Major Events

No meetings, workshops, or other special events are currently announced.

+ Past Meetings & Workshops

Other Upcoming Events

Following are upcoming seminars, workshops and other events of interest to GISS staff and our research partners. Please note that due to security regulations, these presentations are not open to the general public.

Friday, Feb. 5, 2016
11:00 a.m. to 12:30 p.m.
Friday Seminar
Topic: Overview of NASA-Unified WRF
Speaker: Toshi Matsui (NASA GSFC)
Contact: Ann Fridlind
Wednesday, Feb. 10, 2016
11:00 a.m. to 12:30 p.m.
Special Seminar
Topic: Strongly Positive Low Cloud Feedback in GCMs: Real or Artifact?
Speaker: Tony Del Genio (NASA GISS)
Abstract: Read More
Contact: Tony Del Genio

Special Seminar
Speaker: Tony Del Genio (NASA GISS)
Title: Strongly Positive Low Cloud Feedback in GCMs: Real or Artifact?

Abstract: As an outgrowth of a group effort at GISS to implement new treatments of boundary layer turbulence and clouds in the GCM for CMIP6, and simultaneous efforts to focus the observing capabilities of the DOE ARM/ASR programs to address outstanding issues about low clouds, the speaker will discuss his evolving understanding of some of the challenges involved in representing these clouds in climate models and how these challenges are addressed by different modeling groups, as well as speculating on why some GCMs have a very high climate sensitivity and whether we should be circumspect about such predictions.

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Friday, Feb. 19, 2016
11:00 a.m. to 12:30 p.m.
Friday Seminar
Topic: Impacts of US Emissions Reductions Consistent with 2°C
Speaker: Drew Shindell (Duke University)
Abstract: Read More
Contact: Darren Engwirda

Friday Seminar
Speaker: Drew Shindell (Duke University)
Title: Impacts of US Emissions Reductions Consistent with 2°C

Abstract: Nations around the world, including the US, have pledged to limit warming to well-below 2°C, but have not yet put forward plans to achieve such a goal. Doing so would require dramatic societal changes, making it crucial to understand the associated benefits. We have therefore examined the impacts of highly ambitious scenarios for clean energy and vehicles consistent with 2°C warming. I will discuss how climate and human health impacts vary in space and time, and how economic valuation of these impacts compares with the costs of implement such a transformation.

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Friday, Mar. 11, 2016
11:00 a.m. to 12:30 p.m.
Friday Seminar
Topic: Organization of tropical convection: Self-aggregation and spontaneous tropical cyclogenesis
Speaker: Allison Wing (CU/LDEO)
Abstract: Read More
Contact: Darren Engwirda

Friday Seminar
Speaker: Allison Wing (CU/LDEO)
Title: Organization of tropical convection: Self-aggregation and spontaneous tropical cyclogenesis

Abstract: Tropical clouds and relative humidity play a key role in both the planetary energy balance and the sensitivity of global climate to radiative forcing. Both clouds and relative humidity are also strongly modulated by the organization of tropical convection, which results in a large fraction of tropical cloudiness and rainfall. Here, we investigate the organization of tropical convection in the context of self-aggregation, a spontaneous transition in idealized numerical simulations from randomly distributed to organized convection despite homogeneous boundary conditions. Specifically, the System for Atmospheric Modeling is used to perform 3-d simulations of radiative-convective equilibrium in a non-rotating framework, with interactive radiation and surface fluxes and fixed sea surface temperatures. The results of simulations employing a highly elongated 3-d channel domain, in which self-aggregation takes the form of multiple moist and dry bands, are compared to that of a square domain, in which self-aggregation takes the form of a single moist cluster. For both domain types, and across a range of temperatures, we characterize the fundamental physical mechanisms that lead to self-aggregation as well as its growth rate and spatial scale. In both geometries, cloud-radiative feedbacks and surface flux feedbacks are found to be important in the initial instability, but advection only contributes to aggregation in the square geometry. Self-aggregation has primarily been studied in a non-rotating framework, but it has been hypothesized to be important to tropical cyclogenesis. In numerical simulations of tropical cyclones, a broad vortex or moist bubble is often used to initialize the circulation. Here, we instead allow a circulation to develop spontaneously from a homogeneous environment in 3-d cloud-resolving simulations of radiative-convective equilibrium (RCE) in a rotating framework, and compare the resulting tropical cyclogenesis to non-rotating self-aggregation. We find that in the initial development of a broad circulation, the feedback processes leading to cyclogenesis are similar to the initial phase of non-rotating aggregation. Sensitivity tests in which the degree of interactive radiation is modified are also performed to determine the extent to which the radiative feedbacks that are essential to non-rotating self-aggregation are important for tropical cyclogenesis.

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This event listing was last updated 2016-02-01.

Seminars & Colloquia

Most seminars at GISS are held during the academic year, September through May.

Formal seminar presentations by visiting scientists are held many Fridays at 11:00 a.m.

Informal lunchtime presentations by NASA GISS staff take place on Wednesdays at 1:00 p.m. about twice per month.

Other special seminars occur from time to time as visitors' schedules permit.

Security Note

Regulations require that visitors arrange in advance for a building pass. Persons attending a NASA GISS seminar or colloquium should contact the event host at least two days in advance of the event for assistance. Please include your affiliation in your e-mail.

Effective July 21, 2014, the implementation of Phase II of the Real-ID Act (2005) restricts the use of state ID from non-compliant states (including New York) as an acceptable form of identification for federal facilities such as NASA GISS. If you are scheduled to visit GISS and only have a standard driver's license from a non-compliant state, please be sure to bring a second form of ID (passport, military ID, etc.).

Special arrangements must be made for persons who are not U.S. citizens or U.S. permanent residents. Such persons planning to attend a NASA GISS event should contact the event host at least 2 days in advance of visiting GISS.