# Insights from Idealized Modelling into the Quasi-Biennial Oscillation

> **NSF 01002526DB NSF RESEARCH & RELATED ACTIVIT** · University of Utah (UT) · $797,237

## Abstract

This work is focused on advancing understanding of the Quasi-Biennial Oscillation (QBO), a prominent and persistent mode of variability in the tropical stratospheric winds with a period of approximately 28 months. The QBO influences higher latitude phenomena such as the stability of the stratospheric polar vortex (the “Holton-Tan effect”) that subsequently impacts the tropospheric mid-latitude jet stream.  As the QBO vertically propagates from the middle stratosphere to the tropopause, it also influences the position of the North Pacific jet as well as the variability in the tropical troposphere through its interactions with deep convection and the Madden-Julian oscillation. The persistence and quasi regular nature of the QBO offers the potential for predictability out to several years if well represented in global models. This study aims to provide insight into the longstanding model bias in QBO strength in the lower stratosphere, with the QBO being too weak in the models, and the inability of models to correctly capture the QBO modulation of the stratospheric polar vortex. The project includes the training of two graduate students in climate dynamics and provides research opportunities for undergraduate students in a STEM field. It additionally includes creating outreach materials for the University of Utah and the Natural History Museum of Utah on the QBO and its role in the climate system.

The main goals of the project, to better understand the weak QBO bias in the low

## Key facts

- **NSF award ID:** 2439958
- **Awardee organization:** University of Utah (UT)
- **SAM.gov UEI:** LL8GLEVH6MG3
- **PI:** Thomas J Reichler
- **Primary program:** 01002526DB NSF RESEARCH & RELATED ACTIVIT
- **All programs:** —
- **Estimated total:** $797,237
- **Funds obligated:** $797,237
- **Transaction type:** Standard Grant
- **Period:** 07/01/2025 → 06/30/2028

## Primary source

NSF Award Search: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2439958

## Citation

> US National Science Foundation, Award 2439958, Insights from Idealized Modelling into the Quasi-Biennial Oscillation. Retrieved via AI Analytics 2026-06-06 from https://api.ai-analytics.org/grant/nsf/2439958. Licensed CC0.

---

*[NSF Awards dataset](/datasets/nsf-awards) · CC0 1.0*