An assessment of the potential impact of a downward shift of tropospheric water vapor on climate sensitivity

Harvey, L. D. Danny

doi:10.1007/s003820000055

Cited by 4 publications

(4 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a warmer climate, the amount of water vapor is predicted to increase as air temperature rises, with a consequent increase in the natural greenhouse effect [e.g., Schneider et al , 1999]. This water vapor feedback could approximately double the warming expected due to greenhouse gases alone [ Houghton et al , 2001], although there is debate over the distribution of water vapor in a warmer atmosphere and the magnitude of the feedback effect [ Harvey , 2000]. For these reasons it is extremely important to obtain reliable observations of water vapor and also to validate the modeling tools which will be used to analyze water vapor in the present climate and to predict future changes.…”

Section: Introductionmentioning

confidence: 99%

Comparison of GPS and ERA40 IWV in the Alpine region, including correction of GPS observations at Jungfraujoch (3584 m)

Morland¹,

Liniger²,

Kunz³

et al. 2006

J. Geophys. Res.

View full text Add to dashboard Cite

[1] The 31 stations in the Global Positioning System (GPS) network of Switzerland span an altitude range of 330 to 3584 m. The highest station in the network, Jungfraujoch, suffers from a constant negative bias in the Integrated Water Vapor (IWV) due to a protective radome. We compared Jungfraujoch GPS IWV measurements with coincident Precision Filter Radiometer (PFR) observations and showed that the bias in the GPS is fairly constant with respect to the time of year and to the PFR IWV value. A correction was developed for the GPS data and validated by comparison with coincident Raman lidar observations. The IWV observations from nine GPS stations, including Jungfraujoch, were then compared with the IWV field of the ECMWF 40 year reanalysis (ERA40) data. Altitude differences between the ERA40 surface level and the GPS stations resulted, as expected, in a positive bias in the ERA40 IWV. A fairly linear relationship, with an intercept of À0.3 mm, was found between this bias and the difference between the ERA40 surface pressure and the surface pressure at the GPS station. The ERA40 reanalysis captured water vapor variations on timescales of several days very well, as evidenced by an r 2 correlation greater than 0.9 where the altitude difference between ERA40 and the GPS station was less than 1000 m. A comparison between ERA40 and GPS at Davos showed that the reanalysis underestimates IWV during winter temperature inversions.

show abstract

Section: Introductionmentioning

confidence: 99%

Comparison of GPS and ERA40 IWV in the Alpine region, including correction of GPS observations at Jungfraujoch (3584 m)

Morland¹,

Liniger²,

Kunz³

et al. 2006

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…Furthermore, Wielicki et al (2002) found that a suite of current climate models were unable to reproduce the observed data, even when forced with the observed SSTs, indicating a potential problem with the cloud response to SST forcing in the models, as implied by Linzden et al (2001). Harvey (2000), using a simple energy balance climate model, showed that a downward vertical moisture redistribution in the tropics could lead to a decrease in the temperature sensitivity of about 15% -an effect not replicated by more complex climate models and one that is independent of actual cloud properties. Gaffen et al (2000) report that temperature trends derived from data collected by microwave sounding units show that the temperatures in the lower troposphere in the tropics have declined since 1979 while temperature data collected from surface-based instruments show a warming trend during the same period.…”

Section: Adjustment To the Climate Sensitivity Resultingmentioning

confidence: 99%

Revised 21st century temperature projections

Michaels¹,

Knappenberger²,

Frauenfeld³

et al. 2002

Clim. Res.

View full text Add to dashboard Cite

Temperature projections for the 21st century made in the Third Assessment Report (TAR) of the United Nations Intergovernmental Panel on Climate Change (IPCC) indicate a rise of 1.4 to 5.8°C for 1990-2100. However, several independent lines of evidence suggest that the projections at the upper end of this range are not well supported. Since the publication of the TAR, several findings have appeared in the scientific literature that challenge many of the assumptions that generated the TAR temperature range. Incorporating new findings on the radiative forcing of black carbon (BC) aerosols, the magnitude of the climate sensitivity, and the strength of the climate/carbon cycle feedbacks into a simple upwelling diffusion/energy balance model similar to the one that was used in the TAR, we find that the range of projected warming for the 1990-2100 period is reduced to 1.1-2.8°C. When we adjust the TAR emissions scenarios to include an atmospheric CO 2 pathway that is based upon observed CO 2 increases during the past 25 yr, we find a warming range of 1.5-2.6°C prior to the adjustments for the new findings. Factoring in these findings along with the adjusted CO 2 pathway reduces the range to 1.0-1.6°C. And thirdly, a simple empirical adjustment to the average of a large family of models, based upon observed changes in temperature, yields a warming range of 1.3-3.0°C, with a central value of 1.9°C. The constancy of these somewhat independent results encourages us to conclude that 21st century warming will be modest and near the low end of the IPCC TAR projections.

show abstract

“…Finally, the water in the atmosphere is the energy carrier, releasing or accumulating its resources during phase transitions, so it is a significant link in the energy exchange between atmosphere and ocean. Therefore, the water content in the atmosphere is taken into account in global and regional meteorological models [16][17][18]. In practice, PW is used to increase the accuracy of weather forecasts [19][20][21][22][23][24][25][26] and explains the course and occurrence of extreme weather events, such as heavy precipitation, violent storms, super-cell thunderstorms and others [27][28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

“…In practice, PW is used to increase the accuracy of weather forecasts [19][20][21][22][23][24][25][26] and explains the course and occurrence of extreme weather events, such as heavy precipitation, violent storms, super-cell thunderstorms and others [27][28][29][30][31][32][33]. Analyzing PW trends is also crucial because of the observed climate change [16,18,32,34].…”

Section: Introductionmentioning

confidence: 99%

Precipitable Water Content Climatology over Poland

2022

View full text Add to dashboard Cite

In this work, the high-resolution spatial and temporal variability of precipitable water (PW) over Poland is presented. PW is one of the key parameters of the atmosphere taken into account in thermodynamic and radiation models. The daily PW values from years 2001–2010, calculated with the use of the WRF model, were compared with PW from soundings. The WRF modeled PW is in close agreement with measurements for the whole column of the troposphere and for individual levels: below 1.5 km, 1.5–3 km, 3–6 km and 6–10 km. The best agreement is observed in the lower part of the troposphere, especially for winter months. At the levels of 1.5 km to 10 km, the WRF model overestimates the PW values throughout the year, whereas up to 1.5 km PW is underestimated. The study shows an increasing trend of PW annual values between 1983 and 2010, but the trend is statistically insignificant. A significant positive trend with a high Sen’s slope is observed for the summer season up to 3 km in the troposphere, along with a significant negative tendency for spring. The trends in PW over Poland and Central Europe identified in this study contribute to the ongoing discussion on the observed climate changes.

show abstract

An assessment of the potential impact of a downward shift of tropospheric water vapor on climate sensitivity

Cited by 4 publications

References 24 publications

Comparison of GPS and ERA40 IWV in the Alpine region, including correction of GPS observations at Jungfraujoch (3584 m)

Comparison of GPS and ERA40 IWV in the Alpine region, including correction of GPS observations at Jungfraujoch (3584 m)

Revised 21st century temperature projections

Precipitable Water Content Climatology over Poland

Contact Info

Product

Resources

About