Acid Rain Emission limitation who signed and certified any submission that is made.... (b) Monitoring plans. (1) The owner or operator of a unit subject to an Acid Rain emissions... operator of a unit that is not subject to an Acid Rain emissions limitation shall comply with requirements...

40 CFR 96.375 - Petitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is not subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions...

40 CFR 72.65 - Public notice of opportunities for public comment.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.65... area where the source covered by the Acid Rain permit application is located or in a State publication... designated representative for the affected source. (3) Identification of each unit covered by the Acid Rain...

40 CFR 72.90 - Annual compliance certification report.

Code of Federal Regulations, 2013 CFR

2013-07-01

... is subject to the Acid Rain emissions limitations, the designated representative of the source at... the source and the affected units at the source in compliance with the Acid Rain Program, whether each... covered by the report in compliance with the requirements of the Acid Rain Program applicable to the unit...

40 CFR 72.30 - Requirement to apply.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) PERMITS REGULATION Acid Rain Permit Applications § 72.30 Requirement to apply. (a) Duty to apply. The designated representative of any source with an affected unit shall submit a complete Acid Rain permit... permit that states its Acid Rain program requirements. (b) Deadlines—(1) Phase 1. (i) The designated...

40 CFR 74.43 - Annual compliance certification report.

Code of Federal Regulations, 2013 CFR

2013-07-01

... which an opt-in source is subject to the Acid Rain emissions limitations, the designated representative... compliance with the requirements of the Acid Rain Program applicable to the opt-in source, including: (1) Whether the opt-in source was operated in compliance with applicable Acid Rain emissions limitations...

STATE ACID RAIN RESEARCH AND SCREENING SYSTEM - VERSION 1.0 USER'S MANUAL

EPA Science Inventory

The report is a user's manual that describes Version 1.0 of EPA's STate Acid Rain Research and Screening System (STARRSS), developed to assist utility regulatory commissions in reviewing utility acid rain compliance plans. It is a screening tool that is based on scenario analysis...

40 CFR 74.43 - Annual compliance certification report.

Code of Federal Regulations, 2012 CFR

2012-07-01

... which an opt-in source is subject to the Acid Rain emissions limitations, the designated representative... compliance with the requirements of the Acid Rain Program applicable to the opt-in source, including: (1) Whether the opt-in source was operated in compliance with applicable Acid Rain emissions limitations...

40 CFR 72.30 - Requirement to apply.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) PERMITS REGULATION Acid Rain Permit Applications § 72.30 Requirement to apply. (a) Duty to apply. The designated representative of any source with an affected unit shall submit a complete Acid Rain permit... permit that states its Acid Rain program requirements. (b) Deadlines—(1) Phase 1. (i) The designated...

40 CFR 97.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2013 CFR

2013-07-01

...)(1). (2) If the NOX authorized account representative for a NOX Budget unit subject to an Acid Rain... or operator of a unit subject to an Acid Rain emissions limitation shall comply with requirements of... to an Acid Rain emissions limitation shall comply with requirements of § 75.62 of this chapter...

40 CFR 72.65 - Public notice of opportunities for public comment.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.65... area where the source covered by the Acid Rain permit application is located or in a State publication... Acid Rain permit application and the draft permit. (4) Any compliance options proposed for approval in...

40 CFR 72.43 - Phase I reduced utilization plans.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.43 Phase I reduced... any Acid Rain emissions limitation or emissions reduction requirements during Phase I; and (ii) Meets... this section shall include in the Acid Rain permit application for the unit a reduced utilization plan...

40 CFR 72.5 - State authority.

Code of Federal Regulations, 2013 CFR

2013-07-01

... REGULATION Acid Rain Program General Provisions § 72.5 State authority. Consistent with section 116 of the Act, the provisions of the Acid Rain Program shall not be construed in any manner to preclude any... unit or affected source under the Acid Rain Program; provided that such State requirement, if...

40 CFR 72.8 - Retired units exemption.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.8 Retired units exemption. (a) This section... affected unit (except for an opt-in source) that is permanently retired shall be exempt from the Acid Rain... permitting authority otherwise responsible for administering a Phase II Acid Rain permit for the unit. If the...

40 CFR 72.43 - Phase I reduced utilization plans.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.43 Phase I reduced... any Acid Rain emissions limitation or emissions reduction requirements during Phase I; and (ii) Meets... this section shall include in the Acid Rain permit application for the unit a reduced utilization plan...

Human Ecology: Acid Rain and Public Policy.

ERIC Educational Resources Information Center

Bybee, Rodger W.

1983-01-01

A connection between science and society can be seen in the human and ecological dimensions of one contemporary problem: acid rain. Introduces a human ecological theme and relationships between acid rain and public policy, considering scientific understanding and public awareness, scientific research and public policy, and national politics and…

40 CFR 96.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2014 CFR

2014-07-01

... unit subject to an Acid Rain Emission limitation who signed and certified any submission that is made.... (b) Monitoring plans. (1) The owner or operator of a unit subject to an Acid Rain emissions... operator of a unit that is not subject to an Acid Rain emissions limitation shall comply with requirements...

40 CFR 72.80 - General.

Code of Federal Regulations, 2014 CFR

2014-07-01

... REGULATION Permit Revisions § 72.80 General. (a) This subpart shall govern revisions to any Acid Rain permit issued by the Administrator and to the Acid Rain portion of any operating permit issued by a State... 71 of this chapter, the provisions of this subpart shall govern revision of any Acid Rain Program...

40 CFR 72.83 - Administrative permit amendment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.83 Administrative permit amendment. (a) Acid Rain permit... Acid Rain permit, of commencement of operation of qualifying Phase I technology, provided that they are in accordance with § 72.42 of this part; (9) Changes in the date, specified in a new unit's Acid Rain...

40 CFR 72.60 - General.

Code of Federal Regulations, 2014 CFR

2014-07-01

... REGULATION Federal Acid Rain Permit Issuance Procedures § 72.60 General. (a) Scope. This subpart and parts 74, 76, and 78 of this chapter contain the procedures for federal issuance of Acid Rain permits for Phase I of the Acid Rain Program and Phase II for sources for which the Administrator is the permitting...

40 CFR 72.8 - Retired units exemption.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) PERMITS REGULATION Acid Rain Program General Provisions § 72.8 Retired units exemption. (a) This section... affected unit (except for an opt-in source) that is permanently retired shall be exempt from the Acid Rain... permitting authority otherwise responsible for administering a Phase II Acid Rain permit for the unit. If the...

40 CFR 76.10 - Alternative emission limitations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.10 Alternative emission limitations. (a... alternative emission limitation on the date that the application for renewal of the source's Acid Rain permit... demonstration period by administrative amendment (under § 72.83 of this chapter) to the Acid Rain permit. (v...

40 CFR 72.30 - Requirement to apply.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) PERMITS REGULATION Acid Rain Permit Applications § 72.30 Requirement to apply. (a) Duty to apply. The designated representative of any source with an affected unit shall submit a complete Acid Rain permit... permit that states its Acid Rain program requirements. (b) Deadlines—(1) Phase 1. (i) The designated...

