TY - CONF TI - NOAA multi-decadal records of climate variability AU - Banzon, P.V. AU - Peng, G. AU - Semunegus, H. AU - Shi, L. AU - Zhao, X. AU - Bates, J.J. C2 - 2011/10// C3 - WCRP Open Science Conference DA - 2011/10// SP - 24 – ER - TY - JOUR TI - Surface Air Temperature and Humidity from Intersatellite-Calibrated HIRS Measurements in High Latitudes AU - Shi, Lei AU - Peng, Ge AU - Bates, John J. T2 - Journal of Atmospheric and Oceanic Technology AB - Abstract High-latitude ocean surface air temperature and humidity derived from intersatellite-calibrated High-Resolution Infrared Radiation Sounder (HIRS) measurements are examined. A neural network approach is used to develop retrieval algorithms. HIRS simultaneous nadir overpass observations from high latitudes are used to intercalibrate observations from different satellites. Investigation shows that if HIRS observations were not intercalibrated, then it could lead to intersatellite biases of 1°C in the air temperature and 1–2 g kg−1 in the specific humidity for high-latitude ocean surface retrievals. Using a full year of measurements from a high-latitude moored buoy site as ground truth, the instantaneous (matched within a half-hour) root-mean-square (RMS) errors of HIRS retrievals are 1.50°C for air temperature and 0.86 g kg−1 for specific humidity. Compared to a large set of operational moored and drifting buoys in both northern and southern oceans greater than 50° latitude, the retrieval instantaneous RMS errors are within 2.6°C for air temperature and 1.4 g kg−1 for specific humidity. Compared to 5 yr of International Maritime Meteorological Archive in situ data, the HIRS specific humidity retrievals show less than 0.5 g kg−1 of differences over the majority of northern high-latitude open oceans. DA - 2011/// PY - 2011/// DO - 10.1175/JTECH-D-11-00024.1 VL - 29 IS - 1 SP - 3-13 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000299497400001&KeyUID=WOS:000299497400001 ER - TY - CONF TI - A comparison of various Equatorial Pacific surface wind products, AU - Peng, G. AU - Zhang, H.-M. AU - Frank, H.P. AU - Bidlot, J. AU - Higaki, M. AU - Hankins, W. C2 - 2011/7// C3 - Proc. IGARSS 2011 DA - 2011/7// SP - 24 – ER - TY - JOUR TI - Tropical Cyclogenesis Associated with Kelvin Waves and the Madden-Julian Oscillation AU - Schreck, Carl J., III AU - Molinari, John T2 - MONTHLY WEATHER REVIEW AB - The Madden–Julian oscillation (MJO) influences tropical cyclone formation around the globe. Convectively coupled Kelvin waves are often embedded within the MJO, but their role in tropical cyclogenesis remains uncertain. This case study identifies the influences of the MJO and a series of Kelvin waves on the formation of two tropical cyclones. Typhoons Rammasun and Chataan developed in the western North Pacific on 28 June 2002. Two weeks earlier, conditions had been unfavorable for tropical cyclogenesis because of uniform trade easterlies and a lack of organized convection. The easterlies gave way to equatorial westerlies as the convective envelope of the Madden–Julian oscillation moved into the region. A series of three Kelvin waves modulated the development of the westerlies. Cyclonic potential vorticity (PV) developed in a strip between the growing equatorial westerlies and the persistent trade easterlies farther poleward. Rammasun and Chataan emerged from the apparent breakdown of this strip. The cyclonic PV developed in association with diabatic heating from both the MJO and the Kelvin waves. The tropical cyclones also developed during the largest superposition of equatorial westerlies from the MJO and the Kelvin waves. This chain of events suggests that the MJO and the Kelvin waves each played a role in the development of Rammasun and Chataan. DA - 2011/9// PY - 2011/9// DO - 10.1175/mwr-d-10-05060.1 VL - 139 IS - 9 SP - 2723-2734 SN - 0027-0644 ER - TY - JOUR TI - Attributing Tropical Cyclogenesis to Equatorial Waves in the Western North Pacific AU - Schreck, Carl J., III AU - Molinari, John AU - Mohr, Karen I. T2 - JOURNAL OF THE ATMOSPHERIC SCIENCES AB - Abstract Tropical cyclogenesis is attributed to an equatorial wave when the filtered rainfall anomaly exceeds a threshold value at the genesis location. It is argued that 0 mm day−1 (simply requiring a positive anomaly) is too small a threshold because unrelated noise can produce a positive anomaly. A threshold of 6 mm day−1 is too large because two-thirds of storms would have no precursor disturbance. Between these extremes, consistent results are found for a range of thresholds from 2 to 4 mm day−1. Roughly twice as many tropical cyclones are attributed to tropical depression (TD)-type disturbances as to equatorial Rossby waves, mixed Rossby–gravity waves, or Kelvin waves. The influence of the Madden–Julian oscillation (MJO) is even smaller. The use of variables such as vorticity and vertical wind shear in other studies gives a larger contribution for the MJO. It is suggested that its direct influence on the rainfall in forming tropical cyclones is less than for other variables. The impacts of tropical cyclone–related precipitation anomalies are also presented. Tropical cyclones can contribute more than 20% of the warm-season rainfall and 50% of its total variance. The influence of tropical cyclones on the equatorial wave spectrum is generally small. The exception occurs in shorter-wavelength westward-propagating waves, for which tropical cyclones represent up to 27% of the variance. Tropical cyclones also significantly contaminate wave-filtered rainfall anomalies in their immediate vicinity. To mitigate this effect, the tropical cyclone–related anomalies were removed before filtering in this study. DA - 2011/2// PY - 2011/2// DO - 10.1175/2010jas3396.1 VL - 68 IS - 2 SP - 195-209 SN - 0022-4928 ER -