scholarly journals Observed Mesoscale Hydroclimate Variability of North America’s Allegheny Mountains at 40.2° N

Climate ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 91
Author(s):  
Evan Kutta ◽  
Jason Hubbart
Keyword(s):  
Extreme Values ◽  
Dew Point ◽  
Convective Precipitation ◽  
Moisture Advection ◽  
Precipitation Regimes ◽  
Hydroclimate Variability ◽  
Mountain System ◽  
Meteorological Observations ◽  
Allegheny Mountains ◽  
Hydroclimatic Variability

Spatial hydroclimatic variability of Eastern North America’s Allegheny Mountain System (AMS) is commonly oversimplified to elevation differences and the rain-shadow effect. Descriptive and higher order statistical properties of hourly meteorological observations (1948–2017) from seven airports were analyzed to better understand AMS climatic complexity. Airports were located along a longitudinal transect (40.2 °N) and observation infrastructure was positioned to minimize climatic gradients associated with insolation, slope, and aspect. Results indicated average ambient temperature was well correlated with airport elevation (R2 = 0.97). However, elevation was relatively poorly correlated to dew point temperature (R2 = 0.80) and vapor pressure deficit (R2 = 0.61) heterogeneity. Skewness and kurtosis of ambient and dew point temperatures were negative at all airports indicating hourly values below the median were more common and extreme values were less common than a normal distribution implies. Westerly winds accounted for 54.5% of observations indicating prevailing winds misrepresented nearly half of AMS weather phenomena. The sum of maximum hourly precipitation rates was maximized in Philadelphia, PA implying a convective precipitation maximum near the border of Piedmont and Coastal Plain provinces. Results further indicate the AMS represents a barrier to omnidirectional moisture advection suggesting physiographic provinces are characterized by distinct evapotranspiration and precipitation regimes. The current work draws attention to observed mesoscale hydroclimatic heterogeneity of the AMS region and identifies mechanisms influencing local to regional water quantity and quality issues that are relevant to many locations globally.

scholarly journals Stochastorm: A stochastic rainfall simulator for convective storms

2020 ◽  
Author(s):  
Catherine Wilcox ◽  
Claire Aly ◽  
Théo Vischel ◽  
Gérémy Panthou ◽  
Juliette Blanchet ◽  
...  
Keyword(s):  
Impact Analysis ◽  
Extreme Values ◽  
Rain Gauge ◽  
Convective Precipitation ◽  
Precipitation Event ◽  
Storm Event ◽  
Spatial And Temporal Scales ◽  
Convective Storms ◽  
Distribution Parameters ◽  
Temporal Disaggregation

AbstractStochastic rainfall generators aim to reproduce the main statistical features of rainfall at small spatial and temporal scales. The simulated synthetic rainfall series are recognized as suitable for use with impact analysis in water, agricultural, and ecological management. Convection-driven precipitation, dominant in certain regions of the world such as the intertropical belt regions, presents properties that require specific consideration when modeling: (i) strong rainfall intermittency, (ii) high variability of intensities within storms, (iii) strong spatiotemporal correlation of intensities, and (iv) marked seasonality of storm properties. In this article, improvements for an existing statistico-dynamic rainfall generator that models convective storms are presented. Notable novelties include (i) the ability to model precipitation event timing, (ii) an improved temporal disaggregation scheme representing the rainfall distribution at sub-event scales, and (iii) using covariates to reflect seasonal changes in precipitation occurrence and marginal distribution parameters. Extreme values are explicitly considered in the distribution of storm event intensities. The simulator is calibrated and validated using 28 years of five-minute precipitation data from the 30 rain gauge AMMA-CATCH network in the Sahelian region of southwest Niger. Both large propagative systems and smaller local convective precipitation are generated. Results show that simulator improvements coherently represent the local climatology. The simulator can generate scenarios for impact studies with accurate representation of convective precipitation characteristics.

scholarly journals Spatiotemporal Hydroclimate Variability in Finland: Past Trends

2017 ◽  
Vol 18 (6) ◽  
pp. 1765-1782
Author(s):  
Ville Lindgren ◽  
Joseph H. A. Guillaume ◽  
Timo A. Räsänen ◽  
Juho Jakkila ◽  
Noora Veijalainen ◽  
...  
Keyword(s):  
Principal Component ◽  
Weather Extremes ◽  
Absolute Deviation ◽  
The Past ◽  
Temperature And Precipitation ◽  
New Information ◽  
Hydroclimate Variability ◽  
Runoff Variability ◽  
Mean Climate ◽  
Hydroclimatic Variability

Abstract Over the past decades, Finland has experienced changes in its climate: temperature and precipitation have increased, resulting in varying runoff patterns. These trends are well studied, but the changes in interannual variability are less known, despite their importance for understanding climate change. This research aims to assess spatiotemporal changes in variability of temperature, precipitation, and runoff for 1962–2014 at the subbasin scale in Finland. Temporal changes in variability were analyzed by constructing moving-window median absolute deviation time series at annual and seasonal scales. Subbasins with similar patterns of temporal variability were identified using principal component analysis and agglomerative hierarchical clustering. Presence of monotonic trends in variability was tested. Distinct areas with similar patterns of statistically significant changes in variability were found. Decreases in annual, winter, and summer temperature variability were discovered across Finland, in southern Finland, and in northern Finland, respectively. Precipitation variability increased in autumn in northern Finland. It also decreased in winter and spring in northern and central parts of Finland. Runoff variability increased in winter in most parts of Finland and in summer in the central parts, but decreased in spring in southern Finland. Comparison with existing studies illustrates that trends in mean climate and its variability do not necessarily match, highlighting the importance of addressing both aspects. The findings of this study provide new information on hydroclimatic variability in Nordic conditions and improve the possibility to adapt and predict the changes in hydroclimatic conditions, including weather extremes.

scholarly journals Preliminary results of mass-balance observations of Yala Glacier and analysis of temperature and precipitation gradients in Langtang Valley, Nepal

2014 ◽  
Vol 55 (66) ◽  
pp. 9-14 ◽  
Author(s):  
Prashant Baral ◽  
Rijan B. Kayastha ◽  
Walter W. Immerzeel ◽  
Niraj S. Pradhananga ◽  
Bikas C. Bhattarai ◽  
...  
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Lapse Rate ◽  
Convective Precipitation ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Temperature And Precipitation ◽  
Meteorological Observations ◽  
The Impact ◽  
Langtang Valley

AbstractMonitoring the glacier mass balance of summer-accumulation-type Himalayan glaciers is critical to not only assess the impact of climate change on the volume of such glaciers but also predict the downstream water availability and the global sea-level change in future. To better understand the change in meteorological parameters related to glacier mass balance and runoff in a glacierized basin and to assess the highly heterogeneous glacier responses to climate change in the Nepal Himalaya and nearby ranges, the Cryosphere Monitoring Project (CMP) carries out meteorological observations in Langtang Valley and mass-balance measurements on Yala Glacier, a debris-free glacier in the same valley. A negative annual mass balance of –0.89m w.e. and the rising equilibrium-line altitude of Yala Glacier indicate a continuation of a secular trend toward more negative mass balances. Lower temperature lapse rate during the monsoon, the effect of convective precipitation associated with mesoscale thermal circulation in the local precipitation and the occurrence of distinct diurnal cycles of temperature and precipitation at different stations in the valley are other conclusions of this comprehensive scientific study initiated by CMP which aims to yield multi-year glaciological, hydrological and meteorological observations in the glacierized Langtang River basin.