40 CFR 72.44 - Phase II repowering extensions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.44 Phase II repowering... the requirements of paragraph (a)(1)(i) of this section may include in the unit's Phase II Acid Rain... authority shall issue the Acid Rain portion of the operating permit including: (A) The approved repowering...

40 CFR 72.70 - Relationship to title V operating permit program.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.70 Relationship to... operating permit programs and acceptance of State Acid Rain programs, the procedure for including State Acid... of an accepted State program, to issue Phase II Acid Rain permits. (b) Relationship to operating...

40 CFR 96.375 - Petitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is not subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions...

40 CFR 72.80 - General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... REGULATION Permit Revisions § 72.80 General. (a) This subpart shall govern revisions to any Acid Rain permit issued by the Administrator and to the Acid Rain portion of any operating permit issued by a State... 71 of this chapter, the provisions of this subpart shall govern revision of any Acid Rain Program...

40 CFR 72.5 - State authority.

Code of Federal Regulations, 2014 CFR

2014-07-01

... REGULATION Acid Rain Program General Provisions § 72.5 State authority. Consistent with section 116 of the Act, the provisions of the Acid Rain Program shall not be construed in any manner to preclude any... unit or affected source under the Acid Rain Program; provided that such State requirement, if...

40 CFR 72.80 - General.

Code of Federal Regulations, 2012 CFR

2012-07-01

... REGULATION Permit Revisions § 72.80 General. (a) This subpart shall govern revisions to any Acid Rain permit issued by the Administrator and to the Acid Rain portion of any operating permit issued by a State... 71 of this chapter, the provisions of this subpart shall govern revision of any Acid Rain Program...

40 CFR 97.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2014 CFR

2014-07-01

...)(1). (2) If the NOX authorized account representative for a NOX Budget unit subject to an Acid Rain... or operator of a unit subject to an Acid Rain emissions limitation shall comply with requirements of... to an Acid Rain emissions limitation shall comply with requirements of § 75.62 of this chapter...

40 CFR 74.10 - Roles-EPA and permitting authority.

Code of Federal Regulations, 2014 CFR

2014-07-01

... opt-in provisions of the Acid Rain Program: (1) Calculating the baseline or alternative baseline and... withdrawal conditions prior to withdrawal from the Acid Rain Program as provided under § 74.18; and (5) Approving and disapproving the request to withdraw from the Acid Rain Program. (b) Permitting authority...

40 CFR 72.41 - Phase I substitution plans.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Compliance Plan and Compliance Options § 72.41 Phase I substitution... section 410 of the Act. (b)(1) The designated representative may include, in the Acid Rain permit... an Acid Rain permit containing the plan, except that if the substitution plan is conditionally...

40 CFR 97.74 - Recordkeeping and reporting.

Code of Federal Regulations, 2011 CFR

2011-07-01

...)(1). (2) If the NOX authorized account representative for a NOX Budget unit subject to an Acid Rain... or operator of a unit subject to an Acid Rain emissions limitation shall comply with requirements of... to an Acid Rain emissions limitation shall comply with requirements of § 75.62 of this chapter...

40 CFR 96.375 - Petitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is not subject to an Acid Rain emissions... designated representative of a CAIR NOX Ozone Season unit that is subject to an Acid Rain emissions...

Factors contributing to the hydrologic effectiveness of a rain garden network (Cincinnati OH USA)

EPA Science Inventory

Infiltrative rain gardens add retention capacity to sewersheds, yet, their capacity for detention and redistribution of stormwater runoff is dynamic and often unverified by monitoring. Over a 4-year period, we tracked whole system water fluxes in a two-tier rain garden network, a...

Raindrop and flow interactions for interrill erosion with wind-driven rain

USDA-ARS?s Scientific Manuscript database

Wind-driven rain (WDR) experiments were conducted to evaluate interrill component of the Water Erosion Prediction Project (WEPP) model with two-dimensional experimental set-up in wind tunnel. Synchronized wind and rain simulations were applied to soil surfaces on windward and leeward slopes of 7, 15...

Mechanics of interrill erosion with wind-driven rain

USDA-ARS?s Scientific Manuscript database

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...

14 CFR 33.78 - Rain and hail ingestion.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.78 Rain and... alternative to the requirements specified in paragraph (a)(2) of this section, for rotorcraft turbine engines... ingestion of rain with an overall ratio of water droplet flow to airflow, by weight, with a uniform...

14 CFR 33.78 - Rain and hail ingestion.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.78 Rain and... alternative to the requirements specified in paragraph (a)(2) of this section, for rotorcraft turbine engines... ingestion of rain with an overall ratio of water droplet flow to airflow, by weight, with a uniform...

14 CFR 33.78 - Rain and hail ingestion.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.78 Rain and... alternative to the requirements specified in paragraph (a)(2) of this section, for rotorcraft turbine engines... ingestion of rain with an overall ratio of water droplet flow to airflow, by weight, with a uniform...

14 CFR 33.78 - Rain and hail ingestion.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.78 Rain and... alternative to the requirements specified in paragraph (a)(2) of this section, for rotorcraft turbine engines... ingestion of rain with an overall ratio of water droplet flow to airflow, by weight, with a uniform...

Rain Forest Murals

ERIC Educational Resources Information Center

Kleiner, Cheryl

2010-01-01

The rain forest murals in the author's school began as a request from her principal to have students decorate the cafeteria with their own paintings. She decided to brainstorm ideas with her eighth-grade students. Taking into consideration the architectural space and the environmental concerns they wanted to convey, students chose the rain forest…

Enhancing Rain Garden Design to Promote Nitrate Removal: Testing a media carbon amendment

EPA Science Inventory

Rain gardens effectively remove some stressors from stormwater, in particular heavy metals, phosphorus, and oil and grease, but in most cases they show much smaller removal rates of nitrate. This is likely due to the high sand and low organic matter content specified for rain ga...

Rainfall effects on Ku-band satellite link design in rainy tropical climate

NASA Astrophysics Data System (ADS)

Mandeep, J. S.; Hassan, S. I. S.; Tanaka, K.

2008-03-01

The performance of rain attenuation models in equatorial zones is still a debated issue due to the lack of measurements reported from these areas. Therefore,Therefore the rainfall path attenuation at 12.255 GHz measured at Universiti Sains Malaysia (USM) for three years is presented. It shows that the power law function of rain attenuation with ground rain rate deviates at very high rain rate. A comparison is made between the measured cumulative distributions and current prediction models, in order to determine which model gives the best prediction for this location.

Investigation of vertical transportation of Cs-137 in the different soil types and for the different raining regime

NASA Astrophysics Data System (ADS)

Varinlioglu, Ahmet; Tugrul, A. Beril

2018-02-01

Cs-137 is an important fission product that is produced in the nuclear reactors. Therefore it can create risk for the environment during the accident condition of the nuclear plants. In this study, vertical transportation of Cs-137 in the soil searched for three different soil types and three different raining regimes. The experiments observed in lyzimetric conditions in the laboratory. The results of the experiments show that in every raining regime the activities of different types of soils (sand, loam and clay) were related with descending activity order. When the results of the experiments were evaluated according to the raining regime it can be seen that the relative activity for every type of soil is always towards higher to lower raining conditions.

Design of the primary pre-TRMM and TRMM ground truth site

NASA Technical Reports Server (NTRS)

Garstang, Michael

1988-01-01

The primary objective of the Tropical Rain Measuring Mission (TRMM) were to: integrate the rain gage measurements with radar measurements of rainfall using the KSFC/Patrick digitized radar and associated rainfall network; delineate the major rain bearing systems over Florida using the Weather Service reported radar/rainfall distributions; combine the integrated measurements with the delineated rain bearing systems; use the results of the combined measurements and delineated rain bearing systems to represent patterns of rainfall which actually exist and contribute significantly to the rainfall to test sampling strategies and based on the results of these analyses decide upon the ground truth network; and complete the design begun in Phase 1 of a multi-scale (space and time) surface observing precipitation network centered upon KSFC. Work accomplished and in progress is discussed.

Validation of Rain Rate Retrievals for the Airborne Hurricane Imaging Radiometer (HIRAD)

NASA Technical Reports Server (NTRS)

Jacob, Maria; Salemirad, Matin; Jones, Linwood; Biswas, Sayak; Cecil, Daniel

2015-01-01

NASA's Global Hawk aircraft (AV1)has two microwave sensors: the passive Hurricane Imaging Radiometer (HIRAD), and the active High-altitude Imaging Wind and Rain Airborne Profiler(HIWRAP). Results are presented for a rain measurement validation opportunity that occurred in 2013, when the AV1 flew over a tropical squall-line that was simultaneously observed by the Tampa NEXRAD radar. During this experiment, Global Hawk made 3 passes over the rapidly propagating thunderstorm, while the TAMPA NEXRAD performed volume scans every 5 minutes. In this poster, the three-way inter-comparison of HIRAD Tb (base temperature), HIWRAP dbZ (decibels relative to equivalent reflectivity) and NEXRAD rain rate imagery are presented. Also, observed HIRAD Tbs are compared with theoretical radiative transfer model results using HIWRAP Rain Rates.

A Robust Response of Precipitation to Global Warming from CMIP5 Models

NASA Technical Reports Server (NTRS)

Lau, K. -M.; Wu, H. -T.; Kim, K. -M.

2012-01-01

How precipitation responds to global warming is a major concern to society and a challenge to climate change research. Based on analyses of rainfall probability distribution functions of 14 state-of-the-art climate models, we find a robust, canonical global rainfall response to a triple CO2 warming scenario, featuring 100 250% more heavy rain, 5-10% less moderate rain, and 10-15% more very light or no-rain events. Regionally, a majority of the models project a consistent response with more heavy rain events over climatologically wet regions of the deep tropics, and more dry events over subtropical and tropical land areas. Results suggest that increased CO2 emissions induce basic structural changes in global rain systems, increasing risks of severe floods and droughts in preferred geographic locations worldwide.

Rain-fed fig yield as affected by rainfall distribution

NASA Astrophysics Data System (ADS)

Bagheri, Ensieh; Sepaskhah, Ali Reza

2014-08-01

Variable annual rainfall and its uneven distribution are the major uncontrolled inputs in rain-fed fig production and possibly the main cause of yield fluctuation in Istahban region of Fars Province, I.R. of Iran. This introduces a considerable risk in rain-fed fig production. The objective of this study was to find relationships between seasonal rainfall distribution and rain-fed fig production in Istahban region to determine the critical rainfall periods for rain-fed fig production and supplementary irrigation water application. Further, economic analysis for rain-fed fig production was considered in this region to control the risk of production. It is concluded that the monthly, seasonal and annual rainfall indices are able to show the effects of rainfall and its distribution on the rain-fed fig yield. Fig yield with frequent occurrence of 80 % is 374 kg ha-1. The internal rates of return for interest rate of 4, 8 and 12 % are 21, 58 and 146 %, respectively, that are economically feasible. It is concluded that the rainfall in spring especially in April and in December has negatively affected fig yield due to its interference with the life cycle of Blastophaga bees for pollination. Further, it is concluded that when the rainfall is limited, supplementary irrigation can be scheduled in March.

Performance analysis of 60-min to 1-min integration time rain rate conversion models in Malaysia

NASA Astrophysics Data System (ADS)

Ng, Yun-Yann; Singh, Mandeep Singh Jit; Thiruchelvam, Vinesh

2018-01-01

Utilizing the frequency band above 10 GHz is in focus nowadays as a result of the fast expansion of radio communication systems in Malaysia. However, rain fade is the critical factor in attenuation of signal propagation for frequencies above 10 GHz. Malaysia is located in a tropical and equatorial region with high rain intensity throughout the year, and this study will review rain distribution and evaluate the performance of 60-min to 1-min integration time rain rate conversion methods for Malaysia. Several conversion methods such as Segal, Chebil & Rahman, Burgeono, Emiliani, Lavergnat and Gole (LG), Simplified Moupfouma, Joo et al., fourth order polynomial fit and logarithmic model have been chosen to evaluate the performance to predict 1-min rain rate for 10 sites in Malaysia. After the completion of this research, the results show that Chebil & Rahman model, Lavergnat & Gole model, Fourth order polynomial fit and Logarithmic model have shown the best performances in 60-min to 1-min rain rate conversion over 10 sites. In conclusion, it is proven that there is no single model which can claim to perform the best across 10 sites. By averaging RMSE and SC-RMSE over 10 sites, Chebil and Rahman model is the best method.

Effects of simulated acid rain and ozone on foliar chemistry of field-grown Pinus ponderosa seedlings and mature trees.

PubMed

Momen, B; Helms, J A

1996-01-01

We investigated the additive and interactive effects of simulated acid rain and elevated ozone on C and N contents, and the C:N ratio of one-year-old and current-year foliage of field-grown mature trees and their half-sib seedlings of a stress tolerant genotype of ponderosa pine. Acid rain levels (pH 5.1 and 3.0) were applied weekly to foliage only (no soil acidification or N addition), from January to April, 1992. Plants were exposed to two ozone levels (ambient and twice-ambient) during the day from September 1991 to November 1992. The sequential application of acid rain and elevated ozone mimicked the natural conditions. Twice-ambient ozone significantly decreased foliar N content (by 12-14%) and increased the C:N ratio of both one-year-old and current-year foliage of seedlings. Although similar ozone effects were also observed on one-year-old foliage of mature trees, the only statistically significant effect was an increased C:N ratio when twice-ambient ozone combined with pH 3.0 rain (acid rain by ozone interaction). Enhancing the effect of twice-ambient ozone in increasing the C:N ratio of one-year-old foliage of mature trees in June was the only significant effect of acid rain.

Promoting nitrate removal in rain gardens | Science Inventory ...

