Meteorology

Meteor Beliefs Project: East European meteor folk-beliefs

by Tsimafei Avilin

Some folk-beliefs about meteors and meteorites from various East European countries are discussed, illustrating the... more Some folk-beliefs about meteors and meteorites from various East European countries are discussed, illustrating the range of such matters, further to what has been presented in the Meteor Beliefs Project earlier.

http://adsabs.harvard.edu/full/2007JIMO...35..113A

Analysis of flash flood regimes in the North-Western and South-Eastern Mediterranean regions

by Paolo Tarolli

Published in Natural Hazards and Earth System Sciences, 2012. Co-authored with Marco Borga, Efrat Morin, Guy Delrieu.

This work analyses the prominent characteristics of flash flood regimes in two Mediterranean areas: the North-Western... more This work analyses the prominent characteristics of flash flood regimes in two Mediterranean areas: the North-Western Mediterranean region, which includes Catalonia, France and Northern Italy, and the South-Eastern Mediterranean region, which includes Israel. The two regions are characterized by similarities in the hydro-meteorological monitoring infrastructure, which permits us to ensure homogeneity in the data collection procedures. The analysis is articulated into two parts. The first part is based on use of flood peak data, catchment area and occurrence date for 99 events (69 from the North-Western region and 30 from the South-Eastern region). Analysis is carried out in terms of relationship of flood peaks with catchment area and seasonality. Results show that the envelope curve for the South-Eastern region exhibits a more pronounced decreasing with catchment size with respect to the curve of the North-Western region. The differences between the two relationships reflect changes in the effects of storm coverage and hydrological characteristics between the two regions. Seasonality analysis shows that the events in the North-Western region tend to occur between August and November, whereas those in the South-Eastern area tend to occur in the period between October and May, reflecting the relevant patterns in the synoptic conditions leading to the intense precipitation events. In the second part, the focus is on the rainfall-runoff relationships for 13 selected major flash flood events (8 from the North-Western area and 5 from the South-Eastern area) for which rainfall and runoff properties are available. These flash floods are characterised in terms of climatic features of the impacted catchments, duration and amount of the generating rainfall, and runoff ratio. Results show that the rainfall duration is shorter and the rainfall depth lower in the South-Eastern region. The runoff ratios are rather low in both regions, whereas they are more variable in the South-Eastern area. No clear relationship between runoff ratio and rainfall depth is observed in the sample of floods, showing the major influence of rainfall intensity and the initial wetness condition in the runoff generation for these events.

Revolving This Will Teach Thee How to Curse‟: Lessons in Sublunary Exhalation.

by Rebecca Totaro

in Rhetorics of Bodily Disease and Health in Medieval and Early Modern England, ed. Jennifer C. Vaught

http://www.ashgate.com/default.aspx?page=637&calcTitle=1&forthcoming=1&title_id=9812&edition_id=12530

Predicting Meteorological component using remote sensing

by Putri Yasmin N.F

Caribbean and Pacific moisture sources on the Isthmus of Panama revealed from stalagmite and surface water d18O gradients

by William Patterson

Emergence and Assemblage Theory

by Mike Bennett

Draft only. Do not cite without permission.

A novel approach for the estimation of soil ground heat flux

by Zhihua Wang

Agricultural and Forest Meteorology, 154-155: 214-221, 2012

Most conventional numerical schemes for soil ground heat flux estimation rely on the knowledge of the temporal... more Most conventional numerical schemes for soil ground heat flux estimation rely on the knowledge of the temporal evolution of soil temperature. Here we propose and test a novel scheme, which requires no information on soil temperatures to supplement the flux plate measurement. The proposed method is based on the fundamental solution of the one-dimensional heat equation and Duhamel’s principle for the incorporation of inhomogeneous boundary conditions. Being completely independent of the soil temperature, the new scheme therefore avoids a potential source of error in measurements and in heat storage calculation. The only thermal property involved in the new scheme is the thermal diffusivity of the soil, which is a weak function of soil water content and can be approximated as constant with reasonable accuracy. For validation, the proposed method is compared to the conventional approach using a canonical one-dimensional heat conduction problem, as well as real field measurements. Results of comparison highlight that the new model is robust and capable of preserving the good accuracy of the conventional approach with reduced input information. In addition, the effect of inclusion of the heat storage term in the ground heat flux is evaluated in the context of surface energy balance closure for field measurements.

Survey of stable isotope values in Irish surface waters

by William Patterson

Trends of Thermal Parameters and Extreme Incidences on IARI Farm, New Delhi during 1980-2008

by Vinay Sehgal

D.K. DAS, V.K. SEHGAL, R. SINGH, P.K. SHARMA
Journal of Agricultural Physics, Vol. 9, pp. 44-49 (2009)

According to the  Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC), global... more According to the  Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC), global surface temperature increased 0.74 ± 0.18 °C during the 20th century and is likely to rise  further from 1.1 to 6.4 °C  during the 21st century as a result of increasing concentrations of greenhouse gases by human activities such as the burning of fossil fuel and deforestation. A study was conducted to examine the trends of annual mean temperature, annual mean maximum temperature and annual mean minimum temperature at IARI farm, New Delhi.  Temperature extremes, which affect the growth and development of crop plants adversely, were also found out with their time of occurrence and frequencies. The trends of annual mean temperature and annual mean maximum temperature were negative whereas, the trend of annual mean minimum temperature was positive. In case of extreme values, 5 coldest mornings were more recent in nature (2006-2008) than the 5 hottest daytimes (1995-2003). An all time high temperature (46.8oC) was recorded on May 29, 1998 and an all time low temperature (-1.4oC) was recorded on January 9, 2006.  Frequencies of hot days and hot nights were found decreasing, whereas, cold days and cold nights were increasing with the progress of time. The number of 'hot days' was maximum (60) in 1987 and minimum (11) in 1997 and 2008. The number of hot nights (26) was maximum in 2002 and was minimum (0) in 1983, 1997 and 2008. Except the trend of annual mean minimum temperature, all other parameters looked like contradicting the popular global warming concept. Although situated with in metropolitan city, IARI farms are full of greenery consisting of 90% area under trees and croplands during most time of the year. Probably, this has arrested and to some extent reversed the warming effect. The effect of warming may be conspicuous in the areas where rapid deforestation and urbanization has taken place. Every one is aware of global warming and hot extremities, but the cooler side is also increasing and we may have to think about protection of crops against cold extremities like cold injuries and frost in the near future.

DESASTRES NATURALES EN EL MUNDO, COMPILACION DE BERNARDO MENDEZ LUGO. REFLEXION SOBRE RESPUESTA DE CUBA A DESASTRES NATURALES, UN EJEMPLO MUNDIAL RECONOCIDO POR LA UNESCO

by Bernardo Mendez Lugo

Extreme meteorological, hydrological and geomorphological events in Poland

by Zbigniew Zwolinski

Landform Analysis, 15, 2011

In present article the attention has been paid on discussion about characteristic of extreme geomorphologic phenomena... more In present article the attention has been paid on discussion about characteristic of extreme geomorphologic phenomena for big morphogenetic regions of Poland or for specific case study, what results from diverse course and effects of geomorphic processes depending on their spatial scales. Therefore presented description of these phenomena is diversified according to details. Hence in the article the emphasis has been put on extreme geomorphic phenomenon, whereas extreme meteorological and hydrological phenomena were mentioned shortly, only there when they were the reason of geomorphologic events. The main analytical period comprise years between 1951 and 2000 year, however, earlier observations and also from the beginning of XXI century were taken into consideration. As an extreme geomorphologic phenomena in Polish morphoclimatic conditions was recognized every process that, because of its intensity or duration, leads to removing, displacement (transportation) or deposition of huge amounts of mineral matter. Such processes can produce substantial changes of relief, in the form of transformation of existing landforms or can lead to form new erosion and denudation landforms and also accumulation landforms. The extreme geomorphologic phenomena catalogue has been given (G-1 to G-9). As a result of analysis of extreme geomorphologic phenomena on the territory of Poland the main types of these events of individuals regions were gained and, in many cases, their intensity. Express in general spatial diversity, we can verify that differences in the intensity and types of extreme geomorphologic phenomena appear in decreasing longitudinal gradient from the South to the North, with smaller threat in the lake district belt and again small their growth along the seaside. There is also the secondary parallel gradient from the West to the East. In this case the type of the most frequently extreme event changes.
With regard to global warming, recorded also in Poland, we can expect an increase of frequency and intensity of meteorological,
hydrological, and as a result of them also geomorphologic extreme events.

Reading the Skies: a Cultural History of English Weather, 1650-1820

by Vladimir Jankovic

The role of elevation on temperature trends in the western United States: A comparison of two statistical methods

by Ruben Behnke

Mountainous regions account for 25% of the world’s land surface area (Kapos, et al.), serve as home to 26% of the... more Mountainous regions account for 25% of the world’s land surface area (Kapos, et al.), serve as home to 26% of the world’s population (Beniston, 2003), and are very important culturally and socially, and often contain very high biodiversity (Beniston, 2006).  These factors make understanding of temperature trends in mountainous regions an important part of climate change research.  In this study, the PRISM data set, developed by Dr. Christopher Daly at Oregon State University, is used to study potential variation in running 30 year temperature trends by elevation since 1895 in six mountain chains in the western U.S., including the 1) Cascades, 2) Sierra Nevada, 3) North Rockies, 4) Middle Rockies, 5) Southern Rockies, and 6) Wasatch Range.  Similar to studies of other mountainous regions around the world, results indicate that a region-wide temperature trend dependence on elevation is rather difficult to detect, and that results are highly spatially and temporally variable.  Finally, interpolation methodology, statistical limitations, and other sources of error are discussed in some detail, as are opportunities for future improvements and additions to this research.       

A Characterization of the Present-Day Arctic Atmosphere in CCSM4

by Brian Medeiros

de Boer, G., W. Chapman, J. E. Kay, B. Medeiros, M. D. Shupe, S. Vavrus, J. Walsh, In Press J. Climate (CCSM4 Special Collection)
doi: http://dx.doi.org/10.1175/JCLI-D-11-00228.1

Simulation of key features of the Arctic atmosphere in the fourth version of the Community Climate System Model... more Simulation of key features of the Arctic atmosphere in the fourth version of the Community Climate System Model (CCSM4) is evaluated against observational and reanalysis datasets for the present-day (1981-2005). Surface air temperature, sea level pressure, cloud cover and phase, precipitation and evaporation, the atmospheric energy budget and lower tropospheric stability are evaluated. Simulated surface air temperatures are found to be slightly too cold when compared with ERA-40. Spatial patterns and temporal variability are well simulated. Evaluation of the sea level pressure demonstrates some large biases, most noticeably an under-simulation of the Beaufort High during spring and autumn. Monthly Arctic-wide biases of up to 13 mb are reported. Cloud cover is under-predicted for all but summer months, and cloud phase is demonstrated to be different from observations. Despite low cloud cover, simulated all-sky liquid water paths are too high, while ice water path was generally too low. Precipitation is found to be excessive over much of the Arctic compared to ERA-40 and GPCP estimates. With some exceptions, evaporation is well captured by CCSM4, resulting in P-E estimates that are too high. CCSM4 energy budget terms show promising agreement with estimates from several sources. The most noticeable exception to this are TOA fluxes that are found to be too low while surface fluxes are found to be too high during summer months. Finally, the lower troposphere is found to be too stable when compared to ERA-40 during all times of year, but particularly during spring and summer months.

