CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 79:1-8 (2019) - DOI: https://doi.org/10.3354/cr01582 A dynamic linear model of monthly minimum and maximum temperature changes in three physiographic regions of the Central Himalayas Binod Regmi1,3,*, Surya Lamichhane2 1Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72703, USA 2Department of Mathematical Sciences, University of Arkansas, Fayetteville, AR 72703, USA 3Present address: Division of Human Genetics, The Ohio State University College of Medicine, OH 43210, USA *Corresponding author: Binod.Regmi@osumc.edu ABSTRACT: Robust statistical techniques are required to estimate the trend in meteorological data, where data are available only for a limited period with too many missing observations. We examined the application of a dynamic linear model (DLM) for estimating changes in time series meteorological data. For this purpose, we used maximum and minimum monthly temperatures recorded over 36 yr at 6 meteorological stations representing 3 physiographic regions in the Central Himalayas. Temperature changes over time may be influenced by hidden processes, such as seasonality. To elucidate such processes, we estimated a Fourier-form seasonal model with 12 seasons with 2 harmonics. The DLM model fit was evaluated based on the distribution of standardized residuals and the p-value of Ljung-Box statistics. We reported the level of temperature change from 1980 to 2015. The DLM results were compared with more conventional, simple linear regression analysis (SLR). Although a significant trend of temperature increase was observed in the Central Himalayas, the change was not uniform across the physiographic regions. Localized changes in temperature levels may be due to geographic configuration and micro-climate. Notably, the SLR showed a similar trend of average annual temperature change to that of the DLM but overestimated the magnitude of the change. SLR is easily executed but is sensitive to outliers and non-normality in the observations. Under these circumstances, DLM may be a more robust modeling technique for estimating changes in meteorological data. KEY WORDS: Central Himalayas · Global warming · State-space model · Seasonality and trend · Kalman filter · Markov chain · Simple linear regression (SLR) · Mann-Kendall trend test Full text in pdf format NextCite this article as: Regmi B, Lamichhane S (2019) A dynamic linear model of monthly minimum and maximum temperature changes in three physiographic regions of the Central Himalayas. Clim Res 79:1-8. https://doi.org/10.3354/cr01582 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 79, No. 1. Online publication date: October 17, 2019 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2019 Inter-Research.

The Arctic Oscillation (AO) is commonly recognized as a dominant large-scale mode influencing climate over the Northern Hemisphere. Here, the influences of May AO on summer (JJA) extreme precipitation events and summer extreme warm days over the middle reaches of Yangtze River Valley for the period 1961-2014 are investigated. Following a positive May AO, there are usually fewer summer extreme precipitation events but more summer extreme warm days over the middle reaches of Yangtze River Valley. Composite analyses show that positive May AO induces the northward displacement of the East Asian jet stream and northeastward displacement of the western Pacific subtropical high (WPSH), and causes a stronger, more northwestern subtropical northwest Pacific cyclone/anticyclone anomaly, as well as an anticyclonic circulation anomaly on the north side of the South China Sea, resulting in a northward shift of the rainfall belt and an enhancement of the East Asia summer monsoon. Therefore, the cumulative distribution probability of daily precipitation values shift significantly to a lower precipitation value, indicating lower probabilities of summer extreme precipitation events following positive May AO. A weakening of WPSH induces an anomalous sinking motion over the middle reaches of the Yangtze River Valley. The 850 hPa wind field shows southerly wind anomalies over the Jiang-Huai River Basin, which cause a decrease in total cloud cover, resulting in an increase in solar radiation flux. A significant shift of the daily maximum temperature probability distribution towards to higher values indicates higher probabilities of summer extreme warm day occurrences following positive May AO. This study will provide useful insights to help improve the understanding of the dynamics and projections of future regional extreme precipitation changes over the middle reaches of Yangtze River Valley.

Droughts are one of the multifaceted meteorological disasters affecting agriculture, livestock and water resources worldwide. Pakistan has a semiarid climate system with a high degree of interannual rainfall variability. This study evaluates the applicability and comparison of 3 drought indices (deciles index [DI], standardized precipitation index [SPI] and reconnaissance drought index [RDI]) in Pakistan. Monthly rainfall and temperature data (1981-2017) from 30 weather stations were used to analyze the current status of drought occurrence in terms of severity and magnitude. A nonparametric Mann-Kendall test and Sen's slope estimates were applied on drought indices to determine the statistical significance and magnitude of the trend. The DI captured the dry episodes in the region well, as Baluchistan and Sindh provinces have been seen to be more susceptible to droughts. The indices of SPI and RDI were well correlated at 3, 6, 9 and 12 mo timescales. Province-level analysis revealed the highest number of drought years during the 3 mo timescale and the lowest number of drought years during the 12 mo timescale. Overall, a linearly increasing trend of SPI and RDI (towards wetness) was observed, whereas the province-level analysis showed a statistically significant trend at the 95% confidence level for Khyber Pakhtunkhwa, Punjab and Sindh in the long-term drought analysis. Moreover, analyses of historical drought years and their intensity have been investigated and compared with a recent long drought episode (1999)(2000)(2001)(2002). The analysis of historical drought events highlights the challenging nature of drought management in Pakistan. The outcomes of this study would help water resource managers to investigate drought response measures for drought preparedness in the country.

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 77:45-61 (2019) - DOI: https://doi.org/10.3354/cr01539 Observed trends in climate extremes over Bangladesh from 1981 to 2010 Md. Jamal Uddin Khan, A. K. M. Saiful Islam*, Mohan Kumar Das, Khaled Mohammed, Sujit Kumar Bala, G. M. Tarekul Islam Institute of Water and Flood Management, Bangladesh University of Engineering and Technology (BUET), Dhaka 1000, Bangladesh *Corresponding author: saiful3@gmail.com ABSTRACT: Bangladesh regularly faces various extreme events (floods, droughts, cyclones, and heat waves), but there is a knowledge gap between average climate and climate extremes over the country. The purpose of this study is to quantify the trends over Bangladesh for the period 1981-2010 using the extreme temperature and precipitation indices developed by the CCl/WCRP/JCOMM Expert Team on Climate Change Detection and Indices. We used precipitation and temperature data from 26 meteorological stations, calculated trends in the indices using Sen’s slope estimator, and tested significance using the non-parametric Mann-Kendall trend test. For the temperature indices, we found an overall increasing warming trend. Average annual maximum and minimum temperatures increased by 0.3 and 0.4°C decade-1 respectively. A faster rise of both maximum and minimum temperature was found compared with previous studies. The frequency of warm days increased by 12 days decade-1. The frequency of warm (cold) nights increased (decreased) by 7 (11) days decade-1. The overall warming was accelerated at the end of the climatic period (2001-2010). Precipitation indices showed an overall decreasing trend, in contrast to other studies in this region. Trends in consecutive dry days (CDD) indicated a drying tendency at a rate of 10 days decade-1. A decreasing rate of about 84 mm decade-1 was observed in annual average total precipitation. Except for CDD, most of the precipitation trends were statistically not significant and spatially incoherent. Statistically significant change was observed in extreme temperature events, with a strong and consistent spatial pattern. Our results pave the way for further investigations into future changes using results from climate simulations. KEY WORDS: Extreme indices · Expert Team on Climate Change Detection and Indices · ETCCDI · Bangladesh · Observed records · Climate change Full text in pdf format Supplementary material PreviousNextCite this article as: Khan MJU, Islam AKMS, Das MK, Mohammed K, Bala SK, Islam GMT (2019) Observed trends in climate extremes over Bangladesh from 1981 to 2010. Clim Res 77:45-61. https://doi.org/10.3354/cr01539 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 77, No. 1. Online publication date: January 08, 2019 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2019 Inter-Research.

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 76:1-15 (2018) - DOI: https://doi.org/10.3354/cr01522 Determination of the urban heat island intensity in villages and its connection to land cover in three European climate zones Manuel Dienst1,*, Jenny Lindén2, Jan Esper1 1Department of Geography, Johannes Gutenberg University, Johann-Joachim-Becherweg 21, 55128 Mainz, Germany 2IVL Swedish Environmental Research Institute, Aschebergsgatan 44, 41133 Gothenburg, Sweden *Corresponding author: m.dienst@geo.uni-mainz.de ABSTRACT: Although urban heat islands (UHIs) have been found in many cities throughout the world, work on smaller settlements is still limited, especially concerning variations connected to climate zones. Meteorological stations are often regarded as rural when located in a village or small town, and any temperature bias is assumed negligible. In this paper, we therefore present air temperature variations and their connection to land cover in 3 European villages, boreal Haparanda, temperate Geisenheim, and Mediterranean Cazorla, all of them hosting long temperature records that might be biased. The villages were equipped with temperature sensors, and the surrounding areas were digitized to compare UHI effects and to evaluate the contribution of land cover on local cooling and warming. This sensor network reveals significant village UHIs in all 3 climate zones, with seasonal maximum intensities decreasing from north (1.4°C) to south (0.9°C). During summer, urban warming is most emphasized in minimum temperatures in boreal Haparanda and temperate Geisenheim but weakest in Mediterranean Cazorla, presumably because of limited plant transpiration due to high insolation and drought stress. Urban warming is correlated with building density in all 3 settlements and shows little seasonal variation. Even though the mountain river passing Cazorla substantially cools ambient temperatures at distances <100 m, mitigation of warming through water bodies is limited in the Central and Northern European sites. Our results suggest to treat rural instrumental station data with care and to avoid using data recorded in villages as unbiased reference records to adjust measurements from larger cities. KEY WORDS: Urban climate · Urban heat island · Village microclimates · Land cover · Rural stations Full text in pdf format NextCite this article as: Dienst M, Lindén J, Esper J (2018) Determination of the urban heat island intensity in villages and its connection to land cover in three European climate zones. Clim Res 76:1-15. https://doi.org/10.3354/cr01522 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 76, No. 1. Online publication date: September 04, 2018 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2018 Inter-Research.

Traditionally a temperate and hyper-humid region, western Patagonia experienced its most severe drought during the summer and fall of 2016. Along with precipitation deficits larger than 50% there was a similar reduction in river discharge into coastal waters, a decline in vegetation productivity, excessive solar radiation at the surface, and frequent upwelling-favorable wind events offshore. The combination of these regional-scale anomalies seems to have set the stage for environmental disturbances that, although not new in western Patagonia, occurred with unprecedented magnitude, including severe urban air pollution episodes, large forest fires, and the worst ever recorded harmful algae bloom (HAB). The local climate anomalies were in turn related to the concomitant strong El Nino (through atmospheric teleconnections) and, to a lesser extent, anthropogenic climate change mediated by the positive polarity of the Southern Annular Mode (SAM) and internal variability, as both modes weakened the westerlies. Dryer than present conditions are consistently projected for northern Patagonia during the 21st century as a consequence of anthropogenic increases in radiative forcing; superposition of El Nino events in this altered climate may result in a higher frequency of extreme droughts and environmental disruptions like those observed in 2016.

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 74:15-30 (2017) - DOI: https://doi.org/10.3354/cr01487 A climatology of convective available potential energy in the Mediterranean region C. J. Lolis* Laboratory of Meteorology, Department of Physics, University of Ioannina, 45110 Ioannina, Greece *Corresponding author: chlolis@uoi.gr ABSTRACT: The climatic characteristics of convective available potential energy (CAPE) over the Mediterranean region are studied. The data used are daily grid point (1° × 1°) values of CAPE for the period 1979-2015, obtained from the ERA-Interim data base. The main modes of the intra-annual variation and the spatial distribution of CAPE are revealed using a multivariate data reduction technique. Four main modes of intra-annual variation are found, which correspond to specific Mediterranean sub-regions: (1) the continental areas north of the Mediterranean Sea, presenting a maximum in summer and a minimum in winter; (2) the southern Mediterranean Sea and NW Africa, showing a maximum in early autumn; (3) the northern Egyptian coasts, showing a maximum in October; and (4) the continental areas of Asia Minor, characterized by maxima in late spring and early autumn and minima in winter and summer. Four main modes of spatial distribution are found, one for each season: (i) the autumn pattern presents a maximum over the southern Mediterranean Sea; (ii) the winter pattern is characterized by highest CAPE values over the NE Mediterranean Sea; (iii) the spring pattern presents maxima over the inland areas north of the Mediterranean Sea, Asia Minor and the Atlas mountains; and (iv) the summer pattern is characterized by a maximum over the Adriatic Sea. Finally, the linear trends of CAPE during the period 1979-2015 show a significant increase in many parts of the Eastern Mediterranean region, especially in the warm period. KEY WORDS: Convective available potential energy · CAPE · Mediterranean Sea · Seasonal variability · Spatial variability · Trends Full text in pdf format PreviousNextCite this article as: Lolis CJ (2017) A climatology of convective available potential energy in the Mediterranean region. Clim Res 74:15-30. https://doi.org/10.3354/cr01487 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 74, No. 1. Online publication date: October 16, 2017 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2017 Inter-Research.

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 72:239-249 (2017) - DOI: https://doi.org/10.3354/cr01469 Changes in intensity of high temporal resolution precipitation extremes in Romania: implications for Clausius-Clapeyron scaling Aristita Busuioc*, Madalina Baciu, Traian Breza, Alexandru Dumitrescu, Cerasela Stoica, Nina Baghina 1National Meteorological Administration, Sos. Bucuresti-Ploiesti 97, Sect.1, Bucharest 013686, Romania *Corresponding author: busuioc@meteoromania.ro ABSTRACT: We propose a new index for quantifying the maximum rain intensity (IMAX) within a rainfall event. The goal of this paper is 2-fold: first, to analyse the characteristics of variability (trends, change points) for maximum values of this index calculated for spring (April-May), summer (June-August) and autumn (September-October) in comparison with other 2 precipitation indices (daily maximum and total amount). Secondly, to investigate the scaling of the IMAX high percentiles with temperature and compare the results to hourly precipitation extremes. The analysis was carried out at 6 Romanian stations over the period 1966-2007, extended over 1902-2007 for one station. Our results revealed a statistically significant increase of IMAX over the 20th century (intensified over the second half), in contrast with no significant trends in the other 2 precipitation indices. On the other hand, an opposite phase between IMAX variability and its corresponding duration (e.g. shorter durations correspond to higher intensities) was noted. Regarding the scaling behaviour of the IMAX percentiles, there was a difference between summer and spring/autumn. In summer, the 90th and 99th percentiles showed a Clausius-Clapeyron (CC) scaling for temperatures between 14 and 26°C and then a decrease, while the 99.9th percentile showed a super-CC scaling for temperatures lower than 18°C and then a decrease. The spring and autumn 90th and 99th percentiles showed an approximate 2CC scaling for temperatures ranging from 8-20°C. The 99.9th percentile exhibited a scaling close to the 2CC relationship for a temperatures range of 12-18°C (spring) and then a decrease, while the autumn 99.9th percentile exhibited a dependence close to 2CC scaling for temperatures <18°C and then a scaling close to CC. Comparing these results with those referring to hourly and daily precipitation extremes, we conclude that the magnitude of the CC scaling in Romania is mainly dependent on the temporal scale of the extreme precipitation event, storm intensity and season. The proposed index (IMAX) is more sensitive to temperature increases than the hourly and daily extremes, and therefore it is more appropriate to quantifying the climate signal related to intense precipitation events in a warmer climate. KEY WORDS: Extreme precipitation index · Temperature · Scaling · Clausius-Clapeyron relation · Trends · Romania Full text in pdf format Supplementary material PreviousNextCite this article as: Busuioc A, Baciu M, Breza T, Dumitrescu A, Stoica C, Baghina N (2017) Changes in intensity of high temporal resolution precipitation extremes in Romania: implications for Clausius-Clapeyron scaling. Clim Res 72:239-249. https://doi.org/10.3354/cr01469 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 72, No. 3. Online publication date: July 12, 2017 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2017 Inter-Research.

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 72:165-176 (2017) - DOI: https://doi.org/10.3354/cr01462 Information needs, barriers and incentives to adopting climate change mitigation and adaptation actions in boreal agriculture Hanna Mäkinen1,2,*, Karoliina Rimhanen2, Janne Kaseva3, Sari J. Himanen4 1Lappeenranta University of Technology, School of Energy Systems, Sustainability Science, Saimaankatu 11, 15140 Lahti, Finland 2Natural Resources Institute Finland (Luke), Natural Resources and Bioproduction, Latokartanonkaari 9, 00790 Helsinki, Finland 3Natural Resources Institute Finland (Luke), Economics and Society, Tietotie 4, 31600 Jokioinen, Finland 4Natural Resources Institute Finland (Luke), Natural Resources and Bioproduction, Lönnrotinkatu 5, 50100 Mikkeli, Finland *Corresponding author: hanna.makinen@luke.fi ABSTRACT: Effective climate change mitigation and adaptation in agriculture requires farmers to gain sufficient information to plan and implement practical climate-related actions. Science-based knowledge that meets actors' needs supports proactive action taking. The aim of this study was to characterize the views of farmers and other rural stakeholders regarding farmers' climate change information needs, and to identify potential barriers to and necessary incentives for applying climate change mitigation and adaptation in practice. Data were collected by conducting an internet survey in Finland for which 340 responses from farmers, farm advisers and other rural stakeholders were received. Applying cluster analysis, 5 information need profiles were identified: 'information highlighters', 'globally and nationally oriented', 'livestock oriented', 'plant production oriented' and 'no interest'. Half of the respondents believed that climate change would affect their activities in the near future. Among respondent groups, farmers themselves perceived the information on climate change as most uninteresting. The complexity of the current climate change communication and potential economic costs associated with proactivity were found to hinder both mitigation and proactive adaptation actions. Based on our study, climate change communication needs to be practice-oriented and tailored to fit the needs of farmers representing different lines of agricultural production and regional locations. Such information, plus an integration of an assessment of the effects of proactive action taking on farm profitability, is needed to encourage climate change mitigation and adaptation actions on Finnish farms. KEY WORDS: Climate change communication · Adaptation · Agriculture · Information need · Mitigation · Regional adaptation Full text in pdf format Supplementary material NextCite this article as: Mäkinen H, Rimhanen K, Kaseva J, Himanen SJ (2017) Information needs, barriers and incentives to adopting climate change mitigation and adaptation actions in boreal agriculture. Clim Res 72:165-176. https://doi.org/10.3354/cr01462 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 72, No. 3. Online publication date: May 29, 2017 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2017 Inter-Research.

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 72:153-162 (2017) - DOI: https://doi.org/10.3354/cr01463 Global warming drives changes in carnivore communities in the North Sahara Desert Yamna Karssene1,2,*, Mohsen Chammem2, Touhami Khorchani2, Said Nouira1, Fengqing Li3,*,** 1Département de Biologie, Faculté des Sciences de Tunis, Université de Tunis, El-Manar 2092, Tunisia 2Laboratoire d’Elevage et de la Faune Sauvage, Institut des Régions Arides de Médenine, 4119 Médenine, Tunisia 3Department of River Ecology and Conservation, Senckenberg Research Institute and Natural History Museum Frankfurt, 63571 Gelnhausen, Germany *These authors contributed equally. **Corresponding author: qflee3@gmail.com ABSTRACT: Global warming is among the most serious environmental challenges facing ecosystems worldwide, due to rising temperatures and altered precipitation regimes. The North African Sahara Desert is considered to be one of the areas most affected by climate change, which will probably lead to the likely retraction of the Mediterranean ecosystem and an increase in desertification. We examined the effect of global warming on 3 carnivore species (Canis anthus, Vulpes vulpes and V. zerda) in the North African Sahara Desert in the 2000s, 2030s, 2050s and 2080s using species distribution models. Species occurrence records were collected from 175 sites, covering all of the arid and desertified areas of Tunisia between January 2014 and January 2016. Our results show that elevation and annual mean temperature are the most important factors associated with the distribution of V. zerda, while temperature and precipitation have major contributions in the distribution of C. anthus and V. vulpes. Future climate change in the North Sahara will reduce the spatial distribution of suitable habitats for C. anthus and V. vulpes; V. zerda will decrease in numbers around the 2030s and increase again thereafter. Our findings suggest that the ongoing warming effect will cause continued range shifts in carnivores; thus there is an urgent need for efficient conservation practices for carnivores to be implemented in this climatically vulnerable area. KEY WORDS: Desert carnivores · Global warming · North Sahara Desert · Species distribution model · Predicted distribution Full text in pdf format Supplementary material PreviousCite this article as: Karssene Y, Chammem M, Khorchani T, Nouira S, Li F (2017) Global warming drives changes in carnivore communities in the North Sahara Desert. Clim Res 72:153-162. https://doi.org/10.3354/cr01463 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 72, No. 2. Online publication date: May 24, 2017 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2017 Inter-Research.