EPA Pesticide Factsheets

Rain gardens are vegetated surface depressions, often located at low points in landscapes, designed to receive stormwater runoff from roads, roofs, and parking lots. The gardens’ sandy soils allow stormwater to drain quickly to the native soils below and eventually to groundwater. The rain garden vegetation and soils remove pollutants and nutrients from stormwater runoff through biological and physical processes such as plant uptake and sorption to soil particles. In comparison with stormwater release to receiving waters through conventional storm drain systems, infiltrating stormwater through rain gardens reduces peak flows and loadings of both pollutants and nutrients. This reduction improves the physical and biological integrity of receiving streams by reducing stream bank erosion and negative effects on stream communities. While local governments and individual homeowners are building these systems, relatively few scientific studies have documented the ability of rain gardens to remove pollutants and nutrients. This U.S. EPA long-term research project investigates: 1) the performance of rain gardens in removing pollutants, and 2) whether currently-accepted design standards can be adjusted to improve nitrate removal capabilities. Typical rain garden designs provide large removals of pollutants of concern, including heavy metals, phosphorus, total nitrogen, and ammonium. The gardens have been less successful in removing nitrate, an importan

Using Economic Incentives to Manage Stormwater Runoff in ...

EPA Pesticide Factsheets

Communities nationwide are facing increased responsibility for controlling stormwater runoff, and, subsequently, rising costs of stormwater management. In this report we describe and test a methodology that can be used by communities to focus limited budgets on the most efficient and ecologically-effective installation of stormwater management practices. The overall project has two primary objectives: (1) to test the use of an auction to cost-effectively allocate stormwater management practices among landowners, and (2) to determine the effectiveness of the resulting implementation in terms of hydrological, water quality, and ecological measures. Here, we describe the theories, methods, and criteria used to distribute rain gardens and rain barrels to homeowners in a small, midwestern watershed. The first round of the reverse auction in 2007 resulted in 50 rain gardens and 100 rain barrels installed at 67 of the approximately 350 residential properties in the experimental watershed. In 2008, the auction was repeated and we accepted bids for an additional 35 rain gardens and 74 rain barrels. Stormwater management practices were distributed relatively evenly throughout the watershed and are expected to result in significant improvements in stream quality. We describe our monitoring approach, including 1) parcel-scale hydrology and water quality monitoring of selected rain gardens, and 2) stream monitoring following before-after-control-impact approach for as

Rain pulses - how different data streams provide insight in response-times and help to attribute biophysical properties to ecosystem processes.

NASA Astrophysics Data System (ADS)

El-Madany, T. S.; Migliavacca, M.; Perez-Priego, O.; Luo, Y.; Kolle, O.; Carrara, A.; Moreno, G.; Reichstein, M.

2017-12-01

Rain pulses play a major role for the carbon cycle in semiarid ecosystems, as they can release large amounts of stored carbon. Physical and biological processes, triggered by the availability of water start to develop on various time scales and are dependent on the amount of available water. Especially, in savanna type ecosystems with an herbaceous understory and sparsely distributed trees the response time of the two plant functional types to rain pulses might be different. We present results from an ongoing large-scale nutrient manipulation experiment (MANIP) in a Mediterranean savanna type ecosystem and its response to rain pulses. Within MANIP the footprint areas from two out of three ecosystem eddy co-variance (EC) sites were fertilized with nitrogen (NT) and nitrogen plus phosphorous (NPT), the third served as the control (CT). The analysis combines EC data to determine the net ecosystem exchange, PhenoCam data to define the senescence and re-greening period, SAP-flow measurements to evaluate the response of trees to rain pulses, high frequency (1 Hz) CO2-concentration measurements to estimate the response time to of the ecosystem to rain pulses, and meteorological measurements to quantify the intensity of the rain pulses. Additionally, at NT canopy reflectance and SIF are measured continuously for trees and grasses. The combination of SIF and SAP-flow measurements allows to separate the contribution of trees to ecosystem fluxes and can be utilized to partition NEE into ecosystem respiration and gross primary productivity during the senescence period. The analyses focus on three topics; (i) utilizing high frequency dynamics of CO2 concentration to disentangle physical and biological responses to water availability; (ii) fertilization effect of respiration pulses on ecosystem fluxes; (iii) response of tree transpiration to rain pulses. CO2 concentrations show an instantaneous reaction to rain fall. Within minutes concentrations increase strongly and follow distinct patterns. The fertilization effect is not clear in terms of respiration magnitude triggered by the rain pulse but the fertilized areas show slightly more carbon uptake during daytime after a precipitation pulse. Sap-flow measurements indicate a response of the trees to the rain pulses which effect nocturnal and daytime sap velocities.

High resolution radar-rain gauge data merging for urban hydrology: current practice and beyond

NASA Astrophysics Data System (ADS)

Ochoa Rodriguez, Susana; Wang, Li-Pen; Bailey, Andy; Willems, Patrick; Onof, Christian

2017-04-01

In this work a thorough test is conducted of radar-rain gauge merging techniques at urban scales, under different climatological conditions and rain gauge density scenarios. The aim is to provide guidance regarding the suitability and application of merging methods at urban scales, which is lacking at present. The test is conducted based upon two pilot locations, i.e. the cities of Edinburgh (254 km^2) and Birmingham (431 km^2), for which a total of 96 and 84 tipping bucket rain gauges were respectively available, alongside radar QPEs, dense runoff records and urban drainage models. Three merging techniques, namely Mean Field Bias (MFB) adjustment, kriging with external (KED) and Bayesian (BAY) combination, were selected for testing on grounds of performance and common use. They were initially tested as they were originally formulated and as they are reportedly commonly applied using typically available radar and rain gauge data. Afterwards, they were tested in combination with two special treatments which were identified as having the potential to improve merging applicability for urban hydrology: (1) reduction of temporal sampling errors in radar QPEs through temporal interpolation and (2) singularity-based decomposition of radar QPEs prior to merging. These treatments ultimately aim at improving the consistency between radar and rain gauge records, which has been identified as the chief factor affecting merging performance and is particularly challenging at the fine spatial-temporal resolutions required for urban applications. The main findings of this study are the following: - All merging methods were found to improve the applicability of radar QPEs for urban hydrological applications, but the degree of improvement they provide and the added value of radar information vary for each merging method and are also a function of climatological conditions and rain gauge density scenarios. - Overall, KED displayed the best performance, with BAY being a close second and MFB providing the smallest improvements upon radar QPEs. However, as compared to BAY, KED performance is more sensitive to rain gauge density and to the ability of rain gauges to sample critical features of the rainfall field. By incorporating more information from radar than KED, BAY is less sensitive to rain gauge density and to poor rain gauge predictability and proved able to provide a good representation of convective cells even in cases in which gauges completely missed such structures. - Based on the findings of this study, it is recommended that KED be used when gauge densities are relatively high (of the order of 30 km2 per gauge or higher) and/or when the quality of radar QPEs is known to be very poor, in which case it is desirable to rely more upon rain gauge records. For low rain gauge density situations and QPEs of reasonable quality (as is the case in most of EU), BAY may be a more appropriate choice. MFB should be the last choice; however, it is better than no correction at all. - The two special treatments under consideration successfully improved overall merging performance at the spatial-temporal resolutions required for urban hydrology, with benefits being particularly evident at low rain gauge density conditions.

Precipitation and Latent Heating Distributions from Satellite Passive Microwave Radiometry. Part 1; Improved Method and Uncertainties

NASA Technical Reports Server (NTRS)

Olson, William S.; Kummerow, Christian D.; Yang, Song; Petty, Grant W.; Tao, Wei-Kuo; Bell, Thomas L.; Braun, Scott A.; Wang, Yansen; Lang, Stephen E.; Johnson, Daniel E.;

Gypsy moth (Lepidoptera: Lymantriidae) consumption and utilization of northern red oak and white oak foliage exposed to simulated acid rain and ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cannon, W.N. Jr.

1993-06-01

Two-year-old seedlings of white oak, Quercus alba L., and red oak, Q. rubra L., were exposed to ozone (O[sub 3]) fumigations in four continuously stirred tank reactor chambers in the greenhouse for 8 h/d, 3 d/wk for 6 wk. Fumigation treatments were charcoal-filtered air (CFA) and CFA + 0.15 ppm O[sub 3]. Two simulated rain treatments, pH 4.2 and pH 3.0, of-1.25 cm were applied once each week in rain-simulation chambers. Gypsy moth, Lymantria dispar (L.), third instars were allowed to feed on leaf disks from treated seedlings for 24 h. Leaf area consumed, food assimilated, weight gain, and relativemore » growth rate (RGR) were examined. Overall, larvae fed white oak foliage consumed more foliage and gained more weight than those fed red oak foliage. Response to the fumigation and rain treatments was different for each oak species. On white oak foliage, larvae consumed significantly less foliage treated with CFA + pH 3.0 rain, but the lowest RGR occurred with the 0.15 ppm O[sub 3] + pH 4.2 rain treatment. The most food assimilated, greatest weight gain, and highest RGR occurred with the CFA + pH 4.2 rain control. Red oak foliage consumed was equivalent for all treatments, but foliage exposed to CFA + pH 3.0 rain resulted in more food assimilated, greater weight gain, and higher RGR for that species.« less

Dispersal of Salmonella Typhimurium by rain splash onto tomato plants.

PubMed

Cevallos-Cevallos, Juan M; Danyluk, Michelle D; Gu, Ganyu; Vallad, Gary E; van Bruggen, Ariena H C

2012-03-01

Outbreaks of Salmonella enterica have increasingly been associated with tomatoes and traced back to production areas, but the spread of Salmonella from a point source onto plants has not been described. Splash dispersal by rain could be one means of dissemination. Green fluorescent protein-labeled, kanamycin-resistant Salmonella enterica sv. Typhimurium dispensed on the surface of plastic mulch, organic mulch, or soil at 10⁸ CFU/cm² was used as the point source in the center of a rain simulator. Tomato plants in soil with and without plastic or organic mulch were placed around the point source, and rain intensities of 60 and 110 mm/h were applied for 5, 10, 20, and 30 min. Dispersal of Salmonella followed a negative exponential model with a half distance of 3 cm at 110 mm/h. Dispersed Salmonella survived for 3 days on tomato leaflets, with a total decline of 5 log and an initial decimal reduction time of 10 h. Recovery of dispersed Salmonella from plants at the maximum observed distance ranged from 3 CFU/g of leaflet after a rain episode of 110 mm/h for 10 min on soil to 117 CFU/g of leaflet on plastic mulch. Dispersal of Salmonella on plants with and without mulch was significantly enhanced by increasing rain duration from 0 to 10 min, but dispersal was reduced when rainfall duration increased from 10 to 30 min. Salmonella may be dispersed by rain to contaminate tomato plants in the field, especially during rain events of 10 min and when plastic mulch is used.

A Canonical Response in Rainfall Characteristics to Global Warming: Projections by IPCC CMIP5 Models

NASA Technical Reports Server (NTRS)

Lau, William K. M.; Wu, H. T.; Kim, K. M.

2012-01-01

Changes in rainfall characteristics induced by global warming are examined based on probability distribution function (PDF) analysis, from outputs of 14 IPCC (Intergovernmental Panel on Climate Change), CMIP (5th Coupled Model Intercomparison Project) models under various scenarios of increased CO2 emissions. Results show that collectively CMIP5 models project a robust and consistent global and regional rainfall response to CO2 warming. Globally, the models show a 1-3% increase in rainfall per degree rise in temperature, with a canonical response featuring large increase (100-250 %) in frequency of occurrence of very heavy rain, a reduction (5-10%) of moderate rain, and an increase (10-15%) of light rain events. Regionally, even though details vary among models, a majority of the models (>10 out of 14) project a consistent large scale response with more heavy rain events in climatologically wet regions, most pronounced in the Pacific ITCZ and the Asian monsoon. Moderate rain events are found to decrease over extensive regions of the subtropical and extratropical oceans, but increases over the extratropical land regions, and the Southern Oceans. The spatial distribution of light rain resembles that of moderate rain, but mostly with opposite polarity. The majority of the models also show increase in the number of dry events (absence or only trace amount of rain) over subtropical and tropical land regions in both hemispheres. These results suggest that rainfall characteristics are changing and that increased extreme rainfall events and droughts occurrences are connected, as a consequent of a global adjustment of the large scale circulation to global warming.

Polar Rain Gradients and Field-Aligned Polar Cap Potentials

NASA Technical Reports Server (NTRS)

Fairfield, D. H.; Wing, S.; Newell, P. T.; Ruohoniemi, J. M.; Gosling, J. T.; Skoug, R. M.

2008-01-01

ACE SWEPAM measurements of solar wind field-aligned electrons have been compared with simultaneous measurements of polar rain electrons precipitating over the polar cap and detected by DMSP spacecraft. Such comparisons allow investigation of cross-polarcap gradients in the intensity of otherwise-steady polar rain. The generally good agreement of the distribution functions, f, from the two data sources confirms that direct entry of solar electrons along open field lines is indeed the cause of polar rain. The agreement between the data sets is typically best on the side of the polar cap with most intense polar rain but the DMSP f's in less intense regions can be brought into agreement with ACE measurements by shifting all energies by a fixed amounts that range from tens to several hundred eV. In most cases these shifts are positive which implies that field-aligned potentials of these amounts exist on polar cap field lines which tend to retard the entry of electrons and produce the observed gradients. These retarding potentials undoubtedly appear in order to prevent the entry of low-energy electrons and maintain charge quasi-neutrality that would otherwise be violated since most tailward flowing magnetosheath ions are unable to follow polar rain electrons down to the polar cap. In more limited regions near the boundary of the polar cap there is sometimes evidence for field-aligned potentials of the opposite sign that accelerate polar rain electrons. A solar electron burst is also studied and it is concluded that electrons from such bursts can enter the magnetotail and precipitate in the same manner as polar rain.

