ASSESING HISTORICAL (1926-1996) NEAR-SURFACE WIND SPEED VARIABILITY ACROSS SWEDEN

Homogenized near-surface wind speed (NSWS) series of 7 stations from rescued observational journals have been analyzed for the 70-years time-period 1926-1996 to investigate past changes and variations across Sweden. During the whole period, there has been a statistically significant (at p < 0.05) decreasing trend of -0.11 m s-1 decades-1. In particular, there has been a steep slowdown in wind (-0.27 m s-1 decades-1) for 1945-1960, followed by a long period of stabilization until 1990. Complementary data from 1956-2013 and 1997-2019 also reveal a stilling period between 1990-2005, followed by a reversal which is in line with previous studies from Scandinavia. Summer and fall are the season which show the largest decreasing trends (- 0.11 and -0.12 m s-1 decades-1). Winter shows a greater interannual variation, and reports the same, smaller decreasing trend as spring (-0.7 m s-1 decades-1). In addition, wind speed series have been correlated with 4 different large-scale circulation, namely North Atlantic Oscillation (NAO), Artic Oscillation (AO), Scandinavian Pattern (SCA) and East Atlantic Pattern (EA). Correlation with circulation patterns has wide seasonal differences. Correlation with NAO generally shows a positive correlation, which is highest during winter (0.5); AO shows the largest positive correlation in spring and winter (0.45 and 0.5 respectively); and EA has the highest positive correlation with wind speed during spring (0.45). SCA is the only teleconnection system which displays statistically significant (p < 0.05) negative correlation, largest in summer (-0.27). A possible cause for the seasonal variation in wind speed trends is the tendency to a positive phase in NAO, AO and EA during winter and spring, which increases the westerly winds strength; during summer, when large-scale circulation has less tendency for positive phase (i.e., less pressure difference), smaller more-regional and local patterns may affect, for example, the uneven warming in the high latitudes, causing less pressure gradient and leading to decreased wind speeds

Variations of observed near-surface wind speed across Sweden since 1926

Trabajo presentado en el III Encuentro Extremeño de Climatología, celebrado en Badajoz (España) del 29 al 30 de septiembre de 2022

The contribution of large‑scale atmospheric circulation to variations of observed near‑surface wind speed across Sweden since 1926

This study investigates the centennial-scale (i.e., since 1926) variability of observed nearsurface wind speed across Sweden. Results show that wind speed underwent various phases of change during 1926–2019, i.e., (a) a clear slowdown during 1926–1960; (b) a stabilization from 1960 to 1990; (c) another clear slowdown during 1990–2003; (d) a slight recovery/stabilization period for 2003–2014, which may continue with a possible new slowdown. Furthermore, the performance of three reanalysis products in representing past wind variations is evaluated. The observed low-frequency variability is properly simulated by the selected reanalyses and is linked to the variations of different large-scale atmospheric circulation patterns (e.g., the North Atlantic Oscillation). However, the evident periods of decreasing trend during 1926–1960 and 1990–2003, which drive most of the stilling in the last century, are missing in the reanalyses and cannot be realistically modeled through multiple linear regression by only using indexes of atmospheric circulation. Therefore, this study reveals that changes in large-scale atmospheric circulation mainly drive the low-frequency variability of observed near-surface wind speed, while other factors (e.g., changes in surface roughness) are crucial for explaining the periods of strong terrestrial stilling across Swede

Hur påverkas grisen av bogsår och går det att undvika?

Shoulder lesion is a big problem among pig farmers and is rarely noticed by the consumers. It is most common among lactating sows as they spend a lot of time laying down and is relatively hard to get rid of. There is a lot of factors that can affect the occurance of shoulder lesions for instance flesh, bedding and breeding. In this study we examine the occurance of shoulder lesion among Swedish farms in the county of Halland where diffrent farmers were asked to answer a couple of questions regarding their ways to hold pigs. 19 out of the 35 farmers asked said they had shoulder lesions in their herd. This is about 54% of the asked. When compared to what amount of bedding the farmer had it was shown that no shoulder lesions could been seen on pigs in deep litter with an amount of 10cm or more. For treatment against shoulder lesions most commmon among the swedish farmers was bluespray and wood tar, wich is an interesting observation since wood tar is known to cause allergic reactions to your skin. What the cause for shoulder lesion at the farms included in this study is not held, but that shoulder lesions is a problem is a fact. Bogsår är tryckskador som kan liknas vid liggsår som drabbar muskulaturen och underhuden som sedan utvecklas till ett öppet sår. Bogsår drabbar mestadels digivande suggor då de spenderar mycket tid liggandes på sidan vilket lämnar bogen till ett utsatt läge. Det finns olika stadier av bogsår. Eftersom Sverige inte har någon officiell skala att arbeta med används i denna rapport Lunds et al. (2003) skala som bland annat är grunden till bedömning på danska slakterier. Bogsår kan utvecklas från många olika faktorer, några exempel är hull, avel och underlag, det vill säga strömedel samt golvtyp. Det finns inga tydliga instruktioner på hur man behandlar bogsår, utan mycket arbete ligger bakom förebyggande åtgärder för att undvika det. I rapporten blev olika veterinärer rådfrågade och gav svar om vad de gav för tips och åtgärder när bogsår utvecklats. Danmark och Norge är även med som jämförelse då de har en annan djurskyddslag än vad vi i Sverige har. I Danmark har man satsat mycket pengar och resurser på att utreda hur bogsår kan förhindras, förebyggas och behandlas, vilket gör att de har utvecklat mer fakta än vad Sverige har. Sverige har däremot till skillnad mot Danmark en mer utvecklad djurskyddslag, trots att båda länderna följer EU-lagstiftningarna. Detta på grund av den tyngre reglerade nationella lagstiftningen Sverige faller under. Denna undersökning har utarbetats genom studiebesök hos en konventionell och en ekologisk grisproduktion samt att enkäter har skickats ut till grisproducenter i Hallands län. I enkäten ställdes frågor bland annat om hur mycket strömedel djurhållaren har i sin box och hur många procent bogsår som utvecklats hos grisarna. 19 av 35 hade bogsår i sin besättning där bogsårsfrekvensen varierade mellan 1 %-7,5 %. En jämförelse mellan % bogsår och mängd strömedel gjordes där ett svagt samband kunde ses att mer strö är lika med färre bogsår, med undantag från en strömängd på 7,5 cm vilket troligen berodde på att enbart en djurhållare låg inom den radien. Problem med utgödslingsystemet togs också med i resultatet där 26 djurhållare hade spalt varav 9 hade problem. 8 djurhållare hade djupströ varav 1 djurhållare upplevde problem med utgödslingen. Bogsår är något som är ett förekommande problem hos många besättningar men som fått lite uppmärksamhet och få studier har gjorts om bogsår i Sverige. Avel är en stor bidragande orsak till bogsår och mer fokus borde ligga åt forskning angående detta men att problemet i första hand uppmärksammats är ett steg åt rätt riktning.

Variations of observed near-surface wind speed across Sweden during 1926-1996

Trabajo presentado en Swedish Climate Symposium, celebrado en Norrköping (Suecia) del 16 al 18 de mayo de 2022

A century-long homogenized dataset of near-surface wind speed observations since 1925 rescued in Sweden, HomogWS-se

Trabajo presentado en EGU General Assembly, celebrado en Viena (Austria) del 23 al 27 de mayo de 2022.The main reasons for the lack of data rescue and homogenization of early near-surface wind speed (WS) observations before the 1960s are insufficient manpower and lack of funding. Funding from the Swedish Research Council for Sustainable Development (FORMAS) for a joint project (ref. 2019-00509) `Assessing centennial wind speed variability from a historical weather data rescue project in Sweden (WINDGUST)¿ among the Swedish Meteorological and Hydrological Institute, the University of Gothenburg, and the Spanish National Research Council, presents a great opportunity to rescue and homogenize the early paper-based WS data in Sweden, for creating a century-long homogenized WS dataset. Here, we rescued paper-based WS records dating back to the 1920s at 13 stations in Sweden and established a four-step homogenization procedure to generate the first 10-member centennial homogenized WS dataset (HomogWS-se) for community use. First, background climate variation in the rescued WS series was removed, using a verified reanalysis series as a reference series to construct a difference series. A penalized maximal F test at a significance level of 0.05 was then applied to detect artificial change-points. About 38% of the detected change-points were confirmed by the known events recorded in metadata, and the average segment length split by the change-points is ~11.3 years. A mean-matching method using up to five years of data from two adjacent segments was used to adjust the earlier segments relative to the latest segment. The homogenized WS series was then obtained by adding the homogenized difference series back onto the subtracted reference series. Compared with the raw WS data, the homogenized WS data is more continuous and lacks significant non-climatic jumps. The homogenized WS series presents an initial WS stilling and subsequent recovery until the 1990s, whereas the raw WS fluctuates with no clear trend before the 1970s. The homogenized WS shows a 25% reduction in the WS stilling during 1990-2005 than the raw WS, and this reduction is significant when considering the homogenization uncertainty from reference series. The homogenized WS exhibits a significantly stronger correlation with the North Atlantic Oscillation (NAO) than that of the raw WS (0.54 vs 0.29). These results highlight the importance of the century-long homogenized WS series in increasing our ability to detect and attribute multidecadal variability and changes in WS. HomogWS-se will be released on an open-access data repository for community uses, including studying WS changes, assessing model simulations, and constraining future projections of WS and wind energy potential. The proposed homogenization procedure enables other countries or regions to rescue their early climate data and jointly build global long-term high-quality datasets

HomogWS-se: A century-long homogenized dataset of near-surface wind speed observations since 1925 rescued in Sweden for community use

Trabajo presentado en Swedish Climate Symposium, celebrado en Norrköping (Suecia) del 16 al 18 de mayo de 2022

HomogWS-se: a century-long homogenized dataset of near-surface wind speed observations since 1925 rescued in Sweden

Creating a century-long homogenized near-surface wind speed observation dataset is essential to improve our current knowledge about the uncertainty and causes of wind speed stilling and recovery. Here, we rescued paper-based records of wind speed measurements dating back to the 1920s at 13 stations in Sweden and established a four-step homogenization procedure to generate the first 10-member centennial homogenized wind speed dataset (HomogWS-se) for community use. Results show that about 38¿% of the detected change points were confirmed by the known metadata events, and the average segment length split by the change points is ~11.3 years. Compared with the raw wind speed series, the homogenized series is more continuous and lacks significant non-climatic jumps. The homogenized series presents an initial wind speed stilling and subsequent recovery until the 1990s, whereas the raw series fluctuates with no clear trend before the 1970s. The homogenized series shows a 25¿% reduction in the wind speed stilling during 1990¿2005 than the raw series, and this reduction is significant when considering the homogenization uncertainty. The homogenized wind speed series exhibits a significantly stronger correlation with the North Atlantic oscillation index than that of the raw series (0.54 vs. 0.29). These results highlight the importance of the century-long homogenized series in increasing our ability to detect and attribute multidecadal variability and changes in wind speed. The proposed homogenization procedure enables other countries or regions to rescue their early climate data and jointly build global long-term high-quality datasets. HomogWS-se is publicly available from the Zenodo repository at https://doi.org/10.5281/zenodo.5850264 (Zhou et al., 2022).This study was funded by Swedish FORMAS (2019-00509) and VR (2017-03780, 2019-03954), as well as the Swedish National Strategical Research Programs BECC and MERGE. Cesar Azorin-Molina was supported by the IBER-STILLING project RTI2018-095749-A-100 (MCIU/AEI/FEDER,UE), the VENTS project AICO/2021/023 (GVA) and the CSIC Interdisciplinary Thematic Platform PTI-CLIMA. Lorenzo Minola was funded by the International Postdoc grant from the Swedish Research Council (2021-00444)

HomogWS-se: A century-long homogenized dataset of near-surface wind speed observations since 1925 rescued in Sweden [Dataset]

Creating a century-long homogenized near-surface wind speed (WS) observation dataset is essential to improve our knowledge about the uncertainty and causes of WS stilling and recovery. We rescued paper-based WS records dating back to the 1920s at 13 stations in Sweden and established a four-step homogenization procedure to generate the first 10-member centennial homogenized WS dataset (HomogWS-se) for community uses among climatology, ecology, hydrology and energy industry. HomogWS-se can be used to study the WS variability and change, assess climate reanalysis, and constrain climate simulations for better future projection of changes in the WS and wind energy potential. HomogWS-se contains 13 individual text files with 10-member century-long homogenized monthly WS series, as well as the member-mean series.Peer reviewe