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Tropical cyclone precipitation (TCP) has significant impacts on coastal communities through its modulation of flood event frequency as well as the water supply in many regions of the world. Satellite estimates provide our most reliable observations of TCP available globally, however, satellite precipitation estimates were limited because most products only have coverage starting in 1997. In this paper, we present a global dataset of TCP using the newly developed high-resolution Multi-Source Weighted-Ensemble Precipitation, version 2 (MSWEP V2) which spans from January 1979 to date. This Global Multi-Source Tropical Cyclone Precipitation (MSTCP) dataset is comprised of two main files in the format of tables: the main and profile datasets, both from January 1979 to February 2023. The main file provides various TCP statistics per TC track for using the full record from the International Best Track Archive for Climate Stewardship (IBTrACS) dataset, including mean and maximum precipitation rates. The profile dataset comprises the azimuthally averaged precipitation every 10-km away from the center of each storm (until 500 km). The case study of Hurricane Harvey is used to show that MSWEP estimates agree well with another commonly used satellite product. The main statistics of the dataset are analyzed as well, including the differences in the dataset metrics for each of the six TC basins and for each Saffir-Simpson category for storm intensity. [ABSTRACT FROM AUTHOR]

The influence of the quasi-biennial oscillation (QBO) on tropical climate is demonstrated using a 500-yr preindustrial control simulation of the Met Office Hadley Centre model. Robust precipitation responses to the phase of the QBO are diagnosed in the model which show zonally asymmetric features, consistent with observational studies. The response in precipitation resembles the El Nino-Southern Oscillation (ENSO) impacts, however, regression analysis shows that there is a QBO signal in precipitation that is independent from ENSO. Moreover, the observed uneven frequency of ENSO events for each QBO phase is also found in these simulations, with more El Nino events found under the westerly phase of the QBO (QBOW) and more La Nina events for the easterly phase (QBOE). No evidence is found to suggest that these QBO-ENSO relationships are caused by ENSO modulating the QBO in the simulations. A previously unknown relationship between the QBO and a dipole of precipitation in the Indian Ocean is found in models and observations in boreal fall, characterized by a wetter western Indian Ocean and drier conditions in the eastern part for QBOW and the opposite under QBOE conditions. QBO W-E differences show a stronger East Pacific Inter-tropical Convergence Zone (ITCZ) in boreal winter and a northward shift of the Atlantic ITCZ in boreal spring and summer. The Walker circulation is found to be significantly weaker during QBOW compared to QBOE, explaining the observed and simulated zonally asymmetric responses at equatorial latitudes. Further work, including targeted model experiments, is required to betters understand the mechanisms causing these relationships between the QBO and tropical convection. [ABSTRACT FROM AUTHOR]

This study diagnoses the degree of gradient wind balance (GWB) in dropsonde observations of 30 tropical cyclones (TCs) divided into 91 intense observation periods. The diagnosed GWB in these observation periods are composited to investigate which characteristics of a TC are significantly related to departures from GWB. This analysis confirms that on average the flow above the boundary layer is approximately in GWB. Supergradient flow is more common near the radius of maximum wind (RMW) in the upper boundary layer than above in the free troposphere or outside the RMW and is also more common in strong storms than in weak storms. In contrast, the degree of GWB does not differ between intensifying, steady-state and weakening storms. Storms with a peaked wind profile have a higher probability of showing supergradient winds than those with a flat wind profile. The comparison of two commonly used functions to fit observations shows that the diagnosing GWB from dropsonde observations is highly dependent on the analysis technique. The agradient wind magnitude and even sign is shown to depend on which of these functions is used to fit the observations. The use of a polynomial fit consistently diagnoses the presence of supergradient winds far more frequently than a piece-wise function, and also shows a marked degree of imbalance above the boundary layer. Therefore, caution is warranted when determining the degree of GWB with a polynomial fit. [ABSTRACT FROM AUTHOR]