Polar Rain Gradients and Field-Aligned Polar Cap Potentials

NASA Technical Reports Server (NTRS)

Fairfield, D. H.; Wing, S.; Newell, P. T.; Ruohoniemi, J. M.; Gosling, J. T.; Skoug, R. M.

2008-01-01

ACE SWEPAM measurements of solar wind field-aligned electrons have been compared with simultaneous measurements of polar rain electrons precipitating over the polar cap and detected by DMSP spacecraft. Such comparisons allow investigation of cross-polar-cap gradients in the intensity of otherwise-steady polar rain. The generally good agreement of the distribution functions, f, from the two data sources confirms that direct entry of solar electrons along open field lines is indeed the cause of polar rain. The agreement between the data sets is typically best on the side of the polar cap with most intense polar rain but the DMSP f's in less intense regions can be brought into agreement with ACE measurements by shifting all energies by a fixed amounts that range from tens to several hundred eV. In most cases these shifts are positive which implies that field-aligned potentials of these amounts exist on polar cap field lines which tend to retard the entry of electrons and produce the observed gradients. These retarding potentials undoubtedly appear in order to prevent the entry of low-energy electrons and maintain charge quasi-neutrality that would otherwise be violated since most tailward flowing magnetosheath ions are unable to follow polar rain electrons down to the polar cap. In more limited regions near the boundary of the polar cap there is sometimes evidence for field-aligned potentials of the opposite sign that accelerate polar rain electrons. A solar electron burst is also studied and it is concluded that electrons from such bursts can enter the magnetotail and precipitate in the same manner as polar rain.

Satellite passive microwave rain rate measurement over croplands during spring, summer and fall

NASA Technical Reports Server (NTRS)

Spencer, R. W.

1984-01-01

Rain-rate algorithms for spring, summer and fall that have been developed from comparisons between the brightness temperatures measured by the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) and rain rates derived from operational WSR-57 radars over land are described. Data were utilized from a total of 25 SMMR passes and 234 radars, resulting in about 12,000 observations of about 1600 sq/km areas. Multiple correlation coefficients of 0.63, 0.80 and 0.75 are achieved for the spring, summer and fall algorithms, respectively. Most of this information is in the form of multifrequency contrast in brightness temperature, which is interpreted as a measurement of the degree to which the land-emitted radiation is attenuated by the rain systems. The SMMR 37-GHz channel has more information on rain rate than any other channel. By combining the lower frequency channels with the 37-GHz observations, variations in land and precipitation thermometric temperatures can be removed, leaving rain attenuation as the major effect on brightness temperature. Polarization screening at 37 GHz is found to be sufficient to screen out cases of wet ground, which is only important when the ground is relatively vegetation free. Heavy rain cases are found to be significant part of the algorithms' success, because of the strong microwve signatures (low-brightness temperatures) that result from the presence of precipitation-sized ice in the upper portions of heavily precipitating storms. If IR data are combined with the summer microwave data, an improved (0.85) correlation with radar rain rates is achieved.

Growth of ponderosa pine seedlings as affected by air pollution

NASA Astrophysics Data System (ADS)

Momen, B.; Anderson, P. D.; Houpis, J. L. J.; Helms, J. A.

The effect of air pollution on seedling survival and competitive ability is important to natural and artificial regeneration of forest trees. Although biochemical and physiological processes are sensitive indicators of pollution stress, the cumulative effects of air pollutants on seedling vigor and competitive ability may be assessed directly from whole-plant growth characteristics such as diameter, height, and photosynthetic area. A few studies that have examined intraspecific variation in seedling response to air pollution indicate that genotypic differences are important in assessing potential effects of air pollution on forest regeneration. Here, we studied the effects of acid rain (no-rain, pH 5.1 rain, pH 3.0 rain) and ozone (filtered, ambient, twice-ambient) in the field on height, diameter, volume, the height:diameter ratio, maximum needle length, and time to reach maximum needle length in seedlings of three families of ponderosa pine ( Pinus ponderosa Dougl. ex Laws). Seedling diameter, height, volume, and height:diameter ratio related significantly to their pre-treatment values. Twice-ambient ozone decreased seedling diameter compared with ozone-filtered air. A significant family-by-ozone interaction was detected for seedling height, as the height of only one of the three families was decreased by twice-ambient ozone compared with the ambient level. Seedling diameter was larger and the height:diameter ratio was smaller under pH 3.0 rain compared to either the no-rain or the pH 5.1-rain treatment. This suggests greater seedling vigor, perhaps due to a foliar fertilization effect of the pH 3.0 rain.

[Effects of simulated acid rain on decomposition of soil organic carbon and crop straw].

PubMed

Zhu, Xue-Zhu; Huang, Yao; Yang, Xin-Zhong

2009-02-01

To evaluate the effects of acid rain on the organic carbon decomposition in different acidity soils, a 40-day incubation test was conducted with the paddy soils of pH 5.48, 6.70 and 8.18. The soils were amended with 0 and 15 g x kg(-1) of rice straw, adjusted to the moisture content of 400 g x kg(-1) air-dried soil by using simulated rain of pH 6.0, 4.5, and 3.0, and incubated at 20 degrees C. The results showed that straw, acid rain, and soil co-affected the CO2 emission from soil system. The amendment of straw increased the soil CO2 emission rate significantly. Acid rain had no significant effects on soil organic carbon decomposition, but significantly affected the straw decomposition in soil. When treated with pH 3.0 acid rain, the amount of decomposed straw over 40-day incubation in acid (pH 5.48) and alkaline (pH 8.18) soils was 8% higher, while that in neutral soil (pH 6.70) was 15% lower, compared to the treatment of pH 6.0 rain. In the treatment of pH 3.0 acid rain, the decomposition rate of soil organic C in acid (pH 5.48) soil was 43% and 50% (P < 0.05) higher than that in neutral (pH 6.70) and alkaline (pH 8.18) soils, while the decomposition rate of straw in neutral soil was 17% and 16% (P < 0.05) lower than that in acid and alkaline soils, respectively.

[Effects of simulated acid rain on seed germination and seedling growth of different type corn Zea mays].

PubMed

Zhang, Hai-Yan

2013-06-01

Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain (pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0). Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 (CK), the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area.

Improving the rainfall rate estimation in the midstream of the Heihe River Basin using rain drop size distribution

NASA Astrophysics Data System (ADS)

Zhao, G.; Chu, R.; Li, X.; Zhang, T.; Shen, J.; Wu, Z.

2009-09-01

During the intensive observation period of the Watershed Allied Telemetry Experimental Research (WATER), a total of 1074 raindrop size distribution were measured by the Parsivel disdrometer, a latest state of the art optical laser instrument. Because of the limited observation data in Qinghai-Tibet Plateau, the modeling behavior was not well-done. We used raindrop size distributions to improve the rain rate estimator of meteorological radar, in order to obtain many accurate rain rate data in this area. We got the relationship between the terminal velocity of the rain drop and the diameter (mm) of a rain drop: v(D)=4.67 D0.53. Then four types of estimators for X-band polarimetric radar are examined. The simulation results show that the classical estimator R(Z) is most sensitive to variations in DSD and the estimator R (KDP, Z, ZDR) is the best estimator for estimating the rain rate. The lowest sensitivity of the rain rate estimator R (KDP, Z, ZDP) to variations in DSD can be explained by the following facts. The difference in the forward-scattering amplitudes at horizontal and vertical polarizations, which contributes KDP, is proportional to the 3rd power of the drop diameter. On the other hand, the exponent of the backscatter cross section, which contributes to Z, is proportional to the 6th power of the drop diameter. Because the rain rate R is proportional to the 3.57th power of the drop diameter, KDP is less sensitive to DSD variations than Z.

Rain pollination provides reproductive assurance in a deceptive orchid.

PubMed

Fan, Xu-Li; Barrett, Spencer C H; Lin, Hua; Chen, Ling-Ling; Zhou, Xiang; Gao, Jiang-Yun

2012-10-01

Abiotic pollination by wind or water is well established in flowering plants. In some species pollination by rain splashes, a condition known as ombrophily, has been proposed as a floral strategy. However, evidence for this type of abiotic pollination has remained controversial and many reported cases have subsequently been shown to be false. This study investigates ombrophily in the deceptive orchid Acampe rigida to determine the mechanism by which this species is able to maintain high fecundity, despite flowering during the rainy season in south-west China when pollinators are scarce. The floral mechanisms promoting rain pollination in A. rigida were observed and described in detail. Controlled pollination experiments and observations of floral visitors were conducted. A field experiment using rain shelters at 14 sites in Guangxi, south-west China, evaluated the contribution of rain pollination to fruit-set. During rainfall, raindrops physically flicked away the anther cap exposing the pollinarium. Raindrops then caused pollinia to be ejected upwards with the strap-like stipe pulling them back and causing them to fall into the stigmatic cavity, resulting in self-pollination. Neither flower nor pollen function were damaged by water. Although A. rigida is self-compatible, it is incapable of autonomous self-pollination without the assistance of rain splashes. The results of the rain-sheltering experiment indicated that rain pollination contributed substantially to increasing fruit-set, although there was variation among sites in the intensity of this effect. A. rigida flowers during the rainy season, when pollinators are scarce, and ombrophily functions to provide reproductive assurance without compromising opportunities for outcrossing.

Rain pollination provides reproductive assurance in a deceptive orchid

PubMed Central

Fan, Xu-Li; Barrett, Spencer C. H.; Lin, Hua; Chen, Ling-Ling; Zhou, Xiang; Gao, Jiang-Yun

2012-01-01

Background and Aims Abiotic pollination by wind or water is well established in flowering plants. In some species pollination by rain splashes, a condition known as ombrophily, has been proposed as a floral strategy. However, evidence for this type of abiotic pollination has remained controversial and many reported cases have subsequently been shown to be false. This study investigates ombrophily in the deceptive orchid Acampe rigida to determine the mechanism by which this species is able to maintain high fecundity, despite flowering during the rainy season in south-west China when pollinators are scarce. Methods The floral mechanisms promoting rain pollination in A. rigida were observed and described in detail. Controlled pollination experiments and observations of floral visitors were conducted. A field experiment using rain shelters at 14 sites in Guangxi, south-west China, evaluated the contribution of rain pollination to fruit-set. Key Results During rainfall, raindrops physically flicked away the anther cap exposing the pollinarium. Raindrops then caused pollinia to be ejected upwards with the strap-like stipe pulling them back and causing them to fall into the stigmatic cavity, resulting in self-pollination. Neither flower nor pollen function were damaged by water. Although A. rigida is self-compatible, it is incapable of autonomous self-pollination without the assistance of rain splashes. The results of the rain-sheltering experiment indicated that rain pollination contributed substantially to increasing fruit-set, although there was variation among sites in the intensity of this effect. Conclusions A. rigida flowers during the rainy season, when pollinators are scarce, and ombrophily functions to provide reproductive assurance without compromising opportunities for outcrossing. PMID:22851311

Salmonella can reach tomato fruits on plants exposed to aerosols formed by rain.

PubMed

Cevallos-Cevallos, Juan M; Gu, Ganyu; Danyluk, Michelle D; Dufault, Nicholas S; van Bruggen, Ariena H C

2012-08-17

Outbreaks of Salmonella enterica have been associated with tomatoes and traced back to production areas but the spread of Salmonella in agricultural fields is still poorly understood. Post-rain Salmonella transfer from a point source to the air and then to tomato plants was evaluated. GFP-labeled kanamycin-resistant S. enterica serovar Typhimurium (10(8)CFU/mL) with and without expression of the rdar morphotype (rough colonies; cells with fimbriae and cellulose) was used as the point source in the center of a rain simulator. Rain intensities of 60 and 110 mm/h were applied for 5, 10, 20, and 30 min. Petri dishes with lactose broth and tomato plants with fruit (50-80 cm high) were placed in the simulator after the rain had ceased. Salmonella recovery from air was maximum (300 CFU/plate) after a rain episode of 60 mm/h for 10 min at distances of at least 85.5 cm above the source and when the rdar morphotype strain was used. Small scale experiments showed that the smooth-colony strain without fimbriae precipitated from the air in significantly higher numbers than the rdar strain. Transfer of aerial Salmonella with the rdar morphotype to tomato fruits on plants followed a beta distribution (2.5950, 4.7393) within the generalized range from 0 to 30 min of rain. Results show for the first time that Salmonella may transfer from rain to the air and contaminate tomato fruits at levels that could possibly be infectious to humans. Copyright © 2012 Elsevier B.V. All rights reserved.

Acid rain and sugar maple decline

Treesearch

Paul G. Schaberg

2017-01-01

Through the increased combustion of fossil fuels, humans have dramatically increased pollutant additions of sulfur and nitrogen into the atmosphere where it conbines with water to form sulfuric and nitric acids, creating acid rain (Driscoll et al. 2001). Incoming acid rain has various impacts on human and natural systems, including the accelerated degradation of built...

ACID RAIN AND SOIL MICROBIAL ACTIVITY: EFFECTS AND THEIR MECHANISMS

EPA Science Inventory

In the investigation, our aim was to determine if acid rain affects soil microbial activity and to identify possible mechanisms of observed effects. A Sierran forest soil (pH 6.4) planted with Ponderosa pine seedlings was exposed to simulated rain (pH 2.0, 3.0, 4.0 and 5.6) with ...

Rain Premature Susceptibility Study on the Proposed Piezoelectric Contact Fuze System for Triggering the MC-132 in the TX-5X1 Weapon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wehrle, R.D.

1953-06-18

The probability of the occurrence of rain during the "armed" portion of the fall of a bomb is approximately 1/25. Therefore, rain is considered a problem in premature detonation of the warhead through activation of the contact fuze system.