The Norwegian IPY-THORPEX: Polar lows and Arctic fronts during the 2008 Andøya campaign

by Erik W. Kolstad

Autor list: J. E. Kristjánsson, I. Barstad, T. Aspelien, I. Føre, Ø Godøy, Ø Hov, E. Irvine, T. Iversen, E. Kolstad, T. E. Nordeng, H. McInnes, R. Randriamampianina, J. Reuder, Ø Saetra, M. Shapiro, T. Spengler, H. Ólafsson. Published online in the Bulletin of the American Meteorological Society (BAMS), June 2011

From a weather forecasting perspective, the Arctic poses particular challenges for mainly two reasons: 1) The... more From a weather forecasting perspective, the Arctic poses particular challenges for mainly two reasons: 1) The observational data are sparse; and 2) The weather phenomena responsible for severe weather, such as polar lows, Arctic fronts, and orographic influences on airflow, are poorly resolved and described by the operational numerical weather prediction (NWP) models. The Norwegian IPY-THORPEX project (2007–2010) seeks to significantly improve weather forecasts of these phenomena through a combined modeling and observational effort. The crux of the observational effort was a 3-week international field campaign out of Northern Norway in early 2008, combining airborne and surface-based observations. The main platform of the field campaign was the DLR research aircraft FALCON, which is equipped with LIDAR systems for profiling of aerosols, humidity and wind, in addition to in situ measurements and dropsondes. A total of 12 missions were flown, yielding detailed observations of polar lows, Arctic fronts and orographic low-level jets near Spitsbergen, the coast of Northern Norway and the east coast of Greenland. The LIDAR systems enabled exceptionally detailed measurements of orographic jets caused by the orography of Spitsbergen. Two major polar low developments over the Norwegian Sea were captured during the campaign. In the first polar low case, 3 flights were carried out, providing a first-ever probing of the full life cycle of a polar low. Targeting observations by the aircraft in sensitive areas led to improvements in predicted track and intensity of the polar low. We present highlights from the field campaign, as well as from ongoing follow-up investigations. In addition, we present highlights from the development of a new limited-area model ensemble prediction system for the Arctic, as well as an exploitation of new satellite data (IASI).

Orographic influence of east Greenland on a polar low over the Denmark Strait

by Erik W. Kolstad

Author list: Jón Egill Kristjánsson, Sigurdur Thorsteinsson, Erik W. Kolstad, Anne-Marlene Blechschmidt. Published online in the Quarterly Journal of the Royal Meteorological Society, May 2011

We present a numerical study of a polar low which hit western Iceland in January 2007, with heavy snowfall and mean... more We present a numerical study of a polar low which hit western Iceland in January 2007, with heavy snowfall and mean wind speeds exceeding 20 m/s in several locations. The operational models at the time captured the polar low formation rather well, but there was a large spread in their predictions of the subsequent evolution and track of the polar low. The objective of this study is to investigate possible orographic forcing from Greenland as a trigger for the polar low development. In addition to an analysis of surface observations and satellite imagery, sensitivity studies using HIRLAM were carried out with various degradations of Greenland's orography, as well as with modifications to the sea-surface temperature (SST), surface roughness and the data assimilation scheme. Despite the presence of an upper-level trough and weak static stability in all the simulations, the polar low development was found to be very sensitive to the presence of the high mountains of eastern Greenland. Whereas the control run captured well the main features of the polar low, simulations with parts of east Greenland's orography removed gave a southward-displaced polar low which moved rapidly eastward, resulting in substantially underestimated near-surface winds and snowfall amounts. Setting the orographic heights over all of Greenland to zero led to the complete disappearance of the polar low. On the other hand, artificially increasing the SST by 4 K in the Denmark Strait, reducing the orographic roughness or replacing the four-dimensional variational assimilation scheme (4D-Var) by 3D-Var had only a small effect on the polar low. We suggest that hitherto unreported interactions between the high mountains of east Greenland and polar low development over the Denmark Strait may be more important for polar low formation than katabatic flow from valleys in east Greenland that was highlighted in earlier studies.

