Relevant bibliographies by topics / Annual maxima / Journal articles

Journal articles on the topic 'Annual maxima'

To see the other types of publications on this topic, follow the link: Annual maxima.
Author: Grafiati
Published: 14 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Annual maxima.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Bardsley, Earl. "Inconsistencies in Yangtze River annual maxima analyses." Natural Hazards 103, no. 2 (May 21, 2020): 2613–15. http://dx.doi.org/10.1007/s11069-020-04062-0.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Pelosi, Anna, Giovanni Battista Chirico, Pierluigi Furcolo, and Paolo Villani. "Regional Assessment of Sub-Hourly Annual Rainfall Maxima." Water 14, no. 7 (April 6, 2022): 1179. http://dx.doi.org/10.3390/w14071179.

Full text
Abstract:
The assessment of rainfall extremes at sub-hourly scales is generally hindered by a lack of rainfall data at small timescale resolutions. This study proposes a methodology for assessing mean annual maximum rainfall at the sub-hourly scale by blending historical time series of annual maxima recorded by mechanical stations (operating at hourly scales) up to the end of the past century with newer time series of annual maxima at higher time resolutions recorded by automatic stations installed over the past twenty years. A linear correlation was found at the regional scale between the shape parameter controlling the dependency of rainfall maxima with a duration longer than one hour and the shape parameter of the dependency of rainfall maxima with the durations shorter than one hour. Thanks to this correlation, data recorded at the mechanical stations could be exploited to assess sub-hourly mean annual maxima. The proposed hybrid procedure was verified and was found to provide estimates with an accuracy close to those obtained with the high-resolution data, i.e., our best estimates. Moreover, the proposed procedure outperforms what could be achieved by spatially interpolating the best estimates at those locations where only hourly data are available.
APA, Harvard, Vancouver, ISO, and other styles
3

Revfeim, K. J. A. "Annual maxima and totals of seasonally varying processes." Stochastic Hydrology and Hydraulics 5, no. 2 (June 1991): 147–53. http://dx.doi.org/10.1007/bf01543056.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Lompi, Marco, Paolo Tamagnone, Tommaso Pacetti, Renato Morbidelli, and Enrica Caporali. "Impacts of Rainfall Data Aggregation Time on Pluvial Flood Hazard in Urban Watersheds." Water 14, no. 4 (February 11, 2022): 544. http://dx.doi.org/10.3390/w14040544.

Full text
Abstract:
Pluvial floods occur when heavy rainstorms cause the surcharge of the sewer network drainage, representing one of the most impacting natural hazard in urban watersheds. Pluvial flood hazard is usually assessed considering the effect of annual maxima rainfall of short duration, comparable with the typical concentration times of small urban watersheds. However, short duration annual maxima can be affected by an error of underestimation due to the time resolution as well as the aggregation time of the rainfall time series. This study aims at determining the impact of rainfall data aggregation on pluvial flood hazard assessment. Tuscany region (Central Italy) is selected as a case study to perform the assessment of the annual maxima rainfall underestimation error, since the entire region has the same temporal aggregation of rainfall data. Pluvial flood hazard is then evaluated for an urban watershed in the city of Florence (Tuscany) comparing the results obtained using observed (uncorrected) and corrected annual maxima rainfall as meteorological forcing. The results show how the design of rainfall events with a duration of 30 min or shorter is significantly affected by the temporal aggregation, highlighting the importance of correcting annual maxima rainfall for a proper pluvial flood hazard evaluation.
APA, Harvard, Vancouver, ISO, and other styles
5

Decker-Walters, D. S., T. W. Walters, U. Posluszny, and P. G. Kevan. "Genealogy and gene flow among annual domesticated species of Cucurbita." Canadian Journal of Botany 68, no. 4 (April 1, 1990): 782–89. http://dx.doi.org/10.1139/b90-104.

Full text
Abstract:
Over the years, workers have gathered data from various sources in the attempt to understand the evolutionary histories and relationships of the domesticated members of Cucurbita. We used allozyme data to address questions of genealogy, interspecific gene flow, and allelic diversity for 23 commercial cultivars and 17 indigenous landraces of C. maxima, C. mixta, C. moschata, and C. pepo. Allelic diversity was greatest in C. pepo (especially ssp. ovifera) and C. moschata, reflecting complex histories for these taxa. Cucurbita maxima and C. mixta were relatively homogeneous despite morphological heterogeneity. Infraspecific classifications based on morphological characters were not supported by the allozyme data for C. maxima, C. mixta, and C. moschata. The allozymes supported morphological evidence of introgression from C. mixta in Oriental cultivars and southwestern United States and northwestern Mexico landraces of C. moschata. Phylogenetic analyses indicated that C. moschata and C. mixta are probably sister species and that C. pepo shares a common ancestor with these species that is not shared with C. maxima.
APA, Harvard, Vancouver, ISO, and other styles
6

Perdios, Anastasios, and Andreas Langousis. "Revisiting the Statistical Scaling of Annual Discharge Maxima at Daily Resolution with Respect to the Basin Size in the Light of Rainfall Climatology." Water 12, no. 2 (February 24, 2020): 610. http://dx.doi.org/10.3390/w12020610.

Full text
Abstract:
Over the years, several studies have been carried out to investigate how the statistics of annual discharge maxima vary with the size of basins, with diverse findings regarding the observed type of scaling (i.e., simple scaling vs. multiscaling), especially in cases where the data originated from regions with significantly different hydroclimatic characteristics. In this context, an important question arises on how one can effectively conclude on an approximate type of statistical scaling of annual discharge maxima with respect to the basin size. The present study aims at addressing this question, using daily discharges from 805 catchments located in different parts of the United Kingdom, with at least 30 years of recordings. To do so, we isolate the effects of the catchment area and the local rainfall climatology, and examine how the statistics of the standardized discharge maxima vary with the basin scale. The obtained results show that: (a) the local rainfall climatology is an important contributor to the observed statistics of peak annual discharges, and (b) when the effects of the local rainfall climatology are properly isolated, the scaling of the standardized annual discharge maxima with the area of the catchment closely follows that commonly met in actual rainfields, deviating significantly from the simple scaling rule. The aforementioned findings explain to a large extent the diverse results obtained by previous studies in the absence of rainfall information, shedding light on the approximate type of scaling of annual discharge maxima with the basin size.
APA, Harvard, Vancouver, ISO, and other styles
7

Schaefer, M. G. "Regional analyses of precipitation annual maxima in Washington State." Water Resources Research 26, no. 1 (January 1990): 119–31. http://dx.doi.org/10.1029/wr026i001p00119.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Pilon, Paul J., K. Adamowski, and Y. Alila. "Regional analysis of annual maxima precipitation using L-moments." Atmospheric Research 27, no. 1-3 (December 1991): 81–92. http://dx.doi.org/10.1016/0169-8095(91)90009-l.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Schaeffer, Melvin G. "Regional analyses of precipitation annual maxima in Washington state." Water Resources Research 26, no. 1 (1990): 119–31. http://dx.doi.org/10.1029/89wr01513.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

LAMBERTI, P., and S. PILATI. "Probability distributions of annual maxima of seasonal hydrological variables." Hydrological Sciences Journal 30, no. 1 (March 1985): 111–35. http://dx.doi.org/10.1080/02626668509490974.

Full text
APA, Harvard, Vancouver, ISO, and other styles
11

Bardsley, William Earl. "Cautionary note on multicomponent flood distributions for annual maxima." Hydrological Processes 30, no. 20 (June 12, 2016): 3730–32. http://dx.doi.org/10.1002/hyp.10886.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Ledingham, Jamie, David Archer, Elizabeth Lewis, Hayley Fowler, and Chris Kilsby. "Contrasting seasonality of storm rainfall and flood runoff in the UK and some implications for rainfall-runoff methods of flood estimation." Hydrology Research 50, no. 5 (August 14, 2019): 1309–23. http://dx.doi.org/10.2166/nh.2019.040.

Full text
Abstract:
Abstract Using data from 520 gauging stations in Britain and gridded rainfall datasets, the seasonality of storm rainfall and flood runoff is compared and mapped. Annual maximum (AMAX) daily rainfall occurs predominantly in summer, but AMAX floods occur most frequently in winter. Seasonal occurrences of annual daily rainfall and flood maxima differ by more than 50% in dry lowland catchments. The differences diminish with increasing catchment wetness, increase with rainfalls shorter than daily duration and are shown to depend primarily on catchment wetness, as illustrated by variations in mean annual rainfall. Over the whole dataset, only 34% of AMAX daily flood events are matched to daily rainfall annual maxima (and only 20% for 6-hour rainfall maxima). The discontinuity between rainfall maxima and flooding is explained by the consideration of coincident soil moisture storage. The results have serious implications for rainfall-runoff methods of flood risk estimation in the UK where estimation is based on a depth–duration–frequency model of rainfall highly biased to summer. It is concluded that inadequate treatment of the seasonality of rainfall and soil moisture seriously reduces the reliability of event-based flood estimation in Britain.
APA, Harvard, Vancouver, ISO, and other styles
13

Vesuviano, Gianni, Adam Griffin, and Elizabeth Stewart. "Flood Frequency Estimation in Data-Sparse Wainganga Basin, India, Using Continuous Simulation." Water 14, no. 18 (September 15, 2022): 2887. http://dx.doi.org/10.3390/w14182887.

Full text
Abstract:
Monsoon-related extreme flood events are experienced regularly across India, bringing costly damage, disruption and death to local communities. This study provides a route towards estimating the likely magnitude of extreme floods (e.g., the 1-in-100-year flood) at locations without gauged data, helping engineers to design resilient structures. Gridded rainfall and evapotranspiration estimates were used with a continuous simulation hydrological model to estimate annual maximum flow rates at nine locations corresponding with river flow gauging stations in the Wainganga river basin, a data-sparse region of India. Hosking–Wallis distribution tests were performed to identify the most appropriate distribution to model the annual maxima series, selecting the Generalized Pareto and Pearson Type III distributions. The L-moments and flood frequency curves of the modeled annual maxima were compared to gauged values. The Probability Distributed Model (PDM), properly calibrated to capture the dynamics of peak flows, was shown to be effective in approximating the Generalized Pareto distribution for annual maxima, and may be useful in modeling peak flows in areas with sparse data. Confidence in the model structure, parameterization, input data and catchment representation build confidence in the modeled flood estimates; this is particularly relevant if the method is applied in a location where no gauged flows exist for verification.
APA, Harvard, Vancouver, ISO, and other styles
14

Alnuaimi, A. S., M. A. Mohsin, and K. H. Al-Riyami. "A Basic Wind Speed Map for Oman." Journal of Engineering Research [TJER] 11, no. 2 (December 1, 2014): 64. http://dx.doi.org/10.24200/tjer.vol11iss2pp64-78.

Full text
Abstract:
The aim of this research was to develop the first basic wind speed map for Oman. Hourly mean wind speed records from 40 metrological stations were used in the calculation. The period of continuous records ranged from 4–37 years. The maximum monthly hourly mean and the maxima annual hourly mean wind speed data were analysed using the Gumbel and Gringorten methods. Both methods gave close results in determining basic wind speeds, with the Gumbel method giving slightly higher values. Due to a lack of long-term records in some regions of Oman, basic wind speeds were extrapolated for some stations with only short-term records, which were defined as those with only 4– 8 years of continuous records; in these cases, monthly maxima were used to predict the long-term basic wind speeds. Accordingly, a basic wind speed map was developed for a 50-year return period. This map was based on basic wind speeds calculated from actual annual maxima records of 29 stations with at least 9 continuous years of records as well as predicted annual maxima wind speeds for 11 short-term record stations. The basic wind speed values ranged from 16 meters/second (m/s) to 31 m/s. The basic wind speed map developed in this research is recommended for use as a guide for structural design in Oman.
APA, Harvard, Vancouver, ISO, and other styles
15

YACOB, A., and GK RANGARAJAN. "Time variations of Alibag K-indices ( 1946-1965)." MAUSAM 20, no. 2 (April 30, 2022): 135–40. http://dx.doi.org/10.54302/mausam.v20i2.5442.

Full text
Abstract:
Results of analysis of time variations of Alibag K-indices for the period 1946 to 1965 confirm the occurrence of day-time maximum in summer and night-time maximum in the equinoxes and winter. Average magnitude of K-index at each of the 3-hour intervals, for which K-indices are scaled, depicts semi-annual trend with equinoctial maxima. This semi-annual variation is particularly prominent around midnight. Annual trends in equivalent daily range amplitude, At, for Alibag show clear equinoctial maxima for both IQ and m days of the years 1952-54. No clear semi-annual variation in At is seen during sunspot active periods of 1955-57 and 1958.60. Power spectra of At depicts also rotation periodicities for the years around the sunspot minimum year 1954. This periodicity is much less prominent during the years around sunspot maximum. The observed features are discussed.
APA, Harvard, Vancouver, ISO, and other styles
16

Ul Hassan, Mahmood, Zahra Noreen, and Rashid Ahmed. "Regional frequency analysis of annual daily rainfall maxima in Skåne, Sweden." International Journal of Climatology 41, no. 8 (March 11, 2021): 4307–20. http://dx.doi.org/10.1002/joc.7074.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Ben Alaya, M. A., F. W. Zwiers, and X. Zhang. "On estimating long period wind speed return levels from annual maxima." Weather and Climate Extremes 34 (December 2021): 100388. http://dx.doi.org/10.1016/j.wace.2021.100388.

Full text
APA, Harvard, Vancouver, ISO, and other styles
18

Asquith, W. H., and J. S. Famiglietti. "Precipitation areal-reduction factor estimation using an annual-maxima centered approach." Journal of Hydrology 230, no. 1-2 (April 2000): 55–69. http://dx.doi.org/10.1016/s0022-1694(00)00170-0.

