A 32-year perspective on the origin of wind energy in a warming climate

Huang, Junling; Chen, Xinyu

doi:10.1016/j.renene.2014.12.045

Cited by 39 publications

(31 citation statements)

References 40 publications

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“…, which is 20% less than the value obtained by Huang and McElroy (2015) and by us here using three hourly data. Total atmospheric power calculated with a sufficient resolution capturing the motions that cause condensation is thus likely to be around 5 W m −2…”

Section: The Upper Limitcontrasting

confidence: 73%

“…However, the instantaneous value of this integral is not equal to the instantantaneous value of W , see also Appendix (C). In other studies kinetic power is correctly defined and estimated from horizontal velocities as W K (21) (see, e.g., Boville and Bretherton, 2003;Huang and McElroy, 2015). In such studies W K is sometimes confused with total atmospheric power: i.e.…”

Section: Revisiting the Current Understanding Of The Atmospheric Powementioning

confidence: 99%

“…While models suggest general circulation should slow as global temperatures rise, independent observations indicate circulation is getting faster (e.g., de Boisséson et al, 2014). Global wind power appears to be rising as well (Huang and McElroy, 2015). On the other hand, global circulation models tend to overestimate wind power (Boer and Lambert, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…while published observational estimates range from 2 to 2.5 W m −2 (Kim and Kim, 2013;Schubert and Mitchell, 2013;Huang and McElroy, 2015).…”

Section: Introductionmentioning

confidence: 99%

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Quantifying the global atmospheric power budget

Makarieva

Gorshkov

Nefiodov

et al. 2016

Preprint

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Starting from the definition of mechanical work for an ideal gas, we present a novel derivation linking global wind power to measurable atmospheric parameters. The resulting expression distinguishes three components: the kinetic power associated with horizontal motion, the kinetic power associated with vertical motion and the gravitational power of precipitation. We discuss the caveats associated with integration of material derivatives in the presence of phase transitions and how these affect published analyses of global atmospheric power. Using the MERRA database for the years 2009–2015 (three hourly data on the 1.25° x 1.25° grid at 42 pressure levels) we estimate total atmospheric power at 3.1 W m−2 and kinetic power at 2.6 W m−2. The difference between the two (0.5 W m−2) is about half the independently estimated gravitational power of precipitation (1 W m−2). We explain how this discrepancy arises from the limited spatial and temporal resolution of the database. Our analysis suggests that the total atmospheric power calculated with a spatial resolution of the order of one kilometer (thus capturing the small moist convective eddies) should be around 5 W m−2. We discuss the physical constraints on global atmospheric power and how considering the dynamic effects of water vapor condensation offers new opportunities.

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Section: The Upper Limitcontrasting

confidence: 73%

Section: Revisiting the Current Understanding Of The Atmospheric Powementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…while published observational estimates range from 2 to 2.5 W m −2 (Kim and Kim, 2013;Schubert and Mitchell, 2013;Huang and McElroy, 2015).…”

Section: Introductionmentioning

confidence: 99%

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Quantifying the global atmospheric power budget

Makarieva

Gorshkov

Nefiodov

et al. 2016

Preprint

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show abstract

“…The heat engine concept was applied to the atmosphere by many authors attempting to constrain the efficiency of atmospheric circulation (Wulf and Davis, 1952;Peixoto and Oort, 1992;Pauluis et al, 2000;Lorenz and Rennó, 2002;Pauluis, 2011;Huang and McElroy, 2014, 2015bKieu, 2015). However, the relationship between surface pressures and temperatures and the generation of kinetic energy has not been previously established.…”

Section: Introductionmentioning

confidence: 99%

Kinetic energy generation in heat engines and heat pumps: the relationship between surface pressure, temperature and circulation cell size

Makarieva¹,

Gorshkov²,

Nefiodov³

et al. 2017

Tellus A: Dynamic Meteorology and Oceanography

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A B S T R A C T The pattern and size of the Earth's atmospheric circulation cells determine regional climates and challenge theorists.Here the authors present a theoretical framework that relates the size of meridional cells to the kinetic energy generation within them. Circulation cells are considered as heat engines (or heat pumps) driven by surface gradients of pressure and temperature. This approach allows an analytical assessment of kinetic energy generation in the meridional cells from the known values of surface pressure and temperature differences across the cell, Δp s and ΔT s . Two major patterns emerge. First, the authors find that kinetic energy generation in the upper and lower atmosphere respond in contrasting ways to surface temperature: with growing ΔT s , kinetic energy generation increases in the upper atmosphere but declines in the lower. A requirement that kinetic energy generation must be positive in the lower atmosphere can limit the poleward cell extension of the Hadley cells via a relationship between Δp s and ΔT s . The limited extent of the Hadley cells necessitates the appearance of heat pumps (Ferrel cells) -circulation cells with negative work output. These cells consume the positive work output of the Hadley cells (heat engines) and can in theory drive the global efficiency of an axisymmetric atmospheric circulation down to zero. Second, the authors show that, within a cell, kinetic energy generation is largely determined by ΔT s in the upper atmosphere, and by Δp s in the lower. By absolute magnitude, the temperature contribution is about 10 times larger. However, since the heat pumps act as sinks of kinetic energy in the upper atmosphere, the net kinetic energy generation in the upper atmosphere, as well as the net impact of surface temperature, is reduced. The authors use NCAR/NCEP and MERRA data to verify the obtained theoretical relationships. These observations confirm considerable cancellation between the temperature-related sources and sinks of kinetic energy in the upper atmosphere. Both the theoretical approach and observations highlight a major contribution from surface pressure gradients, rather than temperature, in the kinetic energy budget of meridional circulation. The findings urge increased attention to surface pressure gradients as determinants of the meridional circulation patterns.

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Offshore wind climate analysis and variability in the Mediterranean Sea

Soukissian

Karathanasi

Axaopoulos³

et al. 2017

Intl Journal of Climatology

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ABSTRACT:The long-term offshore wind characteristics in the Mediterranean Sea are assessed using the ERA-Interim dataset for the period 1979-2014. Three main aspects of the wind climate analysis are examined in detail; the spatio-temporal behaviour (including variability characteristics) of wind speed and direction for the annual and monthly time scale; the joint association of wind speed and direction for the annual and monthly time scale, and; the wind speed trends and wind direction changes. From this analysis, the systematic wind flow patterns are identified and the general features of the wind climatology patterns are revealed. The most typical examples of stable and intense regional winds are the Mistral (throughout the year) in the Gulf of Lion and the Etesians (during summer) in the Aegean Sea. High values of mean annual variability of wind speed occur over the western part of the basin (Balearic, Tyrrhenian and Ligurian sub-basins) as well as over the Adriatic and N Aegean Seas, and the E Levantine Basin. Moreover, the assessment of the joint association of wind speed and direction indicates that areas with high values of linear-circular correlation are the ones characterized by intense wind climate. As regards, long-term changes of wind speed and direction, the linear trend for the former and the angular distance for the latter variable are provided. The fastest increasing wind speed trends are observed in the Ionian, the N Tyrrhenian and N Adriatic Seas, the eastern part of the Algerian Basin up to Balearic Isl. and the western part of the S Levantine Basin while the fastest decreasing ones are observed offshore Monaco, the central Aegean and the E Alboran Seas and the N Levantine Basin. The highest values of angular variance and mean angular distances are depicted for the Ligurian, Balearic and Alboran Seas.

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A 32-year perspective on the origin of wind energy in a warming climate

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Cited by 39 publications

References 40 publications

Quantifying the global atmospheric power budget

Quantifying the global atmospheric power budget

Kinetic energy generation in heat engines and heat pumps: the relationship between surface pressure, temperature and circulation cell size

Offshore wind climate analysis and variability in the Mediterranean Sea

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