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- Westerberg, Ida, et al.
(författare)
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Precipitation data in a mountainous catchment in Honduras: quality assessment and spatiotemporal characteristics
- 2010
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Ingår i: Theoretical and Applied Climatology. - : Springer Nature. - 0177-798X .- 1434-4483. ; 101:3-4, s. 381-396
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Tidskriftsartikel (refereegranskat)abstract
- An accurate description of temporal and spatial precipitation variability in Central America is important for local farming, water supply and flood management. Data quality problems and lack of consistent precipitation data impede hydrometeorological analysis in the 7,500 km2 Choluteca River basin in central Honduras, encompassing the capital Tegucigalpa. We used precipitation data from 60 daily and 13 monthly stations in 1913–2006 from five local authorities and NOAA's Global Historical Climatology Network. Quality control routines were developed to tackle the specific data quality problems. The quality-controlled data were characterised spatially and temporally, and compared with regional and larger-scale studies. Two gapfilling methods for daily data and three interpolation methods for monthly and mean annual precipitation were compared. The coefficient-of-correlation-weighting method provided the best results for gap-filling and the universal kriging method for spatial interpolation. In-homogeneity in the time series was the main quality problem, and 22% of the daily precipitation data were too poor to be used. Spatial autocorrelation for monthly precipitation was low during the dry season, and correlation increased markedly when data were temporally aggregated from a daily time scale to 4–5 days. The analysis manifested the high spatial and temporal variability caused by the diverse precipitationgenerating mechanisms and the need for an improved monitoring network.
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| 2. |
- Franzén, Lars, 1950, et al.
(författare)
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The potential peatland extent and carbon sink in Sweden, as related to the Peatland / Ice Age Hypothesis
- 2012
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Ingår i: Mires and Peat. - 1819-754X. ; 10:artikel nr 08
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Tidskriftsartikel (refereegranskat)abstract
- Peatlands cover approximately 65,600 km2 (16 %) of the Swedish land area. The available areas suitable for peatland expansion are far from occupied after ca. 12,000 years of the present interglacial. We estimate the potential extent of peatland in Sweden, based on slope properties of possible areas excluding lakes and glaciofluvial deposits. We assume no human presence or anthropic effects, so the calculation is speculative. It may have been relevant for previous interglacials. We calculate the potential final area of peatlands in three scenarios where they cover all available land with different maximum slope angles (1−3 º) using a Digital Elevation Model (DEM). The three scenarios yield potential peatland areas of 95,663 km2 (21 % of total available area), 168,287 km2 (38 %) and 222,141 km2 (50 %). The relative increases from the present 65,600 km2 are 46, 157 and 239 % respectively. The slope scenarios give CO2 uptake rates of 8.9−10.8, 18.1−22.4 and 24.6−30.5 Mt yr−1. Under global warming conditions with isotherms moved northwards and to higher altitudes, following an increase of raised bog area, the CO2 uptake rates might increase to 12.2−13.8, 24.4−27.7 and 33.5−37.9 Mt yr−1; i.e. up to 4.3−4.9 vpb of atmospheric CO2. If we make the speculative extrapolation from Sweden to all high latitude peatlands, and assume that all suitable areas with slope angle ≤ 3 ° become occupied, the global peatland CO2 sink might approach 3.7 Gt yr−1 (about 2 vpm yr−1) and potentially cause a net radiative cooling approaching 5 W m−2.
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| 3. |
- Chen, Deliang, 1961, et al.
(författare)
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European Trend Atlas of Extreme Temperature and Precipitation Records
- 2015
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- This Atlas presents records of climatic variability and change in Europe starting before 1901 and focuses especially on trends of extreme temperatures and precipitation. The authors have used software developed within EMULATE (European and North Atlantic daily to MULtidecadal climATE variability) to obtain the extremes indices and temporal trends. The trend atlas provides an easy way to identify spatial patterns for a given time period, region, season, and index. The Atlas clearly shows that climate in Europe has changed over the last 100 to 150 years, such that the occurrence and intensity of warm temperature extremes have increased. Precipitation extremes have also changed, but with a less clear pattern compared to the temperature extremes.
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| 7. |
- Walther, Alexander, 1976, et al.
(författare)
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Evaluation of the warm season diurnal cycle of precipitation over Sweden simulated by the Rossby Centre regional climate model RCA3
- 2013
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Ingår i: Atmospheric Research. - : Elsevier BV. - 0169-8095. ; 119, s. 131-139
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Tidskriftsartikel (refereegranskat)abstract
- This study examines the diurnal cycle of precipitation over Sweden for the warm season (April to September) both in hourly observational data and in simulations from the Rossby Centre regional climate model (RCA3). A series of parallel long-term simulations of RCA3 with different horizontal resolutions - 50, 25, 12, and 6 km - were analyzed to investigate the sensitivity of the model's horizontal resolution to the simulated diurnal cycle of precipitation. Overall, a clear distinction between an afternoon peak for inland stations and an early morning peak for stations along the Eastern coast is commonly found both in observation and model results. However, the diurnal cycle estimated from the model simulations show too early afternoon peaks with too large amplitude compared to the observation. Increasing horizontal model resolution tends to reduce this bias both in peak timing and amplitude, but this resolution effect seems not to be monotonic; this is clearly seen only when comparing coarser resolution results with the 6 km resolution result. As the resolution increases, the peak timing and amplitude of the diurnal cycle of resolved large-scale precipitation become more similar to the observed cycle of total precipitation while the contribution of subgrid scale convective precipitation to the total precipitation decreases. An increase in resolution also tends to reduce too much precipitation of relatively light intensity over inland compared to the observation, which may also contribute to the more realistic simulation of the afternoon peak in convective precipitation. (C) 2011 Elsevier B.V. All rights reserved.
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| 10. |
- Brunet, Manola, et al.
(författare)
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Long-term changes in extreme temperatures and precipitation in Spain
- 2007
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Ingår i: Contributions to Science: The International Journal of the Institute for Catalan Studies (IEC). - 1575-6343. ; 3:3, s. 331-342
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The development of the Spanish daily adjusted temperatureseries (SDATS) and the Spanish daily adjusted precipitation series(SDAPS) datasets in the framework of the European Community(EC)-funded project EMULATE (European and North Atlanticdaily to MULtidecadal climATE variability) enabled theassessment of long-term annual changes of extreme temperatureand precipitation indices over peninsular Spain for the period1901–2005. Within this framework, a set of procedureswas developed to generate long-term (1850–2005) daily adjustedtemperature and precipitation series and to use them toassess changes in climatic extremes. The present report describesdetails of the data employed to analyze the behavior ofSpanish climate extremes and discusses the results of investigationsinto the annual changes in selected indices that occurredduring the 20th century: exceedances of upper and lowerpercentiles of daily maximum (Tmax) and minimum (Tmin)temperatures, cold-spell duration index (CSDI), warm-spell durationindex (WSDI), daily rainfall (R) exceeding the 95th and 99thpercentiles, simple daily intensity index (SDII), and greatest 1–and 5-day total precipitation. Upper and lower temperaturepercentiles increased during the 20th century over mainlandSpain, but changes in daytime extreme temperatures werelarger than the changes in night-time extreme temperatures.This pattern, however, shifted slightly in the recent period ofstrong warming, with more similar rates of change among daytimeand night-time extreme temperatures. Changes in extremeprecipitation indices were not as evident as those in extreme-temperature indices, but there was a tendency towardsheavier precipitation.
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