Full text
APA, Harvard, Vancouver, ISO, and other styles
19

Johnson, Benjamin K., Frank O. Bryan, Semyon A. Grodsky, and James A. Carton. "Climatological Annual Cycle of the Salinity Budgets of the Subtropical Maxima." Journal of Physical Oceanography 46, no. 10 (October 2016): 2981–94. http://dx.doi.org/10.1175/jpo-d-15-0202.1.

Full text
Abstract:
AbstractSix subtropical salinity maxima (Smax) exist: two each in the Pacific, Atlantic, and Indian Ocean basins. The north Indian (NI) Smax lies in the Arabian Sea while the remaining five lie in the open ocean. The annual cycle of evaporation minus precipitation (E − P) flux over the Smax is asymmetric about the equator. Over the Northern Hemisphere Smax, the semiannual harmonic is dominant (peaking in local summer and winter), while over the Southern Hemisphere Smax, the annual harmonic is dominant (peaking in local winter). Regardless, the surface layer salinity for all six Smax reaches a maximum in local fall and minimum in local spring. This study uses a multidecade integration of an eddy-resolving ocean circulation model to compute salinity budgets for each of the six Smax. The NI Smax budget is dominated by eddy advection related to the evolution of the seasonal monsoon. The five open-ocean Smax budgets reveal a common annual cycle of vertical diffusive fluxes that peak in winter. These Smax have regions on their eastward and poleward edges in which the vertical salinity gradient is destabilizing. These destabilizing gradients, in conjunction with wintertime surface cooling, generate a gradually deepening wintertime mixed layer. The vertical salinity gradient sharpens at the base of the mixed layer, making the water column susceptible to salt finger convection and enhancing vertical diffusive salinity fluxes out of the Smax into the ocean interior. This process is also observed in Argo float profiles and is related to the formation regions of subtropical mode waters.
APA, Harvard, Vancouver, ISO, and other styles
20

Dwyer, I. J., and D. W. Reed. "Effective fractal dimension and corrections to the mean of annual maxima." Journal of Hydrology 157, no. 1-4 (May 1994): 13–34. http://dx.doi.org/10.1016/0022-1694(94)90096-5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
21

Blackman, D. L. "New estimates of annual sea level maxima in the Bristol Channel." Estuarine, Coastal and Shelf Science 20, no. 2 (February 1985): 229–32. http://dx.doi.org/10.1016/0272-7714(85)90039-3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
22

Romanyuk, Romanyuk M. S., and O. I. Lukіanets. "ANALYSIS OF RECURRENCE OF RAIN FLOODS ON RIVERS IN THE TISZA BASIN (WITHIN UKRAINE)." Hydrology, hydrochemistry and hydroecology, no. 2(64) (2022): 22–29. http://dx.doi.org/10.17721/2306-5680.2022.2.2.

Full text
Abstract:
Rain floods on the rivers in the Tisza basin within Ukraine are formed several times during the entire warm period. The purpose of the presented study is a detailed analysis of the frequency of such floods on the rivers of the region under study in terms of the series of annual maximum average daily water discharges and the series of maximum average daily discharges of partial probability. The first series, called the “multi-annual series”, includes only one of the highest discharges each year, in our case, one for the warm period – May-October. The second row includes all values hat exceed some limit value, which corresponds to the smallest value from the series of annual maximum annual water discharges. To carry out the work, we used observational data on the average daily water flow from the following hydrological posts on the rivers: the Uzh River – Uzhgorod, the Latoritsa River – Mukachevo, the Rika River – Mezhgorye, the Teresva River – Ust-Chernaya, the Tisza River – Rakhiv for the observation period 1946 (47 ) to 2019. To obtain the long-term series and partial probability necessary for the study, first, chronological samples of rain flood maxima were formed for both series separately, then they were ranked and the estimated return period was determined for each member of the series. The series of maximums of partial probability according to the data from the studied hydrological stations in their number on average 4-6 times exceed the number of values of the series of annual maxima. The calculated return periods are determined by the inverse formula to the Weibull formula. Graphs of the frequency of rain floods by annual maxima and maxima of partial probability for the stations under study were constructed, which made it possible to notice the following features: 1) the discharges maxima of rain floods with a frequency of less than 5-10 years differ for a number of annual maximum water discharges and a series of partial probability; 2) partial probability series better describe minor floods, especially those with a short return period. The analysis of the frequency of rain floods on the rivers in the Tisza basin within Ukraine made it possible to estimate the possible magnitudes of rain floods that can form during a warm period of time and to estimate their frequency of a certain magnitude. This is of practical interest as knowledge of potential floods can be used to assess the nature of potential floods in the future.
APA, Harvard, Vancouver, ISO, and other styles
23

Rózsás, Árpád, Miroslav Sýkora, and László Gergely Vigh. "Long-Term Trends in Annual Ground Snow Maxima for the Carpathian Region." Applied Mechanics and Materials 821 (January 2016): 753–60. http://dx.doi.org/10.4028/www.scientific.net/amm.821.753.

Full text
Abstract:
The current structural design provisions are prevalently based on experience and on the assumption of stationary meteorological conditions. However, the observations of past decades and advanced climate models show that this assumption is debatable. Therefore, this paper examines the historical long-term trends in ground snow load maxima, and their effect on structural reliability. For this purpose, the Carpathian region is selected, and data from a joint research effort of nine countries of the region are used. Annual maxima snow water equivalents are taken, and univariate generalized extreme value distribution is adopted as a probabilistic model. Stationary and five non-stationary distributions are fitted to the observations utilizing the maximum likelihood method. Statistical and information theory based approaches are used to compare the models and to identify trends. Additionally, reliability analyses are performed on a simple structure to explore the practical significance of the trends. The calculations show decreasing trends in annual maxima for most of the region. Although statistically significant changes are detected at many locations, the practical significance - with respect to structural reliability - is considerable only for a few, and the effect is favourable. The results indicate that contrary to the widespread practice in extreme event modelling, the exclusive use of statistical techniques on the analysed extremes is insufficient to identify practically significant trends. This should be demonstrated using practically relevant examples, e.g. reliability of structures.
APA, Harvard, Vancouver, ISO, and other styles
24

Shinker, Jacqueline J. "Visualizing Spatial Heterogeneity of Western U.S. Climate Variability." Earth Interactions 14, no. 10 (October 1, 2010): 1–15. http://dx.doi.org/10.1175/2010ei323.1.

