scholarly journals Subdaily meteorological measurements of temperature, direction of the movement of the clouds, and cloud cover in the Late Maunder Minimum by Louis Morin in Paris

2022 ◽  
Author(s):  
Thomas Pliemon ◽  
Ulrich Foelsche ◽  
Christian Rohr ◽  
Christian Pfister

Abstract. We have digitized three meteorological variables (temperature, direction of the movement of the clouds, and cloud cover) from copies of Louis Morin’s original measurements (Source: Institute of History / Oeschger Centre for Climate Change Research, University of Bern) and subjected them to quality analysis to make these data available to the scientific community. Our available data cover the period 1665–1709 (temperature beginning in 1676). We compare the early instrumental temperature dataset with statistical methods and proxy data to validate the measurements in terms of inhomogeneities and claim that they are, apart from small inhomogeneities, reliable. The Late Maunder Minimum (LMM) is characterized by cold winters and autumns, and moderate springs and summers, with respect to the reference period of 1961–1990. Winter months show a significant lower frequency of westerly direction of movement of the clouds. This reduction of advection from the ocean leads to a cooling in Paris in winter. The influence of the advection becomes apparent when comparing the last decade of the 17th century (cold) and the first decade of the 18th century (warm). A lower frequency of westerly direction of movement of the clouds can also be seen in summer, but the influence is stronger in winter than in summer. Consequently, the unusually cold winters in the LMM can be attributed to a lower frequency of westerly direction of movement of the clouds. An impact analysis reveals that the winter of 1708/09 was a devastating one with respect of consecutive ice days, although other winters are more pronounced (e.g., the winters of 1676/77, 1678/79, 1683/84, 1692/93, 1694/95 and 1696/97) in terms of mean temperature, ice 15 days, cold days or consecutive cold days. An investigation of the cloud cover data revealed a high discrepancy in the seasons, where the winter season (DJF) (−13.2 %) and the spring season (MAM) (−12.6 %) show a negative anomaly of the total cloud cover (TCC), whereas summer (JJA) (−0.5 %) shows a moderate anomaly of TCC with respect to the 30 year mean of the Meteobluedata (1985–2014).

2021 ◽  
Author(s):  
Thomas Pliemon ◽  
Ulrich Foelsche ◽  
Christian Rohr ◽  
Christian Pfister

<p>Based on copies of the original data (source: Oeschger Center for Climate Change Research) we perform climate reconstructions for Paris between 1665 - 1709. The focus lies on the following meteorological variables: temperature, cloudiness, direction of movement of the clouds, precipitation and humidity. Apart from humidity, these meteorological variables were measured three times a day over the entire period from Louis Morin. Temperature and humidity were measured with instruments, whereas cloud cover, direction of movement of the clouds and precipitation were measured in a descriptive manner. In addition to the quantitative temperature measurements, conclusions about synoptic air movements over Europe are possible due to the additional meteorological variables. The Late Maunder Minimum is characterised by cold winters and moderate summers. Winter is characterised by a lower frequency of westerly direction of movement of the clouds. This reduction of advection from the ocean leads to cooling in Paris and also to less precipitation in winter. This can be seen very strongly between the last decade of the 17<sup>th</sup> century (cold) and the first decade of the 18<sup>th</sup> century (warm). A lower frequency of westerly direction of movement of the clouds can also be seen in summer, but the influence is stronger in winter than in summer. However, this reduction leads to moderate/warm temperatures in summer. So unusually cold winters in the Late Maunder Minimum can be attributed to a lower frequency of westerly direction of movement of the clouds.</p>


2020 ◽  
Author(s):  
Thomas Pliemon ◽  
Ulrich Foelsche ◽  
Christian Rohr ◽  
Christian Pfister

<p>Based on copies of the original data (source: Oeschger Center for Climate Change Research) we perform climate reconstructions for Paris. The focus lies on the following meteorological variables: temperature, cloudiness, moving direction of clouds and precipitation. We assess the early instrumental temperature dataset with state of the art statistical methods to get further knowledge of inhomogeneities. There are already several studies showing monthly and yearly means of the temperature, but a detailed statistical analysis based on the original measurements has not been done yet. Due to the lack of metadata, we do a qualitative analysis. With rare contemporary time series, like the CET (Central England Temperature), and proxydata, like grape harvest dates, we attempt to make a quantitative statement. We analyse and discuss the documentary datasets of the cloudiness and the moving direction of the clouds relating to the cooling in the Late Maunder Minimum. Because of the subjective character of documentary records, we compare these results with available data from former publications. Precipitation is given in terms of intensity and duration. We calculate indices like rainfall frequency and average rainfall per year/season/month.</p>


2018 ◽  
Vol 31 (10) ◽  
pp. 3849-3863 ◽  
Author(s):  
Javier Mellado-Cano ◽  
David Barriopedro ◽  
Ricardo García-Herrera ◽  
Ricardo M. Trigo ◽  
Mari Carmen Álvarez-Castro

Abstract This paper presents observational evidence of the atmospheric circulation during the Late Maunder Minimum (LMM, 1685–1715) based on daily wind direction observations from ships in the English Channel. Four wind directional indices and 8-point wind roses are derived at monthly scales to characterize the LMM. The results indicate that the LMM was characterized by a pronounced meridional circulation and a marked reduction in the frequency of westerly days all year round, as compared to the present (1981–2010). The winter circulation contributed the most to the cold conditions. Nevertheless, findings indicate that the LMM in Europe was more heterogeneous than previously thought, displaying contrasting spatial patterns in both circulation and temperature, as well as large decadal variability. In particular, there was an increase of northerly winds favoring colder winters in the first half of the LMM, but enhanced southerlies contributing to milder conditions in the second half of the LMM. The analysis of the atmospheric circulation yields a new and complete classification of LMM winters. The temperature inferred from the atmospheric circulation confirms the majority of extremely cold winters well documented in the literature, while uncovering other less documented cold and mild winters. The results also suggest a nonstationarity of the North Atlantic Oscillation (NAO) pattern within the LMM, with extremely cold winters being driven by negative phases of a “high zonal” NAO pattern and “low zonal” NAO patterns dominating during moderately cold winters.


2016 ◽  
Vol 7 (3) ◽  
pp. 523-559 ◽  
Author(s):  
Jerry Ellig ◽  
Rosemarie Fike

Numerous regulatory reform proposals would require federal agencies to conduct more thorough economic analysis of proposed regulations or expand the resources and influence of the Office of Information and Regulatory Affairs (OIRA), which currently reviews executive branch regulations. Such reforms are intended to improve the quality of economic analysis agencies produce when they issue major regulations. We employ newly gathered data on variation in current administrative procedures to assess the likely effects of proposed regulatory process reforms on the quality of agencies’ regulatory impact analyses (RIAs). Our results suggest that greater use of advance notices of proposed rulemakings for major regulations, advance consultation with regulated entities, use of advisory committees, and expansion of OIRA’s resources and role would improve the quality of RIAs. They also suggest pre-proposal public meetings with stakeholders are associated with lower quality analysis.


Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1620 ◽  
Author(s):  
Milan Stojkovic ◽  
Slobodan P. Simonovic

Investigating the impact of climate change on the management of a complex multipurpose water system is a critical issue. The presented study focuses on different steps of the climate change impact analysis process: (i) Use of three regional climate models (RCMs), (ii) use of four bias correction methods (BCMs), (iii) use of three concentration scenarios (CSs), (iv) use of two model averaging procedures, (v) use of the hydrological model and (vi) use of the system dynamics simulation model (SDSM). The analyses are performed for a future period, from 2006 to 2055 and the reference period, from 1971 to 2000. As a case study area, the Lim water system in Serbia (southeast Europe) is used. The Lim river system consists of four hydraulically connected reservoirs (Uvac, Kokin Brod, Radojnja, Potpec) with a primary purpose of hydropower generation. The results of the climate change impact analyses indicate change in the future hydropower generation at the annual level from −3.5% to +17.9%. The change has a seasonal variation with an increase for the winter season up to +20.3% and decrease for the summer season up to −33.6%. Furthermore, the study analyzes the uncertainty in the SDSM outputs introduced by different steps of the modelling process. The most dominant source of uncertainty in power production is the choice of BCMs (54%), followed by the selection of RCMs (41%). The least significant source of uncertainty is the choice of CSs (6%). The uncertainty in the inflows and outflows is equally dominated by the choice of BCM (49%) and RCM (45%).


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