scholarly journals Comparison of Early Twentieth Century Arctic Warming and Contemporary Arctic Warming in the light of daily and sub-daily data

2022 ◽  
pp. 1-59
Keyword(s):  
Twentieth Century ◽  
Air Temperature ◽  
Diurnal Temperature Range ◽  
Surface Air Temperature ◽  
The Arctic ◽  
Arctic Warming ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Early Twentieth Century ◽  
Daily Data

Abstract A review of many studies published since the late 1920s reveals that the main driving mechanisms responsible for the Early Twentieth Century Arctic Warming (ETCAW) are not fully recognized. The main obstacle seems to be our limited knowledge about the climate of this period and some forcings. A deeper knowledge based on greater spatial and temporal resolution data is needed. The article provides new (or improved) knowledge about surface air temperature (SAT) conditions (including their extreme states) in the Arctic during the ETCAW. Daily and sub-daily data have been used (mean daily air temperature, maximum and minimum daily temperature, and diurnal temperature range). These were taken from ten individual years (selected from the period 1934–50) for six meteorological stations representing parts of five Arctic climatic regions. Standard SAT characteristics were analyzed (monthly, seasonal, and yearly means), as were rarely investigated aspects of SAT characteristics (e.g., number of characteristic days; day-to-day temperature variability; and onset, end, and duration of thermal seasons). The results were compared with analogical calculations done for data taken from the Contemporary Arctic Warming (CAW) period (2007–16). The Arctic experienced warming between the ETCAW and the CAW. The magnitude of warming was greatest in the Pacific (2.7 °C) and Canadian Arctic (1.9 °C) regions. A shortening of winter and lengthening of summer were registered. Furthermore, the climate was also a little more continental (except the Russian Arctic) and less stable (greater day-to-day variability and diurnal temperature range) during the ETCAW than during the CAW.

scholarly journals Temporal and Spatial Variability in Surface Air Temperature and Diurnal Temperature Range in Spain over the Period 1950–2011

Climate ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 16 ◽  
Author(s):  
Julia Bilbao ◽  
Roberto Román ◽  
Argimiro De Miguel
Keyword(s):  
Spatial Variability ◽  
Air Temperature ◽  
Rural Areas ◽  
Diurnal Temperature Range ◽  
Statistical Significance ◽  
Rate Of Change ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Temporal And Spatial Variability ◽  
Temporal And Spatial

Maximum (Tmax), minimum (Tmin), mean (Tmean) air temperature and diurnal temperature range (DTR) trends on a seasonal and annual time scale are evaluated from data recorded at nine Spanish weather stations during the period 1950–2011. Temporal and spatial variability in temperatures and in the diurnal temperature range (DTR) are presented. The non-parametric Theil-Sen approach and the Mann-Kendall test are used to evaluate anomaly temperature trends and their statistical significance, respectively. An air temperature reduction in Spain between 1950 and 1980 emerges and significant warming is observed between 1980 and 2011. On a seasonal scale, the weakest trends (mostly insignificant at the 5% confidence level) are noted during autumn, while the strongest warming rates were found during summer and spring. The rate of change between 1950 and 2011 in Tmax, Tmin and Tmean was 1.6 °C, 1.1 °C and 1.3 °C, respectively. DTR trends showed a decrease on the Mediterranean coast and a small change in northern, Atlantic and rural areas. The spatial distribution of annual and seasonal trends was plotted as isoline maps and strong trend gradients from the south to the north of the country are observed. DTR values were negatively correlated with relative humidity and precipitation and positively correlated with sunshine hours.

Solar radiation in the Arctic during the Early Twentieth Century Warming period (1921–50)

2020 ◽  
Author(s):  
Rajmund Przybylak ◽  
Pavel Sviashchennikov ◽  
Joanna Uscka-Kowalkowska ◽  
Przemysław Wyszyński
Keyword(s):  
Twentieth Century ◽  
Solar Radiation ◽  
20Th Century ◽  
Solar Irradiance ◽  
Research Work ◽  
The Arctic ◽  
Early 20Th Century ◽  
Solar Forcing ◽  
Arctic Warming ◽  
Early Twentieth Century

<p>The Early Twentieth Century Warming (ETCW) period includes a time when a clear increase in actinometric observations was noted in the Arctic, which is defined for the purpose of the present paper after Atlas Arktiki (Treshnikov ed., 1985). Nevertheless, available information about energy balance, and its components, for the Arctic for the study period is still very limited, and therefore solar forcing cannot be reliably determined. As a result, the literature contains large discrepancies between estimates of solar forcing. For example, reconstructions of the increase of terrestrial solar irradiance (TSI) during the ETCW period range from 0.6 Wm<sup>-2</sup> (CMIP5, Wang et al., 2005), through 1.8 Wm<sup>-2</sup> (Crowley et al., 2003), to 3.6 Wm<sup>-2</sup> (Shapiro et al., 2011). Suo et al. (2013) concluded that the collection and processing of solar data is of paramount and central importance to the ability to take solar forcing into account, especially in modelling work.</p><p>            Having in mind the weaknesses of our knowledge described above, we decided to present in the paper a summary of our research concerning the availability of solar data in the Arctic (including measurements taken during land and marine expeditions). A detailed inventory of data series for the ETCW period (1921–50) also containing all available metadata will be an important part of this work. Based on the gathered data, a preliminary analysis will be presented of the general solar conditions in the Arctic in this time in terms of global, diffuse and direct solar radiation, and their changes from the ETCW period to present times (mainly 1981–2010).</p><p>            The research work in this paper was supported by a grant entitled “Causes of the Early 20th Century Arctic Warming”, funded by the National Science Centre, Poland (grant no. 2015/19/B/ST10/02933).</p><p>References:</p><p>Crowley T.J., Baum S.K., Kim K., Hegerl G.C. and Hyde W.T., 2003. Modeling ocean heat content changes during the last millennium. Geophys. Res. Lett. 30, 1932</p><p>Shapiro A.I., Schmutz W., Rozanov E., Schoell M., Haberreiter M. and co-authors, 2011. A new approach to the long-term reconstruction of the solar irradiance leads to large historical solar forcing. Astron. Astrophys. 529, A67.</p><p>Suo L., Ottera O.H., Bentsen M., Gao Y. and Johannessen O.M., 2013. External forcing of the early 20th century Arctic warming, Tellus A 2013, 65, 20578, http://dx.doi.org/10.3402/tellusa.v65i0.20578</p><p>Treshnikov A.F. (ed.), 1985. Atlas Arktiki. Glavnoye Upravlenye Geodeziy i Kartografiy: Moscow.</p><p>Wang Y.M., Lean J.L. and Sheeley Jr. N.R., 2005. Modeling the sun’s magnetic field and irradiance since 1713. Astroph. J. 625, 522.</p>

scholarly journals Impacts of Small-Scale Urban Encroachment on Air Temperature Observations

2019 ◽  
Vol 58 (6) ◽  
pp. 1369-1380 ◽  
Author(s):  
Ronald D. Leeper ◽  
John Kochendorfer ◽  
Timothy A. Henderson ◽  
Michael A. Palecki
Keyword(s):  
Built Environment ◽  
Air Temperature ◽  
Diurnal Temperature Range ◽  
Small Scale ◽  
Reference Network ◽  
Oak Ridge ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Temperature Observations ◽  
The Impact

AbstractA field experiment was performed in Oak Ridge, Tennessee, with four instrumented towers placed over grass at increasing distances (4, 30, 50, 124, and 300 m) from a built-up area. Stations were aligned in such a way to simulate the impact of small-scale encroachment on temperature observations. As expected, temperature observations were warmest for the site closest to the built environment with an average temperature difference of 0.31° and 0.24°C for aspirated and unaspirated sensors, respectively. Mean aspirated temperature differences were greater during the evening (0.47°C) than during the day (0.16°C). This was particularly true for evenings following greater daytime solar insolation (20+ MJ day−1) with surface winds from the direction of the built environment where mean differences exceeded 0.80°C. The impact of the built environment on air temperature diminished with distance with a warm bias only detectable out to tower B′ located 50 m away. The experimental findings were comparable to a known case of urban encroachment at a U.S. Climate Reference Network station in Kingston, Rhode Island. The experimental and operational results both lead to reductions in the diurnal temperature range of ~0.39°C for fan-aspirated sensors. Interestingly, the unaspirated sensor had a larger reduction in diurnal temperature range (DTR) of 0.48°C. These results suggest that small-scale urban encroachment within 50 m of a station can have important impacts on daily temperature extrema (maximum and minimum) with the magnitude of these differences dependent upon prevailing environmental conditions and sensing technology.

scholarly journals An energy budget approach to understand the Arctic warming during the Last Interglacial

2021 ◽  
Author(s):  
Marie Sicard ◽  
Masa Kageyama ◽  
Sylvie Charbit ◽  
Pascale Braconnot ◽  
Jean-Baptiste Madeleine
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Air Temperature ◽  
Energy Budget ◽  
Surface Air Temperature ◽  
The Arctic ◽  
Last Interglacial ◽  
Near Surface ◽  
Arctic Warming ◽  
The Arctic Ocean

Abstract. The Last Interglacial period (129–116 ka BP) is characterized by a strong orbital forcing which leads to a different seasonal and latitudinal distribution of insolation compared to the pre-industrial period. In particular, these changes amplify the seasonality of the insolation in the high latitudes of the northern hemisphere. Here, we investigate the Arctic climate response to this forcing by comparing the CMIP6 lig127k and pi-Control simulations performed with the IPSL-CM6A-LR model. Using an energy budget framework, we analyse the interactions between the atmosphere, ocean, sea ice and continents. In summer, the insolation anomaly reaches its maximum and causes a near-surface air temperature rise of 3.2 °C over the Arctic region. This warming is primarily due to a strong positive surface downwelling shortwave radiation anomaly over continental surfaces, followed by large heat transfers from the continents back to the atmosphere. The surface layers of the Arctic Ocean also receives more energy, but in smaller quantity than the continents due to a cloud negative feedback. Furthermore, while heat exchanges from the continental surfaces towards the atmosphere are strengthened, the ocean absorbs and stores the heat excess due to a decline in sea ice cover. However, the maximum near-surface air temperature anomaly does not peak in summer like insolation, but occurs in autumn with a temperature increase of 4.0 °C relative to the pre-industrial period. This strong warming is driven by a positive anomaly of longwave radiations over the Arctic ocean enhanced by a positive cloud feedback. It is also favoured by the summer and autumn Arctic sea ice retreat (−1.9 × 106 and −3.4 × 106 km2 respectively), which exposes the warm oceanic surface and allows heat stored by the ocean in summer and water vapour to be released. This study highlights the crucial role of the sea ice cover variations, the Arctic ocean, as well as changes in polar clouds optical properties on the Last Interglacial Arctic warming.

scholarly journals Attribution of Recent Temperature Changes in the Australian Region

2005 ◽  
Vol 18 (3) ◽  
pp. 457-464 ◽  
Author(s):  
David J. Karoly ◽  
Karl Braganza
Keyword(s):  
Twentieth Century ◽  
Diurnal Temperature Range ◽  
Significant Contribution ◽  
Climate Models ◽  
Climate Model ◽  
Temperature Changes ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Climate Model Simulations ◽  
Natural Climate

Abstract Variations of Australian-average mean temperature and diurnal temperature range over the twentieth century are investigated. The observed interannual variability of both is simulated reasonably well by a number of climate models, but they do not simulate the observed relationship between the two. Comparison of the observed warming and reduction in diurnal temperature range with climate model simulations shows that Australian temperature changes over the twentieth century were very unlikely to be due to natural climate variations alone. It is likely that there has been a significant contribution to the observed warming during the second half of the century from increasing atmospheric greenhouse gases and sulfate aerosols.

The Relationship between Diurnal Temperature Range (DTR) and Rainfall over Northern Thailand

2014 ◽  
Vol 931-932 ◽  
pp. 614-618
Author(s):  
Lukas Beule ◽  
Sarintip Tantanee
Keyword(s):  
Diurnal Temperature Range ◽  
Surface Air Temperature ◽  
Lag Time ◽  
Maximum Temperature ◽  
Northern Thailand ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Rainfall Prediction ◽  
The Impact ◽  
The Relationship

Since 1950, it has been found that the global diurnal temperature range (DTR), the difference between the minimum temperature (Tmin) and the maximum temperature (Tmax) of daily surface air temperature, has been temporally decreasing in several places all over the world. The aim of this study is to investigate the effect of DTR on the amount of total monthly rainfall (TRF) and the number of rainy days per month (RD), as well as to evaluate the possibility of using DTR as a parameter in the rainfall prediction process. The study area is in northern Thailand, which covers about one third of the total area of the country. The impact of DTR on rainfall over the studied area is evaluated from the relationship between DTR and TRF, as well as DTR and RD, by using long-term meteorological monthly data over 30 years (1978-2007). Besides, the relationships of RD, TRF, and the temperature of mean monthly Tmax and Tmin are also analysed. The significance of the correlation between the two parameters is identified by the coefficient of correlation. The possibility of using DTR is evaluated by estimating the relationships between DTR and a one month-lag time of RD and TRF. It is found that the DTR has a strong statistically significant ( > 99%) negative correlation with TRF and RD, as well as with the one month-lag time of TRF and RD. Therefore, it is possible to consider DTR as a significant parameter for rainfall prediction.

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