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.

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 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 Reasons for an outstanding plant diversity in the tropical Andes of Southern Ecuador

2009 ◽  
Vol 12 ◽  
pp. 1-35 ◽  
Author(s):  
Michael Richter ◽  
Karl-Heinz Diertl ◽  
Paul Emck ◽  
Thorsten Peters ◽  
Erwin Beck
Keyword(s):  
Human Impact ◽  
Plant Diversity ◽  
Vascular Plant ◽  
Global Scale ◽  
Mountain Range ◽  
Tropical Andes ◽  
Constant Input ◽  
General Role ◽  
Southern Ecuador ◽  
The Impact

Long-term field studies in the scope of a multidisciplinary project in southern Ecuador revealed extraordinary high species numbers of many organismic groups. This article discusses reasons for the outstanding vascular plant diversity using a hierarchical scale-oriented top-down approach (Grüninger 2005), from the global scale to the local microscale. The global scale explains general (paleo-) ecological factors valid for most parts of the humid tropics, addressing various hypotheses and theories, such as the "greater effective evolutionary time", constant input of "accidentals", the "seasonal variability hypothesis", the "intermediate disturbance hypothesis", and the impact of soil fertility. The macroscale focuses on the Andes in northwestern South America. The tropical Andes are characterised by many taxa of restricted range which is particularly true for the Amotape-Huancabamba region, i.e. the so called Andean Depression, which is effective as discrete phytogeographic transition as well as barrier zone. Interdigitation of northern and southern flora elements, habitat fragmentation, geological and landscape history, and a high speciation rate due to rapid genetic radiation of some taxa contribute to a high degree of diversification. The mesoscale deals with the special environmental features of the eastern mountain range, the Cordillera Real and surrounding areas in southern Ecuador. Various climatic characteristics, the orographic heterogeneity, the geologic and edaphic conditions as well as human impact are the most prominent factors augmenting plant species diversity. On microscale, prevailing regimes of disturbance and environmental stresses, the orographic basement, as well as the general role on the various mountain chains are considered. Here, micro-habitats e.g. niches for epiphytes, effects of micro-relief patterns, and successions after small-sized disturbance events are screened. Direct effects of human impact are addressed and a perspective of possible effects of climate change on plant diversity is presented.

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 Temperature thresholds of ecosystem respiration at a global scale

2021 ◽  
Vol 5 (4) ◽  
pp. 487-494
Author(s):  
Alice S. A. Johnston ◽  
Andrew Meade ◽  
Jonas Ardö ◽  
Nicola Arriga ◽  
Andy Black ◽  
...  
Keyword(s):  
Ecosystem Respiration ◽  
Global Scale ◽  
Temperature Thresholds

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 Propagating information from snow observations with CrocO ensemble data assimilation system: a 10-years case study over a snow depth observation network

2021 ◽  
Author(s):  
Bertrand Cluzet ◽  
Matthieu Lafaysse ◽  
César Deschamps-Berger ◽  
Matthieu Vernay ◽  
Marie Dumont
Keyword(s):  
Data Assimilation ◽  
Snow Cover ◽  
Spatial Scales ◽  
Open Loop ◽  
Mountain Range ◽  
Ensemble Data Assimilation ◽  
Ensemble Data ◽  
Analysis Scheme ◽  
Meteorological Observations

Abstract. The mountainous snow cover is highly variable at all temporal and spatial scales. Snowpack models only imperfectly represent this variability, because of uncertain meteorological inputs, physical parameterisations, and unresolved terrain features. In-situ observations of the height of snow (HS), despite their limited representativeness, could help constrain intermediate and large scale modelling errors by means of data assimilation. In this work, we assimilate HS observations from an in-situ network of 295 stations covering the French Alps, Pyrenees and Andorra, over the period 2009–2019. In view of assimilating such observations into a spatialised snow cover modelling framework, we investigate whether such observations can be used to correct neighbouring snowpack simulations. We use CrocO, an ensemble data assimilation framework of snow cover modelling, based on a Particle Filter suited to the propagation of information from observed to unobserved areas. This ensemble system already benefits from meteorological observations, assimilated within SAFRAN analysis scheme. CrocO also proposes various localisation strategies to assimilate snow observations. These approaches are evaluated in a Leave-One-Out setup against the operational deterministic model and its ensemble open-loop counterpart, both running without HS assimilation. Results show that intermediate localisation radius of 35–50 km yield a slightly lower root mean square error (RMSE), and a better Spread-Skill than the strategy assimilating all the observations from a whole mountain range. Significant continuous ranked probability score (CRPS) improvements of about 13 % are obtained in the areas where the open-loop modelling errors are the largest, e.g. the Haute-Ariège, Andorra and the Extreme Southern Alps. Over these areas, weather station observations are generally sparser, resulting in more uncertain meteorological analyses, and therefore snow simulations. In-situ HS observations thus shows an interesting complementarity with meteorological observations to better constrain snow cover simulations over large areas.