scholarly journals VARIABILITY OF SEASONAL AND ANNUAL RUNOFF IN NORWAY

1972 ◽  
Vol 3 (2) ◽  
pp. 72-79 ◽  
Author(s):  
ARNE TOLLAN
Keyword(s):  
Coefficient Of Variation ◽  
Catchment Area ◽  
Annual Runoff ◽  
High Variability ◽  
Convective Precipitation ◽  
Regional Pattern ◽  
Precipitation Regimes ◽  
Runoff Regime ◽  
Monthly Runoff ◽  
Eastern Norway

A preliminary map of variability of annual runoff in Norway has been prepared based on estimates of the coefficient of variation cv for 56 non-regulated discharge stations having more than 35 years of continuous observations. The regional pattern of cv reflects the altitude and possibly also the different precipitation regimes of Norway; low variability characterizes the wet western part of the country where frontal precipitation dominates, and relatively high variability typifies the drier South-Eastern Norway where considerable amounts of convective precipitation are common. cv for annual runoff is slightly affected by catchment area. Variability of monthly runoff also shows a regional pattern which is interpreted in terms of runoff regime characteristics.

scholarly journals Meteorological observations in tall masts for the mapping of atmospheric flow in Norwegian fjords

2020 ◽  
Vol 12 (4) ◽  
pp. 3621-3640
Author(s):  
Birgitte Rugaard Furevik ◽  
Hálfdán Ágústsson ◽  
Anette Lauen Borg ◽  
Zakari Midjiyawa ◽  
Finn Nyhammer ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Complex Terrain ◽  
Meteorological Parameters ◽  
Temporal Frequency ◽  
Three Dimensional ◽  
Dew Point ◽  
The Arctic ◽  
Atmospheric Flow ◽  
Climatological Data ◽  
Meteorological Observations

Abstract. Since 2014, 11 tall meteorological masts have been erected in coastal areas of mid-Norway in order to provide observational data for a detailed description of the wind conditions at several potential fjord crossing sites. The planned fjord crossings are part of the Norwegian Public Roads Administration (NPRA) Coastal Highway E39 project. The meteorological masts are 50–100 m high and located in complex terrain near the shoreline in Halsafjorden, Julsundet and Storfjorden in the Møre og Romsdal county of Norway. Observations of the three-dimensional wind vector are made at 2–4 levels of each mast with a temporal frequency of 10 Hz. The dataset is corroborated with observed profiles of temperature at two masts, as well as observations of precipitation, atmospheric pressure, relative humidity and dew point at one site. The first masts were erected in 2014, and the measurement campaign will continue until at least 2024. The current paper describes the observational setup, and observations of key atmospheric parameters are presented and put in context with observations and climatological data from a nearby reference weather station. The 10 min and 10 Hz wind data, as well as other meteorological parameters, are publicly available through the Arctic Data Centre (https://doi.org/10.21343/z9n1-qw63; Furevik et al., 2019).

scholarly journals Precipitation phase uncertainty in cold region conceptual models resulting from meteorological forcing time-step intervals

2020 ◽  
Vol 51 (2) ◽  
pp. 180-187
Author(s):  
James M. Feiccabrino
Keyword(s):  
Air Temperature ◽  
Climate Models ◽  
Phase Error ◽  
Dew Point ◽  
Time Step ◽  
Meteorological Forcing ◽  
Surface Precipitation ◽  
Phase Uncertainty ◽  
Meteorological Observations ◽  
Precipitation Phase

Abstract Precipitation phase determination is a known source of uncertainty in surface-based hydrological, ecological, safety, and climate models. This is primarily due to the surface precipitation phase being a result of cloud and atmospheric properties not measured at surface meteorological or hydrological stations. Adding to the uncertainty, many conceptual hydrological models use a 24-h average air temperature to determine the precipitation phase. However, meteorological changes to atmospheric properties that control the precipitation phase often substantially change at sub-daily timescales. Model uncertainty (precipitation phase error) using air temperature (AT), dew-point temperature (DP), and wet-bulb temperature (WB) thresholds were compared using averaged and time of observation readings at 1-, 3-, 6-, 12-, and 24-h periods. Precipitation phase uncertainty grew 35–65% from the use of 1–24 h data. Within a sub-dataset of observations occurring between AT −6 and 6 °C representing 57% of annual precipitation, misclassified precipitation was 7.9% 1 h and 11.8% 24 h. Of note, there was also little difference between 1 and 3 h uncertainty, typical time steps for surface meteorological observations.