Full text
Abstract:
Abstract Monthly climatologies (1971–2000 monthly averages) for stations in the western United States, obtained from the NOAA/National Climatic Data Center (NCDC), are used to illustrate the spatial variations in the annual cycle of climate. Animated map sequences of temperature and precipitation, their average, intermonthly changes, and the local timing of annual maxima or minima provide a comprehensive spatiotemporal baseline of regional climate. The animated maps illustrate three scales of variation: 1) broadscale patterns related to the annual cycle of insolation and hemispheric-scale atmospheric circulation features; 2) mesoscale patterns related to location on the continent and the influence of specific regional circulation features like those associated with the North American monsoon; and 3) smaller-scale spatial variations, related to the mediation by local physiography of the influence of large-scale circulation. Although most western U.S. stations have temperature maxima in July, a delay occurs at stations along the West Coast and interior Washington, northern Idaho, and Montana. A seesaw pattern of precipitation maxima is evident between coastal areas (winter dominated) and the interior (summer dominated). Cluster analyses of the ratio of monthly-to-annual precipitation values for each station identify regions with similar annual cycles of precipitation. Regions of high spatial heterogeneity in the timing of when precipitation occurs include the northern Rocky Mountains, Utah, Arizona, and northwestern Montana. The superimposition of these three scales of spatial variability leads to steep gradients and, in some regions, considerable spatial heterogeneity in annual precipitation. The regional patterns of precipitation heterogeneity highlight vulnerability to drought, especially in regions of the interior west that do not have a dominant precipitation month or season.
APA, Harvard, Vancouver, ISO, and other styles
25

Ribereau, P., A. Guillou, and P. Naveau. "Estimating return levels from maxima of non-stationary random sequences using the Generalized PWM method." Nonlinear Processes in Geophysics 15, no. 6 (December 23, 2008): 1033–39. http://dx.doi.org/10.5194/npg-15-1033-2008.

Full text
Abstract:
Abstract. Since the pioneering work of Landwehr et al. (1979), Hosking et al. (1985) and their collaborators, the Probability Weighted Moments (PWM) method has been very popular, simple and efficient to estimate the parameters of the Generalized Extreme Value (GEV) distribution when modeling the distribution of maxima (e.g., annual maxima of precipitations) in the Identically and Independently Distributed (IID) context. When the IID assumption is not satisfied, a flexible alternative, the Maximum Likelihood Estimation (MLE) approach offers an elegant way to handle non-stationarities by letting the GEV parameters to be time dependent. Despite its qualities, the MLE applied to the GEV distribution does not always provide accurate return level estimates, especially for small sample sizes or heavy tails. These drawbacks are particularly true in some non-stationary situations. To reduce these negative effects, we propose to extend the PWM method to a more general framework that enables us to model temporal covariates and provide accurate GEV-based return levels. Theoretical properties of our estimators are discussed. Small and moderate sample sizes simulations in a non-stationary context are analyzed and two brief applications to annual maxima of CO2 and seasonal maxima of cumulated daily precipitations are presented.
APA, Harvard, Vancouver, ISO, and other styles
26

Zou, L., H. Rishbeth, I. C. F. Müller-Wodarg, A. D. Aylward, G. H. Millward, T. J. Fuller-Rowell, D. W. Idenden, and R. J. Moffett. "Annual and semiannual variations in the ionospheric F2-layer. I. Modelling." Annales Geophysicae 18, no. 8 (August 31, 2000): 927–44. http://dx.doi.org/10.1007/s00585-000-0927-8.

Full text
Abstract:
Abstract. Annual, seasonal and semiannual variations of F2-layer electron density (NmF2) and height (hmF2) have been compared with the coupled thermosphere-ionosphere-plasmasphere computational model (CTIP), for geomagnetically quiet conditions. Compared with results from ionosonde data from midlatitudes, CTIP reproduces quite well many observed features of NmF2, such as the dominant winter maxima at high midlatitudes in longitude sectors near the magnetic poles, the equinox maxima in sectors remote from the magnetic poles and at lower latitudes generally, and the form of the month-to-month variations at latitudes between about 60°N and 50°S. CTIP also reproduces the seasonal behaviour of NmF2 at midnight and the summer-winter changes of hmF2. Some features of the F2-layer, not reproduced by the present version of CTIP, are attributed to processes not included in the modelling. Examples are the increased prevalence of the winter maxima of noon NmF2 at higher solar activity, which may be a consequence of the increase of F2-layer loss rate in summer by vibrationally excited molecular nitrogen, and the semiannual variation in hmF2, which may be due to tidal effects. An unexpected feature of the computed distributions of NmF2 is an east-west hemisphere difference, which seems to be linked to the geomagnetic field configuration. Physical discussion is reserved to the companion paper by Rishbeth et al.Key words: Atmospheric composition and structure (thermosphere-composition and chemistry) - Ionosphere (mid-latitude ionosphere; modelling and forecasting)
APA, Harvard, Vancouver, ISO, and other styles
27

Kyrölä, E., J. Tamminen, V. Sofieva, J. L. Bertaux, A. Hauchecorne, F. Dalaudier, D. Fussen, et al. "GOMOS O<sub>3</sub>, NO<sub>2</sub>, and NO<sub>3</sub> observations in 2002–2008." Atmospheric Chemistry and Physics 10, no. 16 (August 20, 2010): 7723–38. http://dx.doi.org/10.5194/acp-10-7723-2010.

Full text
Abstract:
Abstract. The Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument onboard the European Space Agency's ENVISAT satellite measures ozone, NO2, NO3, H2O, O2, and aerosols using the stellar occultation method. Global coverage, good vertical resolution and the self-calibrating measurement method make GOMOS observations a promising data set for building various climatologies and time series. In this paper we present GOMOS nighttime measurements of ozone, NO2, and NO3 during six years 2002–2008. Using zonal averages we show the time evolution of the vertical profiles as a function of latitude. In order to get continuous coverage in time we restrict the latitudinal region to 50° S–50° N. Time development is analysed by fitting constant, annual and semi-annual terms as well as solar and QBO proxies to the daily time series. Ozone data cover the stratosphere, mesosphere and lower thermosphere (MLT). NO2 and NO3 data cover the stratosphere. In addition to detailed analysis of profiles we derive total column distributions using the fitted time series. The time-independent constant term is determined with a good accuracy (better than 1%) for all the three gases. The median retrieval accuracy for the annual and semi-annual term varies in the range 5–20%. For ozone the annual terms dominate in the stratosphere giving early winter ozone maxima at mid-latitudes. Above the ozone layer the annual terms change the phase which results in ozone summer maximum up to 80 km. In the MLT the annual terms dominate up to 80 km where the semiannual terms start to grow. In the equatorial MLT the semi-annual terms dominate the temporal evolution whereas in the mid-latitude MLT annual and semi-annual terms compete evenly. In the equatorial stratosphere the QBO dominates the time development but the solar term is too weak to be determined. In the MLT above 85 km the solar term grows significantly and ozone has 15–20% dependence on the solar cycle. For NO2 below 32 km the annual summer maxima dominates at mid-latitudes whereas in the equatorial region a strong QBO prevails. In northern mid-latitudes a strong solar term appears in the upper stratosphere. For NO3 the annual variation dominates giving rise to summer maxima. The NO3 distribution is controlled by temperature and ozone.
APA, Harvard, Vancouver, ISO, and other styles
28

Uboldi, F., A. N. Sulis, C. Lussana, M. Cislaghi, and M. Russo. "A spatial bootstrap technique for parameter estimation of rainfall annual maxima distribution." Hydrology and Earth System Sciences 18, no. 3 (March 11, 2014): 981–95. http://dx.doi.org/10.5194/hess-18-981-2014.

