Level 4.1 (L4.1) processed upper-air sonde data R/V Revelle, Mirai, Baruna Jaya, and Sagar Kanya released: 11 February 2014 Colombo released: 7 April 2014 Ambon, Biak, Jakartka-Cengkareng, Kupang, Makassar, Manado, Medan, Merauke, Padang, Palu, Pangkal Pinang, and Surabaya released: 27 May 2014 High vertical resolution (5-10m) sonde data that have been interpolated to uniform 5-hPa levels. Quality-control flags are assigned objectively based on a number of QC checks and then adjusted by visual inspection. upaqi_99990_L4.1 - R/V Mirai corrected for deck heating effects upaqi_99991_L4.1 - R/V Revelle corrected for L4.0 error in sfc p upaqi_99992_L4.1 - R/V Baruna Jaya corrected for deck heating effects upaqi_99993_L4.1 - R/V Sagar Kanya corrected for deck heating effects upaqm_43466.txt - Colombo corrected for island effects upaqi_96035 - Medan corrected for RH/temperature errors upaqi_96163 - Padang corrected for RH/temperature errors upaqi_96237 - Pangkal Pinang corrected for RH/temperature errors upaqi_96749 - Jakarta-Cengkareng corrected for RH/temperature errors upaqi_96935 - Surabaya corrected for RH/temperature errors upaqi_97014 - Menado corrected for RH/temperature errors upaqi_97072 - Palu corrected for RH/temperature errors upaqi_97180 - Makassar corrected for RH/temperature errors upaqi_97372 - Kupang corrected for RH/temperature errors upaqi_97560 - Biak corrected for RH/temperature errors upaqi_97724 - Ambon corrected for RH/temperature errors upaqi_97980 - Merauke corrected for RH/temperature errors Ship Correction Description: As shown in Yoneyama et al. (2002), low-level thermodynamic fields from ship soundings can be distorted under certain conditions by the deck heating and cooling effects. These effects were corrected at sites 99990, 99992 and 99993 (Mirai, Baruna Jaya and Sagar Kanya). See section 4c of Ciesielski et al. (2014) and Yoneyama et al. (2002) for additional details. The distortion of low-level fields on the R/V Revelle was more vertically limited due to its smaller size (83 m, 2200 tons) such that eliminating the data below 19 m, as described in Ciesielski et al. (2014) was sufficient to remove these effects. However a small surface pressure error was discover in the L3 and L4 data at this site. In these files surface pressure was too low by 0.23 hPa. This was corrected in L3.1 and L4.1 data as well as the corresponding geopotential height data Yoneyama, K., M. Hanyu, F. Yoshiura, S. Sueyoshi, and M. Katsumata, 2002: Radiosonde observation from the ship in the tropical region. JAMSTECR (Tech Rep), 45, 31-39. Available from: http://www.godac.jamstec.go.jp/catalog/data/doc_catalog/media/shiken45_04.pdf Colombo Correction Description: During the Dynamics of the MJO (DYNAMO) field campaign, upper-air soundings were launched at Colombo, Sri Lanka as part of the enhanced northern sounding array (NSA) of the experiment. The Colombo soundings were affected at low levels by the diurnal heating of this large island and by flow blocking due to elevated terrain to the east of the Colombo site. Because of the large spacing between sounding sites, these small-scale island effects are aliased onto the larger scale impacting analyses and atmospheric budgets over the DYNAMO NSA. To mitigate these local island effects on the large-scale budgets, a procedure was designed which used low-level ECMWF-analyzed fields in the vicinity of Sri Lanka to estimate open-ocean conditions at Colomboâlocation as if the island were not present. These 'perturbed' merged with the observed Colombo soundings. Results indicate a beneficial impact of using these adjusted fields on several aspects of the budget analyses. All 258 Level 4 Colomobo soundings were adjusted using this procedure. Reference: Ciesielski, P.E., R.H. Johnson, K. Yoneyama, and R.K. Taft, 2014: Mitigation of Sri Lanka island effects in Colombo sounding data and its impact on DYNAMO analyses, To appear in J. Meteor. Soc. of Japan. Indonesian Site Correction Description: For Level 3.0 data, corrections of humidity have been applied with two methods. One is a CDF matching based on the intercomparison of Vaisala RS92 and Meisei onboard the Mirai, and the second is a correction for the RH discontinuity at the 0C level following a method provided by Sugidachi and Fujiwara (2013). Details can be found in Ciesielski et al. (2014). In addition to the corrections applied to produce Level 3.0 data, temperature discontinuity at around 300hPa is corrected. Meisei radiosonde receiving system has a software which reduces the influence of solar radiation reflected from the sensor package, which is originally set to act from 300hPa level. Actually, it forces the reduction of temperature at and above 300hPa. In particular, this feature is found not only for daytime sounding but also for nighttime sounding, indicating too much reduction. This is because the software reduces the temperature regardless with actual condition and launch time, while the soundings over the Indonesian Maritime Continent are typically conducted in the local morning and evening time, when the errors caused by solar radiation are expected to be small. Therefore, by assuming that temperature lapse rate is close to the mean value between just below/above layers, the difference of lapse rate from the mean is calculated, and the temperature difference deduced from the lapse rate difference is added to the observed values (typical value is about 0.2C). Sugidachi, T., and M. Fujiwara, 2013: Corection of the stepwise change observed at 0C in Meisei RS2-91, RS-01G, and RS-06G radiosonde relative humidity profiles. J. Meteor. Soc. Japan, 91, 323-336. Questions or isssues with data should be referred to: Paul Ciesielski (paulc@atmos.colostate.edu)