Linking past flood frequencies in Norway to regional atmospheric circulation anomalies

by Erik W. Kolstad

Author list: Støren, E.N., Kolstad, E., Paasche, Ø. In press in the Journal of Quaternary Science

Analysis of two continuous, high-resolution paleo-flood records from Southern Norway reveals that the frequency of... more Analysis of two continuous, high-resolution paleo-flood records from Southern Norway reveals that the frequency of extreme flood events has changed significantly during the Holocene. During the early and middle Holocene, the flood frequency was low; whereas it was high over the last 2300 years when the mean flood frequency was about 2.5 to 3.0 per century. The present regional discharge regime is dominated by spring/summer snowmelt, and our results indicate that the changing flood frequency cannot be explained by local conditions associated with the respective catchments of the two lakes, but rather long-term variations of solid winter precipitation and related snowmelt. Applying available instrumental winter precipitation data and associated sea level pressure re-analysis data as a modern analogue, we document that atmospheric circulation anomalies, significantly different from the North Atlantic Oscillation (NAO), have some potential in explaining the variability of the two different paleo-flood records. Centennial-scale patterns in shifting flood frequency might be indicative of shifts in atmospheric circulation and shed light on paleo-pressure variations in the North Atlantic region, in areas not influenced by the NAO. Major shifts are found at about 2300, 1200 and 200 years ago (cal. a BP).

Climate, stream flow prediction and water management in northeast Brazil: societal trends and forecast value

by Renzo Taddei

Kenneth Broad, Alexander Pfaff, Renzo Taddei, A. Sankarasubramanian, Upmanu Lall & Franciso de Assis de Souza Filho. Climatic Change (2007) 84:217–239.

We assess the potential benefits from innovative forecasts of the stream flows that replenish reservoirs in the... more We assess the potential benefits from innovative forecasts of the stream flows that replenish reservoirs in the semi-arid state of Ceará, Brazil. Such forecasts have many potential applications. In Ceará, they matter for both water-allocation and participatory-governance issues that echo global debates. Our qualitative analysis, based upon extensive fieldwork with farmers, agencies, politicians and other key actors in the water sector, stresses that forecast value changes as a society shifts. In the case of Ceará, current constraints on the use of these forecasts are likely to be reduced by shifts in water demand, water allocation in the agricultural Jaguaribe Valley, participatory processes for water allocation between this valley and the capital city of Fortaleza, and risk perception. Such changes in the water sector can also have major distributional impacts.

A Comunicação Social da Informação sobre Tempo e Clima: o Ponto de Vista do Usuário

by Renzo Taddei

Este artigo discute problemas ligados à comunicação social das informações meteorológicas. O texto sugere a... more Este artigo discute problemas ligados à comunicação social das informações meteorológicas. O texto sugere a necessidade do estudo e compreensão dos contextos de uso das informações disseminadas, das formas habituais de interpretação de mensagens meteorológicas e das associações entre a informação meteorológica e outros temas localmente relevantes. A mensagem deve ser construída buscando levar esses fatores em consideração, e procurando evitar associações que deslocam o significado da informação para outros campos interpretativos. O trabalho de comunicação social, desta forma, deixa de ser meramente burocrático e ganha a dimensão de pesquisa, o que sugere a necessidade da colaboração interdisciplinar sistemática entre a meteorologia e as ciências sociais e da comunicação. Apesar de essa ser uma posição amplamente aceita nas pesquisas das dimensões humanas das mudanças climáticas, parece não haver reconhecimento institucional, até o momento, da necessidade do estudo sistemático das dimensões humanas do clima e do tempo, onde a comunicação social tem papel central.

Digital information and communication networks and scientific research substance – An investigation of meteorology

by Yi Shen

Proceedings of the American Society for Information Science and Technology
Volume 44, Issue 1, pages 1–4, 2007