scholarly journals Tropical Cyclone Contribution to Rainfall over Australia

2012 ◽  
Vol 140 (11) ◽  
pp. 3606-3619 ◽  
Author(s):  
Richard A. Dare ◽  
Noel E. Davidson ◽  
John L. McBride
Keyword(s):  
Tropical Cyclone ◽  
Interannual Variations ◽  
Flood Events ◽  
Coastal Regions ◽  
Total Rainfall ◽  
Water Supplies ◽  
Rainfall Characteristics ◽  
Rainfall Total ◽  
Australian Continent ◽  
Low Levels

Abstract Tropical cyclone (TC) rainfall over the Australian continent is studied using observations from 41 TC seasons 1969/70 to 2009/10. A total of 318 storms, whose centers either crossed the coastline or were located within 500 km of the coast, are considered in this study. Mean seasonal (November/April) contributions by TCs to the total rainfall are largest along the northern coastline from 120°–150°E. However, the percentage contributions by TCs are greatest west of 125°E, with mean coastal values of 20%–40% and inland values of approximately 20%. Farther east, percentages near the coast are only around 10%, and even lower inland. Inland penetration by TC rainfall is generally greatest over western portions of the continent, associated with greater inland penetration of TC tracks. During the peak of the TC season (January–March), TCs contribute around 40% to the rainfall total of coastal regions west of 120°E, while during December, TCs contribute approximately 60%–70% to the total rainfall west of 115°E. Rain from TCs varies sharply between TC seasons, with some longitude bands receiving no TC rain during some seasons. For the 110°–115°E longitude band the TC rain contribution is quite inconsistent, varying interannually from 0%–86%. This has an impact on water supplies, with storage dams falling to low levels during some years, while filling to capacity during TC-related flood events in other years. These large interannual variations and their impacts underline why it is important to understand TC rainfall characteristics over the Australian continent.

scholarly journals Cross Validation of Rainfall Characteristics Estimated from the TRMM PR, a Combined PR–TMI Algorithm, and a C-POL Ground Radar during the Passage of Tropical Cyclone and Nontropical Cyclone Events over Darwin, Australia

2018 ◽  
Vol 35 (12) ◽  
pp. 2339-2358 ◽  
Author(s):  
Anil Deo ◽  
S. Joseph Munchak ◽  
Kevin J. E. Walsh
Keyword(s):  
Tropical Cyclone ◽  
Tropical Rainfall Measuring Mission ◽  
Rainfall Rate ◽  
Rainfall Characteristics ◽  
Significant Difference ◽  
Median Volume ◽  
Precipitation Type ◽  
Correct Direction ◽  
Microwave Imager ◽  
Trmm Microwave Imager

AbstractThis study cross validates the radar reflectivity Z; the rainfall drop size distribution parameter (median volume diameter Do); and the rainfall rate R estimated from the Tropical Rainfall Measuring Mission (TRMM) satellite Precipitation Radar (PR), a combined PR and TRMM Microwave Imager (TMI) algorithm (COM), and a C-band dual-polarized ground radar (GR) for TRMM overpasses during the passage of tropical cyclone (TC) and non-TC events over Darwin, Australia. Two overpass events during the passage of TC Carlos and 11 non-TC overpass events are used in this study, and the GR is taken as the reference. It is shown that the correspondence is dependent on the precipitation type whereby events with more (less) stratiform rainfall usually have a positive (negative) bias in the reflectivity and the rainfall rate, whereas in the Do the bias is generally positive but small (large). The COM reflectivity estimates are similar to the PR, but it has a smaller bias in the Do for most of the greater stratiform events. This suggests that combining the TMI with the PR adjusts the Do toward the “correct” direction if the GR is taken as the reference. Moreover, the association between the TRMM estimates and the GR for the two TC events, which are highly stratiform in nature, is similar to that observed for the highly stratiform non-TC events (there is no significant difference), but it differs considerably from that observed for the majority of the highly convective non-TC events.