NOAA's Merged Land–Ocean Surface Temperature Analysis

2012 ◽  
Vol 93 (11) ◽  
pp. 1677-1685 ◽  
Author(s):  
Russell S. Vose ◽  
Derek Arndt ◽  
Viva F. Banzon ◽  
David R. Easterling ◽  
Byron Gleason ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Data Center ◽  
Ocean Surface ◽  
Global Scale ◽  
Climatic Data ◽  
Temperature Analysis ◽  
Climate Assessment ◽  
National Climatic Data Center ◽  
Time Periods ◽  
Station Location

This paper describes the new release of the Merged Land–Ocean Surface Temperature analysis (MLOST version 3.5), which is used in operational monitoring and climate assessment activities by the NOAA National Climatic Data Center. The primary motivation for the latest version is the inclusion of a new land dataset that has several major improvements, including a more elaborate approach for addressing changes in station location, instrumentation, and siting conditions. The new version is broadly consistent with previous global analyses, exhibiting a trend of 0.076°C decade−1 since 1901, 0.162°C decade−1 since 1979, and widespread warming in both time periods. In general, the new release exhibits only modest differences with its predecessor, the most obvious being very slightly more warming at the global scale (0.004°C decade−1 since 1901) and slightly different trend patterns over the terrestrial surface.

Control of internal temperature threshold for active cutaneous vasodilation by dynamic exercise

1991 ◽  
Vol 71 (6) ◽  
pp. 2476-2482 ◽  
Author(s):  
D. L. Kellogg ◽  
J. M. Johnson ◽  
W. A. Kosiba
Keyword(s):  
Sweat Rate ◽  
Bicycle Ergometer ◽  
Dew Point ◽  
Whole Body ◽  
Temperature Threshold ◽  
Internal Temperature ◽  
Doppler Flowmetry ◽  
Cutaneous Vasodilation ◽  
Temperature Thresholds ◽  
Ergometer Exercise

Exercise induces shifts in the internal temperature threshold at which cutaneous vasodilation begins. To find whether this shift is accomplished through the vasoconstrictor system or the cutaneous active vasodilator system, two forearm sites (0.64 cm2) in each of 11 subjects were iontophoretically treated with bretylium tosylate to locally block adrenergic vasoconstrictor control. Skin blood flow was monitored by laser-Doppler flowmetry (LDF) at those sites and at two adjacent untreated sites. Mean arterial pressure (MAP) was measured noninvasively. Cutaneous vascular conductance was calculated as LDF/MAP. Forearm sweat rate was also measured in seven of the subjects by dew point hygrometry. Whole body skin temperature was raised to 38 degrees C, and supine bicycle ergometer exercise was then performed for 7–10 min. The internal temperature at which cutaneous vasodilation began was recorded for all sites, as was the temperature at which sweating began. The same subjects also participated in studies of heat stress without exercise to obtain vasodilator and sudomotor thresholds from rest. The internal temperature thresholds for cutaneous vasodilation were higher during exercise at both bretylium-treated (36.95 +/- 0.07 degrees C rest, 37.20 +/- 0.04 degrees C exercise, P less than 0.05) and untreated sites (36.95 +/- 0.06 degrees C rest, 37.23 +/- 0.05 degrees C exercise, P less than 0.05). The thresholds for cutaneous vasodilation during rest or during exercise were not statistically different between untreated and bretylium-treated sites (P greater than 0.05). The threshold for the onset of sweating was not affected by exercise (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

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