Full text
Abstract:
Abstract. Estimation of extreme event distributions and depth-duration-frequency (DDF) curves is achieved at any target site by repeated sampling among all available raingauge data in the surrounding area. The estimate is computed over a gridded domain in Northern Italy, using precipitation time series from 1929 to 2011, including data from historical analog stations and from the present-day automatic observational network. The presented local regionalisation naturally overcomes traditional station-point methods, with their demand of long historical series and their sensitivity to very rare events occurring at very few stations, possibly causing unrealistic spatial gradients in DDF relations. At the same time, the presented approach allows for spatial dependence, necessary in a geographical domain such as Lombardy, complex for both its topography and its climatology. The bootstrap technique enables evaluating uncertainty maps for all estimated parameters and for rainfall depths at assigned return periods.
APA, Harvard, Vancouver, ISO, and other styles
29

Uboldi, F., A. N. Sulis, C. Lussana, M. Cislaghi, and M. Russo. "A spatial bootstrap technique for parameter estimation of rainfall annual maxima distribution." Hydrology and Earth System Sciences Discussions 10, no. 9 (September 23, 2013): 11755–94. http://dx.doi.org/10.5194/hessd-10-11755-2013.

Full text
Abstract:
Abstract. Estimation of extreme event distributions and depth-duration-frequency (DDF) curves is achieved at any target site by repeated sampling among all available raingauge data in the surrounding area. The estimate is computed over a gridded domain in Northern Italy, using precipitation time series from 1929 to 2011, including data from historical analog stations and from the present-day automatic observational network. The presented local regionalisation naturally overcomes traditional station-point methods, with their demand of long historical series and their sensitivity to very rare events occurring at very few stations, possibly causing unrealistic spatial gradients in DDF relations. At the same time, the presented approach allows for spatial dependence, necessary in a geographical domain such as Lombardy, complex for both its topography and its climatology. The bootstrap technique enables evaluating uncertainty maps for all estimated parameters and for rainfall depths at assigned return periods.
APA, Harvard, Vancouver, ISO, and other styles
30

Alila, Younes. "A hierarchical approach for the regionalization of precipitation annual maxima in Canada." Journal of Geophysical Research: Atmospheres 104, no. D24 (December 1, 1999): 31645–55. http://dx.doi.org/10.1029/1999jd900764.

Full text
APA, Harvard, Vancouver, ISO, and other styles
31

Debele, S. E., E. Bogdanowicz, and W. G. Strupczewski. "The impact of seasonal flood peak dependence on annual maxima design quantiles." Hydrological Sciences Journal 62, no. 10 (June 29, 2017): 1603–17. http://dx.doi.org/10.1080/02626667.2017.1328558.

Full text
APA, Harvard, Vancouver, ISO, and other styles
32

Apostolov, Emil M., Vojtěch Letfus, and J. Pýcha. "Long-term variation of the semi-annual wave maxima in geomagnetic activity." Studia Geophysica et Geodaetica 33, no. 4 (December 1989): 379–90. http://dx.doi.org/10.1007/bf01637691.

Full text
APA, Harvard, Vancouver, ISO, and other styles
33

Abolverdi, Javad, and Davar Khalili. "Development of Regional Rainfall Annual Maxima for Southwestern Iran by L-Moments." Water Resources Management 24, no. 11 (January 6, 2010): 2501–26. http://dx.doi.org/10.1007/s11269-009-9565-4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Pandey, M. D., and Y. An. "The analysis of design wind speed estimates specified in the National Building Code of Canada." Canadian Journal of Civil Engineering 34, no. 4 (April 1, 2007): 513–24. http://dx.doi.org/10.1139/l06-133.

Full text
Abstract:
The design wind pressures specified in the 2005 National Building Code of Canada (NBCC) have been derived from the Gumbel distribution fitted to annual maximum wind speed data collected up to early 1990s. The statistical estimates of the annual maxima method are affected by a relatively large sampling variability, since the method considers a fairly small subset of available wind speed records. Advanced statistical methods have emerged in recent years with the purpose of reducing both sampling and model uncertainties associated with extreme quantile estimates. The two most notable methods are the peaks-over-threshold (POT) and annually r largest order statistics (r-LOS), which extend the data set by including additional maxima observed in wind speed time series. The objective of the paper is to explore the use of advanced extreme value theory for updating the design wind speed estimates specified in the Canadian building design code. The paper re-examines the NBCC method for design wind speed estimation and presents the analysis of the latest Canadian wind speed data by POT, r-LOS, and annual maxima methods. The paper concludes that r-LOS method is an effective alternative for the estimation of extreme design wind speed.Key words: wind speed, extreme value theory, order statistics, return period, maximum likelihood method, peaks-over-threshold method, generalized extreme value distribution, Gumbel distribution, generalized Pareto distribution.
APA, Harvard, Vancouver, ISO, and other styles
35

Martucci, G., S. Carniel, J. Chiggiato, M. Sclavo, P. Lionello, and M. B. Galati. "Statistical trend analysis and extreme distribution of significant wave height from 1958 to 1999 – an application to the Italian Seas." Ocean Science 6, no. 2 (June 4, 2010): 525–38. http://dx.doi.org/10.5194/os-6-525-2010.

Full text
Abstract:
Abstract. The study is a statistical analysis of sea states timeseries derived using the wave model WAM forced by the ERA-40 dataset in selected areas near the Italian coasts. For the period 1 January 1958 to 31 December 1999 the analysis yields: (i) the existence of a negative trend in the annual- and winter-averaged sea state heights; (ii) the existence of a turning-point in late 80's in the annual-averaged trend of sea state heights at a site in the Northern Adriatic Sea; (iii) the overall absence of a significant trend in the annual-averaged mean durations of sea states over thresholds; (iv) the assessment of the extreme values on a time-scale of thousand years. The analysis uses two methods to obtain samples of extremes from the independent sea states: the r-largest annual maxima and the peak-over-threshold. The two methods show statistical differences in retrieving the return values and more generally in describing the significant wave field. The r-largest annual maxima method provides more reliable predictions of the extreme values especially for small return periods (<100 years). Finally, the study statistically proves the existence of decadal negative trends in the significant wave heights and by this it conveys useful information on the wave climatology of the Italian seas during the second half of the 20th century.
APA, Harvard, Vancouver, ISO, and other styles
36

Davison, A. C., and M. M. Gholamrezaee. "Geostatistics of extremes." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468, no. 2138 (October 12, 2011): 581–608. http://dx.doi.org/10.1098/rspa.2011.0412.