Surface-based precipitation phase determination methods in hydrological models

2012 ◽  
Vol 44 (1) ◽  
pp. 44-57 ◽  
Author(s):  
James Feiccabrino ◽  
David Gustafsson ◽  
Angela Lundberg
Keyword(s):  
Air Temperature ◽  
Dew Point ◽  
Temperature Threshold ◽  
Phase Determination ◽  
Probability Curve ◽  
Linear Decrease ◽  
Meteorological Observations ◽  
Second Category ◽  
Model Precipitation ◽  
Precipitation Phase

We compared solid and liquid precipitation mass output from three categories of common model precipitation phase determination schemes (PPDS) to the recorded precipitation phase in a set of 45 years of 3-hour manual meteorological observations from 19 Swedish meteorological stations. In the first category of rain/snow thresholds, it was found that rain/snow air temperature threshold (ATT) is a better precipitation phase indicator than a rain/snow dew point temperature threshold. When a rain/snow ATT of 0.0 °C (a default value used in some recent models) was replaced by 1.0 °C, misclassified precipitation was reduced by almost one half. A second category of PPDS use two ATTs, one snow and one rain, with a linear decrease in snow fraction between. This category identified precipitation phase better than a rain/snow ATT at 17 stations. Using all observations from all the meteorological stations, a final category using an air-temperature-dependent snow probability curve resulted in slightly lower misclassified precipitation mass at 13 of the 19 stations. However, schemes from the linear decrease in snow fraction category had the lowest misclassified precipitation mass at four meteorological stations.

scholarly journals Meteorological observations in tall masts for mapping of atmospheric flow in Norwegian fjords

2020 ◽  
Author(s):  
Birgitte Rugaard Furevik ◽  
Hálfdán Ágústson ◽  
Anette Lauen Borg ◽  
Midjiyawa Zakari ◽  
Finn Nyhammer ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Complex Terrain ◽  
Meteorological Parameters ◽  
Temporal Frequency ◽  
Three Dimensional ◽  
Dew Point ◽  
Atmospheric Parameters ◽  
Atmospheric Flow ◽  
Wind Climate ◽  
Meteorological Observations

Abstract. Since 2014, 11 tall meteorological masts have been erected in coastal areas of mid-Norway in order to provide observational data for a detailed description of the wind climate at several potential fjord crossing sites. The planned fjord crossings are part of the Norwegian Public Roads Administration (NPRA) Coastal Highway E39-project. The meteorological masts are 50–100 m high and located in complex terrain near the shoreline in Halsafjorden, Julsundet and Storfjorden in the Møre og Romsdal county of Norway. Observations of the three-dimensional wind vector are done at 2–4 levels in each mast, with a temporal frequency of 10 Hz. The dataset is corroborated with observed profiles of temperature at two masts, as well as precipitation, atmospheric pressure, relative humidity and dew point at one site. The first masts were erected in 2014 and the measurement campaign will continue to at least 2024. The current paper describes the observational setup and observations of key atmospheric parameters are presented and put in context with observations and climatological normals from a nearby reference weather station. The quality-controlled 10-minute and 10 Hz data as well as other meteorological parameters is publicly available through Arctic Data Centre (https://adc.met.no/datasets/10.21343/z9n1-qw63; Furevik et al., 2019).

scholarly journals Temperature scaling of extreme precipitation events – an application of the new DWD event catalogue