40 CFR 96.374 - Recordkeeping and reporting.

Code of Federal Regulations, 2011 CFR

2011-07-01

... quarterly reports, as follows: (1) If the CAIR NOX Ozone Season unit is subject to an Acid Rain emissions... not subject to an Acid Rain emissions limitation or a CAIR NOX emissions limitation, then the CAIR... are also subject to an Acid Rain emissions limitation or the CAIR NOX Annual Trading Program or CAIR...

40 CFR 97.534 - Recordkeeping and reporting.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Acid Rain Program or a TR NOX Annual emissions limitation or if the owner or operator of such unit... not subject to the Acid Rain Program or a TR NOX Annual emissions limitation, then the designated... Ozone Season units that are also subject to the Acid Rain Program, TR NOX Annual Trading Program, TR SO2...

40 CFR 72.33 - Identification of dispatch system.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Permit Applications § 72.33 Identification of dispatch system. (a... approval of the petition, all provisions of the Acid Rain Program applicable to an affected source or an... provision of the Acid Rain Program and shall not change the liability of the owners and operators of an...

40 CFR 97.4 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... an unaffected unit under § 72.6(b)(4) of this chapter for 1995 or 1996 under the Acid Rain Program...(b)(4) of this chapter for 1997 or 1998 under the Acid Rain Program. (C) For units commencing... the Acid Rain Program for any year. (2)(i) For units other than cogeneration units— (A) For units...

40 CFR 96.175 - Petitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... designated representative of a CAIR NOX unit that is subject to an Acid Rain emissions limitation may submit... representative of a CAIR NOX unit that is not subject to an Acid Rain emissions limitation may submit a petition... representative of a CAIR NOX unit that is subject to an Acid Rain emissions limitation may submit a petition...

40 CFR 72.33 - Identification of dispatch system.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Permit Applications § 72.33 Identification of dispatch system. (a... approval of the petition, all provisions of the Acid Rain Program applicable to an affected source or an... provision of the Acid Rain Program and shall not change the liability of the owners and operators of an...

40 CFR 72.1 - Purpose and scope.

Code of Federal Regulations, 2013 CFR

2013-07-01

... REGULATION Acid Rain Program General Provisions § 72.1 Purpose and scope. (a) Purpose. The purpose of this... affected sources and affected units under the Acid Rain Program, pursuant to title IV of the Clean Air Act... regulations under this part set forth certain generally applicable provisions under the Acid Rain Program. The...

40 CFR 97.4 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... an unaffected unit under § 72.6(b)(4) of this chapter for 1995 or 1996 under the Acid Rain Program...(b)(4) of this chapter for 1997 or 1998 under the Acid Rain Program. (C) For units commencing... the Acid Rain Program for any year. (2)(i) For units other than cogeneration units— (A) For units...

40 CFR 72.7 - New units exemption.

Code of Federal Regulations, 2012 CFR

2012-07-01

... REGULATION Acid Rain Program General Provisions § 72.7 New units exemption. (a) Applicability. This section... be exempt from the Acid Rain Program, except for the provisions of this section, §§ 72.2 through 72.6... administering a Phase II Acid Rain permit for the unit. If the Administrator is not the permitting authority, a...

40 CFR 72.1 - Purpose and scope.

Code of Federal Regulations, 2010 CFR

2010-07-01

... REGULATION Acid Rain Program General Provisions § 72.1 Purpose and scope. (a) Purpose. The purpose of this... affected sources and affected units under the Acid Rain Program, pursuant to title IV of the Clean Air Act... regulations under this part set forth certain generally applicable provisions under the Acid Rain Program. The...

40 CFR 72.33 - Identification of dispatch system.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Permit Applications § 72.33 Identification of dispatch system. (a... approval of the petition, all provisions of the Acid Rain Program applicable to an affected source or an... provision of the Acid Rain Program and shall not change the liability of the owners and operators of an...

40 CFR 97.4 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... an unaffected unit under § 72.6(b)(4) of this chapter for 1995 or 1996 under the Acid Rain Program...(b)(4) of this chapter for 1997 or 1998 under the Acid Rain Program. (C) For units commencing... the Acid Rain Program for any year. (2)(i) For units other than cogeneration units— (A) For units...

40 CFR 76.5 - NOX emission limitations for Group 1 boilers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.5 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the... 404(d) of the Act, the date the unit is required to meet Acid Rain emissions reduction requirements...

40 CFR 97.4 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... an unaffected unit under § 72.6(b)(4) of this chapter for 1995 or 1996 under the Acid Rain Program...(b)(4) of this chapter for 1997 or 1998 under the Acid Rain Program. (C) For units commencing... the Acid Rain Program for any year. (2)(i) For units other than cogeneration units— (A) For units...

40 CFR 72.72 - Criteria for State operating permit program.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.72 Criteria for State operating permit program. A State operating permit program (including a State Acid Rain program) shall meet... withdrawal of all or part of the Acid Rain portion of an approved State operating permit program by the...

40 CFR 96.374 - Recordkeeping and reporting.

Code of Federal Regulations, 2013 CFR

2013-07-01

... quarterly reports, as follows: (1) If the CAIR NOX Ozone Season unit is subject to an Acid Rain emissions... not subject to an Acid Rain emissions limitation or a CAIR NOX emissions limitation, then the CAIR... are also subject to an Acid Rain emissions limitation or the CAIR NOX Annual Trading Program or CAIR...

40 CFR 72.1 - Purpose and scope.

Code of Federal Regulations, 2011 CFR

2011-07-01

... REGULATION Acid Rain Program General Provisions § 72.1 Purpose and scope. (a) Purpose. The purpose of this... affected sources and affected units under the Acid Rain Program, pursuant to title IV of the Clean Air Act... regulations under this part set forth certain generally applicable provisions under the Acid Rain Program. The...

40 CFR 72.73 - State issuance of Phase II permits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.73 State issuance of Phase II permits... permit program under part 70 of this chapter and that has a State Acid Rain program accepted by the Administrator under § 72.71 shall be responsible for administering and enforcing Acid Rain permits effective in...

A Demonstration of Acid Rain

ERIC Educational Resources Information Center

Fong, Man Wai

2004-01-01

A demonstration showing acid rain formation is described. Oxides of sulfur and nitrogen that result from the burning of fossil fuels are the major pollutants of acid rain. In this demonstration, SO[subscript 2] gas is produced by the burning of matches. An acid-base indicator will show that the dissolved gas turns an aqueous solution acidic.

40 CFR 97.374 - Recordkeeping and reporting.

Code of Federal Regulations, 2012 CFR

2012-07-01

...: (1) If the CAIR NOX Ozone Season unit is subject to an Acid Rain emissions limitation or a CAIR NOX... Acid Rain emissions limitation or a CAIR NOX emissions limitation, then the CAIR designated...) of this chapter. (4) For CAIR NOX Ozone Season units that are also subject to an Acid Rain emissions...

40 CFR 72.22 - Alternate designated representative.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the term “designated representative” is used under the Acid Rain Program, the term shall be construed...), whenever the term “alternate designated representative” is used under the Acid Rain Program, the term shall...” is used under the Acid Rain Program, the term shall be construed to include either of the alternate...