Observations do not exist Clause Samples

Observations do not exist. The main gap in the Arctic is the lack of data and especially the lack of spatial coverage. For land meteorological observations the coordination has been weak and many independent and somehow overlapping archives exist. Many observations are only available through request, and documentation and quality control may be sparse and difficult to assess. The lack of data and the existence of very data-sparse regions is the main gap with respect to Arctic in situ data. There are large gaps over the Arctic oceans and the inner Arctic. In particular, there is a lack of observations over northern and eastern Greenland, east of Svalbard and in particular east of the ▇▇▇▇ delta, around the ▇▇▇▇▇▇ Bay, over the Labrador Sea as well as over large parts of the coastal areas of Nunavut and Yukon. In general, the SYNOP coverage over Greenland is not good. Upper-air measurements are also very sparse in the Arctic. There are very few observations north of 70°N, no radiosonde observations at all in the inner Arctic, only 5 on Greenland and virtually none over the entire Canadian Arctic. There is also no upper air information available over the oceans as the ocean weather ships have closed down due to the high cost. A concerted action to revive one or several of them would be worth considering. For projects doing data assimilation, a limited amount of missing data is not a problem but lack of spatial coverage is. It would also be beneficial if more variables were measured. Further, the ongoing rapid climate change creates new “hotspots” with large changes. As sea ice disappears, regions with enhanced variability may evolve in areas previously covered with ice. There is no reason to expect that these new hotspots will be found where we already have stations. Candidate regions for this kind of changes are the northern part of Svalbard and the Greenlandic east coast, both of which have very few recent observations.
Observations do not exist. For verification with in situ data, missing data in space is inevitable. The CAMS service is interested in all sort of atmospheric composition observations both from in situ observations and ground-based remote sensing. CAMS is also very interested in observations of wet and dry deposition fluxes and precipitation chemistry as well as in dry-deposition velocities for a wide range of atmospheric constituents. Observations of pollen are also of interest for CAMS. In order to follow pollution episodes, track variability and to continuously monitor the performance of CAMS (including yearly system upgrades) it is necessary to have uninterrupted measurement records. Biases or excessive noise in data makes it difficult to achieve goals in validation of the CAMS products over the Arctic. The limited availability of near-real time data is often more limiting than the data quality. The current number of stations (IASOA) is limited given the large area concerned. For an adequate assessment of the transport of pollution to the Arctic during individual events, a larger number of ground stations would be helpful. The longer the data record, the more valuable. In particular for reanalysis evaluation, long time records are needed, ideally for the full period of the reanalysis. These often do not exist.