2021 ◽  
Author(s):  
Tanja Winterrath ◽  
Ewelina Walawender ◽  
Katharina Lengfeld ◽  
Elmar Weigl ◽  
Andreas Becker
Keyword(s):  
Extreme Precipitation ◽  
Ambient Air ◽  
Precipitation Intensity ◽  
Convective Precipitation ◽  
Precipitation Event ◽  
Extreme Precipitation Events ◽  
Precipitation Regimes ◽  
Temperature Scaling ◽  
First Results ◽  
Precipitation Events

<p>According to the Clausius-Clapeyron equation on saturation vapour pressure a temperature increase of 1 K allows an atmospheric air mass to hold approximately 7 % more water vapour thus increasing its potential for heavy precipitation. Several published measurement studies on the relation between precipitation intensity and temperature, however, revealed an increase of even up to twofold the CC rate for short-term precipitation events. Model conceptions explain this scaling behaviour with increasing temperature by different intensification pathways of convective processes and/or a transition between stratiform and convective precipitation regimes that both can hardly be verified by point measurements alone. In this presentation, we present first results of the correlation between ambient air temperature and different attributes of the Catalogue of Radar-based Heavy Rainfall Events (CatRaRE) recently published by Deutscher Wetterdienst (DWD). This object-oriented event catalogue files and characterizes extreme precipitation events that have occurred on German territory since 2001. It is based on the high-resolution precipitation climate data set RADKLIM of DWD, i.e. contiguous radar-based reflectivity measurements adjusted to hourly station-based precipitation totals and corrected for typical measurement errors applying specific climatological correction methods. Our analysis gives new insights into potential explanations of the observed temperature scaling relating not only precipitation intensity but characteristic event properties like area, duration, and extremity indices with ambient temperature data. With this approach, extreme precipitation events can be analysed in a comprehensive way that is significant in the context of potential impact. The presented analysis moreover allows testing the hypothesis of regime changing based on objective precipitation event criteria that are typical for different precipitation types. We will briefly present the methodological background of CatRaRE with special focus on the event attributes used in the analysis of Clausius-Clapeyron scaling and give first results on the retrieved temperature dependencies of extreme precipitation events.</p>

scholarly journals A new GIS landscape classification method for rain/snow temperature thresholds in surface based models

2016 ◽  
Vol 48 (4) ◽  
pp. 902-914 ◽  
Author(s):  
James M. Feiccabrino ◽  
Laurie D. Grigg
Keyword(s):  
Global Scale ◽  
Dew Point ◽  
Mountain Range ◽  
Classification Methods ◽  
Landscape Classification ◽  
Elevation Change ◽  
Temperature Thresholds ◽  
Meteorological Observations ◽  
Station Location ◽  
Snow Temperature

Landscape air temperature thresholds (TA) and percent misclassified precipitation (error) for 12 years of meteorological observations from 40 stations across the Scandinavian Peninsula were derived and compared using both manual and geographic information system (GIS) landscape classification methods. Dew-point, wet-bulb, and wet bulb 0.5 were also tested. Both classification methods used the following west to east landscape categories: windward (WW) ocean, coast, fjord, hill, and mountain in Norway; and leeward (LW) mountain, hill, rolling terrain, and coast in Sweden. GIS landscape classification has the advantages of automating the classification process and increasing objectivity. The GIS classification was based on station location (LW or WW) relative to the Scandinavian mountain range, and the % water or range of elevation change within 15 km. The GIS and manual method had the same TA for 20 stations, and similar total reduction in error (2.29 to 2.17% respectively) when compared to country TA. Therefore, automated GIS landscape classification can be used to decrease error from common country or global scale TA. Wet-bulb temperature thresholds for GIS landscapes resulted in a greater reduction in error (8.26%) compared to air (2.29%), and dew-point (−16.67%) thresholds. However, finding stations reporting relative humidity or wet-bulb temperature may limit its widespread use.

Sign in / Sign up

Export Citation Format

Share Document