Tropical Cyclone Impacts on Coastal Regions: the Case of the Yucatán and the Baja California Peninsulas, Mexico

2014 ◽  
Vol 37 (6) ◽  
pp. 1388-1402 ◽  
Author(s):  
Luis M. Farfán ◽  
Eurico J. D’Sa ◽  
Kam-biu Liu ◽  
Victor H. Rivera-Monroy
Keyword(s):  
Tropical Cyclone ◽  
Baja California ◽  
Coastal Regions

scholarly journals Future Change in Tropical Cyclone Activity over the Western North Pacific in CORDEX-East Asia Multi-RCMs Forced by HadGEM2-AO

2019 ◽  
Vol 32 (16) ◽  
pp. 5053-5067 ◽  
Author(s):  
Hyeonjae Lee ◽  
Chun-Sil Jin ◽  
Dong-Hyun Cha ◽  
Minkyu Lee ◽  
Dong-Kyou Lee ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
East Asia ◽  
North Pacific ◽  
Western North Pacific ◽  
Climate Models ◽  
Regional Climate ◽  
Vertical Wind Shear ◽  
Coastal Regions ◽  
The Future ◽  
Cordex East Asia

AbstractFuture changes in tropical cyclone (TC) activity over the western North Pacific (WNP) are analyzed using four regional climate models (RCMs) within the Coordinated Regional Climate Downscaling Experiment (CORDEX) for East Asia. All RCMs are forced by the HadGEM2-AO under the historical and representative concentration pathway (RCP) 8.5 scenarios, and are performed at about 50-km resolution over the CORDEX-East Asia domain. In the historical simulations (1980–2005), multi-RCM ensembles yield realistic climatology for TC tracks and genesis frequency during the TC season (June–November), although they show somewhat systematic biases in simulating TC activity. The future (2024–49) projections indicate an insignificant increase in the total number of TC genesis (+5%), but a significant increase in track density over East Asia coastal regions (+17%). The enhanced TC activity over the East Asia coastal regions is mainly related to vertical wind shear weakened by reduced meridional temperature gradient and increased sea surface temperature (SST) at midlatitudes. The future accumulated cyclone energy (ACE) of total TCs increases significantly (+19%) because individual TCs have a longer lifetime (+6.6%) and stronger maximum wind speed (+4.1%) compared to those in the historical run. In particular, the ACE of TCs passing through 25°N increases by 45.9% in the future climate, indicating that the destructiveness of TCs can be significantly enhanced in the midlatitudes despite the total number of TCs not changing greatly.

The Track Integrated Kinetic Energy of Atlantic Tropical Cyclones

2013 ◽  
Vol 141 (7) ◽  
pp. 2383-2389 ◽  
Author(s):  
V. Misra ◽  
S. DiNapoli ◽  
M. Powell
Keyword(s):  
Tropical Cyclone ◽  
Kinetic Energy ◽  
Tropical Cyclones ◽  
Warm Pool ◽  
Equatorial Pacific ◽  
Interannual Variations ◽  
Tropical Atlantic ◽  
Cyclone Activity ◽  
Atlantic Warm Pool ◽  
Atlantic Tropical Cyclone

Abstract In this paper the concept of track integrated kinetic energy (TIKE) is introduced as a measure of seasonal Atlantic tropical cyclone activity and applied to seasonal variability in the Atlantic. It is similar in concept to the more commonly used accumulated cyclone energy (ACE) with an important difference that in TIKE the integrated kinetic energy (IKE) is accumulated for the life span of the Atlantic tropical cyclone. The IKE is, however, computed by volume integrating the 10-m level sustained winds of tropical strength or higher quadrant by quadrant, while ACE uses the maximum sustained winds only without accounting for the structure of the storm. In effect TIKE accounts for the intensity, duration, and size of the tropical cyclones. In this research, the authors have examined the seasonality and the interannual variations of the seasonal Atlantic TIKE over a period of 22 yr from 1990 to 2011. It is found that the Atlantic TIKE climatologically peaks in the month of September and the frequency of storms with the largest TIKE are highest in the eastern tropical Atlantic. The interannual variations of the Atlantic TIKE reveal that it is likely influenced by SST variations in the equatorial Pacific and in the Atlantic Oceans. The SST variations in the central equatorial Pacific are negatively correlated with the contemporaneous seasonal (June–November) TIKE. The size of the Atlantic warm pool (AWP) is positively correlated with seasonal TIKE.

scholarly journals Interannual Variations of Wind Regimes off the Subtropical Western Australia Coast during Austral Winter and Spring

2012 ◽  
Vol 25 (16) ◽  
pp. 5587-5599 ◽  
Author(s):  
Evan Weller ◽  
Ming Feng ◽  
Harry Hendon ◽  
Jian Ma ◽  
Shang-Ping Xie ◽  
...  
Keyword(s):  
Western Australia ◽  
Geopotential Height ◽  
General Circulation ◽  
Circulation Model ◽  
Interannual Variations ◽  
Storm Events ◽  
Austral Winter ◽  
Easterly Wind ◽  
Upper Troposphere ◽  
Australian Continent

Abstract Off the Western Australia coast, interannual variations of wind regime during the austral winter and spring are significantly correlated with the Indian Ocean dipole (IOD) and the southern annular mode (SAM) variability. Atmospheric general circulation model experiments forced by an idealized IOD sea surface temperature anomaly field suggest that the IOD-generated deep atmospheric convection anomalies trigger a Rossby wave train in the upper troposphere that propagates into the southern extratropics and induces positive geopotential height anomalies over southern Australia, independent of the SAM. The positive geopotential height anomalies extended from the upper troposphere to the surface, south of the Australian continent, resulting in easterly wind anomalies off the Western Australia coast and a reduction of the high-frequency synoptic storm events that deliver the majority of southwest Australia rainfall during austral winter and spring. In the marine environment, the wind anomalies and reduction of storm events may hamper the western rock lobster recruitment process.

scholarly journals Use of a Genesis Potential Index to Diagnose ENSO Effects on Tropical Cyclone Genesis

2007 ◽  
Vol 20 (19) ◽  
pp. 4819-4834 ◽  
Author(s):  
Suzana J. Camargo ◽  
Kerry A. Emanuel ◽  
Adam H. Sobel
Keyword(s):  
Tropical Cyclone ◽  
Relative Humidity ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Vertical Wind Shear ◽  
Vertical Shear ◽  
Interannual Variations ◽  
Genesis Potential Index ◽  
Potential Index

Abstract ENSO (El Niño–Southern Oscillation) has a large influence on tropical cyclone activity. The authors examine how different environmental factors contribute to this influence, using a genesis potential index developed by Emanuel and Nolan. Four factors contribute to the genesis potential index: low-level vorticity (850 hPa), relative humidity at 600 hPa, the magnitude of vertical wind shear from 850 to 200 hPa, and potential intensity (PI). Using monthly NCEP Reanalysis data in the period of 1950–2005, the genesis potential index is calculated on a latitude strip from 60°S to 60°N. Composite anomalies of the genesis potential index are produced for El Niño and La Niña years separately. These composites qualitatively replicate the observed interannual variations of the observed frequency and location of genesis in several different basins. This justifies producing composites of modified indices in which only one of the contributing factors varies, with the others set to climatology, to determine which among the factors are most important in causing interannual variations in genesis frequency. Specific factors that have more influence than others in different regions can be identified. For example, in El Niño years, relative humidity and vertical shear are important for the reduction in genesis seen in the Atlantic basin, and relative humidity and vorticity are important for the eastward shift in the mean genesis location in the western North Pacific.

IN SITU NITROGEN FIXATION BY WHITE CLOVER IN MIXED SWARDS IN NOVA SCOTIA

1984 ◽  
Vol 64 (3) ◽  
pp. 625-636 ◽  
Author(s):  
J. K. VESSEY ◽  
D. G. PATRIQUIN
Keyword(s):  
Nitrogen Fixation ◽  
White Clover ◽  
Management Strategy ◽  
Acetylene Reduction Activity ◽  
Total Rainfall ◽  
Reduction Activity ◽  
Main Factors ◽  
Low Levels ◽  
A Site

At three sites, clover cover increased from less than 10% in April to 50–70% during anthesis in July. It began to decline in September, reaching 20–30% in December. Acetylene-reduction activity (ARA), measured by an in situ technique, commenced in April when soil temperature was 5–7 °C. "Clover-specific ARA" (ARA measured in clover patches where cover of clover was 100%) was generally high through most of May, June and July, and then declined, reaching low levels by November. Clover-specific ARA was correlated with total rainfall during the period between 7 and 28 days before the assay (r = 0.720, P < 0.01). The amount of N2 fixed by white clover over a 1-yr period was estimated at 66 and 81 kg N/ha for two pasture sites and 100 kg N/ha at a lawn site. Clover cover and thermal regime appeared to be the two main factors influencing the amount of N2 fixed by white clover at a site. Eight sites of widely varying clover cover (2–53%) were compared in July with regard to cover, clover-specific ARA, edaphic characteristics and fertilizer and grazing management. Management strategy appeared to have the greatest influence on clover abundance in pasture.Key words: White clover, Trifolium repens, nitrogen fixation

scholarly journals Comparison of Tropical Cyclone Activities over the Western North Pacific in CORDEX-East Asia Phase I and II Experiments

2020 ◽  
Vol 33 (24) ◽  
pp. 10593-10607
Author(s):  
Minkyu Lee ◽  
Dong-Hyun Cha ◽  
Myoung-Seok Suh ◽  
Eun-Chul Chang ◽  
Joong-Bae Ahn ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
East Asia ◽  
North Pacific ◽  
Western North Pacific ◽  
Regional Climate ◽  
Horizontal Resolution ◽  
Added Value ◽  
Convective Precipitation ◽  
Coastal Regions ◽  
Cordex East Asia

AbstractThis study evaluated tropical cyclone (TC) activity simulated by two regional climate models (RCMs) incorporated in the Coordinated Regional Climate Downscaling Experiment (CORDEX) framework with two different horizontal resolutions. Evaluation experiments with two RCMs (RegCM4 and MM5) forced by reanalysis data were conducted over the CORDEX-East Asia domain for phases I and II. The main difference between phases I and II is horizontal resolution (50 and 25 km). The 20-yr (1989–2008) mean performances of the experiments were investigated in terms of TC genesis, track, intensity, and TC-induced precipitation. In general, the simulated TC activities over the western North Pacific (WNP) varied depending on the model type and horizontal resolution. For both models, higher horizontal resolution improved the simulation of TC tracks near the coastal regions of East Asia, whereas the coarser horizontal resolution led to underestimated TC genesis compared with the best track data because of greater convective precipitation and enhanced atmospheric stabilization. In addition, the increased horizontal resolution prominently improved the simulation of TCs landfalling in East Asia and associated precipitation around coastal regions. This finding implies that high-resolution RCMs can improve the simulation of TC activities over the WNP (i.e., added value by increasing model resolution); thus, they have an advantage in climate change assessment studies.

Recent migration of tropical cyclones toward coasts

Science ◽  
2021 ◽  
Vol 371 (6528) ◽  
pp. 514-517 ◽  
Author(s):  
Shuai Wang ◽  
Ralf Toumi
Keyword(s):  
Tropical Cyclone ◽  
Trend Analysis ◽  
Tropical Cyclones ◽  
Tropical Cyclone Activity ◽  
Maximum Intensity ◽  
Coastal Regions ◽  
Cyclone Activity ◽  
Steering Flow ◽  
Annual Frequency ◽  
Tropical Cyclone Tracks

Poleward migrations of tropical cyclones have been observed globally, but their impact on coastal areas remains unclear. We investigated the change in global tropical cyclone activity in coastal regions over the period 1982–2018. We found that the distance of tropical cyclone maximum intensity to land has decreased by about 30 kilometers per decade, and that the annual frequency of global tropical cyclones increases with proximity to land by about two additional cyclones per decade. Trend analysis reveals a robust migration of tropical cyclone activity toward coasts, concurrent with poleward migration of cyclone locations as well as a statistically significant westward shift. This zonal shift of tropical cyclone tracks may be mainly driven by global zonal changes in environmental steering flow.

Sign in / Sign up

Export Citation Format

Share Document