Full text
Abstract:
We describe a prototype approach to flexible modelling for maxima observed at sites in a spatial domain, based on fitting of max-stable processes derived from underlying Gaussian random fields. The models we propose have generalized extreme-value marginal distributions throughout the spatial domain, consistent with statistical theory for maxima in simpler cases, and can incorporate both geostatistical correlation functions and random set components. Parameter estimation and fitting are performed through composite likelihood inference applied to observations from pairs of sites, with occurrence times of maxima taken into account if desired, and competing models are compared using appropriate information criteria. Diagnostics for lack of model fit are based on maxima from groups of sites. The approach is illustrated using annual maximum temperatures in Switzerland, with risk analysis proposed using simulations from the fitted max-stable model. Drawbacks and possible developments of the approach are discussed.
APA, Harvard, Vancouver, ISO, and other styles
37

Buishand, T. A., and G. R. Demar�. "Estimation of the annual maximum distribution from samples of maxima in separate seasons." Stochastic Hydrology and Hydraulics 4, no. 2 (June 1990): 89–103. http://dx.doi.org/10.1007/bf01543284.

Full text
APA, Harvard, Vancouver, ISO, and other styles
38

Prokoph, Andreas, Jan Adamowski, and Kaz Adamowski. "Influence of the 11year solar cycle on annual streamflow maxima in Southern Canada." Journal of Hydrology 442-443 (June 2012): 55–62. http://dx.doi.org/10.1016/j.jhydrol.2012.03.038.

Full text
APA, Harvard, Vancouver, ISO, and other styles
39

Ulrich, Jana, Felix S. Fauer, and Henning W. Rust. "Modeling seasonal variations of extreme rainfall on different timescales in Germany." Hydrology and Earth System Sciences 25, no. 12 (December 2, 2021): 6133–49. http://dx.doi.org/10.5194/hess-25-6133-2021.

Full text
Abstract:
Abstract. We model monthly precipitation maxima at 132 stations in Germany for a wide range of durations from 1 min to about 6 d using a duration-dependent generalized extreme value (d-GEV) distribution with monthly varying parameters. This allows for the estimation of both monthly and annual intensity–duration–frequency (IDF) curves: (1) the monthly IDF curves of the summer months exhibit a more rapid decrease of intensity with duration, as well as higher intensities for short durations than the IDF curves for the remaining months of the year. Thus, when short convective extreme events occur, they are very likely to occur in summer everywhere in Germany. In contrast, extreme events with a duration of several hours up to about 1 d are conditionally more likely to occur within a longer period or even spread throughout the whole year, depending on the station. There are major differences within Germany with respect to the months in which long-lasting stratiform extreme events are more likely to occur. At some stations the IDF curves (for a given quantile) for different months intersect. The meteorological interpretation of this intersection is that the season in which a certain extreme event is most likely to occur shifts from summer towards autumn or winter for longer durations. (2) We compare the annual IDF curves resulting from the monthly model with those estimated conventionally, that is, based on modeling annual maxima. We find that adding information in the form of smooth variations during the year leads to a considerable reduction of uncertainties. We additionally observe that at some stations, the annual IDF curves obtained by modeling monthly maxima deviate from the assumption of scale invariance, resulting in a flattening in the slope of the IDF curves for long durations.
APA, Harvard, Vancouver, ISO, and other styles
40

Kohnová, Silvia, Ladislav Gaál, Tomáš Bacigál, Ján Szolgay, Kamila Hlavčová, Peter Valent, Juraj Parajka, and Günter Blöschl. "Process-based selection of copula types for flood peak-volume relationships in Northwest Austria: a case study." Contributions to Geophysics and Geodesy 46, no. 4 (December 1, 2016): 245–68. http://dx.doi.org/10.1515/congeo-2016-0015.

Full text
Abstract:
Abstract The case study aims at selecting optimal bivariate copula models of the relationships between flood peaks and flood volumes from a regional perspective with a particular focus on flood generation processes. Besides the traditional approach that deals with the annual maxima of flood events, the current analysis also includes all independent flood events. The target region is located in the northwest of Austria; it consists of 69 small and mid-sized catchments. On the basis of the hourly runoff data from the period 1976- 2007, independent flood events were identified and assigned to one of the following three types of flood categories: synoptic floods, flash floods and snowmelt floods. Flood events in the given catchment are considered independent when they originate from different synoptic situations. Nine commonly-used copula types were fitted to the flood peak - flood volume pairs at each site. In this step, two databases were used: i) a process-based selection of all the independent flood events (three data samples at each catchment) and ii) the annual maxima of the flood peaks and the respective flood volumes regardless of the flood processes (one data sample per catchment). The goodness-of-fit of the nine copula types was examined on a regional basis throughout all the catchments. It was concluded that (1) the copula models for the flood processes are discernible locally; (2) the Clayton copula provides an unacceptable performance for all three processes as well as in the case of the annual maxima; (3) the rejection of the other copula types depends on the flood type and the sample size; (4) there are differences in the copulas with the best fits: for synoptic and flash floods, the best performance is associated with the extreme value copulas; for snowmelt floods, the Frank copula fits the best; while in the case of the annual maxima, no firm conclusion could be made due to the number of copulas with similarly acceptable overall performances. The general conclusion from this case study is that treating flood processes separately is beneficial; however, the usually available sample size in such real life studies is not sufficient to give generally valid recommendations for engineering design tasks.
APA, Harvard, Vancouver, ISO, and other styles
41

Muhammed Naseef, T., and V. Sanil Kumar. "Variations in return value estimate of ocean surface waves – a study based on measured buoy data and ERA-Interim reanalysis data." Natural Hazards and Earth System Sciences 17, no. 10 (October 19, 2017): 1763–78. http://dx.doi.org/10.5194/nhess-17-1763-2017.

Full text
Abstract:
Abstract. An assessment of extreme wave characteristics during the design of marine facilities not only helps to ensure their safety but also assess the economic aspects. In this study, return levels of significant wave height (Hs) for different periods are estimated using the generalized extreme value distribution (GEV) and generalized Pareto distribution (GPD) based on the Waverider buoy data spanning 8 years and the ERA-Interim reanalysis data spanning 38 years. The analysis is carried out for wind-sea, swell and total Hs separately for buoy data. Seasonality of the prevailing wave climate is also considered in the analysis to provide return levels for short-term activities in the location. The study shows that the initial distribution method (IDM) underestimates return levels compared to GPD. The maximum return levels estimated by the GPD corresponding to 100 years are 5.10 m for the monsoon season (JJAS), 2.66 m for the pre-monsoon season (FMAM) and 4.28 m for the post-monsoon season (ONDJ). The intercomparison of return levels by block maxima (annual, seasonal and monthly maxima) and the r-largest method for GEV theory shows that the maximum return level for 100 years is 7.20 m in the r-largest series followed by monthly maxima (6.02 m) and annual maxima (AM) (5.66 m) series. The analysis is also carried out to understand the sensitivity of the number of observations for the GEV annual maxima estimates. It indicates that the variations in the standard deviation of the series caused by changes in the number of observations are positively correlated with the return level estimates. The 100-year return level results of Hs using the GEV method are comparable for short-term (2008 to 2016) buoy data (4.18 m) and long-term (1979 to 2016) ERA-Interim shallow data (4.39 m). The 6 h interval data tend to miss high values of Hs, and hence there is a significant difference in the 100-year return level Hs obtained using 6 h interval data compared to data at 0.5 h interval. The study shows that a single storm can cause a large difference in the 100-year Hs value.
APA, Harvard, Vancouver, ISO, and other styles
42

Chang, Kian Boon, Sai Hin Lai, and Othman Faridah. "RainIDF: automated derivation of rainfall intensity–duration–frequency relationship from annual maxima and partial duration series." Journal of Hydroinformatics 15, no. 4 (March 1, 2013): 1224–33. http://dx.doi.org/10.2166/hydro.2013.192.

Full text
Abstract:
RainIDF, a software tool for derivation of rainfall intensity–duration–frequency (IDF) relationship is developed as an Excel add-in by using Visual Basics for Applications (VBA). The tool is integrated with two of the most widely used statistical distributions for determination of IDF relationship: the generalized extreme value (GEV) distribution for annual maxima series, and the generalized Pareto (GPA) distribution for partial duration series (PDS). It provides automated distribution fitting for rainfall data in the form of annual maxima or PDS for multiple intervals, solving and plotting of rainfall IDF curves. RainIDF uses the Solver add-in function in Excel to solve the coefficients of the empirical IDF formula in one step. The methodology built into RainIDF is discussed and rainfall IDF relationships for several stations in Peninsular Malaysia are derived and compared. RainIDF is available for download on GitHub (http://github.com/kbchang/rainidf) as an Excel add-in.
APA, Harvard, Vancouver, ISO, and other styles
43

Macdonald, N., T. R. Kjeldsen, I. Prosdocimi, and H. Sangster. "Reassessing flood frequency for the Sussex Ouse, Lewes: the inclusion of historical flood information since AD 1650." Natural Hazards and Earth System Sciences 14, no. 10 (October 30, 2014): 2817–28. http://dx.doi.org/10.5194/nhess-14-2817-2014.

Full text
Abstract:
Abstract. The application of historical flood information as a tool for augmenting instrumental flood data is increasingly recognised as a valuable tool. Most previous studies have focused on large catchments with historic settlements, this paper applies the approach to the smaller lowland system of the Sussex Ouse in southeast England. The reassessment of flood risk on the Sussex Ouse is pertinent in light of the severe flooding in October 2000 and heightened concerns of a perceived increase in flooding nationally. Systematic flood level readings from 1960 and accounts detailing past flood events within the catchment are compiled back to ca. 1750. This extended flood record provides an opportunity to reassess estimates of flood frequency over a timescale not normally possible within flood frequency analysis. This paper re-evaluates flood frequency at Lewes on the Sussex Ouse downstream of the confluence of the Sussex Ouse and River Uck. The paper considers the strengths and weaknesses in estimates resulting from contrasting methods of analysis and their corresponding data: (i) single site analysis of gauged annual maxima; (ii) combined analysis of systematic annual maxima augmented with historical peaks of estimated magnitude; (iii) combined analysis of systematic annual maxima augmented with historical peaks of estimated magnitude exceeding a known threshold, and (iv) sensitivity analysis including only the very largest historical flood events. Use of the historical information was found to yield much tighter confidence intervals of risk estimates, with uncertainty reduced by up to 40% for the 100-year return frequency event when historical information was added to the gauged data.
APA, Harvard, Vancouver, ISO, and other styles
44

Macdonald, N., T. R. Kjeldsen, I. Prosdocimi, and H. Sangster. "Reassessing flood frequency For the Sussex Ouse, Lewes: the Inclusion of historical Flood Information since AD 1650." Natural Hazards and Earth System Sciences Discussions 1, no. 6 (December 19, 2013): 7615–46. http://dx.doi.org/10.5194/nhessd-1-7615-2013.

Full text
Abstract:
Abstract. The application of historical flood information as a tool for augmenting instrumental flood data is increasingly recognised as a valuable tool; most previous studies have focused on large catchments with historic settlements, this paper applies the approach to the smaller lowland system of the Sussex Ouse in Southeast England. The reassessment of flood risk on the Sussex Ouse is pertinent in light of severe flooding in October 2000 and heightened concerns of a perceived increase in flooding nationally. Systematic flood level readings from 1960 and accounts detailing past flood events within the catchment are compiled back to c.1750. This extended flood record provides an opportunity to reassess estimates of flood frequency over a timescale not normally possible within flood frequency analysis. This paper re-evaluates flood frequency at Lewes on the Sussex Ouse downstream of the confluence of the Sussex Ouse and River Uck. The paper considers the strengths and weaknesses in estimates resulting from contrasting methods of analysis and their corresponding data: (i) single site analysis of gauged annual maxima; (ii) combined analysis of systematic annual maxima augmented with historical peaks of estimated magnitude; (iii) combined analysis of systematic annual maxima augmented with historical peaks of estimated magnitude exceeding a known threshold, and (iv) sensitivity analysis including only the very largest historical flood events. Use of the historical information was found to yield much tighter confidence intervals of risk estimates, with uncertainty reduced by up to 40% for the 100 yr return frequency event when historical information was added to the gauged data.
APA, Harvard, Vancouver, ISO, and other styles
45

Baulon, Lisa, Emma Imen Turki, Nicolas Massei, Gaël André, Yann Ferret, and Nicolas Pouvreau. "Versatile Modelling of Extreme Surges in Connection with Large-Scale Circulation Drivers." Atmosphere 13, no. 5 (May 23, 2022): 850. http://dx.doi.org/10.3390/atmos13050850.

Full text
Abstract:
In this article, we investigate the dependence of extreme surges on the North Atlantic weather regime variability across different timescales using the North Atlantic Oscillation (NAO) and Scandinavian blocking (SCAND) indices. The analysis was done using time series of surges along the North French Coast, covering long time periods (43 to 172 years of data). Time series that exhibited gaps were filled using linear interpolation to allow spectral analyses to be conducted. First, a continuous wavelet analysis on monthly maxima surges in the North French Coast was conducted to identify the multi-timescale variability. Second, a wavelet coherence analysis and maximum overlap discrete wavelet transform (MODWT) were used to study the timescale-dependent relationships between maxima surges and NAO or SCAND. Finally, NAO and SCAND were tested as physical covariates for a nonstationary generalized extreme value (GEV) distribution to fit monthly maxima surge series. Specific low-frequency variabilities characterizing these indices (extracted using MODWT) were also used as covariates to determine whether such specific variabilities would allow for even better GEV fitting. The results reveal common multi-annual timescales of variability between monthly maxima surge time series along the North French coasts: ~2–3 years, ~5–7 years, and ~12–17 years. These modes of variability were found to be mainly induced by the NAO and the SCAND. We identified a greater influence of the NAO on the monthly maxima surges of the westernmost stations (Brest, Cherbourg, Le Havre), while the SCAND showed a greater influence on the northernmost station (Dunkirk). This shows that the physical climate effects at multi-annual scales are manifested differently between the Atlantic/English Channel and the North Sea regions influenced by NAO and SCAND, respectively. Finally, the introduction of these two climate indices was found to clearly enhance GEV models as well as a few timescales of these indices.
APA, Harvard, Vancouver, ISO, and other styles
46

Walker, W. S. G., G. C. D. Herdman, and B. F. Marino. "Cepheid Measures at Auckland Observatory." Publications of the Astronomical Society of Australia 9, no. 1 (1991): 127–28. http://dx.doi.org/10.1017/s1323358000025194.

