scholarly journals The influence of the circulation on surface temperature and precipitation patterns over Europe

2009 ◽  
Vol 5 (2) ◽  
pp. 259-267 ◽  
Author(s):  
P. D. Jones ◽  
D. H. Lister
Keyword(s):  
Surface Temperature ◽  
20Th Century ◽  
Surface Pressure ◽  
Classification Scheme ◽  
Weather Types ◽  
Circulation Types ◽  
Temperature And Precipitation ◽  
Four Seasons ◽  
Circulation Patterns

Abstract. The atmospheric circulation clearly has an important influence on variations in surface temperature and precipitation. In this study we illustrate the spatial patterns of variation that occur for the principal circulation patterns across Europe in the standard four seasons. We use an existing classification scheme of surface pressure patterns, with the aim of considering whether the patterns of influence of specific weather types have changed over the course of the 20th century. We consider whether the long-term warming across Europe is associated with more favourable weather types or related to warming within some of the weather types. The results indicate that the latter is occurring, but not all circulation types show warming. The study also illustrates that certain circulation types can lead to marked differences in temperature and/or precipitation for relatively closely positioned sites when the sites are located in areas of high relief or near coasts.

scholarly journals The influence of the circulation on surface temperature and precipitation patterns over Europe*

2009 ◽  
Vol 5 (1) ◽  
pp. 535-555 ◽  
Author(s):  
P. D. Jones ◽  
D. H. Lister
Keyword(s):  
Surface Temperature ◽  
20Th Century ◽  
Surface Pressure ◽  
Classification Scheme ◽  
Weather Types ◽  
Circulation Types ◽  
Temperature And Precipitation ◽  
Four Seasons ◽  
Circulation Patterns

Abstract. The atmospheric circulation clearly has an important influence on variations in surface temperature and precipitation. In this study we illustrate the spatial patterns of variation that occur for the principal circulation patterns across Europe in the standard four seasons. We use an existing classification scheme of surface pressure patterns, with the aim of considering whether the patterns of influence of specific weather types have changed over the course of the 20th century. We consider whether the long-term warming across Europe is associated with more favourable weather types or related to warming within some of the weather types. The results indicate that the latter is occurring, but not all circulation types show warming. The study also illustrates that certain circulation types can lead to marked differences in temperature and/or precipitation for relatively closely positioned sites when the sites are located in areas of high relief or near coasts.

scholarly journals Identification of possible dynamical drivers for long-term changes in temperature and rainfall patterns over Europe

2020 ◽  
Vol 143 (1-2) ◽  
pp. 177-191
Author(s):  
Peter Hoffmann ◽  
Arne Spekat
Keyword(s):  
Decadal Variability ◽  
Meteorological Data ◽  
Weather Type ◽  
Seasonal Rainfall ◽  
Weather Types ◽  
Temperature And Precipitation ◽  
Long Term Changes ◽  
Rainfall Patterns ◽  
Climate Station

AbstractThis study looks into the question to what extent long-term change patterns of observed temperature and rainfall over Europe can be attributed to dynamical causes, in other words: Are the observed changes due to a change in frequency of the patterns or have the patterns’ dynamical properties changed? By using a combination of daily meteorological data and a European weather-type classification, the long-term monthly mean temperature and precipitation were calculated for each weather-type. Subsequently, the observed weather-type sequences were used to construct analogue time series for temperature and precipitation which only include the dynamical component of the long-term variability since 1961. The results show that only a fraction of about 20% of the past temperature rise since 1990, which for example amounted to 1 °C at the Potsdam Climate Station can be explained by dynamical changes, i.e. most of the weather-types have become warmer. Concerning long-term changes of seasonal rainfall patterns, a fraction of more than 60% is considerably higher. Moreover, the results indicate that for rainfall compared with temperature, the decadal variability and trends of the dynamical component follow the observed ones much stronger. Consequently, most of the explained seasonal rainfall variances can be linked to changes in weather-type sequences in Potsdam and over Europe. The dynamical contribution to long-term changes in annual and seasonal rainfall patterns dominates due to the fact that the alternation of wet and dry weather-types (e.g. the types Trough or High pressure over Central Europe), their frequencies and duration has significantly changed in the last decades.

scholarly journals Development of a longterm dataset of solid/liquid precipitation

2011 ◽  
Vol 6 (1) ◽  
pp. 39-43 ◽  
Author(s):  
B. Chimani ◽  
R. Böhm ◽  
C. Matulla ◽  
M. Ganekind
Keyword(s):  
High Resolution ◽  
20Th Century ◽  
Alpine Region ◽  
Nonlinear Relationship ◽  
Solid Precipitation ◽  
Temperature And Precipitation ◽  
Solid Liquid ◽  
Climate Studies ◽  
Liquid Precipitation

Abstract. Solid precipitation (mainly snow, but snow and ice pellets or hail as well), is an important parameter for climate studies. But as this parameter usually is not available operationally before the second part of the 20th century and nowadays is not reported by automatic stations, information usable for long term climate studies is rare. Therefore a proxy for the fraction of solid precipitation based on a nonlinear relationship between the percentage of solid precipitation and monthly mean temperature was developed for the Greater Alpine Region of Europe and applied to the existing longterm high resolution temperature and precipitation grids (5 arcmin). In this paper the method is introduced and some examples of the resulting datasets available at monthly resolution for 1800–2003 are given.

Synoptic Circulation Patterns and Climate Regionalization of East Africa

2020 ◽  
Author(s):  
Markos Ware ◽  
Paolo Mori ◽  
Kisten Warrach -Sagi ◽  
Mark Jury ◽  
Thomas Schiwtalla ◽  
...  
Keyword(s):  
East Africa ◽  
Principal Component ◽  
Domain Size ◽  
Optimal Number ◽  
Final Decision ◽  
Test Technique ◽  
Circulation Types ◽  
Circulation Patterns ◽  
Climate Regionalization

<p><strong>Abstract</strong>. Climate regionalization is crucial for climate studies, especially in the case of heterogeneous regions like East Africa. This paper focuses on categorizing Ethiopia into homogeneous climatic sub-regions by applying a classification of circulation patterns on precipitation. The sub-regions obtained will be applied on the verification of WRF-NOAHMP seasonal simulations performed over the Horn of Africa. We analyzed the occurrence of each circulation type per month and per year over the whole country. Then, trend analysis of temperature and precipitation over the respective sub-regions were performed. Principal Component Analysis (PCA) were applied to group daily mean Sea Level Pressure (SLP) into Circulation Types (CTs). Then, PCA coupled with k-means clustering employed to regionalize precipitation fields (distributed spatially) following CTs into homogeneous climatic sub-regions. Observational data were obtained from the National Center for Environmental Prediction (NCEP) reanalysis, Climate Hazards Group Infrared Precipitation with Stations (CHIRPS version 2), and National Meteorology Agency (NMA) of Ethiopia (gauge 1st and 2nd classes). Five principal components, which explain 98% of the total variance, were maintained using the Scree test technique. Ten CTs were obtained using positive and negative phases of each principal component scores following the extreme score values (> 2 and < −2) procedure. From ten CTs, we found that three (CT1, CT3, and CT8) were characterized by low pressure over the southwest corner of the domain, which consequently brings rainfall over the Ethiopian highlands. The number of days classified under different CTs shows different trends. CTs seasonal distribution agreed with the regional seasons. Long-term monthly mean rainfall ranges from 0-600 mm over the region. Ethiopia is clustered into four homogeneous sub-regions based on the spatial distribution of precipitation following CTs. Rainfall from CHIRPS and gauge did not have any specific trend over the sub-regions, however high standardized anomalies were observed compared to the long term mean. The temperature showed a 2 °C change for the past three decades. There was a negligible difference in the shape, size, and location of regions using data from different sources. The final decision on the optimal number of homogeneous climatic sub-regions depends upon the research objective, geographical domain size, and topographic features of the domain. This study provides an assessment and decision pathway.</p><p> </p><p><strong>Keywords: </strong>climatology, regionalization, Ethiopia, precipitation, k-means, circulation types</p>

scholarly journals Changes in the Atmospheric Circulation Conditions and Regional Climatic Characteristics in Two Remote Regions Since the Mid-20th Century

Atmosphere ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 11 ◽  
Author(s):  
Maria G. Lebedeva ◽  
Anthony R. Lupo ◽  
Yury G. Chendev ◽  
Olga V. Krymskaya ◽  
Aleksandr B. Solovyev
Keyword(s):  
Flow Regime ◽  
Atmospheric Circulation ◽  
Classification Scheme ◽  
Zonal Flow ◽  
Positive Temperature ◽  
Vegetation Growth ◽  
Circulation Types ◽  
Temperature And Precipitation ◽  
Precipitation Regimes ◽  
Central Usa

A meridional Northern Hemisphere (NH) circulation epoch, which began in 1957, is marked by changes in the temperature and precipitation regimes over southwest Russia and central USA depending on the occurrence of NH atmospheric circulation regimes. A classification scheme proposed in 1968, and studied later put forth 13 NH circulation types, fitting more broadly into four groups, two of which are more zonal type flows and two of which are more meridional flows. Using the results of a previous study that showed four distinct sub-periods during the 1957–2017 epoch, the temperature and precipitation regimes of both regions were studied across all seasons in order to characterize modern day climate variability and their suitability for vegetation growth. Then the Hydrologic Coefficient, which combined the temperature and precipitation variables, was briefly studied. The most optimal conditions for vegetation growth, positive temperature and precipitation anomalies, were noted during the period 1970–1980 for southwest Russia, which was dominated by an increasingly more zonal flow regime in the Belgorod region and NH in general. For the central USA, the HTC showed more ideal conditions for agriculture in recent years due to favorable precipitation occurrence. In southwest Russia, variable precipitation regimes were noted during the meridional flow periods, and with the increase in temperature (since 1998), these can adversely affect the hydrothermal characteristics of the growing season. Finally, a comparison of the 13 NH circulation types with several teleconnection indexes demonstrated the robustness of the NH flow regime classification scheme used here.

scholarly journals Changes in the Dynamics of the Northern Hemisphere Atmospheric Circulation and the Relationship to Surface Temperature in the 20th and 21st Centuries

Atmosphere ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 255 ◽  
Author(s):  
Nina K. Kononova ◽  
Anthony R. Lupo
Keyword(s):  
Surface Temperature ◽  
Atmospheric Circulation ◽  
Northern Hemisphere ◽  
21St Century ◽  
Circulation Type ◽  
Early 21St Century ◽  
Circulation Patterns ◽  
Global Atmospheric Circulation ◽  
The Early 21St Century

This study examines the long-term fluctuations in the Northern Hemisphere (NH) and global atmospheric circulation, teleconnections, including blocking, and surface temperature over the period 1899–2018. The teleconnection and blocking data were available from the mid-20th century. The classification of the global atmospheric circulation was developed from an early subjective categorization of atmospheric circulation conditions for the NH that considered the number, location, and amplitude of waves on the jet stream for frequently occurring circulation patterns. This work updated earlier studies that identified three circulation epochs based on the predominance of one of four different flow types that were grouped primarily based on whether the flow was zonal or meridional. This work noted a significant correlation between the early 21st century flow change toward the occurrence of more meridional flows and the increase in the occurrence of blocking as well as changes in the teleconnection indexes. The early 21st century was associated with a distinct change in the Northern Hemisphere flow entropy as measured using Information or Shannon Entropy, a change that was shown to be statistically significant. Additionally, this demonstrated that this quantity has utility as a dynamic diagnostic tool in atmospheric science. Finally, a comparison of these flow regimes to the 20th and 21st century variations in surface temperature were considered here. The global average annual surface temperature variations correlated strongly to fluctuations in the predominant atmospheric circulation type.

Long-term changes/trends in surface temperature and precipitation during the satellite era (1979–2012)

2015 ◽  
Vol 46 (3-4) ◽  
pp. 1091-1105 ◽  
Author(s):  
Guojun Gu ◽  
Robert F. Adler ◽  
George J. Huffman
Keyword(s):  
Surface Temperature ◽  
Temperature And Precipitation ◽  
Long Term Changes

scholarly journals What Causes Long-Term North Atlantic Surface Temperature Cycles?

Eos ◽  
2016 ◽  
Vol 97 ◽  
Author(s):  
Sarah Stanley
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Temperature Fluctuations ◽  
Sea Surface ◽  
Temperature Cycles ◽  
Circulation Patterns ◽  
New Evidence

New evidence strengthens a likely link between 20- to 40-year sea surface temperature fluctuations and varying ocean circulation patterns.

Long-term climate patterns in Alaskan surface temperature and precipitation and their biological consequences

2002 ◽  
Vol 40 (5) ◽  
pp. 1164-1184 ◽  
Author(s):  
J.J. Simpson ◽  
G.L. Hufford ◽  
M.D. Fleming ◽  
J.S. Berg ◽  
J.B. Ashton
Keyword(s):  
Surface Temperature ◽  
Temperature And Precipitation ◽  
Climate Patterns
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