scholarly journals The Lorenz energy cycle: trends and the impact of modes of climate variability

2021 ◽  
Vol 73 (1) ◽  
pp. 1-15
Author(s):  
Qiyun Ma ◽  
Valerio Lembo ◽  
Christian L.E. Franzke
Keyword(s):  
Climate Variability ◽  
Energy Cycle ◽  
Lorenz Energy Cycle ◽  
The Impact ◽  
Modes Of Climate Variability

The Lorenz Energy Cycle: Trends and the Impact of Modes of Climate Variability

2021 ◽  
Author(s):  
Qiyun Ma ◽  
Valerio Lembo ◽  
Christian Franzke
Keyword(s):  
Kinetic Energy ◽  
Climate Variability ◽  
Potential Energy ◽  
Atmospheric Circulation ◽  
Southern Hemisphere ◽  
Transient Eddy ◽  
Energy Cycle ◽  
Conversion Rates ◽  
Lorenz Energy Cycle ◽  
Modes Of Climate Variability

<p>The atmospheric circulation is driven by heat transport from the tropics to the polar regions, implying energy conversions between available potential and kinetic energy through various mechanisms. The processes of energy transformations can be quantitatively investigated in the global climate system through the Lorenz energy cycle formalism. In this study, we examine these variations and the impacts of modes of climate variability on the Lorenz energy cycle by using reanalysis data from the Japanese Meteorological Agency (JRA-55). We show that the atmospheric circulation is overall becoming more energetic and efficient. For instance, we find a statistically significant trend in the eddy available potential energy, especially in the transient eddy available potential energy in the Southern Hemisphere. We find significant trends in the conversion rates between zonal available potential and kinetic energy, consistent with an expansion of the Hadley cell, and in the conversion rates between eddy available potential and kinetic energy, suggesting an increase in mid-latitudinal baroclinic instability. We also show that planetary-scale waves dominate the stationary eddy energy, while synoptic-scale waves dominate the transient eddy energy with a significant increasing trend. Our results suggest that interannual variability of the Lorenz energy cycle is determined by modes of climate variability. We find that significant global and hemispheric energy fluctuations are caused by the El Nino-Southern Oscillation, the Arctic Oscillation, the Southern Annular Mode, and the meridional temperature gradient over the Southern Hemisphere.</p>

scholarly journals The impact of oceanic heat transport on the atmospheric circulation

2014 ◽  
Vol 5 (2) ◽  
pp. 1463-1490
Author(s):  
M.-A. Knietzsch ◽  
V. Lucarini ◽  
F. Lunkeit
Keyword(s):  
Potential Energy ◽  
Heat Transport ◽  
Atmospheric Circulation ◽  
General Circulation ◽  
Hadley Cell ◽  
Oceanic Heat Transport ◽  
Energy Cycle ◽  
Lorenz Energy Cycle ◽  
The Impact ◽  
Global Mean

Abstract. A general circulation model of intermediate complexity with an idealized earthlike aquaplanet setup is used to study the impact of changes in the oceanic heat transport on the global atmospheric circulation. Focus is put on the Lorenz energy cycle and the atmospheric mean meridional circulation. The latter is analysed by means of the Kuo–Eliassen equation. The atmospheric heat transport compensates the imposed oceanic heat transport changes to a large extent in conjunction with significant modification of the general circulation. Up to a maximum about 3 PW, an increase of the oceanic heat transport leads to an increase of the global mean near-surface temperature and a decrease of its equator-to-pole gradient. For larger transports, the gradient is reduced further but the global mean remains approximately constant. This is linked to a cooling and a reversal of the temperature gradient in the tropics. A larger oceanic heat transport leads to a reduction of all reservoirs and conversions of the Lorenz energy cycle but of different relative magnitude for the individual components. The available potential energy of the zonal mean flow and its conversion to eddy available potential energy are affected most. Both the Hadley and Ferrel cell show a decline for increasing oceanic heat transport, with the Hadley cell being more sensitive. Both cells exhibit a poleward shift of their maxima, and the Hadley cell broadens for larger oceanic transports. The partitioning, by means of the Kuo–Eliassen equation, reveals that zonal mean diabatic heating and friction are the most important sources for changes of the Hadley cell, while the behaviour of the Ferrell cell is mostly controlled by friction.

scholarly journals Thermodynamics of climate change: generalized sensitivities

2010 ◽  
Vol 10 (2) ◽  
pp. 3699-3715 ◽  
Author(s):  
V. Lucarini ◽  
K. Fraedrich ◽  
F. Lunkeit
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Surface Temperature ◽  
Entropy Production ◽  
Theoretical Approach ◽  
Climate Model ◽  
Co2 Concentration ◽  
Energy Cycle ◽  
Lorenz Energy Cycle ◽  
The Impact

Abstract. Using a recent theoretical approach, we study how the impact of global warming of the thermodynamics of the climate system by performing experiments with a simplified yet Earth-like climate model. In addition to the globally averaged surface temperature, the intensity of the Lorenz energy cycle, the Carnot efficiency, the material entropy production and the degree of irreversibility of the system are linear with the logarithm of the CO2 concentration. These generalized sensitivities suggest that the climate becomes less efficient, more irreversible, and features higher entropy production as it becomes warmer.

scholarly journals Risk of extreme high fatalities due to weather and climate hazards and its connection to large-scale climate variability

2020 ◽  
Vol 162 (2) ◽  
pp. 507-525
Author(s):  
Christian L. E. Franzke ◽  
Herminia Torelló i Sentelles
Keyword(s):  
Climate Variability ◽  
Large Scale ◽  
Heat Waves ◽  
Generalized Pareto Distribution ◽  
Extreme Value Distribution ◽  
Economic Indicators ◽  
Weather And Climate ◽  
Climate Hazards ◽  
The Impact ◽  
Modes Of Climate Variability

Abstract Weather and climate hazards cause too many fatalities each year. These weather and climate hazards are projected to increase in frequency and intensity due to global warming. Here, we use a disaster database to investigate continentally aggregated fatality data for trends. We also examine whether modes of climate variability affect the propensity of fatalities. Furthermore, we quantify fatality risk by computing effective return periods which depend on modes of climate variability. We find statistically significant increasing trends for heat waves and floods for worldwide aggregated data. Significant trends occur in the number of fatalities in Asia where fatalities due to heat waves and floods are increasing, while storm-related fatalities are decreasing. However, when normalized by population size, the trends are no longer significant. Furthermore, the number of fatalities can be well described probabilistically by an extreme value distribution, a generalized Pareto distribution (GPD). Based on the GPD, we evaluate covariates which affect the number of fatalities aggregated over all hazard types. For this purpose, we evaluate combinations of modes of climate variability and socio-economic indicators as covariates. We find no evidence for a significant direct impact from socio-economic indicators; however, we find significant evidence for the impact from modes of climate variability on the number of fatalities. The important modes of climate variability affecting the number of fatalities are tropical cyclone activity, modes of sea surface temperature and atmospheric teleconnection patterns. This offers the potential of predictability of the number of fatalities given that most of these climate modes are predictable on seasonal to inter-annual time scales.

scholarly journals Assessing Impact of Climate Variability in Southwest Coastal Bangladesh Using Livelihood Vulnerability Index

Climate ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 107
Author(s):  
Sabrina Mehzabin ◽  
M. Shahjahan Mondal
Keyword(s):  
Climate Variability ◽  
Linear Regression Analysis ◽  
Kendall Test ◽  
Vulnerability Index ◽  
Precipitation Anomaly ◽  
Primary Data ◽  
Precipitation Concentration Index ◽  
Coastal Bangladesh ◽  
Present Decade ◽  
The Impact

This study analyzed the variability of rainfall and temperature in southwest coastal Bangladesh and assessed the impact of such variability on local livelihood in the last two decades. The variability analysis involved the use of coefficient of variation (CV), standardized precipitation anomaly (Z), and precipitation concentration index (PCI). Linear regression analysis was conducted to assess the trends, and a Mann–Kendall test was performed to detect the significance of the trends. The impact of climate variability was assessed by using a livelihood vulnerability index (LVI), which consisted of six livelihood components with several sub-components under each component. Primary data to construct the LVIs were collected through a semi-structed questionnaire survey of 132 households in a coastal polder. The survey data were triangulated and supplemented with qualitative data from focused group discussions and key informant interviews. The results showed significant rises in temperature in southwest coastal Bangladesh. Though there were no discernable trends in annual and seasonal rainfalls, the anomalies increased in the dry season. The annual PCI and Z were found to capture the climate variability better than the currently used mean monthly standard deviation. The comparison of the LVIs of the present decade with the past indicated that the livelihood vulnerability, particularly in the water component, had increased in the coastal polder due to the increases in natural hazards and climate variability. The index-based vulnerability analysis conducted in this study can be adapted for livelihood vulnerability assessment in deltaic coastal areas of Asia and Africa.

From water to bioethanol: The impact of climate variability on the water footprint

2012 ◽  
Vol 444-445 ◽  
pp. 180-186 ◽  
Author(s):  
Anna Dalla Marta ◽  
Marco Mancini ◽  
Francesca Natali ◽  
Francesca Orlando ◽  
Simone Orlandini
Keyword(s):  
Climate Variability ◽  
Water Footprint ◽  
The Impact

South Africa’s increasing climate variability and its effect on food production

2021 ◽  
pp. 003072702110049
Author(s):  
Mashudu Tshikovhi ◽  
Roscoe Bertrum van Wyk
Keyword(s):  
South Africa ◽  
Climate Variability ◽  
Food Production ◽  
Fixed Effects ◽  
Crop Yields ◽  
Negative Impact ◽  
Secondary Data ◽  
Mean Annual Temperature ◽  
Fixed Effects Panel Regression ◽  
The Impact

This study examines the impact of increasing climate variability on food production in South Africa, focusing on maize and wheat yields. A two-way fixed effects panel regression model was used to assess the climate variability impacts, analysing secondary data for the period 2000 to 2019 for nine provinces in South Africa. The study found that increasing climate variability has a negative impact on maize and wheat production in South Africa. Specifically, the results indicated a negative correlation between mean annual temperature with both maize and wheat yields. A decrease in precipitation affected maize yields negatively, while the impact on wheat yields was positive, although insignificant. This analysis, therefore, depicted that crop yields generally increase with more annual precipitation and decrease with higher temperatures. The study recommends that funding initiatives to educate farmers on increasing climate variability and its effects on farming activities in South Africa should be prioritised.

Modeling the impact of climate variability on Black Sea anchovy recruitment and production

2014 ◽  
Vol 23 (5) ◽  
pp. 436-457 ◽  
Author(s):  
Ceren Güraslan ◽  
Bettina A. Fach ◽  
Temel Oguz
Keyword(s):  
Climate Variability ◽  
Black Sea ◽  
The Impact

scholarly journals Tree-ring-based spring precipitation reconstruction in the Sikhote-Alin' Mountain range

2021 ◽  
Vol 17 (2) ◽  
pp. 951-967
Author(s):  
Olga Ukhvatkina ◽  
Alexander Omelko ◽  
Dmitriy Kislov ◽  
Alexander Zhmerenetsky ◽  
Tatyana Epifanova ◽  
...  
Keyword(s):  
Climate Variability ◽  
Tree Ring ◽  
Southern Oscillation ◽  
Russian Far East ◽  
Pinus Koraiensis ◽  
Mountain Range ◽  
Korean Pine ◽  
Sikhote Alin ◽  
The Impact ◽  
Standard Tree

Abstract. Climate reconstructions provide important insight into past climate variability and help us to understand the large-scale climate drivers and impact of climate change. However, our knowledge about long-term year-to-year climate variability is still limited due to the lack of high-resolution reconstructions. Here, we present the first precipitation reconstructions based on tree rings from Pinus koraiensis (Korean pine) from three sites placed along a latitudinal (330 km) gradient in the Sikhote-Alin' mountains in the Russian Far East. The tree-ring width chronologies were built using standard tree-ring procedures. We reconstructed the April–June precipitation for the southern Sikhote-Alin' (SSA), March–June precipitation for the central Sikhote-Alin' (CSA) and March–July precipitation for the northwestern Sikhote-Alin' (NSA) over the years 1602 to 2013, 1804 to 2009 and 1858 to 2013, respectively. We found that an important limiting factor for Korean pine growth was precipitation within the period when the air current coming from the continent during the cold period is replaced with the impact of the wet ocean air current. We identified that common wet years for SSA, CSA and NSA occurred in 1805, 1853, 1877, 1903, 1906, 1927, 1983 and 2009 and common dry years occurred in 1821, 1869, 1919, 1949 and 2003. Our reconstructions have 3-, 15- and 60-year periods, which suggests the influence of the El Niño–Southern Oscillation and Pacific Decadal Oscillation on the region's climate and relevant processes. Despite the impact of various global processes, the main contribution to precipitation formation in the study area is still made by the Pacific Ocean, which determines their amount and periodicity.

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