Full text
Abstract:
AbstractObservations of five cepheids in Crux are described and annual epochs of maxima presented. The O–C diagram of S Crucis shows changes between two alternative periods. The observing method appears suited to sites with only a limited number of hours available.
APA, Harvard, Vancouver, ISO, and other styles
47

De Michele, C., A. Montanari, and R. Rosso. "The effects of non-stationarity on the evaluation of critical design storms." Water Science and Technology 37, no. 11 (June 1, 1998): 187–93. http://dx.doi.org/10.2166/wst.1998.0465.

Full text
Abstract:
The critical storm is generally carried out to design urban drainage systems and other flood management works starting from the available historical information. Its evaluation associated with a fixed return period is usually obtained by fitting the annual maxima of the rainfall depth with an extreme value distribution. This statistical procedure, however, leads to dubious results when the data present a non-stationarity, induced for example, by a long-term variability. To assess the effects of non-stationarity, four daily rainfall series observed in Italy, with at least 90 years of continuous data, are analysed here. For each record and each year of the observation period, critical design storms are estimated fitting the annual maxima collected in the past, so allowing us to assess the progress of the design storm along time. Four different extreme value distributions are used. The results show that an analysis of non-stationarity is required when urban drainage systems and other hydraulic engineering works are designed.
APA, Harvard, Vancouver, ISO, and other styles
48

Baxter, J. M., A. M. Jones, and J. A. Simpson. "A study of long-term changes in some rocky shore communities in Orkney." Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences 87, no. 1-2 (1985): 47–63. http://dx.doi.org/10.1017/s0269727000004152.

Full text
Abstract:
SynopsisThe distribution and relative abundance of various types of coastline are reviewed briefly. The results of a 9 year investigation of selected rocky shore communities are presented. Climatic parameters showed a marked variation during the study but were not correlated with the observed variations in flora and fauna. The main study was based on annual sampling of 8 bedrock shore transects using percentage cover or density for sessile and mobile species respectively. Seasonal fluctuations were studied in fixed areas at 2 sites over a 5 year period. Patterns of seasonal variation in various algal and faunal categories are described and discussed, canopy algae showed summer maxima while understorey species showed winter maxima. Annual studies showed species stability to be site specific: in species which showed marked, apparently cyclic, patterns of change, the changes were often asynchronous both between sites and, to a lesser degree, between stations at a site. The value of obtaining a measure of ‘patchiness’ is discussed.
APA, Harvard, Vancouver, ISO, and other styles
49

Chakraborty, Kajal, and Deepu Joseph. "Inter-annual and seasonal dynamics of amino acid, mineral and vitamin composition of silver belly Leiognathus splendens." Journal of the Marine Biological Association of the United Kingdom 95, no. 4 (September 3, 2014): 817–28. http://dx.doi.org/10.1017/s0025315414001155.

Full text
Abstract:
Silver bellies, Leiognathus splendens were studied for their spatial (south-west and south-east coasts of India), annual (2008–2011) and seasonal (pre-monsoon, monsoon and post-monsoon) variations of protein, amino acids, vitamins and minerals. The monthly mean Sea Viewing Wide Field-of-view Sensor data for the period from January 2008 to December 2011 were taken into account to indicate the distribution of the photosynthetic pigment chlorophyll-a to test the hypothesis that surface productivity might be related to nutritional biochemistry of this species. The four year average total protein content and chlorophyll-a showed good correlation during monsoon on the south-west coast and monsoon/post-monsoon on the south-east coast, suggesting that the protein content is prejudiced by the chlorophyll-a concentration. Amino acid scores observed monsoon maxima along the south-west and south-east coasts. Significant seasonal variations in vitamin content were observed at the study locations with high content of vitamins D3, E, K1 and C on the south-west coast. Na content was maximal during pre-monsoon on the south-west coast, while post-monsoon maxima of Ca and K content were observed. The Fe, Mn and Zn were abundant in the samples collected from the south-west coast. The concentration of Se exhibited maximum values post-monsoon along the south-west and south-east coasts. The present study demonstrated L. splendens as a valuable source of the protein, amino acids, minerals and vitamins, showing that this low-value species is a good source of well balanced proteins with high biological value to be qualified as a preferred healthy food for human consumption.
APA, Harvard, Vancouver, ISO, and other styles
50

Kyrölä, E., J. Tamminen, V. Sofieva, J. L. Bertaux, A. Hauchecorne, F. Dalaudier, D. Fussen, et al. "GOMOS O<sub>3</sub>, NO<sub>2</sub>, and NO<sub>3</sub> observations in 2002–2008." Atmospheric Chemistry and Physics Discussions 10, no. 2 (February 1, 2010): 2169–220. http://dx.doi.org/10.5194/acpd-10-2169-2010.

Full text
Abstract:
Abstract. The Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument onboard the European Space Agency's ENVISAT satellite measures ozone, NO2, NO3, H2O, O2, and aerosols using the stellar occultation method. Global coverage, good vertical resolution and the self-calibrating measurement method make GOMOS observations a promising data set for building various climatologies and time series. In this paper we present GOMOS nighttime measurements of ozone, NO2, and NO3 during six years 2002–2008. Using zonal averages we show the time evolution of the vertical profiles as a function of latitude. In order to get continuous coverage in time we restrict the latitudinal region to 50° S–50° N. Time development is analysed by fitting constant, annual and semi-annual terms as well as solar and QBO proxies to the daily time series. Ozone data cover the stratosphere, mesosphere and lower thermosphere (MLT). NO2 and NO3 data cover the stratosphere. In addition to detailed analysis of profiles we derive total column distributions using the fitted time series. The time-independent constant term is determined with a good accuracy (better than 1%) for all the three gases. The median retrieval accuracy for the annual and semi-annual term varies in the range 5–20%. For ozone the annual terms dominate in the stratosphere giving early winter ozone at mid-latitudes. Above the ozone layer the annual terms change the phase which results to ozone summer maximum up to 80 km. In the MLT the annual terms dominate up to 80 km where the semiannual terms start to grow. In the equatorial MLT the semi-annual terms dominate the temporal evolution whereas in the mid-latitude MLT annual and semi-annual terms compete evenly. In the equatorial stratosphere the QBO dominates the time development but the solar term is too weak to be determined. In the MLT above 85 km the solar term grows significant and ozone has 15–20% dependence on the solar cycle. For NO2 below the maximum at 30 km the annual summer maxima dominates at mid-latitudes whereas in the equatorial region a strong QBO prevails. For NO3 the annual variation dominates giving rise to summer maxima. The NO3 distribution is controlled by temperature.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Annual maxima' for other source types:
Dissertations / Theses
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography