Overview

Climate modeling has become a central component for hypothesis testing, theoretical development, climate analysis and a tool for prediction. While the physical underpinnings of climate models are well understood and based on well established physics, the use (and abuse) of climate models in climate science, policy and the media is often shrouded is a veil of skepticism. Is this reasonable, or paranoia? What can be learned from climate models and analysis of the climate data? How are they used successfully in scientific inquiry?

In his 1985 review paper, Ed Lorenz talked about the great challenges in understanding the general circulation. The solutions to the first three, regarding an explanation for surface winds has been provided by Halley, Hadley, Ferrel, Dole, Rossby and Charney for the case of the dry atmosphere. Lorenz notes that the next great challenge is to understand the role of the water cycle in the general circulation, and suggested that this would be a task for early in the new millennium. In this seminar class we will read a sequence of papers that capture the latest thinking on atmospheric humidity, the hydrologic cycle and its links to the large scale atmospheric circulation.

 

Instructor: David Noone<dcn@colorado.edu>

When: 2-3 pm Tuesday

Where: CIRES Reading room (Ekeley Sciences, room S231)

Prerequisites: none - although knowledge of the ATOC core will be useful.

Grading: participation in discussion, leading discussion (100%)

Office hours: by arrangement

Exam: None

Size limit: About 12 people - but quite informal. Please come along or email David if you'd like to join the group.

Upcoming topics

Feedback in the climate models, the water vapour feedback, the ice albedo feedback, projections of hydrology change, use of model ensembles in estimating uncertainty, uncertainty in future scenarios uncertainty in models, model descriptions, aerosols and aerosol effects in climate models, ocean heat content changes and ENSO interactions, paleoclimate, hurricane variations, land use change and biomass burning. Please suggest others.

Reading and assignments

In addition to the assigned reading, the enthusiastic student would follow up on key citations in each of the paper, and follow up on the paper we read. Is it cited? Please feel free to add historical accounts, and a bio of the authors to your presentations. Also, send me a copy of your presentation so I can add it to the site for later reference. Also send along other material (papers, web links, etc) that you would like to include.

Papers for upcoming weeks can be suggested by emailing David. The list below is subject to change.

Week Date Paper (click to download PDF) Who Other
1 22 Jan Planning David  
2 29 Jan Cau, Methven, and Hoskins, 2007: Origins of Dry Air in the Tropics and Subtropics, J. Climate, 20, 2745–2759. Lansing  
3 05 Feb Schneider, T., K. L. Smith, P. A. O'Gorman, and C. C. Walker, 2006: A climatology of tropospheric zonal-mean water vapor fields and fluxes in isentropic coordinates. Journal of Climate, 19, 5918–5933. Scott  
4 12 Feb Emanuel, K.A., and R.T. Pierrehumbert, 1996: Microphysical and dynamical control of tropospheric water vapor.  In Clouds, Chemistry, and Climate, P. J. Crutzen and V. Ramanathan, Eds., Springer-verlag, Berlin, 264 pp. Peter  
5 19 Feb Yang H., and R. T. Pierrehumbert, 1994: Production of dry air by isentropic mixing. J. Atmos. Sci., 51, 3437-3454. Patrick  
6 26 Feb Sun D.-Z., and R. Lindzen, 1993: Distribution of tropical tropospheric water vapor. J. Atmos. Sci., 50, 1643–1660. Stephanie Special guest - De Zheng Sun (NOAA-PSD)
7 04 Mar

Sherwood S. C., E. R. Kursinski, and W. G. Read, 2006: A distribution law for free-tropospheric relative humidity. J. Climate, 19, 6267–6277.

 Ryan  
8 11 Mar

Soden et al., 2002: Global Cooling After the Eruption of Mount Pinatubo: A Test of Climate Feedback by Water Vapor. Science, 727-730.

 Brian Also, read the "perspectives" note. and the supplementary material
9 18 Mar Frierson, DMW, The dynamics of idealized convection schemes and their effect on the zonally averaged tropical circulation, J Atmos. Sci., 64, 1959, 2007 Stephanie  
  25 Mar Spring break    
10 01 Apr Tompkins, A. M. and K. A. Emanuel, 2000: Simulated equilibrium tropical temperature and water vapor profiles and their sensitivity to vertical resolution. Quart. J. Roy. Meteor. Soc., 126, 1219-1238. Nik  
11 08 Apr No meeting
12 15 Apr Sun et al., 2007: How often will it rain? J. Climate, 20, 4801-4818. Derek  
13 22 Apr Pierrehumbert R., 1995: Thermostats, radiator fins, and the local runaway greenhouse. J. Atmos. Sci., 52, 1784–1806. Katherine  
14 29 Apr Newall and Zhu, Tropospheric Rivers: A One-Year Record and a Possible Application to Ice Core Data, GRL, 21, 113–116, 1994
Shu and Newall, Atmospheric rivers and bombs, GRL, 21, 1999-2002, 1994		 Brian  
         
         
         

Possible papers

Galewsky J., A. Sobel, and I. Held, 2005: Diagnosis of subtropical humidity dynamics using tracers of last saturation. J. Atmos. Sci., 62, 3353–3367.

SHERWOOD SC, The general circulation and robust relative humidity, JOURNAL OF CLIMATE 19 : 6278 2006

Pierrehumbert R. T., H. Brogniez, and R. Roca, 2006: On the relative humidity of Earth’s atmosphere. The Global Circulation of the Atmosphere: Phenomena, Theory, Challenges, T. Schneider and A. H. Sobel, Eds., Princeton University Press, in press. [Available online at geosci.uchicago.edu/~rtp1.].

 

SODEN BJ, The sensitivity of the tropical hydrological cycle to ENSO.JOURNAL OF CLIMATE 13 : 538 2000

Nilsson, J., and K.A. Emanuel, 1999: Equilibrium atmospheres of a two-column radiative convective model. Quart. J. Roy. Meteor. Soc., 125,  2239-2264.

Emanuel, K.A., 1993:  The effect of convective response time on WISHE modes.  J. Atmos. Sci., 50, 1763-1775.

Waugh D., and L. Polvani, 2000: Climatology of intrusions into the tropical upper troposphere. Geophys. Res. Lett., 27, 3857–3860.

Emanuel, K., 2003: A similarity hypothesis for air-sea exchange at extreme wind speeds. J. Atmos. Sci., 60, 1420-1428.

Tompkins, A. M. and K. A. Emanuel, 2000:  Simulated equilibrium tropical temperature and water vapor profiles and their sensitivity to vertical resolution. Quart. J. Roy. Meteor. Soc., 126, 1219-1238.

 

 

Last updated: