[Eoas-seminar] TODAY 3 PM: Prof. Michael Bell (CSU) and Prof. James Ruppert (OU)

Tue Nov 4 07:45:00 EST 2025

Dear all,

This is a reminder of today’s MET seminar, featuring two short presentations by Prof. Michael Bell<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftropical.colostate.edu%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571161587307%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=8Vmo%2BlrMOkBsfNwQerb3gVeDhe8QSMko5dzENnYKoHw%3D&reserved=0> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftropical.colostate.edu%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571167917121%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=gb3Ie5K0VLtaowDYenl9tAQZMIIRYn3KOkorpY%2FeIsw%3D&reserved=0> from Colorado State University and Prof. James <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fjruppert.oucreate.com%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571167980691%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=yvk79UTcwRGobn0kJ%2B84oN9W73KF3MLEiHDpHF0PjsI%3D&reserved=0> Ruppert<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fjruppert.oucreate.com%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571167997907%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=Vj%2BlJSgxBSZnwbUcs0U8GnHB3fQ2De0DtEBcyEsHD4k%3D&reserved=0> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fjruppert.oucreate.com%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571168010576%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=hWFDXSjHJQkxylSeYVLlxpbrd86nxlt0SUdfbNqfpoc%3D&reserved=0> from University of Oklahoma. See below for details.

3 pm in 1044, see you there!

Cheers,

Allison

---------------------------------------------------

Allison A. Wing, Ph.D.

Werner A. and Shirley B. Baum Associate Professor

Department of Earth, Ocean and Atmospheric Science

Florida State University

awing at fsu.edu<mailto:awing at fsu.edu>

From: Eoas-seminar <eoas-seminar-bounces at lists.fsu.edu> on behalf of eoas-seminar--- via Eoas-seminar <eoas-seminar at lists.fsu.edu>
Date: Wednesday, October 29, 2025 at 9:46 AM
To: Eoas-seminar <eoas-seminar at lists.fsu.edu>
Subject: [Eoas-seminar] MET Seminar Nov 4, 3 PM: Prof. Michael Bell (CSU) and Prof. James Ruppert (OU)

Dear all,

Please join us for our next Meteorology seminar on Tuesday November 4 at 3 PM. This will be a special combined MET seminar which will feature shorter presentations by two visiting speakers: Prof. Michael Bell<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftropical.colostate.edu%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571168022928%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=OGGYUh7YGl8cwqUYuNBN4iMDfXzUPRTfpa4F8wm2prQ%3D&reserved=0> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftropical.colostate.edu%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571168037131%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=Sgm2FpUEpeP%2FqoABewDluVrK0tAOy5sKgy6F9aTNRZA%3D&reserved=0> from Colorado State University and Prof. James <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fjruppert.oucreate.com%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571168051433%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=956EhBaf96Wlw6AD51vDHyI%2BWzyC%2FSkAfO%2Fc7kdhU5Y%3D&reserved=0> Ruppert<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fjruppert.oucreate.com%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571168066299%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=36gQhfpHNLG06HUTO4IWegHWHPb0vneq0oQ%2B0tSJzbM%3D&reserved=0> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fjruppert.oucreate.com%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571168082303%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=gZefO63pqAoIN5%2BTGkFNe5k13gj8fY2BK6Dj2GEvNJA%3D&reserved=0> from University of Oklahoma.

Prof. Bell will speak about "Relationships between Rotation and Rainfall in African Easterly Waves” and Prof. Ruppert will speak about "Interpreting longwave radiative feedback from stratiform and anvil clouds”. Their abstracts are below.

Both speakers will present in person in EOA 1044 but a Zoom link is available for those with approved work off-campus or a medical excuse. Please contact Allison Wing (awing at fsu.edu) for the Zoom link.

DATE: Tuesday November 4
TIME: 3-4 PM, please join early for refreshments
LOCATION:  EOA 1044 (speakers in person)
SPEAKER: Prof. Michael Bell<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftropical.colostate.edu%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571168097175%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=x8B4Oo78bfV1YjBZRgIqfC3%2BxxUv%2BSzRbi%2BoQHbxqRQ%3D&reserved=0> & Prof. James Ruppert<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fjruppert.oucreate.com%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571168109285%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=5Zk2OWOSAjKVeqz3EhWhuyqXcw29Fi2pMpmzg4VM5DQ%3D&reserved=0>

SPEAKER 1: Prof. Michael Bell<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftropical.colostate.edu%2F&data=05%7C02%7Ceoas-seminar%40lists.fsu.edu%7Ccc68a6a60ec8487a273a08de1b9fffb3%7Ca36450ebdb0642a78d1b026719f701e3%7C0%7C0%7C638978571168121072%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=1VjIfePIPYmvTa%2FF1OWkTVGl3aBR%2FODXrV5paOf8bmU%3D&reserved=0>
TITLE: Relationships between Rotation and Rainfall in African Easterly Waves

ABSTRACT: Recent observations have shown a positive correlation between rotating flow and higher rain rates associated with mesoscale convective organization. The ability of convection to enhance rotation can be understood through the direct effects of vortex stretching and convective heating, but the reverse influence of rotation on convection is more complicated and indirect. Multiple physical mechanisms can lead to enhanced convection associated with mesoscale potential vorticity (PV) anomalies, including isentropic uplift, mesoscale pressure perturbations, boundary layer pumping, moisture advection, and interactions with larger scale environmental flow. These mechanisms are not mutually exclusive, leading to complex vertical motion patterns that are sometimes difficult to ascribe to any single factor. This talk will explore these mechanisms in African Easterly Waves (AEWs) which are broad, weakly rotating systems in the tropical Atlantic. AEWs contribute substantially to the total rainfall over the tropical Atlantic and Caribbean and also serve as the precursor disturbances for 85% of major hurricanes. The relationships between PV, moisture, and convective organization are examined using aircraft observations from the NASA 2006 NAMMA (NASA African Monsoon Multidisciplinary Analysis) and 2022 CPEX-CV (Convective Processes Experiment - Cabo Verde) field campaigns and idealized modeling. Observations show that deep convection is organized into different regions within AEWs associated with higher mid-level moisture and PV interacting with the environmental flow. Idealized modeling experiments show that boundary layer pumping associated with the rotating flow is weak in AEWs, but becomes progressively more important with increased rotation and smaller circulations. A positive feedback between rotation and rainfall, in which PV promotes convection that further amplifies the PV through convective heating, becomes more effective with increased rotation and can lead to cyclogenesis and hurricane development.

SPEAKER 2: Prof. James Ruppert
TITLE: Interpreting longwave radiative feedback from stratiform and anvil clouds

ABSTRACT: Our emphasis on distinct tropical cloud types has evolved over the decades with advancements in our understanding, especially of the complex links between the convective scale and larger scales. Early undilute plume views of tropical convection emphasized deep cumulonimbi and their associated latent heating as a fundamental component of the ascending branch of the Hadley cell. Later, emphasis on tropical shallow and congestus clouds increased as we better grasped the acute sensitivity of tropical convection to water vapor in the free troposphere, prompting major reconsiderations for how to represent moist convection in numerical models. In this context, we advocate for revisiting the role of stratiform and anvil clouds: we argue that these clouds play an essential role in convective-scale dynamics in the tropics through their longwave radiative forcing. The magnitude of longwave radiative forcing relative to latent heating within these clouds is very large, significantly affecting both buoyancy and circulation. It increases moist entropy and suppresses evaporatively driven mesoscale downdrafts, resulting in greater upward motion per unit precipitation. This effect fosters growth of the parent convective system, constituting a positive feedback. The radiative forcing of these clouds, which are much larger and longer-lived than their parent deep convective elements, acts as an important link between the convective scale and larger scales. Hence, while stratiform and anvil clouds are indeed biproducts of deep convection, they should also be recognized as active players in tropical organized convection. Consequently, any comprehensive model or parameterization of tropical convection must account for the bidirectional forcing between deep convective systems and their attendant stratiform and anvil cloud signatures.

We look forward to seeing you there!

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Allison A. Wing, Ph.D.
Werner A. and Shirley B. Baum Associate Professor
Department of Earth, Ocean and Atmospheric Science
Florida State University
awing at fsu.edu<mailto:awing at fsu.edu>

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