scholarly journals The Tropospheric Land–Sea Warming Contrast as the Driver of Tropical Sea Level Pressure Changes

2013 ◽  
Vol 26 (4) ◽  
pp. 1387-1402 ◽  
Author(s):  
Tobias Bayr ◽  
Dietmar Dommenget
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Large Scale ◽  
Warm Pool ◽  
Sea Level Pressure ◽  
Model Simulations ◽  
Level Pressure ◽  
Pacific Warm Pool ◽  
Tropical Sea ◽  
Sea Warming

Abstract This article addresses the causes of the large-scale tropical sea level pressure (SLP) changes during climate change. The analysis presented here is based on model simulations, observed trends, and the seasonal cycle. In all three cases the regional changes of tropospheric temperature (Ttropos) and SLP are strongly related to each other [considerably more strongly than (sea) surface temperature and SLP]. This relationship basically follows the Bjerknes circulation theorem, with relatively low regional SLP where there is relatively high Ttropos and vice versa. A simple physical model suggests a tropical SLP response to horizontally inhomogeneous warming in the tropical Ttropos, with a sensitivity coefficient of about −1.7 hPa K−1. This relationship explains a large fraction of observed and predicted changes in the tropical SLP. It is shown that in climate change model simulations the tropospheric land–sea warming contrast is the most significant structure in the regional Ttropos changes relative to the tropical mean changes. Since the land–sea warming contrast exists in the absence of any atmospheric circulation changes, it can be argued that the large-scale response of tropical SLP changes is to first order a response to the tropical land–sea warming contrast. Furthermore, as the land–sea warming contrast is mostly moisture dependent, the models predict a stronger warming and decreasing SLP in the drier regions from South America to Africa and a weaker warming and increasing SLP over the wetter Indo-Pacific warm pool region. This suggests an increase in the potential for deep convection conditions over the Atlantic sector and a decrease over the Indo-Pacific warm pool region in the future.

scholarly journals Comments on “The Tropospheric Land–Sea Warming Contrast as the Driver of Tropical Sea Level Pressure Changes”

2015 ◽  
Vol 28 (10) ◽  
pp. 4293-4307 ◽  
Author(s):  
A. M. Makarieva ◽  
V. G. Gorshkov ◽  
A. V. Nefiodov ◽  
D. Sheil ◽  
A. D. Nobre ◽  
...  
Keyword(s):  
Sea Level ◽  
Tropospheric Temperature ◽  
Sea Level Pressure ◽  
Sea Temperature ◽  
Mean Values ◽  
Level Pressure ◽  
Two Parameters ◽  
Pressure Changes ◽  
Tropical Sea ◽  
Sea Warming

Abstract In their paper “The tropospheric land–sea warming contrast as the driver of tropical sea level pressure changes,” Bayr and Dommenget proposed a simple model of temperature-driven air redistribution to quantify the ratio between changes of sea level pressure ps and mean tropospheric temperature Ta in the tropics. This model assumes that the height of the tropical troposphere is isobaric. Here problems with this model are identified. A revised relationship between ps and Ta is derived governed by two parameters—the isobaric and isothermal heights—rather than just one. Further insight is provided by the earlier model of Lindzen and Nigam, which was the first to use the concept of isobaric height to relate tropical ps to air temperature, and they did this by assuming that isobaric height is always around 3 km and isothermal height is likewise near constant. Observational data, presented here, show that neither of these heights is spatially universal nor does their mean values match previous assumptions. Analyses show that the ratio of the long-term changes in ps and Ta associated with land–sea temperature contrasts in a warming climate—the focus of Bayr and Dommenget’s work—is in fact determined by the corresponding ratio of spatial differences in the annual mean ps and Ta. The latter ratio, reflecting lower pressure at higher temperature, is significantly impacted by the meridional pressure and temperature differences. Considerations of isobaric heights are shown to be unable to predict either spatial or temporal variation in ps. As noted by Bayr and Dommenget, the role of moisture dynamics in generating sea level pressure variation remains in need of further theoretical investigations.

scholarly journals Influence of Sea Level Pressure on Inter-Annual Rainfall Variability in Northern Senegal in the Context of Climate Change

2022 ◽  
Vol 12 (01) ◽  
pp. 113-131
Author(s):  
Aichetou Dia-Diop ◽  
Malick Wade ◽  
Sinclaire Zebaze ◽  
Abdoulaye Bouya Diop ◽  
Eric Efon ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Rainfall Variability ◽  
Annual Rainfall ◽  
Sea Level Pressure ◽  
Level Pressure

scholarly journals European precipitation connections with large-scale mean sea-level pressure (MSLP) fields

2013 ◽  
Vol 58 (2) ◽  
pp. 310-327 ◽  
Author(s):  
David Lavers ◽  
Christel Prudhomme ◽  
David M. Hannah
Keyword(s):  
Sea Level ◽  
Large Scale ◽  
Sea Level Pressure ◽  
Mean Sea Level ◽  
Level Pressure

Searching for resemblance between large-scale sea level pressure patterns leading to “intense” precipitation events over Italy

2008 ◽  
Vol 95 (1-2) ◽  
pp. 183-196 ◽  
Author(s):  
N. Tartaglione ◽  
M. Maugeri ◽  
F. Dalan ◽  
M. Brunetti ◽  
T. Nanni ◽  
...  
Keyword(s):  
Sea Level ◽  
Large Scale ◽  
Sea Level Pressure ◽  
Level Pressure ◽  
Intense Precipitation ◽  
Precipitation Events

scholarly journals Impacts of Some Climatic Variables on Productivity of Boro rice in South-Western Coastal Regions of Bangladesh

2016 ◽  
Vol 9 (1) ◽  
pp. 95-98
Author(s):  
MM Islam ◽  
MA Farukh ◽  
MA Baten
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Climatic Variability ◽  
Rice Production ◽  
Maximum Temperature ◽  
Climatic Data ◽  
Sea Level Pressure ◽  
Level Pressure ◽  
Average Temperature ◽  
Boro Rice

Climate change is the top most important issue in the modern world. Various aspects of Bangladesh are verily affected by climate change. An agro-climatic study was conducted in Khulna, Satkhira and Bagerhat district in Khulna division as well as the Southwestern coastal part of Bangladesh with last 30 (1981-2011) years of some climatic data of average temperature, maximum temperature, seasonal total rainfall, average humidity and sea level pressure to address the climatic variability and its impacts on Boro rice production in Southwestern coastal part of Bangladesh. The average temperature increased by 0.51°C in Boro season in this area. The sea level pressure was about stable here. The Boro rice production increased by 0.04 and 0.3 tha-1 in Khulna and Bagerhat district. However most of the time the production showed increasing trends except in 2007 and 2009 affected by two devastating natural calamities as “SIDR” and “AILA” occurred in these two year respectively.J. Environ. Sci. & Natural Resources, 9(1): 95-98 2016

scholarly journals Decadal variability and trends of the Benguela Upwelling System as simulated in a high-resolution ocean simulation

2015 ◽  
Vol 12 (2) ◽  
pp. 403-447
Author(s):  
N. Tim ◽  
E. Zorita ◽  
B. Hünicke
Keyword(s):  
Statistical Analysis ◽  
Pressure Gradient ◽  
Sea Level ◽  
Wind Stress ◽  
Large Scale ◽  
Sea Level Pressure ◽  
Subtropical Anticyclone ◽  
Level Pressure ◽  
Benguela Upwelling ◽  
Atmospheric Variables

Abstract. Detecting the atmospheric drivers of the Benguela Upwelling Systems is essential to understand its present variability and its past and future changes. We present a statistical analysis of an ocean-only simulation driven by observed atmospheric fields over the last decades with the aim of identifying the large-scale atmospheric drivers of upwelling variability and trends. The simulation is found to reproduce well the seasonal cycle of upwelling intensity, with a maximum in the June-to-August season in North Benguela and in the December-to-February season in South Benguela. The statistical analysis of the interannual variability of upwelling focuses on its relationship to atmospheric variables (sea level pressure, 10 m-wind, wind stress). The relationship between upwelling and the atmospheric variables differ somewhat in the two regions, but generally, the correlation patterns reflect the common atmospheric pattern favoring upwelling: southerly wind/wind stress, strong subtropical anticyclone, and an ocean-land sea level pressure gradient. In addition, the statistical link between upwelling and large-scale climate variability modes was analyzed. The El Niño Southern Oscillation and the Antarctic Oscillation exert some influence on austral summer upwelling velocities in South Benguela. The decadal evolution and the long-term trends of upwelling and of ocean-minus-land air pressure gradient do not agree with Bakun's hypothesis that anthropogenic climate change should generally intensify coastal upwelling.

scholarly journals Assimilating monthly precipitation data in a paleoclimate data assimilation framework

2020 ◽  
Vol 16 (4) ◽  
pp. 1309-1323
Author(s):  
Veronika Valler ◽  
Yuri Brugnara ◽  
Jörg Franke ◽  
Stefan Brönnimann
Keyword(s):  
Data Assimilation ◽  
Sea Level ◽  
Monthly Precipitation ◽  
Precipitation Data ◽  
Sea Level Pressure ◽  
Model Simulations ◽  
Level Pressure ◽  
Proxy Records ◽  
Climate Reconstructions ◽  
Data Source

Abstract. Data assimilation approaches such as the ensemble Kalman filter method have become an important technique for paleoclimatological reconstructions and reanalysis. Different sources of information, from proxy records and documentary data to instrumental measurements, were assimilated in previous studies to reconstruct past climate fields. However, precipitation reconstructions are often based on indirect sources (e.g., proxy records). Assimilating precipitation measurements is a challenging task because they have high uncertainties, often represent only a small region, and generally do not follow a Gaussian distribution. In this paper, experiments are conducted to test the possibility of using information about precipitation in climate reconstruction with monthly resolution by assimilating monthly instrumental precipitation amounts or the number of wet days per month, solely or in addition to other climate variables such as temperature and sea-level pressure, into an ensemble of climate model simulations. The skill of all variables (temperature, precipitation, sea-level pressure) improved over the pure model simulations when only monthly precipitation amounts were assimilated. Assimilating the number of wet days resulted in similar or better skill compared to assimilating the precipitation amount. The experiments with different types of instrumental observations being assimilated indicate that precipitation data can be useful, particularly if no other variable is available from a given region. Overall the experiments show promising results because with the assimilation of precipitation information a new data source can be exploited for climate reconstructions. The wet day records can become an especially important data source in future climate reconstructions because many existing records date several centuries back in time and are not limited by the availability of meteorological instruments.

scholarly journals Interannual to decadal variability within and across the major Eastern Boundary Upwelling Systems

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Giulia Bonino ◽  
Emanuele Di Lorenzo ◽  
Simona Masina ◽  
Doroteaciro Iovino
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Sea Level ◽  
Low Frequency ◽  
Global Ocean ◽  
Thermocline Depth ◽  
Sea Level Pressure ◽  
Level Pressure ◽  
Eastern Boundary ◽  
Low Frequency Variability

AbstractClimate variability and climate change in Eastern Boundary Upwelling Systems (EBUS) affect global marine ecosystems services. We use passive tracers in a global ocean model hindcast at eddy-permitting resolution to diagnose EBUS low-frequency variability over 1958–2015 period. The results highlight the uniqueness of each EBUS in terms of drivers and climate variability. The wind forcing and the thermocline depth, which are potentially competitive or complementary upwelling drivers under climate change, control EBUS low-frequency variability with different contributions. Moreover, Atlantic and Pacific upwelling systems are independent. In the Pacific, the only coherent variability between California and Humboldt Systems is associated with El Niño Southern Oscillation. The remaining low-frequency variance is partially explained by the North and South Pacific expressions of the Meridional Modes. In the Atlantic, coherent variability between Canary and Benguela Systems is associated with upwelling trends, which are not dynamically linked and represent different processes. In the Canary, a negative upwelling trend is connected to the Atlantic Multi-decadal Oscillation, while in the Benguela, a positive upwelling trend is forced by a global sea level pressure trend, which is consistent with the climate response to anthropogenic forcing. The residual variability is forced by localized offshore high sea level pressure variability.

Sign in / Sign up

Export Citation Format

Share Document